Genetic Diversity and Population Structure of Endangered Orchid Cypripedium flavum in Fragmented Habitat Using Fluorescent AFLP Markers

Genetic diversity is crucial for determining the evolutionary potential of a species and is essential for developing optimal conservation strategies. The impact of habitat fragmentation on the genetic diversity of food-deceptive orchids seems to be unpredictable because of their specialized seed and pollen dispersal mechanisms. The habitat of deceptive <i>Cypripedium flavum</i> was severely fragmented during the past half century. This study investigated the genetic diversity and structure of seven fragmented <i>Cypripedium flavum</i> populations in Shangrila County using AFLP markers. A total of 376 alleles were identified, with a range of 70 to 81 alleles per locus. The species exhibited considerable genetic diversity, as evidenced by an average Nei's gene diversity (<i>H</i>) of 0.339 and a Shannon's information index (<i>I</i>) of 0.505, with all loci being polymorphic. Based on Molecular Variance (AMOVA), 8.75% of the genetic differentiation was found among populations, while the remaining 91.25% of genetic variation occurred within populations. Population structure analysis revealed that the <i>C. flavum</i> germplasm can be categorized into 2 distinct groups, among which there was significant gene flow. Despite habitat fragmentation, <i>C. flavum</i> still retained a high level of genetic diversity, and the substantial gene flow (5.0826) is a key factor in maintaining the genetic diversity. These findings offer valuable insights for the conservation and potential use of <i>C. flavum</i> genetic resources.