YAN Han-wei, CHENG Ya-jing, YU Tong-tong, YU Na, ZHOU Liang, LIU Sheng-quan
Objective The purpose of this research is to study the differences and genetic characteristics of various timber traits among Section Aigeiros clones, and to evaluate the excellent degree of wood properties of the clones, so as to provide theoretical basis for breeding clones with excellent comprehensive characters in experimental areas, and promote the directional cultivation of industrial timber. Method The wood properties (anatomical features, physical properties, and chemical composition) of ten-year-old sample trees (5 plants per clone) were measured from 8 experimental Section Aigeiros clones in Jiaozuo, He'nan Province. The genetic variation and genetic parameters of 18 wood traits were analyzed, and principal component analysis was used to evaluate the clones. Result Except the hemicellulose, the other 17 wood properties of poplar clones showed significant differences among clones. The variation range of clone repeatability was 0.49-0.93, in which the absolutely dried density, basic density, total cellulose, radial cell diameter and radial lumen diameter were more than 0.8. The phenotypic variation of clones was greater than the genetic variation. Populus × euramericana 'Zhonglin 46' was selected as the superior clones based on the highest core of principal component factors. Conclusion The eight poplar clones showed genetic differences in 18 wood properties, which were under strong genetic control and possessed the conditions of genetic improvement. There were radial differences in clone repeatability. With the increase of annual rings, the variation range of physical properties was the smallest, and the absolutely dried density and basic density were relatively stable. More >
HE Xiao, XU Qi-gang, LEI Xiang-dong
Objective To Establish stand biomass model and analyze the effects of stand factors and climatic factors on stand biomass, so as to provide a model for the biomass estimation for regional scale. Method Taking Larix spp. plantations from 7 provinces in Northeast and North China as samples, the data from 8th national forest inventory of permanent sample plots were used to establish the basic stand biomass models of aboveground and total base on log-transformed by least square regression and robust regression, respectively. The climate variables were screened by principal component analysis and correlation analysis, and climate-sensitive stand biomass models (including aboveground biomass AGB and total biomass TGB) were established. The determination coefficient (R2), root mean square error (RMSE) and relative root mean square error (rRMSE) were used to evaluate the models. The interpretation rate of each factor was divided into independent interpretation and covariant parts and the interpretation rate of different factors was quantified. Result (1) The form of the optimal basic model was the direct introduction of variables. The R2 of the optimal AGB and TGB models were 0.967 and 0.953, respectively, and the AGB were larger than the TGB biomass. The result of ordinary least square regression was similar to that of robust regression, and robust regression was slightly better than ordinary least square regression. The RMSE and rRMSE of the optimal model based on robust regression were lower than the corresponding ordinary least square regression for AGB by 0.046 t·hm−2 and 0.085%, respectively, and for TGB by 0.059 t·hm−2 and 0.081%, respectively. (2) The correlation coefficients between AGB, TGB and moisture-heat index (AHM) were −0.350 and −0.363, respectively. The climate-sensitive stand biomass model further improved the prediction effect of the model. The R2 of AGB increased by 0.41%, while RMSE and rRMSE decreased by 6.85%. The R2 of TGB increased by 0.63%, and the error statistics decreased by 6.79%. (3) The independent interpretations of stand factor of AGB and TGB were 87.37% and 82.32% respectively, the independent interpretations of climate factor were 0.40% and 0.60% respectively, and the covariant parts were 9.33% and 9.98%. The interpretation rate of stand factor was much higher than that of climate factor and the covariant part was large. Conclusion When the modeling data quality of the stand biomass model is high, there is little difference between the models established by robust regression and ordinary least square regression, but climate factors have a significant impact on stand biomass. It is necessary to establish a climate-sensitive stand biomass model to estimate the biomass. More >
LYU Zhong-rui, LIU Hong, ZHANG Guo-yun, YU Li-yang, LUO Hong-mei, HE Cai-yun
Objective To study the characteristics and potential functions of sea buckthorn (Hippophae rhamnoides) and to analyze the biosynthesis mechanism and accumulation pattern of flavonoid glycosides by identifying the UGT gene family members in sea buckthorn. Method BLASTP and hmmsearch were used to identify the members of the HrUGT gene family based on sea buckthorn genome database. The protein physical and chemical properties, phylogenesis, protein motif and gene structure and gene duplication were analyzed by using Prot-Param, MUSCLE, MAGA7.0, MEME and MCScanX. Result 89 HrUGTs containing the plant secondary product glycosyltransferase motif (PSPG) were identified from the sea buckthorn genome. The length of sea buckthorn UGT proteins ranged from 266 to 533 amino acids, the average molecular weight was 50.00 KDa, and the average isoelectric point was 5.89. According to the phylogenetic relationship, the 89 HrUGTs could be divided into 16 major groups. 84 HrUGTs were distributed on 11 chromosomes except chromosome 7. Tandem duplication was a predominant duplication event which caused the expansion of HrUGT genes. Transcriptomic data and RT-qPCR analysis indicated that most of UGT genes had a wide range of fruit development stage expression characteristics. Conclusion The complete information of the HrUGT gene family is obtained, which will benefit the study on the biological functions of HrUGTs. More >
Differences in the Response of Radial Growth and Intrinsic Water Use Efficiency of Robinia pseudoacacia to Climatic Factors in Minquan of He'nan Province and Baishui of Shaanxi Province
ZHOU Jia, MENG Ping, ZHANG Jin-song, GUAN Chong-fan, SUN Shou-jia
Objective To analyze the response of radial growth and intrinsic water use efficiency (WUEi) of Robinia pseudoacacia to climate factors at different locations, and to determine the dominant factors affecting the growth and water use mechanism, so as to provide reference for the management of R. pseudoacacia plantations in China under climate change. Method The ring width chronologies were established in Minquan (MQ) of He'nan Province and Baishui (BS) of Shaanxi Province. The stable carbon isotopic composition (δ13C) of tree ring was measured to calculate the WUEi. The differences in the response of R. pseudoacacia to climatic variation were analyzed with meteorological data. Result The plantations at the two locations were in similar age. The tree-ring width at BS presented a trend of initially increasing and thereafter decreasing with the increase of tree age, whereas at MQ, the tree-ring width showed a linear decreasing trend with tree age increase. The trends of basal area increment (BAI) of R. pseudoacacia at the two locations were similar, presenting a trend of initially increasing and thereafter decreasing with the increase of tree age. The δ13C value and WUEi of the trees in MQ were lower than those of BS. The Pearson correlation results showed that on a monthly scale, the STD index of R. pseudoacacia in the two locations was mainly positively correlated with the summer precipitation and drought index (SPEI) (P < 0.05), and the R. pseudoacacia in BS was significantly negatively correlated with the average precipitation and SPEI in November of the previous year (P < 0.05). The WUEi of trees in MQ was significantly positively correlated with the average temperature and maximum temperature in March and August (P < 0.05), while that of trees in BS was significantly positively correlated with the average temperature, maximum temperature and minimum temperature from March to April of the current year, and June to July of the previous and current year (P < 0.05). The path analysis model showed that on the annual scale, the STD index of R. pseudoacacia in BS had a significant positive effect on the average precipitation and average temperature (P < 0.05), while the R. pseudoacacia in MQ had no significant response to climate factors. The annual average temperature had significantly positive effect on WUEi of trees at both the locations (P < 0.05). Conclusion The average precipitation is the dominant factor influencing the radial growth of R. pseudoacacia at both the locations, and the sensitivity of growth of trees in BS is higher than that of trees in MQ. The average temperature is the dominant factor influencing WUEi at the two locations, and the WUEi of trees in BS is more sensitive to the temperature than that of trees in MQ. More >
Journal Introduction
Forestry Science Research is a comprehensive academic journal of forestry science sponsored by the Chinese Academy of Forestry Science. The main task is to timely reflect the latest research results, academic papers and reports, scientific and technological trends and information of forestry science with the Chinese Academy of Forestry as the main body, to promote academic exchanges at home and abroad, to carry out academic discussions, to prosper forestry science and to better serve China's forestry construction. The main contents are: forest seeds, seedling raising and afforestation, forest plants, forest genetic breeding, tree physiology and biochemistry, forest insects, resource insects, forest pathology, forest microorganisms, forest birds and animals, forest soil, forest...
Effect of Partial Crown on Calculation of Vertical Projection Area of Crown
SUN Zhao, PAN Lei, QIAO Jing-jing, DING Zhi-dan, SUN Yu-jun, WANG Yi-fu
, Available online , doi: 10.13275/j.cnki.lykxyj.2022.01.019
[Abstract](402) [FullText HTML](298) [PDF 926KB](13)
Objective Aiming at solve the problems of complex structure and irregular shape of tree crown to realize the automatic calculation of vertical projection area of tree crown and improve the calculation accuracy of projection area of tree crown. Method A total of 453 Cunninghamia lanceolata trees were selected in the study area, and the crown width of each tree in 8 directions were accurately measured. Visual studio and ArcGIS mixed programming were used to convert the coordinates of the measured canopy radius. And the Bezier curve was used to smooth the boundary, so as to realize the automatic extraction of the vertical projection area of the tree crown, and the results were compared with that of the traditional calculation method. The "roundness" were used to evaluate the crown partial crown, and the correlation between the partial crown index and the vertical crown projection area were calculated. Result The method proposed in this paper can calculate the real canopy vertical projection area. The result indicates that the more the measurements of crown radius during calculating the canopy vertical projection area, the closer the calculation result to the real crown area. Compared with the ellipse method, the area obtained by treating the crown as a circle is closer to the real area. It is also found that, there is a significant positive correlation between the results of calculating the crown vertical projection area with different methods and the difference of the crown vertical projection area and the crown deviation index. Conclusion The area calculation method based on the shape of the canopy projection area is more accurate than the traditional area calculation method, which provides a alternative idea for the verification of forestry remote sensing crown extraction accuracy.
Effects of Resin-Tapping Year on Wood Properties of Living Pinus elliottii
WU Hao-ran, FAN Yan-ru, NIU Xiao-yun, LUAN Qi-fu, LI Yan-jie, JIANG Jing-min, JIN Jian-er
[Abstract](348) [FullText HTML](278) [PDF 929KB](6)
Objective To study the influnence of resin-tapping duration on the basic density and lignin content of resin-tapping parts and trunk of Pinus elliottii in order to optimize the genetic improvement and resource utilization of P. elliottii. Method Twenty-years-old P. elliottii trees that have been resin-tapped for 8, 6, 3, and 0 years were studied using Resistograph technology to measure the relative value of density and width of tree in the resin-tapping part and the base of the trunk. The wood core was extracted from the same plant by electric growth cone drill and the sawdust was collected. The basic density of wood was determined by submerged water method and the lignin content was determined by Reagent test kit. The correlation around basic density, lignin content and the Resistograph was analyzed. Result The correlation coefficients between the basic density of P. elliottii wood and the Resistograph values after 8, 6, 3 and 0 years of resin-tapping were 0.45, 0.39, 0.50 and 0.63, respectively. The linear regression equations for predicting the basic density of wood using Resistograph values were established. There was no significant correlation between lignin content and Resistograph values (P > 0.05). The base density of the tree trunk of P. elliottii after 3 years of resin-tapping was significantly higher than that after 0, 6 and 8 years of resin-tapping, and the base density of the tree trunk after 6 and 8 years of resin-tapping was significantly lower than that of the tree trunk without resin-tapping, but there was no significant difference between the base density of the tree trunk after 6 and 8 years of resin-tapping. The basic density of P. elliottii after 3 years of resin-tapping was significantly higher than that after 0 and 6 years of resin-tapping, but there was no difference with that after 8 years of resin-tapping. There was no significant difference among the basic density after 0, 6 and 8 years of resin-tapping. The analysis results of lignin content showed that the lignin content in the base of the tree trunk was lower than that after 0, 3 and 8 years of resin-tapping, and there was no significant difference in the rest, but the lignin content in the base of the tree trunk was lower after 6 years of resin-tapping than that after the other three durations. Conclusion Resistograph determination is suitable for predicting the basic density of P. elliottii after resin-tapping, but not for lignin content. To a certain extent, the basic density of P. elliottii at the base and site of tree trunk will increase in initial and then decrease, and the lignin content at the site of tree trunk will decrease in initial and then increase, but shows no effect on the lignin content at the base of tree trunk. When the resin is harvested over a certain years, the basic density of the resin-tapping part will be higher than that of the base of tree trunk, but the lignin content of the two parts is not affected.
Response of Individual Height of Larix principis-rupprechtii Plantation to Site Factors and Stand Characteristics in Liupan Mountain Area
ZHANG Zhong-hui, WANG Yan-hui, GUO Jian-bin, WANG Xiao
[Abstract](742) [FullText HTML](519) [PDF 1158KB](17)
Objective For the main afforestation species of Larix principis-rupprechtii in the forest area of Liupan Mountains, To study the response of individual tree height in Larix principis-rupprechtii, the main afforestation species in the forest area of Liupan Mountain Area, to site conditions and stand structure, in order to predict tree height growth more accurately, and to determine the suitable site for afforestation and proper stand structure for forest management, so as to guide the accurate and precise management of stand structure. Method The tree height growth data of L. principis-rupprechtii were obtained by carrying out the survey of analytic trees of various dominances in selected typical plots with various site conditions and stand structure characters, and the response law and suitable function forms of tree height response to all single factors were determined by the upper boundary line method. Then the tree height growth model which can reflect the influence of multiple factors was formed by a continuous multiplication. The model parameters were fitted using the measured data for getting the optimal tree height growth model. Result (1) The growth process of individual tree height of L. principis-rupprechtii showed a "S" curve. (2) Correlation analysis showed that the influence on tree height growth by the factors except tree age followed the order of elevation > canopy density > tree dominance > stand density > slope aspect > slope. (3) The most suitable conditions for the height growth of L. principis-rupprechtii are the elevation range of 2 000−2 400 m, the slope aspect range from shade slope to half shade slope, the slope gradient range of 20°−225°, the canopy density range of 0.49−20.64, the stand density of 1100−21300 trees/hm2. In addition, the height of individual trees increased with rising tree dominance but with a leveling-off increase rate after the dominance is higher than 0.2. (4) The height growth model of individual trees was established by coupling the response functions to the main influencing factors, with a satisfactory fitness. Conclusion The individual tree height growth of L. principis-rupprechtii is affected by both site conditions and stand structure characteristics. The main influencing factors are tree age, elevation, canopy density, and tree dominance. When considering the influencing factors, the coupled model of individual tree height growth can predict the spatio-temporal variation of individual tree height more accurately, and benefit the rational management of L. principis-rupprechtii plantation.
