Abstract

Cymbidium sinense cultivars exhibit an incredible range of diversity in the foliar morphology as well as the range of flower colors and shapes, which make them more popular among horticultural plants with great economic value. Understanding the genetic diversity and population structure in target populations will be of great importance for germplasm collection, breeding improvement and conversation of this species. In this study, Inter-simple sequence repeat (ISSR) markers were used to assess the genetic diversity and population structure of 151 C. sinense cultivars collected from China and Japan. C. sinense cultivars exhibited moderate levels of genetic diversity (H = 0.24, I = 0.38, Ppl = 100%) and genetic differentiation (Gst = 0.17) with gene flow estimate Nm of 2.4 among six geographical groups. With neighbor joining (NJ) analysis, 151 cultivars were clustered into seven main groups, and approximately related to their geographical distribution. Population structure analysis revealed six subpopulations, generally consistent with NJ-clustering. The results in our study suggest that different provenance collection and in situconversation are important for C. sinense conservation and genetic improvement.

Key words: Cymbidium sinense, DNA polymorphism, genetic diversity, inter-simple sequence repeat, population structure.