Study On Genetic Diversity And Population Genetic Structure Of Large-leaf Tea And Dali Te

Tea tree(Camellia sinensis)is one of the most important beverages in the world.It has been cultivated in China for more than 2000 years.Studies on genetic diversity and population genetic structure have great significance in the conservation and utilization of tea tree germplasms.In this study,we sampled 16 populations of C.sinensis var.assamica and 13 populations of C.taliensis to investigate the genetic diversity and population genetic structure by using nuclear microsatellite loci.The main conclusions are summarized as follows.1.The genetic diversity and genetic differentiation of C.sinensis var.assamicaFive nuclear microsatellite loci were used for genetic diversity analysis of 16 populations from C.sinensis var.assamica.The results showed that C.sinensis var.assamica had a high genetic diversity.The average number of observed alleles(A)and effective alleles(Ne)were 9.2 and 3.385,respectively the expected heterozygosity(He)was 0.678.Shannon diversity index(1)was 1.490;and the Nei’s diversity index(Nei)was 0.677.The coefficient of genetic differentiation(FST)was 0.100 on average,showing that genetic variation harboured 90.0%within populations.The cluster analysis exhibited that these 16 populations could be divided into four major groups based on Nei’s genetic distances.2.The genetic diversity and genetic differentiation of C.taliensisFive microsatellite loci were used for genetic diversity analysis of 13 populations from C.taliensis.The results showed that C.taliensis had a high genetic diversity.The average number of observed alleles(A)and effective alleles(Ne)were 9.4 and 3.588,respectively the expected heterozygosity(He)was 0.720.Shannon diversity index(I)was 1.639;and the Nei’s diversity index(Nei)was 0.716.The coefficient of genetic differentiation(FST)was 0.128 on average,showing that genetic variation harboured 87.2%within populations.The cluster analysis exhibited that these 13 populations could be divided into four major groups based on Nei’s genetic distances.3.The genetic diversity and population genetic structure of C.sinensis var.assamica and C.taliensisThe genetic diversity resided among populations of C.taliensis was higher than that of C.sinensis var.assamica.According STRUCTURE analysis,the highest likelihood for K was 4.When K was 2 C.taliensis and C.sinensis var.assamica were distinctly divided into two clades.The results clearly suggest that the species C.taliensis and C.sinensis var.assamica have different genetic structure.