Genetic Diversity of Tea Germplasm Resources in Yunnan Province Based on Phenotypic Characteristics

Yunnan province of China is regarded as the origin center of tea plant,where maintains rich genetic resources of tea plant and its relative species.This study was to understand the phenotypic diversity of these germplasm resources.A total of 830accessions of Thea section were collected from 10 regions of the province and 27 traits including 13 descriptive and 14 numerical characteristics were tested.In the descriptive characteristics,the genetic diversity index(DI)ranged from 0.64 to 1.40 with an average of 1.04.The largest and the smallest DI values were observed in young shoot color and leaf base shape,respectively.The regional DI was the largest in Honghe(0.99),followed by Lincang(0.93)and Wenshan(0.91),and the smallest in Zhaotong(0.76).In the numerical characteristics,average coefficient of variation(CV)was 26.43%,ranging from 10.27% of water extract to 48.14% of the ratio of polyphenol to amino acid.The regional CV was 16.09%–25.75%,of which Wenshan and Honghe had the highest value and Zhaotong and Dali had the lowest one.The genetic diversity and CV of phenotypic traits showed a tendency of Southeast West Northeast.The clustering analysis showed that these germplasm resources were geographically clustered into three groups,i.e.,Zhaotong,Honghe,and other-region group,respectively.These results demonstrate an obvious differentiation of tea germplasm resources among Southeast,West,and Northeast of Yunnan,and Southeast is primarily deduced as the distribution center of genetic diversity.