Soil Enzyme Activity Related to Nitrogen Cycling in Chinese Fir (Cunninghamia lanceolata) Plantation with Different Stand Age
PENG Zi-wei, JIAO Peng-yu, GAO Li-wen, GUO Wen, LIU Xian, HU Ya-lin, WANG Yu-zhe
, Available online
[Abstract](46) [FullText HTML](23) [PDF 816KB](0)
Objective To study the variation of soil nitrogen (N)-cycling enzyme activities and rhizosphere effect during the development of Chinese fir (Cunninghamia lanceolata) plantation and its driving factors. Method Rhizosphere and non-rhizosphere soils were collected from Chinese fir plantation with the ages of 7, 15, 24 and 34. The enzyme activities regulating soil nitrogen cycling (β-glucosidase (BG), acetyl-β-D-glucosaminidase (NAG), proteolytic enzyme (PRO), urease (URE), leucine aminopeptidase (LAP) and nitrate reductase (NR)) were measured. Redundancy analysis (RDA) and Pearson correlation were conducted to explore the relationship between soil nitrogen-cycling enzyme activities and the soil physico-chemical properties. Result Forest age and rhizosphere had significant effects on soil N-cycling enzyme activities (P<0.05). The enzyme activities regulating soil nitrogen cycling in the non-rhizosphere soil decreased at first and then increased with the increase of forest age. The activities of BG, NAG, PRO, URE and LAP in rhizosphere soil were significantly higher than those in non-rhizosphere soil (P<0.05). The difference of NR activity between rhizosphere and non-rhizosphere soil varied with forest age. The NR activity in rhizosphere soil was significantly higher than that of non-rhizosphere soil in 15- and 24-years-old Chinese fir plantations (P<0.01). The rhizosphere effects of soil NR activities in 15-years-old Chinese fir plantation were significantly higher than those in 7-years-old and 34-years-old Chinese fir plantations (P<0.05). The key factors regulating soil N-cycling enzyme activities in rhizosphere and non-rhizosphere soil were C/N and ammonium nitrogen content. Conclusion Soil N-cycling enzyme activities was the lowest in middle-age Chinese fir plantations in mid-subtropical China, indicating that nitrogen may still be one of the main limiting factors in the fast-growing stage of Chinese fir plantations. In the future, we should focus on the middle-age Chinese fir plantation, so as to meet the nitrogen demand of Chinese fir and achieve the purpose of sustainable management.
Interspecific Association of Shrub Species in Burned Site of Picea asperata-Abies fabri Forest on the Northern Slope of Dieshan Mountains
ZHAO An, TIAN Qing, ZHOU Xiao-lei, SHI Rui-jin, HUANG Hai-xia, CAO Xue-ping, LU Gang, ZHOU Xu-jiao
Objective To reveal the interspecific association of shrub species in the burned area of Picea asperata-Abies fabri forest on the north slope of Dieshan mountains, the northeastern margin of Qinghai -Tibetan Plateau. Method Based on the field survey data, the interspecific association of 17 shrub species in the burned area was studied by using variance ratio method (VR), chi-square (χ2) test, association coefficient (AC) and Jaccard similarity coefficient (PC) with 2 × 2 contingency table. Result The VR value of overall association was equal to 0.93; χ2 test showed that 9 species pairs reached extremely significant positive association, 2 species pairs reached significant association, 125 species pairs showed no significant association; there were 27 species pairs with the AC value of [0.6, 1], 9 species pairs with the AC value of [0.2, 0.6), 40 species pairs with the AC value of [−0.2, 0.2), 13 species pairs with the AC value of [−0.6, −0.2), and 47 species pairs with the AC value of [−1, −0.6); the value of Jaccard was similar, there were 17 pairs with PC value of [0.57, 1], 12 pairs with PC value of [0.29, 0.57) and 107 pairs with PC value of [0, 0.29). The results obtained by each research method were basically similar, but there were some differences among the test methods. Conclusion The correlation among the pairs is not strong, few species pairs are significant or extremely significant, and the overall association among species in the community shows no significantly negative trends. The results show that the interspecific association of shrub species is not strong and the community stability is not high. The interspecific association of shrub species is mainly affected by plant biological characteristics, ecological adaptability and human activities, soil, climate, competition and allelopathy.
Identification and Expression Analysis of NAC Gene Family in Taxus × media Rehder
ZHANG Kai-kai, YANG Li-ying, FENG Mei-jing, ZHANG Lin-feng, CHEN Duan-fen, QIU De-you, YANG Yan-fang
Objective To obtain the key NAC genes involving in regulating the root growth and development of yew trees. Method Basing on the full-length transcriptome data of Taxus × media, bioinformatics methods were used to identify NAC transcription factors. The protein structure and gene tissue expression profile of the selected NAC genes were analyzed. Result A total of 44 NAC transcription factors were identified, which have typical conserved NAC domains at the N-terminal, and most of the members contain 5 conserved structural functional subdomains. Phylogenetic tree analysis showed that 44 Taxus × media NAC (TmNAC) proteins were clustered into 7 subfamilies of Arabidopsis. Sequence structure analysis indicated that the tertiary structures of the TmNAC proteins were similar, but the structures of the representative member of different subfamily also showed obvious differences. The expression results showed that TmNAC15, 16, 18, 21, 22, 29, 39, 40, 41, and 44 had higher expression level in root than stem and needle. Conclusion In this study, 44 TmNAC transcription factors were identified from Taxus × media and they were clustered into 7 subfamilies. Among them, TmNAC21, 22, 39, 40, and 44 may be involved in the root growth and development progresses of yew trees.
Relationship between Leaf Biomass and Radial Growth of Larix olgensis Based on Pipe Model Theory
PAN Lei, WANG Yi-fu, SUN Zhao, QIAO Jing-jing, QIU Si-yu, SUN Yu-jun
[Abstract](26) [FullText HTML](25) [PDF 1103KB](0)
Objective To understand the relationship between leaf biomass and radial growth of Larix olgensis in Xiaoxing'anling Mountains. Method The relationship between leaf biomass and radial growth at individual tree level and at different direction interval of individual tree was studied based on pipe model theory, and the correlation between crown distribution and radial growth was analyzed. Result Leaf biomass was significantly and positively correlated with stem diameter, basal area and sapwood area at breast height and height to crown base, as well as basal area growth in recent 1 year, 2 years, 3 years and 5 years, and the leaf biomass model using breast height basal area as a predictor had the best fitting effect. The leaf biomass in different direction interval of a single tree was significantly positively correlated with the stem radius and basal area at the corresponding DBH and the height to crown base, and the growth of basal area in recent 1, 2, 3 and 5 years. Conclusion When estimating the leaf biomass per tree, the basal area of breast height is the best predictor. The leaf biomass of different direction interval in a individual tree is significantly and positively correlated with the stem radius, basal area and basal area growth of corresponding directions, and there is a certain correlation between crown displacement and pith eccentricity.
Selection and Validation of Reference Genes for Leaf Color Phenotype in 'Maiyuanjinqiu', a Catalpa fargesii Variety, by qRT-PCR
YANG Ying-ying, ZHAO Lin-jiao, YANG Gui-juan, ZHANG Yu, FU Peng-yue, HU Ji-wen, LIU Ying, WANG Nan
Objective To select the housekeeping genes stably expressed in leaves in order to support the study of the molecular mechanism of leaf color formation on 'Maiyuanjinqiu', a Catalpa fargesii variety. Method The relative expression of seven candidate genes, including CfUBC, CfActin11, CfPP2A, CfMADH, CfGADPH, CfEF-1 and CbuActin were detected by real-time quantitative PCR (qRT-PCR) technology using leaves of different leaf color sectors of 'Maiyuanjinqiu' and the corresponding sectors of Catalpa fargesii Bur. The stability of the seven candidate reference genes was evaluated by using internal reference analysis software such as GeNorm, NormFinder and BestKeeper. Furthermore, the expression patterns of terpenoid biosynthesis related gene (CfGES) in the leaves of different leaf color parts of 'Maiyuanjinqiu' and the corresponding sectors of C. fargesii were analyzed respectively. The results verified the stability evaluation results mentioned above. Result All the seven candidate reference genes can be used as internal reference genes in the leaves of 'Maiyuanjinqiu' and C. fargesii. The expression levels of CfMADH and CfEF-1 were the most stable in different color tissues, followed by CfGADPH and CfActin11, while the CfUBC was the worst. The stability of internal reference gene was verified by terpenoid biosynthesis related gene (CfGES). It was found that the expressions of CfGES gene were consistent with the trend of transcriptome data, when CfEF-1 and CfMADH genes were used as internal reference for qRT-PCR alone or in combination. Conclusion Using CfMADH and CfEF-1 individually or in combination to calibrate the gene expression levels of different leaf color parts in 'Maiyuanjinqiu' can greatly improve the reliability of experimental results.
Dynamic Variation of Growth Traits in Open-pollinated Families of Quercus acutissima Superior Tree and Selection of Superior Families Among Three Sites
YUAN Hai-jing, CHENG Xiang-rong, YU Mu-kui, WANG Yang-dong, TAI Jian-wu, ZHANG Chun-xiang, WANG Xin-yang
Objective To study the genetic variation of growth traits in superior open-pollinated families of Quercus acutissima with the increase of stand age, and to select the superior families for Q. acutissima plantation cultivation. Method Eighteen superior tree open-pollination families coming from Rongshui of Guangxi Zhuang Autonomous Region were planted in 3 test sites (Yongfeng of Jiangxi Province, Kaihua of Zhejiang Province and Chuzhou of Anhui Province). The variation in tree growth among the families and the dynamic changes of above-ground biomass of individual tree (AGB) with stand age were investigated. The stability of growth traits was evaluated using the AMMI model, and then the superior families were selected. Result The tree height, diameter at breast (or ground) height, and the AGB significantly differed among the 3 test sites. The AGB of Q. acutissima trees was significantly affected by the site, family, and family × site. The site had the greatest impact on growth variation, followed by family and family × site. The growth performance of 1-3 years old and 6-11 years old families had great difference among test sites. Based on the AGB at the 11st year, the superior families in Yongfeng were M11, M9 and M15, their genetic gain was 4.08%-7.45%; the superior families in the Kaihua were M16 and M2, their genetic gain was 28.01%-37.02%; the superior families in the Chuzhou were M17, M1 and M18, their genetic gain was 15.05%-30.29%. According to growth performance and stability analysis, it was showed that the families M1, M18 and M20 were suitable for cultivation at all the 3 test sites. The average biomass of the AGB was 31.58kg, and the average Dg(e) was 1.10. Conclusion The growth of superior open-pollinated families of Q. acutissima will be affected by the interaction of site and family, and some superior families were selected for Q. acutissima plantation cultivation.
Leaf Color Diversity and the Change of Physiological Characteristics of Quercus spp. During the Discoloration Period in Autumn
AN Ran, WANG Shu-feng, CHEN Yi-tai, WANG Yang-dong, FU Huo-yong, ZHANG Yong-zhi, SHI Xiang
Objective To study the change of physiological characteristics changes of Quercus spp. during the discoloration period and found the relationship between leaf color diversity and physiological changes. Method 4-year-old seedlings of Sect. Lobatae (Quercus texana, Q. shumardii, Q. phellos, Q. laurifolia and Q. pagoda) and Sect. Quercus (Q. lyrata, Q. michauxii and Q. fabri) were used to measure chromatic aberration parameters (L*, a*, and b*), pigment, soluble sugar, C, N and P contents during the leaf senescence stage. Result During the autumn, the leaf senescence period, the variation range of L* value was small and stable. The values of a* and b*, chlorophyll and carotenoid contents decreased whereas the anthocyanin content increased gradually. The leaf N and P contents decreased gradually in the senescing leaves, but the contents of soluble sugar in leaves increased. The a* value showed significantly positive correlations with anthocyanin and soluble sugar content, C:N ratio and C:P ratio; and negative correlations with chlorophyll, carotenoid, N and P content. In general, the leaf color of Sect. Lobatae was redder than that of Sect. Quercus, while there were significant differences among species in terms of leaf color and leaf color retention period. Due to the different magnitude of variation in each index of each species, the leaf color of Quercus spp. changed from green to yellow-red, crimson, bright red or brown in the late stage of leaf discoloration. The leaf color of Q. texana was the reddest in autumn and the red leaves occurred the longest. Conclusion Usually, the leaf color of Sect. Lobatae will change earlier than that of Sect. Quercus. In the early stages, the variation of parameters is very small. After, the leaf color of Quercus spp. is mostly affected by chlorophyll and carotenoids break down and anthocyanins will synthesize quickly. The N and P contents will gradually decrease, and the utilization rate increase significantly.
Relationship between Soil Enzyme Activities and Physicochemical Properties in Mangrove Wetland of Qinglan Port
CHEN Xiao-hua, CHEN Zong-zhu, LEI Jin-rui, WU Ting-tian, LI Yuan-ling
Objective To analyze the soil quality of different mangrove communities in Qinglan Port wetland at the aspect of soil enzyme activity, so as to benefit the mangrove wetland soil carbon sink monitoring and ecological restoration in Hainan Province. Method Soil enzyme activities and physicochemical properties of five mangrove communities were analyzed. Result (1) The lowest contents of microbial biomass carbon and nitrogen and microbial entropy of carbon in the soil surface were found in the Lumnitzera racemosa community, which were significantly lower than that of the individual communities. However, the soil microbial entropy of nitrogen had no significant differences among different community types. (2) The soil enzyme activities in the surface layer of wetland in each community type were basically in the order of sucrase > phosphatase > catalase > urease. There were significant differences among different community types. The activities of urease, phosphatase and catalase in Ceriops tagal community were the highest, which were significantly higher than those in B. sexangula and R. apiculata communities. The catalase activity of C. tagal community was the highest, which was significantly higher than that of B. sexangula and R. apiculata communities. The sucrase activity was the highest in Sonneratia alba community, which was significantly higher than that in B. sexangula and R. apiculata communities. (3) The soil urease activity was significantly positively correlated with water content (SWC), organic carbon (SOC), microbial biomass carbon (MBC), total nitrogen (TN), total phosphorus (TP), total potassium (TK) and total reducing substances (RS). The phosphatase activity was significantly positively correlated with soil SWC, MBC, microbial biomass nitrogen (MBN) and RS, and significantly positively correlated with TN and TK. The catalase activity was significantly positively correlated with SWC, SOC, MBC and TN. The sucrase activity was significantly positively correlated with SWC, SOC, MBC, TN and MBN. (4) The results of redundancy analysis showed that SWC, MBC and RS were the main factors affecting the soil enzyme activities of mangrove communities in Qinglan Port. Conclusion Soil enzyme activity can be used to characterize the soil quality of mangrove wetland in Qinglan Port, and there are differences among different mangrove community types.
