Abstract：Association analysis is an effective method for the germplasm resources studying which is fundamental in plant breeding. All 115 tea (Camellia sinensis) were tested in several traits related to tea quality based on association analysis using 67 EST-SSR markers. All 67 EST-SSR markers were polymorphic with different diversity among 115 tea germplasm. All 161 alleles were amplified with 2.4 per markers on an average. The polymorphic information content (PIC) ranged from 0.03 to 0.68 with the average of 0.36, TM096 was highest, while TM099 was the lowest. The observed heterozygosity (Ho) varied from 0.03 to 1 with the average of 0.45. The expected heterozygosity (He) varied from 0.03 to 0.72 with the average of 0.43. Linkage disequilibrium (LD) is the basis of association analysis. So the analysis of LD was carried out. The results demonstrated that 2 211 pairs of loci were detected, 259 of which were in high level (D'＞0.5). And then 115 tea germplasm was divided into 4 groups through the method of population structure. Based on the Q-value (K=4) of each individual as covariant, association analysis between quality-related traits with EST-SSRs was performed. The results showed that 19 EST-SSR markers associating with these traits were detected in all, 5 for the content of water extract, of which TM066 with the highest explanation of phenotypic variation 13.32%; There were 5 markers associated with the content of ployphenols, of which TM092 with the highest explanation of phenotypic variation 13.68%. Six markers for the content of total free amino, TM083 explanted 7.6% phenotypic variation. Three markers for the content of caffeine, TM111 markers had the highest explanation of phenotypic variation 7.8%. Furthermore, the results showed that some markers were associated with two traits, such as TM066, TM092 and TM074-2 associating with the contents of water extract and polyphenols, TM086-1 associating with the contents of polyphenols and total free amino; and TM088, TM111 and TM124 associating with the contents of total free amino and caffeine. The findings can be recommended for improvement of tea quality and early identification of varieties in tea plant through the further research on these markers.
