Hybridization breeding between daylily and nightlily to extend florescence of single-flower
Among species and cultivars of the genus Hemerocallis, various colors and easiness of adapting to the environment make them be widely used in landscaping. In addition, their daily blooming rhythm is a visible and stable trait which is associated with circadian clock. There are two types of highly controlled blooming patterns in wild species of Hemerocallis diurnal flowers with deeper colors and almost no fragrance; nocturnal flowers with bright colors and distinct fragrance. The flowering period for every single flower is less than 12h. Although flowering time isolation exists between daylily and nightlily, there seems no reproductive isolation, and their single flower durations are heritable. In this study, we obtained hybrids by crossing daylilies and nightlilies using artificial pollination method. Parent materials included different wild species and cultivars with different ploidy levels. In total 2456 flowers had been pollinated, and 571 fruit, 4862 seeds and 1849 seedlings were obtained. Results showed that single flower durations were nuclear inherited, and this trait in the progenies was closer to their nocturnal parents. Furthermore, flower duration could be prolonged effectively in F1 and F2 generations if their parents are cultivars with longer flowering time (especially Childrens festival, Red rum, Merlins moth and Zirong). In 8 of 43 combinations at least 50% of the individuals had a flower duration that was longer compared to the value in their parents. In 2 combinations it was 100%. Eighteen combinations had a flowering time longer than 12h and the longest duration within the F1 populations was 23h. These results provide guidance for further breeding in modern Hemerocallis so that they can be used in wider applications.
Ren, Y., Gao, Y.K., Yuan, L. and Zhang, Q.X. (2020). Hybridization breeding between daylily and nightlily to extend florescence of single-flower. Acta Hortic. 1283, 169-174
crossing, Hemerocallis, blooming rhythm, flower duration