Latitudinal Variations of Soil C-N-P Stoichiometry in Pinus massoniana (Lamb.) Plantations
JIAN Zun-ji, NI Yan-yan, XU Jin, ZENG Li-xiong, LEI Lei, ZHU Jian-hua, XIAO Wen-fa
Objective To explore the latitudinal variations of soil organic carbon (C), total nitrogen (N) and total phosphorus (P) and their ecological stoichiometry in Pinus massoniana (Lamb.) plantations of subtropical China. Method Soil samples of 0-20 cm layer were collected from the pure plantations in eight sites ranging from southeast to northwest to determine the contents of soil organic C, total N and total P. The variations of soil C-N-P contents and their ecological stoichiometry along the latitudinal gradient were explored by regression analysis. The relationships of climatic factors (mean annual temperature, MAT and mean annual precipitation, MAP), stand characteristics (age, density and DBH) and soil key properties (pH value and clay content) with soil C-N-P contents and stoichiometry were examined by Pearson's correlation analysis and redundancy analysis. Besides, the relative contribution rates of these environmental factors to the variations in soil C-N-P contents and stoichiometry were analyzed using the variation partitioning analysis. Result The average contents of soil organic C, total N and total P were 16.02, 1.22, and 0.35 g·kg-1, respectively; and the average ratios of soil C:N, C:P and N:P were 14.18, 47.01, and 3.59, respectively. Both soil organic C and total N decreased significantly (P<0.01) with increasing latitude, while no obvious spatial pattern of total P was found. Soil C:N significantly increased (P<0.05) while soil C:P and N:P decreased (P<0.01) over latitude. The soil organic C and total N were significantly positively correlated with MAT, MAP, and diameter at breast height (DBH) (P<0.05), but negatively correlated with soil pH value (P<0.05). The soil C:P and N:P were significantly positively correlated with MAT, MAP, DBH, and soil clay content (P<0.05), while negatively correlated with stand age (P<0.05). Climatic factors, stand characteristics and soil key properties totally explained 63.8% of latitudinal variations in soil organic C, total N, total P and soil C:N, C:P, N:P, with characteristics of climatic factors (46.3%) > stand characteristics (43.3%) > soil properties (35.5%). Conclusion Soil C:N, C:P and N:P in P. massoniana (Lamb.) plantations follows obvious latitudinal patterns, which are driven by MAT, MAP, stand age, stand density, DBH, soil pH value, and soil clay content. Importantly, the interaction effects of these environmental factors are greater than the single effects.
Selection of Reference Genes for Real-time Quantitative PCR in Clerodendrum trichotomum Thunb. Leaves
HUA Ya-jie, YUE Yuan-zheng, YANG Xiu-lian, HE Qing
[Abstract](175) [FullText HTML](97) [PDF 836KB](1)
Objective To select the stable internal reference genes by real-time PCR (qRT-PCR) under different abiotic stress conditions in Clerodendrum trichotomum leaves. Method Based on previous transcriptome data, 17 reference genes were selected under different abiotic stresses (salt, drought and heat) for C. trichotomum. Four reference gene analysis software i.e. GeNorm, NormFinder, BestKeeper and ReFinder were used to select the optimal internal reference gene, to select the genes for Na + /H + Exchanger1 (ClNHX1) and to verify the stability of internal reference genes elected. Result Genes RPL and AP-2 were the most stable under salt stress; MDH and AP-2 were the most stable under drought stress; UBCE2 and ACT were the most stable under heat stress. For abiotic treatments, AP-2 and UBCE2 were the most stable reference genes. Conclusion AP-2 and UBCE2 can be used as internal reference genes for gene quantification in abiotic stress studies of C. trichotomum leaves. This study can provide reliable normalization for gene expression analysis and ensured more accurate data for further molecular mechanism research in C. trichotomum.
Comprehensive Evaluation of Fruit Phenotype and Quality of Main Chinese Chestnut Cultivars in the Middle and Lower Reaches of the Yangtze River
JIANG Xi-bing, TENG Guo-xin, FAN Jin-gen, LUO Xiu-bao, SHENG Jian-hong, GONG Bang-chu
Objective To evaluate the fruit traits of main Chinese chestnut (Castanea mollissima) cultivars from the middle and lower reaches of the Yangtze River and provide references for the selection of chestnut cultivars with excellent comprehensive performance and suitable for planting and promoting in Zhejiang Province. Method Twenty-five main Chinese chestnut cultivars in the middle and lower reaches of the Yangtze River and five representative northern Chinese chestnut cultivars were used as materials, their fruit phenotype and quality traits were continuously measured and statistically analyzed. Then comprehensive evaluation was performed by principal component analysis and grey correlation analysis. Result Twenty traits of fruit phenotype and quality had different degrees of variation, and the coefficient of variation ranged from 7.85% to 41.20%. There were 23 pairs and 18 pairs of correlation among all traits reached extremely significant (P<0.01) and significant level (P<0.05), respectively. There was a certain correlation between the fruit phenotype and the quality traits. The cumulative contribution rate of the top five principal components was 79.25%, which retained most of the information of fruit phenotype and quality traits. Grey correlation analysis showed that there were significant differences in the weight values of each trait, in which the weight coefficient of potassium content was the largest and the weight coefficient of total flavonoids content was the smallest. The overall trend of the comprehensive performance ranking of the 30 Chinese chestnut cultivars performed by the two analysis methods was relatively consistent. The correlation coefficient of the comprehensive score of the cultivars by the two analysis was 0.7621, which reached a very significant level. Conclusion Six Chinese chestnut cultivars from the middle and lower reaches of the Yangtze River are ranked in the top by the two analysis, the comprehensive performance of their fruit traits is excellent, so the six cultivars can be popularized as the main cultivar in Zhejiang Province.
Prediction of Potential Distribution of Endangered Species Corylus chinensis Franch. in Climate Change Context
HE Xin, MA Wen-xu, ZHAO Tian-tian, MA Qing-hua, LIANG Li-song, WANG Gui-xi, YANG Zhen
[Abstract](354) [FullText HTML](243) [PDF 1336KB](4)
Objective To explore the change trend of the geographical distribution pattern of Corylus chinensis with climate, divide the suitable areas and provide references for the protection and utilization of C. chinensis. Method Based on 83 modern distribution records of C. chinensis and the screened data of 18 environmental variables, the maximum entropy model (MaxEnt) in the species distribution model was used to simulate the potential distribution areas of C. chinensis in six periods since the last interglacial period. Result The results of the area under receiver operating curve (AUC) show that the simulation results are more accurate, and temperature is an important factor affecting the geographical distribution of C. chinensis in six different periods. During the last interglacial period, the total suitable area of C. chinensis decreased by about 9% compared with modern times, and there was little change during the last glacial maximum period. The total suitable area increased by 4.4% compared with modern times in the middle Holocene. It is predicted that the suitable area will increase in 2050s and 2070s. The distribution centers of C. chinensis in different periods are all located in Hubei Province. In the future, the distribution center will show a tendency to migrate to high latitudes under the condition of future climate warming. From the perspective of the suitable area, C. chinensis shows a shrinking trend in the glacial period, and shows an expansion trend in the mid-Holocene and future global warming scenarios. Conclusion The distribution area of C. chinensis suitable for climate change is different. Temperature is the main factor affecting its distribution. Under the condition of climate warming in the future, the distribution center will migrate to high latitude.
Absorption and Transformation of Sulfur Dioxide by Populus × euramericana cv. 'Purui'
FENG Jin-xia, MA Jie, WAN Xian-chong
Objective To investigate the absorption and transformation of sulfur dioxide in the air by three poplar varieties in order to study the mechanism of sulfur dioxide resistance and the capacity of Populus × euramericana cv. 'Purui' in purifying the atmosphere. Method Three poplar varieties (Populus × euramericana cv. 'Purui' (Purui), Populus × euramericana cv. '74/76' (107) and Populus × euramericana cl. 'Zhonglin 46' (Zhonglin 46)) were selected to compare their effects on absorbing and purifying the sulfur dioxide in atmosphere. The diurnal dynamic changes of sulfur dioxide concentration in the air inside and outside the forests were measured. The concentrations of sulfate (SO42-) in the leaves of Purui, Zhonglin 46 and 107 under different sulfur dioxide pollution environments were measured. Result The daily dynamic changes of sulfur dioxide concentration inside and outside the forests indicated that the three poplar varieties were able to absorb sulfur dioxide, and hence purify the air. Among them, Purui had significantly greater capacity in sulfur dioxide absorption and air purification than Zhonglin 46 and 107. Sulfate ion concentration in Purui leaves was significantly higher than that in Zhonglin 46 and 107. Whether in the environment of high or low concentration of sulfur dioxide, the sulfate ion in the leaves of Purui was higher than that of the other two varieties, indicating that Purui had stronger ability to absorb sulfur dioxide and convert it into non-toxic sulfur compounds. This is also an important mechanism of sulfur dioxide resistance for Purui. Conclusion Among the three poplar varieties, Purui has stronger ability to purify the atmosphere polluted by sulfur dioxide, thereby detoxifying sulfur dioxide, so as to better purify the air and reduce the harm of haze to human body. Compared with other poplar species, Purui has stronger ability to convert sulfur dioxide into non-toxic sulfate ions, which can facilitates its detoxification.
Transformation of Eucalyptus urophylla × Eucalyptus grandis Clone Plantation into Mixed-species Forest Using Precious Tree Species
ZHOU Fang-ping, XU Jian-min, LU Hai-fei, LI Guang-you, FAN Chun-jie, LIANG Bao-zhi1, ZHANG Lei
Objective To discuss the mixed forest model of interplanting precious tree species under Eucalyptus urophylla × Eucalyptus grandis clone plantation with different cutting intensity and analyze the change trend of stand growth and understory vegetation diversity of mixed forest after interplanting, in order to provide a theoretical basis for the transformation of E. urophylla × E. grandis clone plantation into mixed forest of Eucalyptus and precious tree species. Method According to the split plot experimental design, the transformation experiment of 9-year-old E. urophylla × E. grandis clone plantation in State-owned Dongmen Forest Farm was carried out with precious tree species. Four cutting treatments were set in the main area: A: cutting 1 row every other row (1 E. urophylla × E. grandis + 1 precious species trees; B: cutting 2 rows every other 2 rows (2 E. urophylla × E. grandis + 2 precious species trees); C: cutting 2 rows every other 3 rows (3 E. urophylla × E. grandis + 2 precious species trees); D: cutting 3 rows every other 2 rows (2 E. urophylla × E. grandis + 3 precious species trees); six tree species were used for interplanting, i.e. Castanopsis hystrix Hook. f. & Thomson ex A. DC., Erythrophleum fordii Oliv., Manglietia conifera Dandy, Acacia melanoxylon R. Br., Dalbergia cochinchinensis Pierre ex Laness, and Aquilaria sinensis (Lour.) Spreng., and the control plot without transformation was set up. Each tree in the test area was measured, and the understory vegetation was investigated according to the conventional method at the age of 3.5 years after interplanting. Result The average tree height, DBH and individual volume of E. urophylla × E. grandis increased significantly under different mixed forest models, with the highest values of 27.63 m, 21.89 cm and 0.38 m3 respectively, which increased by 16.98%, 19.75% and 80.96% compared with the CK. The growth indexes of C. hystrix were the best among the interplanting species, followed by Manglietia conifera and Acacia melanoxylon. The volume of E. urophylla × E. grandis plantation interplanting Acacia melanoxylon in 3 Eucalyptus + 2 precious species trees was the best, reaching 244.87 m3·hm−2, which was 3.65% higher than CK. In addition, the Simpson indexes of herb layer of 2 Eucalyptus and 2 precious trees and the Shannon-Winner index of herb layer of 3 Eucalyptus and 2 precious species trees interplanting C. hystrix were 0.84 and 1.71 respectively, which were 25.40% and 30.50% higher than that of the CK; while the Simpson index and Shannon-Winner index of shrub layer in the stand with interplanting of D. cochinchinensis were 0.80 and 1.61, respectively, which were 42.9% and 71.27% higher than that of the CK. Conclusion In this study, the precious tree species were used to transform E. urophylla × E. grandis clone plantation to form a Eucalyptus and precious trees multi-layer mixed forest, which significantly improved the average tree height, DBH and single tree volume, optimized the stand structure, enriched the species diversity of the stand, changed the landscape of a single forest phase of E. urophylla × E. grandis and helped to improve the ecological and economic benefits of E. urophylla × E. grandis clone plantation. The results may provide scientific and technological support for the cultivation of medium- and large-diameter Eucalyptus and the management of national reserve forest.
Forest Sub-compartment Delineation Based on Airborne LiDAR Canopy Height Model
XIONG Hao, PANG Yong, JIA Wen, LI Chun-gan
Objective Based canopy height model (CHM) to automatically delineate the forest sub-compartments of forest resources management inventory similar to the manual delineation. Method Supported by tree species derived from hyperspectral image, the CHM generated from airborne LiDAR data was used for multi-resolution segmentation and optimization. First, the segmentation was applied on 1 m resolution CHM to obtain the over-segmentation results. Then 1-m resolution CHM was down sampled to 5 m resolution and segmented to get the under-segmentation results. By combining and optimizing these two results, the final sub-compartment delineation was obtained. The manual sub-compartments, the sub-compartments delineated based on 0.1-m spatial resolution Digital Orthophoto Map (DOM) and the Logging sub-compartments were used as reference data. The Ultimate Measurement Accuracy (UMA) rule was used to validate the accuracy of boundary drawing of stand segmentation results in its consistency with the reference sub-compartments. The UMA has 8 indexes, which are Roundness, Compactness, Shape index, Radius of smallest enclosing ellipse, Elliptic fit, P2A etc. And the Intersection Over Union (IOU) ratio was also introduced to quantify the consistency between the automatic segments and reference sub-compartments. The explained variance of mean height and mean DBH was calculated using the field data to validate the internal consistency and external variability accuracy of automatic segments. Result The automatic segments were similar to that of the reference sub-compartments in shape, area and other characteristics of UMA, and were most similar to the manual sub-compartments. The proportions of automatic segments whose IOU ratio was more than 70% with manual sub-compartments, the DOM sub-compartments and the Logging sub-compartments were 46%, 37%, and 43%, respectively. The proportions of automatic segments whose IOU ratio more than 70% were 61%, 54%, and 55%. The explained variances of mean DBH and mean height of automatically delineated sub-compartments were 97% and 98%, indicating the high internal consistency and distinct differences with adjacent sub-compartments of automatic sub-compartments. The explained variances of mean canopy height was 84.81%, which was 1.77% higher than that of the manual sub-compartments. Conclusion The sub-compartments automatically delineated by multi-scale segmentation method with CHM and tree species derived from hyperspectral image have obvious advantages in terms of internal consistency and boundary accuracy, and are more consistent with the distribution of trees at sub-compartments boundaries. This method saves time, increases efficiency, and increases the accuracy of forest sub-compartment delineation, which can support forest delicacy management planning.
