ISSR Analysis On Genetic Diversity Of The Ancient Ginkgo Trees Of Three Regional Populations In Hubei Province

Ginkgo biloba L., endemic to China, is one of the oldest remained tree species in gymnosperm and known as "living fossil". As Ginkgo trees can live very long, there are lots of ancient ginkgo trees in China. Hubei Province is one of the main large scale concentrated distribution regions of ancient Ginkgo trees. In this paper, we collected leaf samples from 259 ancient ginkgo trees in Hubei province and analyzed the genetic diversity of ancient ginkgo trees in Hubei province by applying ISSR molecular markers. Results are as follows:(1) A total of 120 bands were amplified using 9 ISSR primers to the genome DNA of those 259 Ginkgo leaf samples of 3 populations. Of these bands, 114 were polymorphic, and the percentage of polymorphic bands (PPB) was 95.00%. At the species level, Nei's gene diversity (He) was 0.2591, shannon's information index was 0.3971. It showed that ancient ginkgo trees here have high genetic diversity.(2) Percentage of polymorphic bands (PPB), observed number of alleles per locus (Ao), effective number of alleles per locus (A_E), Nei's gene diversity(H_E) and shannon's information index (Ho) were used to display genetic variation of the 3 regional populations. It is discovered that the genetic diversity of Dahong mountain population (DHS) was the highest, the population of the southwest mountain area of Hubei province (EXS) the second, and the Dabie mountain population(DBS) the lowest.(3) Nei's genetic diversity analysis and AMOVA (Analysis of Molecular Variance) were made based on ISSR experiment data to analyze the genetic differentiation among the three regional ancient Ginkgo populations in Hubei province. The results showed that G_st=0.2896, φ_ST= 24.22%, revealing that the genetic variation of ancient Ginkgo trees in Hubei province was main distributed within populations.(4) Comparison was conducted to the genetic diversity of the six county populations of the ancient ginkgo trees of Hubei province, i.e. Suizhou population(SZ), Anlu population(AL), Badong population(BD), Macheng population(MC), Luotian population (LT) and Hong'an population (HA) according to the collecting place. The result showed that the genetic diversity of Suizhou population was the highest, Anlu population the second, and the Hong'an population the lowest. Nei's gene diversity (H_e) of these six...