Effect of ultraviolet B irradiation on accumulation of catechins in tea (Camellia sinensis (L) O. Kuntze

Effect of UV-B irradiation time on accumulation of foliar catechins in two tea cultivars was investigated. Low influence rate and short term irradiation of UV-B stimulated accumulation of major tea catechins, resulting in an increase in level of total catechins. Excessive irradiation of UV-B supressed the accumulation of tea catechins. Epigallocatechin gallate (EGCG) increased more quickly than the other catechins under appropriate UV-B irradiation. The difference in response of different tea cultivars toUV-B is discussed.