Abstract: Twenty-five tea landrace from Guizhou province, as well as three developed cultivar tea, were analyzed by 29 EST-SSR markers. A total of 104 alleles were identified with an average of 3.58 alleles per marker. The average of effective number of alleles, observed heterozygosity, expected heterozygosity and polymorphism information content were 2.85, 0.56, 0.66 and 0.58, respectively. The Qianbei tea germplasms showed lower values of the five indexes mentioned above, compared to the Qiannan Region. The Fis, Fit, Fst and gene flow were 0.04, 0.12, 0.08, and 3.01, respectively. The population structure analysis showed the genetic similarity coefficient ranged from 0.39 to 0.89,could divide all the 28 accessions into 4 groups. Tea germplasms were grouped into groupⅠ,Ⅱ,Ⅲ,Ⅳ, including 4,5,8,11 tea germplasms, respectively. It was suggested that the materials used in the experiment possessed a broad genetic differences and a higher genetic diversity. The results objectively reflect information including population structure and regional differences. The genetic diversity of tea germplasms in the Qianbei Region was lower than that of Qiannan Region. The tea germplasms in Qianbei Region showed richer genetic diversity than that in Qiannan Region, with relatively high genetic divergence and weak gene flow．

Key words: tea plant, landrace, EST-SSR, genetic diversity