ISSR Analysis of Genetic Diversity in Natural Populations of Castanea henryi

Genetic diversity and genetic relationships of 16 natural populations of Castanea henryi.were assessed by ISSR.379 loci were identified in 449 individuals,of which 378 loci were polymorphic,the polymorphic loci percent(PPL) was 99.74%.The mean expected heterozygosity(He) and the Shannon information index(I) was 0.2950 and 0.4522,respectively.In population level,the PPL was 46.09%.The genetic diversity in different population was not consistent.Compared with those from other 15 regions,Xiangxi region had the higher level of diversity(PPL =53.30%,He = 0.1861,I = 0.2781).A high level of genetic differentiation was detected among populations based on analysis of Nei's genetic diversity and molecular variance(AMOVA),Which showed that a large genetic differentiation existed among populations(Gst = 0.4466),and distribution of genetic variation within and among populations was 52.51% and 47.49%,respectively.16 populations were clustered into 2 groups and 5 subgroups by the UPGMA analysis.Xiangxi region might the secondary distribution center and modern center of genetic diversity of C.henryi,also was the resource center.It was the most valuable gene pool,therefore,natural populations of C.henryi in this region need deserve prior conservation.