ISSR Analyasis of Genetic Diversity in Callerya speciosa Accessions
To study the genetic variation and genetic relationship of Callerya speciosa and provide reference information on the identification, conservation and utilization of the germplasm resources, fifty-seven individuals of19 population of C. speciosa collected from Hainan, Guangdong and Guangxi, as well as its three relative species,were analyzed by ISSR markers. A total of 91 bands were scored from the 8 primers, and 76 of them were polymorphic, which accounted for 84.4%. At the species level, the Nei's genetic diversity(H) and the Shannon information index(I) was 0.258 3 and 0.396 0, respectively, reflecting the high diversity within the accessions of C.speciosa. The coefficient of genetic differentiation among population(Gst) and gene flow was 0.651 5 and 0.267 5,indicating strong genetic differentiation and low gene flow among the population. Cluster analysis revealed that all the samples of C. speciosa could be divided into two major classes but not corresponding to the biogeographical distribution of the species. The genetic distance among the four relative species ranged from 0.235 2 to 0.416 2 and C. fordii showed the closest genetic relationships with C. speciosa than other two species. Four ISSR markers selected in the study could be used as a rapid molecular diagnostic technique for species identification because of the obvious different amplified bands in these four species.