Studies On Genetic Relationship And Genetic Diversity Of Camellia Sinensis Var.assamica CV.Jianghua

Thea assamica CV.Jianghua is a good local population species in Hunan province which was authenticated in 1987.It is mainly distributed in the Nanling Mountains in Jiang Hua area of southern Hunan province.It is a valuable tea resource.Based on the investigation of the resources of Thea assamica CV.Jianghua and the method of combining fluorescence SSR molecular marker and cpDNA sequence analysis,the relationship,genetic diversity and genetic differentiation of 32 resources of 4 natural populations were studied.The results of the study are as follows:1.The 27 samples with high representative were obtained in different areas of Jiang Hua County.In combination with five samples of tea garden of Hunan Province Tea Institute,a total of 32 samples were used in this test.2.After extracting the DNA of the sample,the suitable primers were screened.The four pairs of primers were finally selected for cpDNA sequencing.The equencing results showed that the mutation rate was about 0.78%.The molecular phylogenetic tree was constructed by the MP method,and 32 samples were divided into 4 major classes.After haplotype analysis with Dnasp,it was divided into five haplotypes.Neutral detection and mismatch analysis,it was thought that Jiang Hua expansion events did not happen because of.After comprehensive calculation,we found the mutations of cpDNA in Thea assamica CV.Jianghua mainly occurred in the area,population,the ratio was 89.29%.3.The extraction of DNA was studied by fluorescence SSR molecular marker technique.The data obtained by popgen were analyzed by popgen software.The results showed that 13 high polymorphic and reproducible fluorescent SSR primers obtained 99 bands in 32 resource samples,Na,NE,Shannon information index.(I)were 7.62,3.38 and 1.39,respectively.The expected heterozygosity(Ho),observed heterozygosity(He)and Nei's heterozygosity(Nei)of the Jiang Hua group were 0.56,0.65 and 0.64 respectively,and the population had higher genetic diversity.The calculated FST was 0.0971,indicating that the Thea assamica CV.Jianghua gene flow was strong and the level of genetic differentiation among the populations was low.The analysis of AMOVA data also showed that the variation of Thea assamica CV.Jianghua SSR was mainly in the region and within the population,the ratio was 90.89%.The genetic distance and genetic consistency between populations indicate that the diversity of Thea assamica CV.Jianghua is largely influenced by human activities.After analyzing the resource among ntsys software,we get genetic similarity between resources and get clustering diagram.4.The results showed that Jiang Hua's bitter tea community has high genetic diversity as a place in Hunan,and has high utilization value in resource breeding.The genetic diversity of Thea assamica CV.Jianghua occurs mainly in the region,and there is no expansion in the history.This study has laid a foundation for our better research on the collection and protection of bitter tea resources.