Study On The Summer Differentiation Of Buds In Different Nodes And Its Influence Factors In Kyoho Grape

6-year-old ’Kyoho’ grape (Vitis vinifera L.×Vitis labrusca L.) was employed as plant material in this study. The changes of morphology and correlated endogenous hormones in the buds situated in the 7th,8th and the 9th nodes were investigated during summer flower buds differentiation, meanwhile the main nutrient contents, activity of oxidase, content of malondialdehyde in leaves were measured. We aimed to find the characteristic of morphological change in different node buds during the summer flower bud differentiation and the effect of endogenous hormone, the main nutrient contents and oxidase in leaves on the flower bud differentiation in the ’Kyoho’grape. In order to deeper the understanding of the mechanism of flower bud differentiation on the one-year-two-harvest grape and the influence factors, providing a theoretical basis for one-year-two-harvest grape product and the flower bud regulation. The results showed as follow:1. The flower bud differentiation in’Kyoho’grape experienced five main stages: undifferentiation stage, the early differentiation of the inflorescence, the inflorescence anlagen appearance, the formation of the main axis of the inflorescence primordium and the second branching of the inflorescence primordium. It took 50 days for the bud of the 7th node and 56 days for the bud of 8th and 9th nodes respectively from the stage of early differentiation of the inflorescence to the stage of second branching of the inflorescence primordium.2. The flowering ability of buds on the 7th,8th and the 9th nodes in’Kyoho’ grape was as following:bud of the 7th node>bud of the 8th node>bud of the 9th node. There was a from-bottom-to-top trend for the flowering ability of buds at different nodes on a branch:the flower differentiation of buds in higher nodes is lower and the buds in the middle nodes on branch had strong flowering ability.3. The higher content of CTK and ABA and the lower content of IAA and GA3 in the buds may contribute to the flower bud differentiation in ’Kyoho’ grape.4. The higher levels of soluble sugar, sugar, starch and soluble protein content in leaves may contribute to the flower bud differentiation in’Kyoho’grape.5. The lower levels of the content of N and higher levels of the content of P, K, Ca and Mg may contribute to the flower bud differentiation in’Kyoho’grape.6. The higher levels of the CAT and POD activity may contribute to the flower bud differentiation in’Kyoho’grape. There is no obvious relationship between SOD activity, MDA content and the flower bud differentiation stage.