Biomass and Its Distribution Pattern of Four Tree Species Plantation in South Subtropical China
GUO Shi, ZHAO Hou-ben, ZHOU Guang-yi, LONG Wei-ge, GAN Gu-lie, WU Shang-yong, MENG Min-yan, CHEN Jin-lan
Objective To compare the differences of biomass and its distribution pattern among plantations of 4 tree species in south subtropical area, provide data for evaluating the production capacity and carbon sink potential of plantation, and provide support for the selection of tree species for improving quality and efficiency of regional plantation and building high-efficiency carbon sink forest. Method The biomass and its distribution pattern of 33-years-old Schima superba, Mytilaria laosensis, Nyssa sinensis and Cunninghamia lanceolata plantations planted in the same period on Pinus massoniana clear-cutting site in Liuzhou City, Guangxi, were studied by the method of standard plot investigation combined with biomass measurement. Result Under the same site conditions, management measures and forest age, there were significant differences in tree layer and stand biomass among different tree species plantations, the order of stand biomass was S. superba plantation (376.37 t·hm−2) > M. laosensis plantation (284.51 t·hm−2) > C. lanceolata plantation (200.02 t·hm−2) > N. sinensis plantation (175.56 t·hm−2). The biomass of tree layer accounted for 93.0%-98.3% of the stand biomass, which was in an absolute dominant position. The biomass of shrub and herb layers accounted for a relatively low proportion (0.9% in average) and had a large spatial heterogeneity but no significant difference among different plantations. The biomass proportion of humus layer (2.3% in average) was higher than that of shrub and herb layers, and the humus pool of S. superba plantation was significantly higher than that of the other three plantations. The distribution pattern of biomass in tree layer was the largest in trunk, followed by root or branch, and the lowest in leaf. The distribution pattern of biomass in shrub and herb layers was different among different plantations. Conclusion In south subtropical plantation management and stand transformation, the selection of fast-growing broad-leaved tree species for afforestation can obtain higher stand productivity and carbon sequestration benefits than coniferous forest. It is suggested to take appropriate control measures to increase understory vegetation and to increase the system stability and sustainable development potential.
Screening, Identifying and Optimizing the Culture Conditions of High-efficiency Potassium-solubilizing Bacteria in the Rhizosphere of Cunninghamia lanceolata in Red Soil Area of South China
ZHAO Jun, RAO Hui-ling, FENG Qing-yu, HUANG Wei, WU Cheng-zhen, LI Jian
Objective To screen, identify and optimize the culture conditions of high-efficiency potassium-solubilizing bacteria strains in low-potassium-stressed rhizosphere soil of Cunninghamia lanceolata plantations in red soil area of south China. Method 79 potassium-solubilizing strains were screened from the rhizosphere soil under 2-, 4-,10- and 15-years-old C. lanceolata plantations, and 20 dominant strains were selected according to their morphological and growth characteristics. The soluble potassium content and potassium-solubilizing rate of fermentation fluid were screened out for an optimal potassium-resolving strain and the genus was determined by 16S rDNA identification. The culture medium components and culture conditions of the high-efficiency potassium-solubilizing strain were optimized by single-factor experiments and orthogonal tests. Result (1) Among the 20 potassium-solubilizing bacteria strains, the potassium-releasing rate of 13 strains was positive, the potassium-solubilizing bacteria effectively decomposing potassium-feldspar accounted for 65%. (2) strain JK13, identified as Bacillus altitudinis, was identified as the best potassium-solubilizing bacterium, and its fermentation liquid soluble potassium content was 81.06 μg·mL−1, with a potassium solution rate of 60.49%, significantly higher than that of the other strains (P<0.05). (3) The results of single-factor experiment and orthogonal test showed that the strain JK13 had an initial pH of 9, a liquid loading of 30 mL·100 mL−1, an inoculation of 1%, and a culture temperature of 35℃ when the value of the liquid OD600 was significantly higher than the CK (P<0.05). Conclusion Strain JK13, which belongs to the genus B. altitudinis, shows an efficient ability to dissolve potassium, and after optimization, 0.5% mannitol and 1.5% yeast powder are the most suitable medium components, the culture conditions are weak alkali, high temperature, which can significantly improve the growth of the strains.
Effects of Interspecific Relationship on Natural Regeneration and Community Stability of Pinus tabuliformis Plantation in Zhongtiao Mountain
PEI Shun-xiang, FA Lei, DU Man-yi, GUO Jia, XIN Xue-bing
Objective To examine the influence of interspecific relationship on the natural regeneration and community stability of Pinus tabuliformis plantation in Zhongtiao Mountain, and provide a theoretical basis for the management of P. tabuliformis plantation. Method Based on the survey data of the P. tabuliformis plantation community plots in Zhongtiao Mountain, the interspecific association, niche overlap and community stability of the dominant plants under the P. tabuliformis plantation were analyzed, and based on this, the role of interspecies association and niche theory in the formation of natural renewal barriers and community stability of P. tabuliformis plantations were discussed. Result The common species under the P. tabuliformis plantation in Zhongtiao Mountain are generally positively connected. The chi-square test results show that the unlinked species (372 pairs) are much higher than the linked species pairs (34 pairs), indicating that the common interspecies connections are loose. Association coefficient analysis results show that the positively connected species pairs are greater than the negatively connected species pairs, but the species pairs with significant positive association (AC≥0.20, 145 pairs) are smaller than those with significant negative association (AC≤−0.20, 168 pairs), and the most intensely competitive species with the natural regeneration of P. tabuliformis are Spiraea pubescens, Acer pictum subsp. mono, A. davidii, Clematis argentilucida, Rubia membranacea and Elymus dahurica. Pearson correlation analysis results show that the positively related species pairs are greater than the negatively related species pairs, but the significantly related species pairs are much smaller than the non-significantly related species pairs. Under the P. tabuliformis plantation, the niche of Carex lancifolia is the widest (23.47), and that of the Swida hemsleyi is the narrowest (3.87). The niche width of the natural regeneration of P. tabuliformis is 14.69, which is relatively high. The overall niche overlap of common species is low, but 11 species-pair niche overlap indexes are greater than 0.98, indicating that some species have greater ecological similarities. The niche of the natural regeneration of P. tabuliformis has the largest overlap with the niche of Sedum aizoon, Carex lancifolia, Pinus armandii and Thladiantha dubia, however, the results of the association coefficient analysis show that the natural regeneration of P. tabuliformis are positively associated with the species mentioned above, it shows that the natural regeneration of P. tabuliformis is similar to the resource utilization of these types of plants or it occupies a similar ecological space with these types of plants. The coordinate of the intersection point of the stability of the P. tabuliformis plantation community is (61.28, 38.72), which shows that the community stability is poor. Conclusion The maturity of the P. tabuliformis plantation community in Zhongtiao Mountain is relatively low, there are some species competing for the same resources, and the overall resource utilization and stability of the community is low. Competition may be one of the main reasons impeding the natural regeneration of P. tabuliformis in this area. Therefore, in the forest management activities targeting at P. tabuliformis species, more attention should be paid to removing the species that compete with the natural regeneration of P. tabuliformis under forest.
Characteristics of Particulate Organic Carbon and Nitrogen in Soil of Leucaena leucocephala Plantation in the Dry-hot Valley
LUO Ming-mo, MAO Jiao-yan, SHI Rui, LI Wei, HU Bin, FENG De-feng
Objective To investigate the change characteristics of soil particulate carbon and nitrogen content in the process of plantation restoration and to provide references for studying the response mechanism of soil carbon and nitrogen dynamics to plantation restoration. Method Leucaena leucocephala plantations at young age, middle age and matured age in Yuanmou dry-hot valley were selected and the natural shrub-grass plot as the control, the change characteristics of the soil particulate carbon and nitrogen content of natural shrub-grass plot and L. leucocephala plantations with different ages were studied. Result Compared with the natural shrub-grass plot, the age stage of L. leucocephala plantations significantly affected the soil organic carbon (SOC), total nitrogen (TN), particulate organic carbon (POC), particulate organic nitrogen (PON), POC/SOC, PON/TN, POC/PON. The proportion of mass of soil particle, SOC and TN contents were the highest in the matured plantation, while the POC, PON, POC/SOC, PON/TN, and POC/PON were the highest in the middle aged plantation. Conclusion The invasion of L. leucocephala into shrubs in dry-hot valley will significantly change the dynamics of soil carbon and nitrogen and its stability. The soil nutrient content in the matured plantation is the highest, while the soil stability in the middle-aged plantation is the lowest. This study could provide data support for the comprehensive evaluation of the effect of L. leucocephala on improving the soil ecological function in dry-hot valley.
Variation and Selection of Seedling Growth Traits Among Juglans mandshurica Provenances and Families
LU Xian-bo, XU Lian-feng, PANG Zhong-yi, LIU Ji-feng, WEN Bao-yang, PEI Xiao-na, ZHAO Ling, WANG Xue-gang, ZHAO Xi-yang
Objective To analyze and select the genetic variation of growth traits among provenances and families of Juglans mandshurica, in order to promote the selection and breeding of J. mandshurica superior varieties. Method In this study, the growth characteristics (tree height, annual growth of tree height, ground diameter, crown width, straightness, branch angle, number of side branches and taperingness) of 28 J. mandshurica families (6-years-old) within 4 provenances at Wanrenhuan Forest Farm were measured and analyzed. Result The results of analysis of variance showed that most of the traits reached extremely significant differences among various sources (P < 0.01). The phenotypic and genetic coefficient of variation of these traits ranged from 14.049% to 41.519% and from 8.754% to 23.873%, respectively. The family heritability and individual heritability were ranged from 0.284 to 0.797 and from 0.110 to 0.886, respectively. The results of correlation analysis showed that the correlation of almost all traits reached a significant level (P < 0.05), except the correlations between sharpness and branch angle, between sharpness and number of side branches, and between straightness and crown width. The results of general combining ability analysis showed that with a selection rate of 20%, 6 excellent parents were screened according to different traits. The results of principal component analysis (PCA) showed that the cumulative contribution rate of the three principal components reached 73.264%, indicating that the three principal components contained most information of the measured trait. According to the comprehensive scores of PCA, one excellent provenance, three excellent families and 10 excellent individual plants were initially selected. The realistic gains of tree height, average annual increase in tree height, ground diameter and crown width of selected provenance were 3.109%, 5.014%, 2.193%, and 1.040%, respectively. The genetic gains of the 4 traits of the families selected were 5.835%, 5.410%, 7.908%, and 6.069%, respectively. The genetic gains of the 4 traits of selected individuals were 26.74%, 24.11%, 23.91% and 26.53%, respectively. Conclusion The growth traits of J. mandshurica have rich variations within provenances and families. The excellent provenances, parents, families and individuals preliminary selected could lay a basis for the selection and application of J. mandshurica varieties.
Study on the Gallery System of Monochamus alternatus Hope
GAO Shang-kun, MA Shen-cheng, YANG Hua-wei, YANG Qing-he, ZHOU Cheng-gang, QIAO Lu-qin
[Abstract](110) [FullText HTML](70) [PDF 1212KB](1)
Objective To analyze the gallery structure and boring characteristics of Monochamus alternatus in Pinus densiflora and P. thunbergii in order to further understand the bio-ecological characters of M. alternatus in the hidden life process and benefit the application of natural enemy insects, pathogenic microorganisms, and injection drugs to control it. Method During the overwintering period, the gallery structure of M. alternatus in P. densiflora and P. thunbergii were systematically dissected. The gallery length, blocked frass length, internal diameter of entrance holes and pupal chambers, moisture content of frass, relative orientation between entrance holes and emergence holes were measured and the relationships between body size of larvae and host species and boring characteristics were analyzed. Result The galleries in both trees were U-shaped, single, not got through each other, blocked at the end of the entrance hole, and most of emergence holes were above the entrance holes. The boring characters of M. alternatus showed little correlation with individual body size and tree species. Conclusion The hidden and boring characteristics of M. alternatus in xylem are relatively regular, which is less affected by the host species. Its gallery is U-shaped, and part of that is blocked by the mixture of frass and fece.
Effects of Photoperiod and Light Quality on Seedling Growth and Chlorophyll Fluorescence Kinetics of Quercus L.
YAO Ning, LIU Jian-feng, JIANG Ze-ping, CHANG Er-mei, ZHAO Xiu-lian, XIE Rui, Wang Qi
Objective To study the growth and photochemical mechanism of leaves in Quercus L. seedlings responding to photoperiod and light quality in order to provide reference for seedling cultivation and artificial assisted regeneration of Quercus L. Method The growth parameter and chlorophyll fluorescence parameters of Quercus spp. seedlings (3 Q. variabilis provenances + 1 Q. mongolica + 1 Q. glandulifera) under three photoperiods (the lengths of light and dark were 10 h/14 h, 14 h/10 h, 18 h/6 h, respectively) and three red - far red light ratios (R : FR = 0.83 ± 0.04, 1.37 ± 0.04, 4.69 ± 0.04, respectively) were investigated. Result (1) At the species' level, the Fv/Fo, Fv/Fm, Ψo, φEo and PIAbs increased, while Mo, Vi, Vj, ABS/RC, DIo/RC and φDo decreased with the prolonging of photoperiod. Specially, Mo, Vi and Vj of Q. variabilis seedlings were the highest, Ψo and φEo were the lowest under medium photoperiod. Q. glandulifera and Q. variabilis showed a stronger response to photoperiod than Q. mongolica. The shortening photoperiod would significantly reduce the Fv/Fm and relative growth rate (RGR) of Q. glandulifera, and the prolonging photoperiod would significantly improve the RGR of Q. glandulifera and Q. variabilis, but the Fv/Fm and RGR of Q. mongolica showed no significant response to photoperiod changes. At the intra-species level, long photoperiod significantly increased the Fv/Fo and Fv/Fm of the Yunnan provenance and the RGR of all the three provenances of Q. variabilis increased with photoperiod. (2) Light quality ratio had no significant effects on RGR, energy allocation parameters and quantum yield parameters among three Quercus species and different provenances of Q. variabilis. (3) The significantly interactive effects between light quality ratio and photoperiod on RGR were observed. Under medium photoperiod, the seedlings showed an obvious shade-avoidance response, namely, the RGR of seedlings with low light quality ratio was the highest, which was significantly higher than that in the normal and high light quality ratio. Conclusion The results show that there are intraspecific and interspecific differences in response to photoperiod and light quality ratio. The south provenance of Q. variabilis are more sensitive to photoperiod. Q. glandulifera and Q. variabilis have a stronger response to photoperiod than Q. mongolica. Light quality ratio generally has no significant effects among Quercus L. seedlings. The seedlings show obvious shade-avoidance responses only under specific photoperiod.
