Development and characterization of single nucleotide polymorphism markers in Camellia sinensis (Theaceae)

Tea is the second most popular non-alcoholic beverage in the world. In recent years, several molecular markers have been used in genetic studies of the tea plant. Yet, only a few single nucleotide polymorphisms (SNPs) have been reported. Here, we identified 818 putative SNPs from expressed sequence tag (EST) databases for the tea plant, which produced a frequency of 1 SNP/170 bp. A direct sequencing method was then used to verify 253 putative SNPs in genome DNA of 17 tea varieties. Fifty (20%) candidate and 299 new SNPs were identified. The haplotype polymorphism and nucleotide diversity of these markers ranged from 0 to 0.960 and 0 to 1.797%, respectively. Using these SNPs, the 17 varieties were classified into 2 groups by cluster analysis. The results indicate that Camellia sinensis-derived ESTs provide a valuable resource for SNP discovery. Furthermore, the abundance of SNPs in tea varieties is anticipated to generate the development of associated genetic studies, in addition to enhancing tea plant-breeding programs.