西北干旱区葡萄净光合速率变化及其影响因素

Variation of net photosynthetic rate of grape and its influencing factors in arid area of Northwest China

葡萄作为西北干旱区主要经济作物之一,认识其光合生产过程对种植栽培至关重要。为探究大田自然条件下葡萄光合生理特征及影响葡萄光合作用的主要影响因子,该研究于2019年6—9月测定葡萄(品种:无核白)叶片光合作用及其生理生态因子日变化,采用通径分析方法分析各因子对叶片净光合速率的直接和间接作用,确定其主要影响因子,同时在全天分时段模式下进一步分析葡萄叶片净光合速率对各生理生态因子的响应。结果表明:(1)葡萄叶片净光合速率日变化总体呈现先升高、后下降的单峰型曲线变化特征。(2)葡萄叶片净光合速率与光合有效辐射、饱和水汽压差、空气温度、气孔导度和蒸腾速率呈极显著正相关,与相对湿度和胞间CO_(2)浓度呈极显著负相关。(3)各月影响葡萄叶片净光合速率变化的主要决定因子6月、8月和9月为蒸腾速率,而7月为气孔导度。(4)6—9月的葡萄叶片净光合速率与空气温度、光合有效辐射、饱和水汽压差的响应均呈“迟滞回环”关系,与蒸腾速率、气孔导度呈良好的线性关系(R^(2)>0.85),与胞间CO_(2)浓度呈指数函数关系(R^(2)=0.53)。研究认为,葡萄对西北干旱区环境具有较强的适应能力,可以通过控制蒸腾速率和气孔导度来优化管理并提高产量,此外还需要考虑其他因子的直接和间接作用。

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 main influencing factors affecting grape photosynthesis under natural conditions in the field,the daily variation of net photosynthetic rate of grape(variety:Seedless White)leaf and its daily variation of physiological and ecological factors in typical season of grape were measured from June to September in 2019.The path analysis method is used to analyze the direct and indirect effects of various factors on the net photosynthetic rate of grape leaf,and to determine its main influencing factors.In addition,the response of the net photosynthetic rate of grape leaf to various physiological and ecological factors was further analyzed in the whole day time-phased mode.The results were as follows:(1)The daily variation of net photosynthetic rate of grape leaf showed a single peak pattern,which first increased and then decreased;(2)The net photosynthetic rate of grape leaf was positively correlated with photosynthetic active radiation,vapor pressure deficit,air temperature,stomatal conductance and transpiration rate,and negatively correlated with relative humidity and intercellular CO_(2)concentration.Among them,the correlation coefficient with stomatal conductance and transpiration rate was the largest;(3)The main determinant that affected the variation of net photosynthetic rate of grape leaf was the transpiration rate in June,August and September,and the stomatal conductance in July;(4)The net photosynthetic rate of grape leaf in each month showed a“hysteretic loop”relationship with air temperature,photosynthetic active radiation,vapor pressure deficit,and a good linear relationship with transpiration rate and stomatal conductance(R^(2)>0.85),and an exponential function relationship with intercellular CO_(2)concentration(R~2=0.53).Studies have shown that grapes have a strong ability to adapt to the environment in the arid area of Northwest China.In cultivation,we can optimize management and increase yield by controlling transpiration rate and stomatal conductance,but the direct and indirect effects of other factors need to be considered.