Study on Safety of Grafted and Self-rooted Seedlings of 4-year-old Transgenic Populus tomentosa in Trial Plots
HOU Rong-xuan, ZHAO Ye, TIAN Yan-ting, SI Hua-yu, ZHANG Hua-xin, LI Juan, JI Qing-ju, YANG Qing-shan, SUN Yu-han, LI Yun
Objective To study the safety of transgenic Populus tomentosa with AhDREB1 gene from self-rooted seedlings planted in Binhai of Tianjin and transgenic seedlings planted in Yanshan of Hebei in order to evaluate the possible impact of transgenic Populus tomentosa on the environment. Method PCR amplification and electrophoresis were used to detect the genomic DNA of the 4-year-old transgenic P. tomentosa, soil DNA, root DNA of grafted seedlings from Yanshan and the genomic DNA of resistant microorganisms in Binhai. The amount of rhizosphere microorganisms in the soil of Binhai trial plot was monitored continuously (March, April and May). The degradation time of different organs (new shoots, perennial branches, new root tips, perennial lateral roots, new young leaves and old leaves) at different growth stages of transgenic P. tomentosa plants were measured in Binhai and Yanshan trial plots under simulated natural conditions. The allelopathic test was conducted to determine whether the transgenic leaves of P. tomentosa had any effect on the growth of Brassica pekinensis seeds. Result The electrophoretic results showed that exogenous genes stably existed in the genome of transgenic P. tomentosa, and no target gene fragment was found in soil DNA, root stock DNA of Yanshan grafted seedlings and DNA samples of resistant microorganisms. There was no significant difference in the amount of culturable microorganisms in the rhizosphere soil between non-transgenic plants and transgenic plants in Binhai. Exogenous genes were degraded in the litter of transgenic P. tomentosa after 2 months, whether it fell on the weed surface, soil surface or buried in soil. The allelopathic results showed that there was no significant difference between the non-transgenic plants and the transgenic plants on the growth of the hypocotyl and radicle of Brassica pekinensis seed. Conclusion No effect of transgenic P. tomentosa on the surrounding environment is found after 4 years of planting in the trial plot .
Analysis of Endogenous Hormones and Transcriptome in Sophora japonica Infected with Fasciation Disease
LIU Wen-ru, JI Sheng-xin, ZHEN Zhi-xian
Objective To investigate the pathogenesis of banding disease of Sophora japonica, so as to provide data for the prevention and control of the disease. Method In this study, the contents of auxin, zeatin, gibberellin and abscisic acid in the healthy and diseased branches of Sophora japonica were determined continuously in May, August, September and November. The differentially expressed genes were screened by transcriptome sequencing and the qPCR analysis was performed. Result In May, August, September and November, the contents of auxin, zeatin, gibberellin and abscisic acid in healthy tree, infected and symptomless shoots of the diseased trees were basically the same, but during the vigorous growth period of S. japonica in August, the content of zeatin in the infected branches was significantly higher than that in the healthy control; the contents of auxin and gibberellin were significantly lower than that of the healthy control. However, in the late growth stage of the plants in November, only the abscisic acid content of the diseased plants was significantly higher than that of the healthy control. Transcriptome sequencing results showed that the down-regulation of differential genes was significantly higher than up-regulation, and GO functional annotation analysis of differential genes showed that the differential genes were mainly concentrated in cell component, molecular function and biological process, especially in cell component and molecular function, while the KEGG metabolic pathway analysis showed that the differentially expressed genes in susceptible plants were mainly concentrated in signal transduction, plant pathogen interaction and plant hormone signal transduction. The results of endogenous hormone metabolic pathway annotation showed that AUX1 and CRE were down regulated, while the TF and ABF were up-regulated. The genes (GHLAX5, GHAHK4, GHAHP4,GHARR8, GHTF and GHABF2) regulating auxin, zeatin, gibberellin and abscisic acid metabolism and signal transduction were obtained by screening the transcriptome data for qPCR verification. Although there were some differences between the results and the transcriptome data, the expression trend was basically the same. These results suggested that the differential expression of these genes may play an important role in regulating the endogenous hormone content of S. japonica. Conclusion The significant increase of zeatin content and the significant decrease of auxin and gibberellin contents may hinder the immune response of plants and the differential expression of key genes regulating the metabolism of these three hormones, which may be the main reason for the occurrence and lateral growth of the diseased branches of S. japonica.
Molecular Cloning and Expression Analysis of Transcription Factor Gene CoSOC1-like in Camellia oleifera
HUANG Guo-wen, GUAN Tian-qiu, ZHAO Yu-yun, CHEN Mo-lin, LIU Hong-hui
Objective To clone the homologous gene of SOC1 from Camellia oleifera (CoSOC1-like) and to analyze its sequence structure, expression pattern and protein evolution. Method Total RNA was extracted from the young leaves of three-years-old C. oleifera, and the CoSOC1-like gene was cloned by using RT-PCR technology and RACE (rapid amplification of cDNA ends) technology. The sequence and expression pattern of CoSOC1-like were analyzed using the bioinformatic tools and fluorescence quantitative PCR, respectively. The subcellular localization and evolution of CoSOC1-like protein were analyzed using the method of gene transient expression and MEGA7 software, respectively. Result The full length cDNA of CoSOC1-like contained 654 bases, encoding 217 amino acids, and the relative molecular weight was 24.958 kD and the isoelectric point was 6.8. The Genbank accession number of CoSOC1-like is MT036382. The CoSOC1-like protein had the structure of MADS-box family transcription factors of plant type Ⅱ, and there was a SOC1 MOTIF in C-domain. The CoSOC1-like protein had 31 phosphorylative loci in its amino acid sequence, and its tertiary structure based on secondary structure had obvious active sites, and the transient expression of CoSOC1-like gene showed the CoSOC1-like protein located in nuclear, which was consistent with the nuclear localization characteristics of transcription factors. The phylogenetic analysis showed that the CoSOC1-like protein was clustered in the same evolutionary branch with SOC1-like protein of Camellia sinensis. Fluorescence quantitative PCR analysis showed that the CoSOC1-like gene could be detected in all organs, and there was a maximal relative expression level in flower buds of C. oleifera. Conclusion The CoSOC1-like gene may play an important role in the flower bud differentiation, and participate in the growth and development of other organs such as root, stem, leaf and seed of C. oleifera.
Cloning and Functional Analysis of JrWOX4b in Juglans hindsii × J. regia 'Zhongningsheng'
LEI Xia-shuo, CHANG Ying-ying, ZHANG Pu, SONG Xiao-bo, BAI Yong-chao, PEI Dong
Objective To provide theoretical support for exploring the regulatory function of WOX4b gene in walnut adventitious rooting. Method Using the cDNA of Juglans hindsii × J. regia 'Zhongningsheng' as template, the full-length CDS of JrWOX4b was cloned. The multiple sequence alignments and evolution analysis were applied by using bioinformatics technology to analyze its molecular characteristics. The fusion expression vector of JrWOX4b and yellow fluorescent protein (YFP) tag were constructed for subcellular localization analysis. After completing the genetic transformation and phenotype analysis of Populus alba × P. glandulosa, the function of this gene was determined. Result The CDS of JrWOX4b is 678 bp in length, encoding 226 amino acids, and molecular weight is 25.42 KDa. The results of multiple alignment and phylogenetic analysis of the amino acid sequences showed that walnut JrWOX4b has the closest genetic relationship with the homologous protein of Carya illinoinensis, followed by Quercus lobata, while has the farthest genetic relationship with Panicum miliaceum and Brachypodium distachyon. Phenotypic analysis of JrWOX4b overexpression plants showed that both the transgenic and control plants grew normally. However, under the same culture conditions, JrWOX4b could significantly increase the number of adventitious roots. The number of adventitious roots of 2-week-old overexpression plants is 3 ~ 4 times that of the control plants, and the length of adventitious roots is 1/2 of that of control plants. Conclusion JrWOX4b, the member of WOX gene family, was successfully cloned from walnut, and its overexpression can significantly promote the number of adventitious roots. The results provide theoretical support for the research on adventitious root regulation mechanism, and also provide excellent genetic resources for the rapid propagation of other difficult-to-root plant species.
Optimal Band Combination for Vegetation Type Recognition in Sanjiang Nature Reserve
JIANG Yi, LIU Hua, ZHAO Feng, MA Yong-kang, LIU Hao-dong
Objective To find the best band combination of GF6 image data for the identification of vegetation types, especially wetland vegetation information, so as to provide reference for the further application of GF6 data in wetland resources monitoring. Method Taking Sanjiang Nature Reserve as example and basd on the GF6 data, the research mentioned above was conducted combing with the features of local vegetation. From the perspective of image information characteristics, the best index factor, the spectral characteristic curve and the separability of ground objects, the best band combination for vegetation type identification in Sanjiang Nature Reserve based on GF6 data were obtained. At the same time, through comparative experiment, the support vector machine classification method was used to extract the vegetation type information of the sample area, and the reliability of the results was confirmed. Result The band combination of 1-4-5 showed the highest accuracy in vegetation classification with 89.15% overall accuracy and 0.8463 Kappa coefficient. Conclusion The band combination of 4(R)-5(G)-1(B) is the optimal band combination for vegetation classification in Sanjiang Nature Reserve. This study can provide a reference for monitoring the returning farmland to Wetland project in Northeast China.
Characterization of Differentially Expressed Genes in Root Tips of Poplar Under Different Nitrogen Forms
ZHOU Jing, LI Zhuo-rong, WU Jiang-ting
Objective To understand the molecular regulation mechanism of Populus × canescens root tips in response to different nitrogen forms. Method High-throughput transcriptome sequencing technology was used to screen and analyze the differentially expressed genes in poplar root tips under nitrate or ammonium treatments. At the same time, the effects of differently expressed genes on the growth and development process of poplar root tips were analyzed and described. The root tips of P. × canescens were treated with 0.5 mmol·L−1nitrate (NO3−) and 0.5 mmol·L−1 ammonium (NH4 + ) for 10 days, and transcriptome sequencing and bioinformatics analysis were performed on the root tips of the plants. Result The root length under nitrate treatment was almost twice that under ammonium treatment. 2207 differentially expressed genes were identified from the root tip transcriptome library of poplar treated with two nitrogen forms. Fifty GO functional clusters and 20 KEGG pathways were obtained by means of differential gene GO and KEGG functional clustering analysis, respectively. Furthermore, 36 differentially expressed genes related to nitrogen metabolism pathway, biosynthesis of various amino acids and metabolic process were screened by MapMan analysis. Analysis of the regulatory network of these differential gene interactions showed that nitrate reductase (Potri.005G172400) gene played an important role in affecting root tip growth and development by responding to different nitrogen forms. Conclusion Differentially expressed genes of poplar root tips under different nitrogen forms treatments were obtained. The functions of the differentially expressed genes were analyzed, which may help to understand the molecular mechanism of poplar root tip growth and development process by responding to different nitrogen forms.
Floral Volatile Components from Five Dendrobium Species Based on SPME-GC-MS
WANG Yuan-cheng, ZHANG Meng, ZHOU Xiao-xing, SHAN Yu-ying, SUN Zhen-yuan, LI Zhen-jian
[Abstract](1299) [FullText HTML](178) [PDF 802KB](9)
Objective To identify and analyze the floral volatile components of Dendrobium, a medical herb commonly used in China. Method The floral volatile components of Dendrobium pendulum Roxb., D. findlayanum Par. ex Rchb. f., D. crepidatum Lindl. ex Paxt., D. chrysanthum Lindl. and D. primulinum Lindl. were qualitatively analyzed by HS-SPME and GC-MS. Result A total of 112 volatile components were identified from the flowers, the main components were alcohols, alkanes, alkenes and ketones. For the first time, the fragrance components were analyzed in fresh flowers of D. pendulum, D. findlayanum, D. crepidatum, and D. chrysanthum. Conclusion The aroma components of fresh flowers are different among Dendrobium species. The aroma components in D. findlayanum are basilene and β-caryophyllene, that in D. chrysanthum are basilene, pinene and linalool, that in D. pendulum are linalool, luollene and β-caryophyllene, that in D. crepidatum are d-limonene, pinene and luollene. Both D. findlayanum and D. pendulum contain β-caryophyllene, a substance with the effect of anti- depression.
Investigation and Analysis on Host Species and Their Resistance Substances to Bacterial Bark Canker of Populus × euramericana
LI Yong, CHANG Ju-pu, GUO Li-min, SUN Shang, YANG Xu-qi, PIAO Chun-gen
[Abstract](1802) [FullText HTML](1144) [PDF 1005KB](8)
Objective To investigate and analyze the host species of bacterial canker of Populus × euramericana, the disease-resistant varieties and the possible disease-resistant substances they contain. Method The host of the pathogen and the resistant varieties were determined by field investigation and inoculation tests. The content of active substances in the bark of disease-resistant and susceptible varieties was analyzed by HPLC. Result The hosts of bacterial pathogen of P. × euramericana canker are P. deltoides, P. × euramericana and Salix matsudana. P. × euramericana cl. 'Zhonglin 46', P. deltoides cl. '2025', P. × euramericana cv. '2001', P. deltoides cl '313', P. deltoides 'Zhonghe-1' and P. deltoides '16-09' were highly susceptible to the bark canker disease; P. × euramericana 'Yukang 1' and P. deltoides '16-10' were highly resistant varieties, P. deltoides '131', P. deltoides '03-59', P. deltoides '02-212' and P. deltoides '03-34' were resistant varieties. Hybrid willows and Salix babylonica are resistant to the pathogen, and Salix × aureo-pendula can be affected, but do not cause serious disease. The HPLC analysis showed that the contents of catechol, benzoic acid and chlorogenic acid in the bark of resistant and highly susceptible poplar varieties were significantly different. The catechol and catechin increased when the hosts were infected by Lonsdalea populi. Conclusion In this study, the host species of bacterial canker of P. × euramericana are determined, and resistant and highly susceptible poplar varieties are screened. It is showed the catechol and catechin are important compound for host to defense the pathogen infection. The results will be helpful to the control of the bacterial disease of poplar.
Effects of Castanopsis kawakamii Forest Litter on Seed Germination of Pinus massoniana
JIA Mei-hua, WANG Zhe, LIU Jin-fu, JIN Meng-ran, HE Zhong-sheng, XING Cong, SHI You-wen, SHEN Cai-xia
[Abstract](2405) [FullText HTML](1553) [PDF 935KB](19)
Objective To understand the effect of litter of Castanopsis kawakamii natural forest on the competitive intensity of regeneration of Pinus massoniana. Method The allelopathic effects of litter extract of natural forest with different concentration and decomposition degree on seed germination and radicle growth of P. massoniana were studied. Result (1) The main factor affecting the germination of P. massoniana seeds was the degree of litter decomposition. Compared with the blank control, the litter of undecomposed layer and fully decomposed layer had no significant effect on the germination of P. massoniana seeds; the semi-decomposed layer inhibited the germination rate and germination index and promoted the germination potential. (2) The main factors affecting the growth of radicle were the concentration and action time of litter extract, and the effect of undecomposed layer on the whole radicle growth period of P. massoniana seeds was enhanced with the decrease of concentration, but increased with the decrease of concentration, and the promoting effect was the strongest at the concentration of 1 ≤ 100, and the effect of semi-decomposition layer was promoted by low concentration and high concentration, and the intermediate concentration was inhibited by the undecomposed layer. The fully decomposition layer showed promoting effect as a whole, and the promoting effect decreased with the decrease of concentration. (3) Correspondence analysis showed that different decomposition degree-concentration had no significant effect on seed germination of P. massoniana, but had significant correlation with radicle growth. Conclusion The result proves that the litter extract of different decomposition degree has a weak promoting or inhibiting effect on the seed germination of P. massoniana, promotes the growth of radicle at low concentration, and promotes the regeneration of P. massoniana, which will intensify the interspecific competition in the forest, and lead to the inhibition of the natural regeneration of C. kawakamii.
