PHYSIOLOGICAL EFFECTS OF "longan Fanjicuhualing" ON REGULATING THE OFF-SEAAON BLOSSOM OF LONGAN

Two Longan varieties, i.e. Shixia and Tewanshu , were employed as the plant materials. The plants were treated with 1kg "Longan Fanjicuhualing" in the root soil. The effect of Longan fanjicuhualing on nutrient elements, C/N and endogenous hormones during the differentiation period of flower buds, and the relations between nutrient elements,C/N,endogenous hormones and the flower bud formation of longan were studied. The main results were as follows:1.After treatment of "Longan Fanjicuhualing", the contents of N, P and K were lowered compared with the untreated trees. The treatment also promoted the absorptions of Ca and Mg, and a little accumulation of Cl in leaves, but had no effect on Na. In the leaves of Tewanshu variety, K and Mg contents were higher.and Cl accumulation was found in the leaves at early flower bud differentiation period for the treatment of "Longan Fanjicuhualing, there weren't any obvious effects on N,P,Ca and Na. These results indicated that nutrient elements N, P, K and Ca were closely related to the blossom of Longan.2.Longan Fanjicuhualing increased the C/N ratio in leaves of the blooming variety Shixia in a relative long period,and It decreased the starch content but increased the soluble sugars content and had little effect on the C/N ratio. These results indicated that the higher C/N ratio and soluble sugar content benefited to Longan flower bud differentiation.3.Longan Fanjicuhualing promoted the leaves to release ethylene during the blooming period of shixia Longan, but decreased the IAA content in the physiological differentiation to the morphological period of flower bud. And it decreased the ABA content in the critical physiological differentiation to morphological differentiationperiod of the flower buds. It decreased the GA content during the physiological differentiation and early stage of morphological differentiation while increased the iPA content in the period of flower morphological differentiation. The GA in the stem-top were decreased, while the ABA and IAA increased and the latter risen sharply. This showed that five endogenous hormones had important effect on Longan flower bud differentiation at different stage. The effect of Longan Fanjicuhualing on Tewanshu was irregular.4.During the blooming period of Shixia Longan, the IPA/GA ratio in the leaves is higher in the Longan Fanjicuhualing treatment than in the control for a long time. There was a higher peak value during the critical period of bud physiological differentiation to morphological differentiation in the treatment. Besides in this period, IAA/ABA and IAA/GA ratios showed another peak in flower bud morphological differentiation period. This indicated high iPA/GA ratio was advantageous to the flower bud differentiation .The ratios of IPA/ABA, IAA/ABA and IAA/GA played an important role in Longan's flower bud differentiation in different periods.