In this study, sequence-related amplified polymorphism (SRAP) markers were applied to molecular phylogeny analysis and species identification of 31 Chinese Dendrobium species.  Fourteen SRAP primer pairs produced 727 loci, 97% of which (706) showed polymorphism.  Average polymorphism information content of the SRAP pairs was 0.987 (0.982-0.991), showing that plenty of genetic diversity exists at the interspecies level of Chinese Dendrobium.  Our results indicate the SRAP marker system is informative and would facilitate further application in germplasm appraisal, evolution, and genetic diversity studies in the genus Dendrobium.
SRAP
The molecular phylogeny analysis (UPGMA) grouped the 31 Dendrobium species into six clusters. 
UPGMA