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Cloning and Transient Expression Analysis of CUC1 Gene from Fraxinus mandshurica Rupr.
CUI Jing-hong, YU Lei, LIANG Nan-song, SONG Ting-ting, LYU Yi-pin, JI Xin-tong, XU Liang, ZHAO Fu-jiang, ZHAN Ya-guang
Objective To clone the CUC1 gene of Fraxinus mandshurica and analyze its expression characteristics, so as to lay a foundation for the regulation of the gene in the regeneration of F. mandshurica Method The FmCUC1 gene was cloned from F. mandshurica seedlings. The nucleotide sequence of FmCUC1 gene and the amino acid sequence of its coding protein were analyzed by bioinformatics software, and the phylogenetic tree was constructed. The FmCUC1 gene was transferred into onion inner epidermis cells by Agrobacterium tumefaciens infection method for subcellular localization. The tissue surface of FmCUC1 gene in root, stem, leaf and apical bud was analyzed by real-time fluorescence quantitative analysis. At the same time, the seedlings of F. mandshurica were sprayed with IAA, 6-BA and BR hormones to analyze the expression pattern of FmCUC1 gene induced by different hormone signals; the FmCUC1 gene was transiently transformed into F. mandshurica by A. tumefaciens for 72 hours. Result The full length of FmCUC1 gene was 807 bp, encoding 269 amino acids. FmCUC1 was a stable hydrophobic protein with a conserved NAC domain protein domain. The sequence similarity of FmCUC1 protein and Olea europaea subsp. europaea protein was 86.17%, which was close to each other. FmCUC1 protein was located in the nucleus. q-RT PCR analysis showed that the expression of FmCUC1 gene was the highest in the terminal bud of F. mandshurica; during hypocotyl bud regeneration, the expression of FmCUC1 gene was high in both bud point formation and clump formation; during seed germination, the expression of FmCUC1 gene reached two peaks on the 4th and 8th day, which were 8.56 and 8.46 times of that on the first day. The results of exogenous spraying IAA, 6-BA and BR showed that the expression of FmCUC1 gene was up-regulated compared with the control, and reached the highest value after 72 h of IAA and BR treatment, which were 45.72 times and 20.36 times of the control, respectively, and reached the peak value after 48 h of 6-BA treatment, which was 59.40 times of the control. Agrobacterium tumefaciens mediated transient overexpression of FmCUC1 gene for 72 hours, the expression of FmCUC1 gene and its downstream STM gene increased significantly. Conclusion FmCUC1 gene belongs to NAC family and is a nuclear transcription factor. It participates in the process of shoot regeneration of F. mandshurica, and responds to the induction of IAA, 6-BA and BR plant hormone signals. Overexpression of FmCUC1 gene can activate the expression of its downstream STM gene, which is conducive to the formation of apical meristem.
Application of 3-PG Model in the Prediction of Growth Factors in Natural Larix gmelinii Forest
QU Ling-hao, ZHAO Xiu-hai, ZHANG Chun-yu
Objective To simulate and predict the biomass and volume growth of natural forest using process-based model. Method Taking Larix gmelinii natural forest in Daxing'anling mountains as the research object, the application of 3-PG model was studied based on physiological process in natural forest. By adjusting the parameters of built-in module equation of the model and optimizing the fitting results of measured value and simulated value, the model parameter group suitable for deciduous forest in Northeast China was finally obtained, and the test results of different forest ages were compared. Result The model achieved good results in the simulation of DBH, stem biomass, root biomass, above ground biomass and total biomass. The coefficient of determination R2 of stem biomass and total biomass equation reached 0.98, and the relative mean error was controlled within 8%. The results of total biomass prediction and DBH prediction for different aged forest showed that the model had a good fitting effect on young, half-mature and near-mature forests. Conclusion After adjustment of the local parameters, 3-PG model can be applied to the growth prediction of natural L. gmelinii forest, and it can achieve good results in biomass prediction and DBH prediction.
Impact of Fallen Trees in The Southern Section of Daxing'anling on Forest Regeneration
GUAN Li-juan, ZHAO Peng-wu, ZHOU Mei, SHU Yang, LIU Bing-bing, GUO Jiao-yu, ZHANG Jin-qi, ZHOU Li-wen
Objective To study the distribution of fallen wood and the impact of fallen wood on forest regeneration of Saihanwula forest ecosystem,a typical area of Hanshan Mountains secondary forests locating at the southern parts of Daxing'anling Mountains,Inner Mongolia. Method The sample plot survey method was used to investigate the fallen wood and forest regeneration. Result The regeneration density of the fallen wood plot was 4 050±824 plants·hm−2, the regeneration density of the standing wood plot was 2 950±265 plants·hm−2, the regeneration density of the control plot was 2 625±237 plants·hm−2; the average reserve of the fallen wood in Saihanwula was 58.51±16.56 m3·hm−2. Among them, the distribution densities of the fallen wood for decomposition grades II, III, IV, and V were 50±21, 806±198, 189±76, and 22±5 plants·hm−2. The fallen logs in the study area mainly existed in the form of "trunk base fracture", accounting for 68.78% of the total number of fallen logs. Conclusion A large amount of fallen wood accumulates in the forest, which has the effect of obstructing, intercepting and shading the renewal of seeds, seedlings, saplings, etc. At the same time, the fallen wood will severely crush the renewed seedlings and other plants under the forest at the moment of dumping and for a long time after dumping. Negative effects such as crushing injuries, the rate of crushing injuries is 5.3% ~ 7.8%. However, the proper amount of fallen trees with high decomposition levels can promote the growth of seedlings and young trees, and the rational use of the relationship between fallen trees and forest regeneration can effectively promote the healthy development of forests.
Microbial Diversity Analysis of Pinus massoniana Before and After Infected by Pine Wood Nematode
WEN Xiao-jian, WU Jian-jun, LI Yong-xian, WANG Xuan, LI Yong-xia, ZHANG Xing-yao
Objective Taking healthy and dead Pinus massoniana Lamb. in Bursaphelenchus xylophilus infected area in Zhejiang province as research object to examine the differences in the microbial communities structure of P. massoniana trees before and after infected by B. xylophilus, and to accumulate the microbial resources for controlling pine wilt disease by using endophytic microorganisms of P. massoniana. Method The methods of tissue isolation, morphology and molecular biology were used to isolate and identify the fungi and bacteria in different tissues (root, stem and needle) of healthy and dead P. massoniana. Phylogenetic tree was constructed for the isolated Trichoderma strains, and the effect of Trichoderma spp. on B. xylophilus population was analyzed by feeding experiments. Result 106 fungal strains belonging to 19 genera were isolated from healthy P. massoniana, and 86 strains belonging to 10 genera were isolated from the dead pine, the dominant genera were both Trichoderma. There were differences in fungal diversity among different tissues, the diversity indexes of stem and needle were higher than those of root. The Shannon-Wiener index, Simpson index and evenness index of fungal community from healthy pine were 2.37, 0.87 and 0.51, respectively, they were all higher than those of dead pine, which were 1.72, 0.76 and 0.39. The similarity indexes of fungal community in healthy and dead P. massoniana were less than 0.5. 59 bacterial strains belonging to 13 genera were isolated from healthy P. massoniana, and 56 strains belonging to 12 genera were isolated from the dead pine, the dominant groups were Burkholderia, Enterobacter and Serratia. The bacterial diversity of stem was the highest in both the healthy and dead pine, and that of needle was the lowest. The similarity indexes of bacterial community in healthy and dead P. massoniana were more than 0.5. Trichoderma was the dominant group in P. massoniana, six species were isolated in this study. The feeding experiment showed that the sample FXY7 of Trichoderma significantly inhibited the population of B. xylophilus. Conclusion The fungal diversity in healthy P. massoniana is higher than that in dead P. massoniana, the similarity of fungal community between healthy and dead pine is low, and the similarity of fungal community among different tissues is also low. However, the bacterial communities of healthy and dead pine are similar to some extents. This indicates that the invasion of B. xylophilus will affect the fungal community diversity in P. massoniana, but there is a little effect on the bacterial community. In addition, a number of endophytic bacteria with bio-control potential against pine wilt disease were isolated in this study, which is helpful for exploring prevention and control technology of pine wilt disease.
2021, 34(6): 0--1.
2021, 34(6): 1-2.
2021, 34(6): 1-8. doi: 10.13275/j.cnki.lykxyj.2021.06.001
Objective To analyze the response of radial growth and intrinsic water use efficiency (WUEi) of Robinia pseudoacacia to climate factors at different locations, and to determine the dominant factors affecting the growth and water use mechanism, so as to provide reference for the management of R. pseudoacacia plantations in China under climate change. Method The ring width chronologies were established in Minquan (MQ) of He'nan Province and Baishui (BS) of Shaanxi Province. The stable carbon isotopic composition (δ13C) of tree ring was measured to calculate the WUEi. The differences in the response of R. pseudoacacia to climatic variation were analyzed with meteorological data. Result The plantations at the two locations were in similar age. The tree-ring width at BS presented a trend of initially increasing and thereafter decreasing with the increase of tree age, whereas at MQ, the tree-ring width showed a linear decreasing trend with tree age increase. The trends of basal area increment (BAI) of R. pseudoacacia at the two locations were similar, presenting a trend of initially increasing and thereafter decreasing with the increase of tree age. The δ13C value and WUEi of the trees in MQ were lower than those of BS. The Pearson correlation results showed that on a monthly scale, the STD index of R. pseudoacacia in the two locations was mainly positively correlated with the summer precipitation and drought index (SPEI) (P < 0.05), and the R. pseudoacacia in BS was significantly negatively correlated with the average precipitation and SPEI in November of the previous year (P < 0.05). The WUEi of trees in MQ was significantly positively correlated with the average temperature and maximum temperature in March and August (P < 0.05), while that of trees in BS was significantly positively correlated with the average temperature, maximum temperature and minimum temperature from March to April of the current year, and June to July of the previous and current year (P < 0.05). The path analysis model showed that on the annual scale, the STD index of R. pseudoacacia in BS had a significant positive effect on the average precipitation and average temperature (P < 0.05), while the R. pseudoacacia in MQ had no significant response to climate factors. The annual average temperature had significantly positive effect on WUEi of trees at both the locations (P < 0.05). Conclusion The average precipitation is the dominant factor influencing the radial growth of R. pseudoacacia at both the locations, and the sensitivity of growth of trees in BS is higher than that of trees in MQ. The average temperature is the dominant factor influencing WUEi at the two locations, and the WUEi of trees in BS is more sensitive to the temperature than that of trees in MQ.
2021, 34(6): 9-19. doi: 10.13275/j.cnki.lykxyj.2021.06.002
2021, 34(6): 20-27. doi: 10.13275/j.cnki.lykxyj.2021.06.003
Construction of Core Collection of Catalpa fargesii Bur. Based on Phenotype
YU Xiao-chi, LI Feng, OU Yang, ZHANG Peng, GUO Xiao-long, XIAO Yao, ZHAO Qiu-ling, YANG Gui-juan, WANG Jun-hui, MA Wen-jun
Objective To obtain a more reliable primary core germplasm group of Catalpa fargesii, to strengthen the breeding, development and utilization and molecular genetics research, to reduce the conservation cost of germplasm resources, and to promote the identification and effective utilization of C. fargesii germplasm resources. Method Based on the leaf traits, the growth traits and the wood traits of 200 C. fargesii clones from Gansu, Shaanxi, Shanxi and He'nan provinces, five genetic distance calculation methods, six clustering methods, three sampling methods and five sampling ratios were used to construct the primary core germplasm resources, and then evaluated them. Result Using the Euclidean distance and the Single system clustering method, the deviation sampling with 15% sampling proportion was adopt to construct the primary core collection of 30 clones, the mean difference percentage was 10%, the variance difference percentage was 40%, the coincidence rate of range was 91.95%, and the changeable rate of coefficient of variation was 136.96%, which could best represent the original germplasm group. The construction of core collection increased the percentage of germplasm with leaf length, leaf width, leaf length width ratio, petiole length, diameter at breast height, crown width and elastic modulus higher than the average, and reduced the percentage of germplasm with Pilodyn value higher than the average. The percentage of core collection in Shaanxi, Shanxi and He'nan provinces were higher than that of the original collection. Conclusion This research showed that there are abundant genetic variation in each trait of C. fargesii clones. The 30 core germplasms not only retain the mean, range and degree of variation of the original germplasms, but also increase the variationcoefficient of the germplasms, and slightly increase the growth and the material quality level of the germplasms. This research laid a foundation for promoting the identification and effective utilization of germplasm resources.
Cloning and Functional Analysis of JcBRL3 Gene from Jatropha curcas During Flower Development
CHEN Yu-qian, LEI Shi-kang, XU Gang
Objective To explore the function of BRL3 gene in flower development of Jatropha curcas. Method The full-length cDNA sequence of JcBRL3 gene was obtained by RACE PCR. The prokaryotic expression system was used to induce the expression of JcBRL3 gene. The expression products were identified by mass spectrometry using LC-MS/MS. The structure and basic physicochemical properties of the protein were analyzed by bioinformatics. The relative expression levels of JcBRL3 gene during the key stages of flower development of Jatropha curcas were analyzed by qRT-PCR. The overexpression JcBRL3 gene was transformed into tobacco by leaf plate method to analyze the influence of overexpression of JcBRL3 gene on the morphology and structure of tobacco flowers. Result The length of the open reading frame of JcBRL3 gene was 3 618 bp and encoded 1 205 amino acids. The results of mass spectrometry showed that the expression of this gene encoded a JcBRL3 protein. Protein structure analysis showed that JcBRL3 protein was a transmembrane protein with multiple leucine-rich repeats and conserved repeats: LxxLxLxxN/CxL. qRT-PCR analysis showed that the expression of JcBRL3 in female flowers reached the highest level at mononuclear embryo sac stage, and in male flowers reached the highest level at pollen grain maturation stage, which was significantly higher than at any other stage. The morphological structure analysis of transgenic tobacco flower showed that the stigma position of transgenic tobacco was lower than that of anther, and the malformation rate of pollen grains was lower. Conclusion JcBRL3 protein is a LRR-RLK, which is a membrane protein. JcBRL3 gene may participate in the development process of female flower mononuclear embryo sac stage and pollen grain maturation of male flower and promote filament elongation in Jatropha curcas.
Prediction of Carbon, Nitrogen, and Phosphorus Contents of Chinese Fir Based on Ecological Factors and Artificial Neural Networks
TONG Ran, CHEN Qing-biao, ZHOU Ben-zhi
Objective To achieve the accurate, economical and quick prediction of leaf carbon, nitrogen, and phosphorus contents of Chinese fir. Method Taking the Chinese fir (Cunninghamia lanceolata) plantations in subtropical China as objects, a RBF (radial basis function) neural network with highly nonlinear mapping relationships between input layer and output layer was used to build the optimal prediction models for the leaf C, N, and P contents of Chinese fir and ecological factors including geography, climate and soil properties. Result The simulation prediction of leaf average C, N, and P contents were 476.68, 12.27, and 1.24 mg·g−1, respectively, the leaf N content of Chinese fir was far less than that of terrestrial plants in China; the leaf average C/N, C/P, and N/P were 40.28, 412.01, and 10.50, respectively. The prediction results were well consistent with the measured values, indicating that it was feasible to use the RBF neural network model for predicting the relationships between leaf C, N, and P contents and ecological factors. Conclusion These models could accurately estimate the leaf C, N, and P contents of Chinese fir, the mean errors are 1.82%, 9.88%, and 7.02%, respectively. Both the relatively low leaf N content and N/P indicate the growth of Chinese fir is limited by N element in subtropical China.
