Abstract: Ninety local tea landraces collected from Sichuan and Chongqing provinces were used to analyze genetic diversity and population structure based on 84 EST-SSR markers. A total of 275 alleles were amplified, with an average of 3.3 alleles and 0.33 of heterozygosity per locus. The mean gene diversity (H) and polymorphic information content (PIC) were estimated to be 0.462 and 0.407, respectively, among 90 tested accessions. The level of genetic diversity among local tea landraces in Chongqing was higher than that in Sichuan. And comparing to tea landraces from north part (Lat.≥N32°), the genetic diversity was significant higher in the southern part (Lat.<N30°) of Sichuan and Chongqing. Meanwhile, this study revealed that there was a significant difference between Sichuan and Chongqing populations according to clustering analysis based on either statistics model or Nei’ genetic distance. It indicated the origin and spread of local tea landraces might be different in Sichuan and Chongqing.

Key words: Camellia sinensis, landrace, genetic diversity, population structure, EST-SSR