SSR标记研究粉花石斛的遗传多样性

New microsatellite DNA was isolated from D. loddigesii genome DNA through the methods of entichment by magnetic beads. Twelve polymorphic microsatellites were development for D. loddigesii, and their polymorphism was tested across all individuals from nine natural populations. A total of 98 alleles were detected with an average of 8.2 alleles per locus. The average expected heterozygosity and polymorphism information content values were 0.690 and 0.637, respectively. Lastly, twelve novel microsatellite markers were employed to investigate the genetic diversity and population genetic structure of D. loddigesii. A high level of genetic diversity was detected. The expected heterozygosity (He) ranged from 0.484 (BS) to 0.665 (HC), with an average of 0.582. Analysis of molecular variance showed that the main variation component existed within populations (82.02%) rather than among populations (17.98%). A dendrogram cluster analysis resolved the nine populations into two main clusters, which was consistent with the result of principal coordinate analysis (PCA). Mantel test revealed that no significant positive correlation was found between genetic distances and geographic distances (r = 0.4126; P > 0.05).