Comparison of Deep Learning and Traditional Models to Simulate the Height-DBH Relationship of Chinese Fir
LIANG Rui-ting, SUN Yu-jun, LI Yun
Objective To explore a more efficient and low-biased tree height prediction method, improve the prediction accuracy of tree height, and to establish a multi-hidden layer neural network model of height- diameter is based on deep learning algorithm. Method Using a set of 2898 groups of tree height and diameter data from 34 Chinese Fir (Cunninghamia lanceolata) sample plots in Jiangle National Forest Farm of Fujian Province, 10 generalized height-diameter models were established based on traditional regression, and the model with the highest accuracy was selected to compare. At the same time, based on the deep learning algorithm of the H2O platform, 70 DLA models with different structures of tree height-diameter at breast height were established. Through analysis and comparison, the most suitable model structure was determined and compared with the traditional optimal model. Result The different height-diameter DLA models can describe the relationship between height and diameter of Chinese Fir well, whose R2 is above 0.84, which is higher than that of the best traditional model, and the RMSE and MAE are smaller than that of the traditional model. The most accurate DLA model structure contains 6 hidden layers, each with 340 neurons. Conclusion The height-diameter DLA model established based on deep learning has higher fitting accuracy and prediction accuracy than the traditional models, especially when predicting higher trees. It can be used to predict the height of Chinese Fir in study area.
Spatiotemporal Expression Analysis of PagAG2 Gene in Populus alba × P. glandulosa '84K'
ZHONG Shan-chen, WU Shu, WANG Li, SU Xiao-hua, ZHANG Bing-yu
Objective To identify the role of PtAG2 gene in the development of male flowers of poplar. Method Based on the regulation of AG genes (PtAG1 and PtAG2) in the stamens and carpels of monoecious plants, the spatial and temporal specificity of PagAG2 gene of Populus alba × P. glandulosa '84K' was studied by means of paraffin section, real-time quantitative PCR and in situ hybridization. Taking the flower branches of P. alba × P. glandulosa '84K' as test materials, the inflorescences were continuously sampled within one week after hydroponic culture to observe the development of male flowers by paraffin sectioned technique. Real-time quantitative PCR was used to detect the expression of PagAG2 in the roots, stems, leaves and inflorescence of P. alba × P. glandulosa '84K'. In situ hybridization was used to detect the specific expression sites of PagAG2 in the flower organs of P. alba × P. glandulosa '84K' male flowers, so the expression pattern of PagAG2 gene was analyzed. Result During the development of male flowers of P. alba × P. glandulosa '84K', the anthers matured gradually. At the same time, the expression of PagAG2 increased at initial and then decreased, and the transcription was also be detected in the roots, stems and leaves of tissue cultured P. alba × P. glandulosa '84K'. The results of in situ hybridization showed that PagAG2 was expressed in the anthers of P. alba × P. glandulosa '84K' male flowers but not in the surrounding tissues. Conclusion PagAG2 gene is closely related to the male flower development of P. alba × P. glandulosa '84K', so it is expected to be a target gene for genetic engineering to improve poplar pollen. However, whether the PagAG2 gene participates in the regulation of the growth and development of other tissues of poplar needs to be further studied.
Hydrological Effects of Litters in Different Types of Cunninghamia lanceolata Plantations in Huitong of Hunan, China
ZHANG Ying, XU Qing, Gao De-qiang, SUI Ming-zhen, ZHANG Bei-bei, REN Ran-ran, ZUO Hai-jun, WANG Si-long
Objective To evaluate the impact of litter on hydrology in different types of Cunninghamia lanceolata plantations, and provide references for the management of understory and the assessment of ecosystem services. Method Based on field investigation and immersion experiments, the authors examined the storage capacity, water retention characteristics, and effective interception capacity of the litters collected from pure Cunninghamia lanceolata forest (PC), mixed forest of Cunninghamia lanceolata and Cinnamomum camphora (MCC) and mixed forest of Cunninghamia lanceolata and Alnus cremastogyne (MCA) in subtropical China. Result (1) The litter storage of different types of Cunninghamia lanceolata plantation varied from 7.94 to 8.88 t·hm−2, with an order of MCC > MCA > PC, and the proportion of semi-decomposed litters was greater than that of undecomposed litters. (2) The water-absorption rate of litter in various plantations increased rapidly within the initial 4 hours of immersion, followed by a slower increase at 4−10 hours of immersion, and finally saturated. Compared with semi-decomposed litter, the undecomposed litter had a higher maximum water-holding capacity and maximum water-holding capacity. Both semi-decomposed and undecomposed litters in mixed plantations exhibited higher maximum water-holding rate and maximum water holding capacity than that in pure Cunninghamia lanceolata plantation. (3) The maximum interception rate of the three types of plantation ranged from 152.33% to 229.55%. The maximum and effective interception capacity were 12.62−17.94 t·hm−2 and 10.26−14.75 t·hm−2, respectively, exhibiting higher in both MCC and MCA than in PC (P < 0.05). Conclusion The hydrological effect of litters varies among different types of Cunninghamia lanceolata plantation in Huitong, while the hydrological characteristics of mixed forests of Cunninghamia lanceolata with broad-leaved species are significantly better than that of pure Cunninghamia lanceolata plantation. Therefore, mixed stand of Cunninghamia lanceolata with broad-leaved species should be recommended in forest management and vegetation restoration.
Remote Sensing Monitoring and Restoration Evaluation of Ecological Environment in Shennongjia Area
QI Zhao, YU Xin-wen, TAN Bing-xiang, DENG Guang, YU Hang, SHEN Ming-tan
Objective To monitor and evaluate the change of ecological environment by using vegetation coverage change information in Shennongjia Forest Region, Shennongjia Nature Reserve and outside the reserve in the past two decades, combined with forest management activities and governance methods in different periods. Method Taking Shennongjia Forest Region, Shennongjia Nature Reserve and outside the reserve as the research area, using the three phases of Landsat remote sensing images in 1999, 2007 and 2019 to estimate the vegetation coverage of the study area based on dimidiate pixel model, and the method of difference analysis was used to calculate the vegetation coverage changes in each region. The results were evaluated and analyzed in conjunction with the changes in national policies and business activities in different period. Result From 1999 to 2019, the mean forest vegetation coverage (FVC) of Shennongjia Forest Region increased by 8.25%, the area with high FVC accounted for 97.50%. The vegetation coverage in protection zone has been better than that out of protection zone in the early stage, but in the late stage, the difference of vegetation coverage in and outside the protected zone is smaller. Conclusion In recent 20 years, the vegetation coverage of Shennongjia Forest Region has been on the trend of increasing, and the ecological environment has gradually become balanced, which indicates that the establishment of nature reserves, the natural forest protection project and the conversion of farmland to forest project are effective for the restoration of the regional ecological environment.
Analysis on Spatial Variability of Soil Trace Elements in Miyaluo Subalpine Primary Dark Coniferous Forest of Western Sichuan, China
XIONG Kai, ZHAO Yu-juan, CHEN Jian, ZHANG Yun, ZHAO Guang-dong, YANG Hong-guo, SHI Zuo-min, XU Ge-xi
2021, 34(6): 99-106. doi: 10.13275/j.cnki.lykxyj.2021.06.012
Objective To study the spatial heterogeneity of soil trace elements in Miyaluo subalpine primary dark coniferous forest of western Sichuan so as to provide scientific basis for soil quality evaluation, the protection of regional ecological environment and the research on biodiversity co-existence mechanism of the subalpine forest in Western Sichuan. Method A subalpine primary dark coniferous forest dynamics plot (400 m × 240 m) was established in Miyaluo of western Sichuan. By combining field sampling, laboratory measurement, classical statistics and geostatistical analysis, the spatial heterogeneity of 0~10 cm surface soil trace elements were analyzed, including Iron (Fe), Manganese (Mn), Copper (Cu), Zinc (Zn) and their correlations with soil pH, soil organic carbon (SOC), total nitrogen (TN) total phosphorus(TP) and total potassium (TK). Result (1) The mean content of Fe was 17.22 g·kg−1, and the mean content of Mn, Cu, and Zn were 423.09, 4.33 and 47.91 mg·kg−1 respectively; (2) The high values of soil Fe, Mn, Cu and Zn contents appeared mainly in the high altitude area of the dynamics plot eastern portion and with patch shape, the spatial distribution characteristics of soil Zn was relatively simple with strong continuity; (3) The coefficient of variance (CV) of all soil trace elements content ranged from 29.76%-63.84% and the CVs of soil Fe and Mn were 29.76% and 63.84%. The Nugget/Sill ratio of soil trace element content ranged from 0.08 to 0.50. Mn and Cu showed a strong spatial autocorrelation, whereas Fe and Zn showed a moderate spatial autocorrelation; (4) In addition to the Cu and pH, Zn and SOC , Zn and TK, the other 17 pairs of soil properties had a significant (P < 0.05) or extremely significant (P < 0.01)correlation. Conclusion The content of trace elements Fe and Mn in the soil of Miyaluo subalpine primary dark coniferous forest in western Sichuan are high, but the content of Cu and Zn are low. The spatial distribution characteristics of soil Fe, Mn, Cu, Zn content show obvious spatial autocorrelation. There is a universal correlation between soil Fe, Mn, Cu, Zn content and soil pH, SOC, TN, TP, and TK.
Anther Structure and Pollen Development Characteristic of Manglietia conifera
PAN Li-qin, HAO Jian, XU Jian-min, LI Hong-lin, LIANG Fu-jiang, ZHANG Qing-qing, JIANG Qing-bin
2021, 34(6): 107-113. doi: 10.13275/j.cnki.lykxyj.2021.06.013
Objective The anther structure and microspore development of Manglietia conifera were studied to determine the abnormal phenomenon of male microspore development, and to provide evidence and accumulation data for further study on the taxonomic status of M. conifera and the phylogeny of Magnoliaceae. Method The anther structure, microspore and male gametophyte development of M. conifera were observed by means of anatomy and morphology. Result The results showed that the mature anther of M. conifera was composed of 5 to 7 layers of cells, including the surface layer, the inner wall, the middle layer and the tapetum. The 4-6 microsporangia were arranged in a linear pattern and the anther dehiscence was centripetal or lateral. There were two types of cytokinesis of microspore mother cell: continuous type and simultaneous type. The arrangement of microspore in a tetrad was isobilateral, linear or tetrahedral, and the mature pollen was two-celled. The pollen wall was smooth with very sparse cave-like ornamentation. Conclusion The anther structure and developmental characteristics of M. conifera were similar to those of other genera in Manglietia, but the structure of pollen sac, the mode of cytoplasm division and the arrangement of microspore tetrad were different. The abnormal phenomenon of microspore development mainly occurs in the tetrad stage, which is one of the reasons for the abortion the pollen and low seed setting rate of fruit.
Effect of Diameter at Breast Height Structure on the Occurrence of Shoot Blight in Pinus densiflora Pure Forest
CHENG Yuan, LIANG Jun, LI Qing, Liu Feng, XIE Xian, GAN Rong-cun, ZHANG Xing-yao
Objective To clarify the effect of diameter at breast height (DBH) structure on the occurrence of shoot blight in Pinus densiflora pure forest, so as to provide theoretical and technical support for taking reasonable forest management measures to adjust the stand DBH structure and prevent and control the prevalence of P. densiflora shoot blight. Method A total of 50 temporary sample plots were set up in P. densiflora pure forest of Kunyu Mountains to investigate the DBH and the disease index of shoot blight. Weibull distribution fitted the location parameter, scale parameter and shape parameter, and \begin{document}$ {x}^{2} $\end{document} test verified three parameters. Then the correlation between disease index of shoot blight and eight DBH structure characteristic indices of P. densiflora, i.e. the three parameters, the average DBH of P. densiflora, the average DBH of infected P. densiflora, the average DBH of uninfected P. densiflora, the average DBH of maximum disease grade P. densiflora, and the average DBH of minimum disease grade of P. densiflora were determined by Spearman rank correlation analysis. Result The DBH structure of temporary sample plots of P. densiflora pure forest conformed to Weibull distribution. The DBH distribution center was 9.66 ~16.25 cm, and the DBH structure of 90.00% plots followed a positively skewed unimodal distribution. The disease indices of P. densiflora shoot blight were negatively correlated with the average DBH of uninfected P. densiflora, the average DBH of maximum disease grade P. densiflora and the average DBH of minimum disease grade P. densiflora, but the test results were not significant. Meanwhile the disease indices of P. densiflora shoot blight were significantly and negatively correlated with the scale parameters, the average DBH of P. densiflora and the average DBH of infected P. densiflora (p<0.05), and highly, significantly and negatively correlated (p< 0.01) with the shape parameters. It was indirectly, significantly and negatively correlated with the position parameters. Conclusion Weibull distribution is able to well fit the DBH structure of P. densiflora pure forest. There are significant or extremely significant negative correlations between the disease indices of shoot blight and the DBH structure characteristic indexes, such as the DBH structure distribution center, the DBH structure distribution curve shape, the average DBH of P. densiflora, the average DBH of infected P. densiflora. There is an indirect and significantly negative correlation between the disease indices of shoot blight and the minimum DBH of P. densiflora. It is suggested to take forest management measures such as tending and thinning to increase the proportion of dominant trees in the forest, reduce the P. densiflora DBH differentiation degree, decrease the infested P. densiflora with small DBH in order to achieve the purpose of ecological regulation of P. densiflora shoot blight.
Response of Soil Labile Organic Carbon to Thinning Intensity in Secondary Forest of Cyclobalanopsis glauca
QI Meng-juan, SHI Shuo-rong, JIANG Chun-qian, WANG Shu-ren, WANG Hui, WANG Jing-di
Objective To study the response of soil labile organic carbon to thinning intensities in the secondary forest of Cyclobalanopsis glauca. Method Experiments were carried out to investigate the changes of SOC and its labile chemical components (MBC, DOC, POC and ROC) as well as their distribution ratio following a short term intensity adjustment of stand woods with 4 treatments: light (15%, LIT), moderate (30%, MIT), high (50%, HIT) and the contrast (unthinning, CK) in secondary forest of Cyclobalanopsis glauca. Result (1) Compared with the CK, the MIT and HIT significantly increased the SOC content, while LIT reduced the SOC content. (2) Thinning increased the soil MBC content and reduced the DOC content. The variation trend of soil POC and ROC contents under different thinning treatments was consistent with that of the SOC. (3) Under different thinning intensity, the distribution proportion for soil MBC and POC, DOC and ROC were 0.23%-0.54%, 0.40%-0.78%, 16.54%-47.30% and 6.46%-14.29%, the HLT significantly Increased the proportion of MBC allocation as well as POC and ROC and reduced the allocation proportion of DOC, showing that thinning treatments increased the proportion of unstable carbon and POC was more sensitive to the thinning processing. (4) Correlation analysis showed that there was a significant positive correlation between soil total organic carbon and labile organic carbon components, and labile organic carbon was positively correlated with soil water content and total nitrogen content, the carbon conversion of soil labile components was dependent on the change of total organic carbon, and it was easy to decompose under certain water and nitrogen conditions. Conclusion Thinning treatment has significant effects on the contents of soil organic carbon and its labile components, and HLT will significantly increase the contents of soil organic carbon and its labile components and accelerate the carbon cycle in the soil.
