Studies On Photosynthetic Physiological Characteristics Of V. Davidii Foex

V. davidii Foex., as an eastern Asia wild grape species, is widely distributed in China. In recent years, V. davidii Foex. is used as raw material to brew featured wines, but the low sugar content of the fruit results that cannot reach the standard of high quality wine. Therefore, how to improve sugar content of grape berry with the cultivation methods, breed high photosynthetic capacity, high quality, high yield wine varieties of V. davidii Foex. varieties has become a new topic.In this paper, take the V. davidii Foex varieties collected by the Grape institute of Hunan Agricultural University over the years as the test object, take research in light response curve, CO2response curve, and temporal dynamic changes of photosynthetic, and evaluated the photosynthesis of V. davidii Foex. varieties, the main findings are as follows:(1) The results show that the response curves of grapes are fitted by the modified rectangular hyperbolic model, rational weak light region was accurately determined by using the descending point of light use efficiency on the light response curve.(2) The light response curve and CO2response curve of V. davidii Foex. varieties are analyzed. The use efficiency of low light and ability adapts to strong light of V. davidii Foex. varieties is under the upper line.The maximum net photosynthetic rate of V. davidii Foex. varieties are higher than V. pseudoreticu lata W.T. Wang., V. quinquangularis Rehd., and V. labruscaxV. vinifera Kyoho, but lower than in V. pseudoreticu lata W.T. Wang., V. quinquangularis Rehd. and V. labrusca×V. vinifera Kyoho, and V. davidii Foex. varieties has higher respiration consumption in the dark environment.(3) Different varieties of V. davidii Foex. have different types of photosynthetic parameters diurnal variation curves. The types of diurnal variation of net photosynthetic rate curve in V. davidii Foex. Ziqiu, V. davidii Foex. Fujian and V. davidii Foex. White are bimodal, with typical "Midday Depression", which maybe due to the stomatal factors. The monthly variation of Pn from May to October showed a single peak curve. The dark respiration rate and leaf temperature of V. davidii Foex varieties have a significant positive correlation. The dark respiration level of a variety of V. davidii Foex in a certain period is relatively stable.(4) It is found that the leaf chlorophyll content of V. davidii Foex varieties and net photo synthetic rate are closely related, and the chlorophyll b content has the most significant effects on the net photosynthetic rate of V. davidii Foex varieties.The intercellular CO? concentration and transpiration rate are a major factor in the level of net photosynthetic rate in V. davidii Foex varieties.