Abstract:

By using Enzyme Linked Immunity Absorb Assay (ELISA) method, the dynamic changes of endogenous GA₃ and ABA contents in leaves of 5 tea cultivars were determined before and after the sprouting of axillary buds from 8 Mar. 2003 to 25 Mar. 2006. Results showed that the dynamic change of GA₃ concentration in mature leaves of various cultivars in the period of 8 Mar. 2003 to 25 Mar. 2006 showed a “sharply decreasing-slightly increasing-decreasing-sharply increasing” pattern with the growth of tea plant in every year. The first ascending time of GA₃ concentration appeared earlier in early-sprouting cultivars, and later in late-sprouting cultivars. The lowest ABA concentration also appeared earlier in early-sprouting cultivars and later in late-sprouting cultivars. The annual average GA₃ concentration in mature leaves of five tea cultivars was higher in early-sprouting cultivars than in medium-sprouting cultivars and much higher than in late-sprouting cultivars. During the dormancy of tea plant in winter season, the GA₃ concentration in mature leaves in the lowest level in the whole year, and the ABA concentration in mature leaves was in the highest level. From Nov. 2003 to Jan. 2006 this three years, the average concentrations of GA₃ and GA₃/ABA ratio in mature leaves were closely related with the sprouting period of overwintering buds. The research data showed that the GA₃ concentration in axillary buds during the sprouting period in spring was higher than that of in mature tea leaves, however, the ABA concentration in the axillary buds was lower than that of in mature tea leaves.

Key words:

Phenology, Tea plant, Endogenous ABA, Endogenous GA₃, Axillary bud sprouting