Site Classification and Quality Evaluation of Eucalyptus urophylla × E. tereticornis Plantation in Hainan Island and Leizhou Peninsula Region
ZHANG Pei-jian, LU Wan-hong, XU Jian-min, LIN Zhi-feng, CHEN Ma-xing, LI Kong-sheng
Objective To study the site type and quality evaluation of Eucalyptus urophylla × E. tereticornis plantation in Hainan Island and Leizhou peninsula coastal area, so as to provide reference for site selection and production potential promotion of E. urophylla × E. tereticornis plantation in Hainan Island and Leizhou peninsula region. Method 112 plots were set up in 1- to 18-years-old E. urophylla × E. tereticornis plantations in Leizhou and Hainan. The growth indexes of E. urophylla × E. tereticornis were investigated, the site factors were recorded, and soil samples were collected to determine the soil physical and chemical properties. The quantitative theory I was used to establish the relationship model between site factors and the dominant high annual mean growth of E. urophylla × E. tereticornis, the site classification and quality evaluation of E. urophylla × E. tereticornis plantation were carried out by k-means cluster analysis and correlation analysis. Result The multiple correlation coefficient between site factors (altitude, slope, soil depth, parent rock, pH value, soil texture, and soil density) and the height growth of the dominant tree was 0.712, which was highly significant (P < 0.01). Soil texture, parent rock and soil density were the main site factors affecting height growth of dominant trees of E. urophylla × E. tereticornis. According to these factors, E. urophylla × E. tereticornis plantation in Hainan island and Leizhou peninsula region could be divided into 12 site types. According to the suitability and productivity, the site quality was evaluated and divided into four grades: high yield group, middle yield group, low yield group and poor yield group. The total proportion of the most suitable, more suitable and suitable grades was 91.89%, which indicated that the distribution of E. urophylla × E. tereticornis plantation area in Hainan island and Leizhou peninsula region was basically reasonable. The soil factors such as pH, organic matter, total phosphorus, total potassium and available potassium had significant effects on the growth of E. urophylla × E. tereticornis plantation. Conclusion Most of the site conditions in Hainan island and Leizhou peninsula region are suitable for the growth of E. urophylla × E. tereticornis. When planting E. urophylla × E. tereticornis plantation, it is suggested to choose the high yield group sites with acid loam soil and medium and low density. In afforestation and tending management, it is necessary to supplement phosphorus and potassium fertilizer in time to give full play to the production potential of forest land, timely replant the unsuitable site to improve the scientificity and rationality of afforestation.
Electroantennogram and Behavioral Responses of Dioryctria abietella to Volatiles from Picea likiangensis var. linzhiensis Cones
TANG Xiao-qin, WANG Si-zhan, LU Jie, GAO Tan, CHEN Yi-qu
Objective To screen the cone volatiles in the cones of Picea likiangensis var. linzhiensis, which have an attractive effect on the Dioryctria abietella, in order to clarify the host selection mechanism of D. abietella and provide a theoretical basis for the pest-free control of pests. Method Electroantennography (EAG) and "Y" olfactometer were used to measure the EAG reaction and olfactory behavior of D. abietella to the main components of the cone volatiles of P. likiangensis var. linzhiensis with different concentrations and formulations. Result The results of GC-MS showed that the healthy new cones and the infested old cones contained six compounds, but the composition and content were slightly different. The results of EAG showed that in the range of 10 μg·μL−1, the higher the concentration of α-pinene, β-pinene, (1S)-(-)-β-pinene, limonene, the bigger the EAG response of the D. abietella in different states. However, the EAG value decreased after 10 μg·μL−1. Under the concentration of 10 μg·μL−1, the EAG value of the moth in different states was significantly higher than under the other concentrations (P < 0.05). The EAG reaction of unmated female and male moths on beta-caryophyllene increased with the concentration, and the EAG reaction value in 0.5 μg·μL−1 was not significantly different from the control (P > 0.05). After reaching 1 μg·μL−1, no significant difference was found in the EAG value among concentrations (P > 0.05), while the EAG reaction between 0.5 μg·μL−1 and 1 μg·μL−1 was significantly different (P < 0.05). The EAG response of the mated female moth and the unmated female moth to myrcene increased with the concentration. When the concentration reached 100 μg·μL−1, the EAG value was the largest, nevertheless the EAG value of 100 μg·μL−1 and 10 μg·μL−1 was not significantly different (P > 0.05). The results of olfactory behavior showed that formula A2, A3, A5, A7 and A8 had obvious attracting effect, especially formula A7, and the attracting rate of D. abietella in different states was over 70%. Unfortunately, formula A4, A9, A10 had obvious avoidance effect, and the avoidance rate of D. abietella in different states was as high as 50%~70%. Conclusion 10 μg·μL−1 of each component is the best stimulation concentration. Beta-caryophyllene has obvious attracting effect, while myrcene has obvious avoidance effect.
Study on the Inhibition Mechanism of Trichoderma songyi Against Sphaeropsis sapinea
ZHANG Ming, LIANG Jun, LI Jing, XIE Xian, CHENG Yuan, ZHANG Xing-yao
Objecive To study the effects of crude fermentation extract of Trichoderma songyi M75 on the metabolism system, physiological and biochemical mechanisms against the pathogen Sphaeropsis sapinea of pine shoot blight. Method Spectrophotometer was used to determine the effect of the crude fermentation extract of T. songyi M75 on the metabolic system enzyme activity of S. sapinea, as well as the electrical conductivity and the content of malondialdehyde in different treatment periods. Result The crude fermentation extract of T. songyi M75 significantly reduced the activity of the key enzymes in the metabolic system of S. sapinea. The treatment of SOD, CAT, PPO and POD reached their peaks within 8 to 12 hours, which were 75.25 U·(g·min)−1, 0.066 U·(g·s) −1, 5.8 U·(g·s) −1 and 12.33 U·(g·s) −1, respectively, and were 1.96, 6.09, 16.37 and 7.86 times of the initial. PK, HK and LDH decreased significantly within 12 to 24 hours of treatment, from 0.55, 0.066, 2.35 U·(g·min)−1 at the initial time to 0.18, 0.03, 0.66 U·(g·min)−1 respectively, and then the downward trend gradually slowed down. The contents of SDH, MDH and coenzyme Ⅰ decreased rapidly from 30.33 U·(g·min)−1, 15.55 U·(g·min)−1 and 5.70 nmol·(g·min)−1 to 10.00 U·(g·min)−1, 3.65 U·(g·min)−1 and 1.34 nmol·(g·min)−1 respectively, and then the decline was slow and the control group was in the continuous increasing trend. The activities of Na+, K+-ATP, Mg++-ATP和Ca++-ATP peaked at 0.09, 1.76 and 3.18μmolPi·(g·h) −1 at the 8th or the 12th hours, after that, it decreased rapidly, and then decreased slowly and gradually to 0 after 24 hours of treatment. The conductivity increased significantly within 12 hours, and the value of the treatment group was always higher than that of the control. MDA increased significantly in 24 hours and reached the peak value of 1.06 nmol·g −1, and decline slowly from the 24th to the 96th hours, however, it was still significantly higher than that of the control in each treatment period. Conclusion The crude fermentation extract of T. songyi M75 can inhibit the normal growth of the S. sapinea by destroying the defense system and normal metabolic pathway of the fungus.
Correlation between External Color and Quality of Mulched Phyllostachys violascens Shoots
HE Yu-you, CHEN Shuang-lin, GUO Zi-wu, XU Sen
Objective To study the change of appearance color and the relationship between color and quality of Phyllostachys violascens shoots from mulched forest land in order to provide references for bamboo shoot production, management and quality evaluation. Method The color parameters, including lightness value (L), redness value (a), and yellowness value (b), in the lower, middle and upper parts of sheath and pulp were determined by colorimeter, and statistical analysis methods such as principal component analysis, cluster analysis, discriminant analysis, ANOVA and correlation analysis were carried out for these color parameters and morphological characters of mulched Ph. violascens shoots. Result The results showed that the L, a, and b of the middle and upper parts of bamboo sheaths were the main color parts and chromaticity factors of the bamboo shoot appearances. The color of bamboo shoots could be divided into three types (dark, medium and light) based on L × a × b clustering. The consistent rate of discriminant analysis and cluster analysis was 95.6%, and the accuracy of regression validation was 93.3%, showing highly feasible and well effective of the clustering method. There were significantly differences in the color of bamboo sheath and bamboo pulp among different color types of mulched Ph. violascens shoots, the same with the morphology of shoot and its sheath, the edible rate, etc., and a strong correlation existed between the internal and external products of the bamboo shoots. Bamboo shoots with lighter color had a well-proportioned yellowish-white appearance, bright white pulp, small and thin sheath, light-weighted stump, and the edible rate was higher by more than 11% compared with that of the darker ones. Conclusion The bamboo shoots of mulched Ph. violascens have abundant changes in appearance traits such as color, morphology, etc., and generally, light-colored bamboo shoots possess more appearance quality advantages.
Measurement of Species Richness of Forest Community by Maximum Tree Species Number
YANG Ai-ming, HUI Gang-ying
Objective This paper attempts to address the forest species richness measurement by presenting a new measurement method to contribute to the forest biodiversity research. Method Monod model was adopted to express the species-area curve. The minimum forest community area and the maximum number of tree species were determined by mathematical means. Result The method applied in this study have been used to measure forest species richness in different climatic zones and the results further prove the fact that there are higher maximum species number and larger minimum community area in tropical forest communities and confirm the general rule that species richness decreased gradually with climatic zones from tropical to cold temperate zones. Conclusion The maximum number of tree species can accurately express the tree species richness of forest communities in different climatic zones, which overcomes the disadvantages of directly taking the number of tree species in survey areas of different sizes as the tree species richness in current studies.
Study on the Species of Long-horned Beetles Carrying Bursaphelenchus xylophilus in Liaoning
FAN Li-chun, SHI Yong, JIANG Sheng-wei, ZHENG Ya-nan
Objective To investigate and study the species of long-horned beetles carrying Bursaphelenchus xylophilus in the occurrence area of B. xylophilus in Liaoning, China, and to further clarify the species of vector insects of B. xylophilus and the carrying amount of B. xylophilus of the main vector insects in the occurrence area, in order to provide reference for the research of prevention and control technology of B. xylophilus in Liaoning epidemic area. Method From the first ten days of May to the late September in 2018 and 2019, the species of long-horned beetles were investigated at the epidemic areas of B. xylophilus in Fushun, Dalian, Dandong and Benxi of Liaoning Province. The adults were collected by traps and their morphological characters were identified and the amount was counted in laboratory. In April, 2020, the amount of Monochamus saltuarius carrying B. xylophilus were investigated in the Dahuofang Forest Farm of Fushun. The M. saltuarius emerging from the infected wood wrapped by iron net were cutting into pieces and soaked into Beman funnel. Then the nematodes were isolated and be identified through both morphological and genetic characters. Result 9 species of long-horned beetles infesting pine trees were trapped in the pine wilt epidemic area in Liaoning Province, namely: M. saltuarius, M. alternatus, Arhopalus rusticus, Asemum striatum, Rhagium inquisitor, Acanthocinus griseus, Moechotypa diphysis, Acanthocinus aedilis, and Dorysthenes sternalis. Among them, there were 4 species of long-horned beetles, such as Monochamus saltuarius, Monochamus alternatus, Arhopalus rusticus, and Asemum striatum carrying B. xylophilus. A total of 160 Monochamus alternatus adults emerged from infested wood were tested. The average number of B. xylophilus tested was 513.69 per beetle, and the maximum of B. xylophilus isolated from one beetle was10060. Conclusion According to the amount of long-horned beetles trapped in the forest and the amount of B. xylophilus isolated from the beetles, it is concluded that Monochamus saltuarius is the main long-horned beetle species in Liaoning epidemic area of pine wilt disease, and Monochamus saltuarius is probably the main insect vectored B. xylophilus. However, the population of Arhopalus rusticus is larger than the other long-horned beetles in Dalian epidemic area, but whether it is a kind of vector of B. xylophilus has yet to be determined. At present, the main vector of B. xylophilus in Dalian is Monochamus alternatus.
Advances in Tissue Culture Techniques of Trees and the Problems Existed
HUANG Lie-jian, WANG Hong
2016, 29(3): 464-471.
[Abstract](2354) [PDF 914KB](1603)
Effect of Thinning on Growth and Timber Outturn in Cunninghamia lanceolata Plantation
XU Jin-liang, MAO Yu-ming, ZHENG Cheng-zhong, FAN Rong-de, ZHOU Shi-shui, CHEN Yong-hui, CHENG Xiang-rong, YU Mu-kui
2014, 27(1): 99-107.
Comparison on Osmotica Accumulation of Different Salt-tolerant Plants under Salt Stress
CHENG Tie-long, LI Huan-yong, WU Hai-wen, LIU Zheng-xiang, WU xiang, YANG Sheng, ZHANG Hua-xin, YANG Xiu-yan
[Abstract](2488) [PDF 1605KB](1108)
On the Maintenance of Long-term Productivity of Plantation in China
SHENG Wei-tong
[Abstract](3110) [FullText HTML](882) [PDF 1291KB](930)
Research Progress of Structure-based Forest Management
HUI Gang-ying, HU Yan-bo, ZHAO Zhong-hua
[Abstract](4039) [FullText HTML](1403) [PDF 2383KB](741)
Quantitative Analysis of Forest Spatial Structure and Optimal Species Composition for the Main Forest Types in Daxing'anling, Northeast China
DONG Ling-bo, LIU Zhao-gang, LI Feng-ri, JIANG Lei
Growth and Structure Differentiation of Phoebe bournei Plantation with Different Sites and Modes of Afforestation
CHU Xiu-li, LIU Qing-hua, FAN Hui-hua, WANG Sheng-hua, CHEN Liu-ying, ZHOU Zhi-chun
Studies on Seedling Photosynthetic Characteristics of Five Tree Species under Drought Stress
HAN Bo, LI Zhi-yong, GUO Hao, ZHANG Jun-pei
2014, 27(1): 92-98.
Stoichiometry Characterization of Soil C, N and P of Pinus massoniana Plantations at Different Age Stages
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