西北干旱区葡萄净光合速率变化及其影响因素

Grapes are one of the main economic crops in the arid area of Northwest China.Understanding its photosynthetic production process is very important for planting and cultivation.In order to analyze the physiological characteristics of grape photosynthesis and the maininfluencing factors affecting grape photosynthesis under natural conditions in the field, the dailyvariation of net photosynthetic rate of grape (variety: Seedless White) leaves and its dailyvariation of physiological and ecological factors in typical season of grape were measured fromJune to September in 2019. The path analysis method is used to analyze the direct and indirecteffects of various factors on the net photosynthetic rate of grape leaves, and determine its maininfluencing factors. In addition, the response of the net photosynthetic rate of grape leaves tovarious physiological and ecological factors was further analyzed in the whole day time-phasedmode. The results were as follows: (1) The daily variation of net photosynthetic rate of grapeleaves showed a single peak pattern, which first increased and then decreased; (2) The netphotosynthetic rate of grape leaves was positively correlated with photosynthetic active radiation, vapor pressure difference, air temperature, stomatal conductance and transpiration rate, andnegatively correlated with relative humidity and intercellular CO2 concentration. Among them, thecorrelation coefficient with stomatal conductance and transpiration rate is the largest.; (3) Themain determinant that affected the variation of net photosynthetic rate of grape leaves is thetranspiration rate in July, August and September, and the stomatal conductance in June; (4) Thenet photosynthetic rate of grape leaves in each month showed a hysteretic loop relationship withecological factors air temperature, photosynthetic active radiation, vapor pressure deficit, and agood linear relationship with physiological factors transpiration rate and stomatal conductance(R2>0.85), and an exponential function relationship with intercellular CO2 concentration(R2=0.53). Studies have shown that grapes have a strong ability to adapt to the environment in thearid area of Northwest China. In cultivation, we can optimize management and increase yield bycontrolling transpiration rate and stomatal conductance, but the direct and indirect effects of otherfactors need to be considered.