Analysis of the genetic diversity of the coastal and island endangered plant species Elaeagnus macrophylla via conserved DNA-derived polymorphism marker

The genetic diversity and genetic structure of five natural populations of the island and coastal endangered plant species Elaeagnus macrophylla were analyzed via conserved DNA-derived polymorphism molecular markers. A total of 289 discernible loci were obtained from 102 individuals via fifteen primers, and 100% of the loci were polymorphic. The observed number of alleles was 1.9654, and the effective number of alleles was 1.2604. Nei's genetic diversity index was 0.1724 on average, and Shannon's information index was 0.2869, indicating that Elaeagnus macrophylla had lower levels of genetic diversity than those reported for its continental relatives and other continental species. The average percentage of polymorphic loci was 42.1%, and the maximum and minimum were 80.97% and 14.88%, respectively, which were associated with the Nanji Island and Liugong Island populations, respectively. The populations of Elaeagnus macrophylla were highly differentiated. Cluster analysis revealed that the similarity between the tested samples was related to their geographical location, that the samples from the same island tended to cluster together, and that there was no cross-clustering between samples. The Nanji Island and Da Rushan populations differentiated into two subpopulations. Last, we detected no correlation between genetic distance and geographic distance between populations (Pearson's correlation coefficient r = 0.256579, p-value = 0.8309).