Comparative response of catechin levels in drought tolerant and drought susceptible tea clones (Camellia sinensis) (L) O. Kuntze under different moisture regimes

In tea (Camellia sinensis) water stress generally affects the content of various plant secondary metabolites including catechins. The objective of the study was to evaluate the effects of different soil moisture content on the catechin levels of various tea clones. We found out that variation of soil water content and accumulation of catechins were strongly correlated. The experiment was conducted in an open field with the drought tolerant clones namely; SFS150, TRFK 303/577, and drought susceptible clones; TRFK 6/8, TRFK 12/9, TRFK 301/4, TRFK 31/11, S15/10, TRFK 7/9, TRFK 31/8, and BBK 35. During the cold and wet periods, the effect of plant water content on catechin level was not clearly expressed. However, significant clone × soil water content interactions (p≤ 0.05) were observed for all clones during the dry and hot periods. This observation indicated that declining plant water content (PWC) due to soil moisture stress reduced catechin levels. It was concluded that variation of catechin in various tea clones over different soil water content could be of great significance in evaluating water stress tolerance ability of tea clones. Key words: Catechins, clones, water content, dry and hot periods.