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[目的]研究短期高温胁迫对不同生育期马铃薯光合作用的影响。[方法]选取在宁夏广泛种植的粉用马铃薯陇薯3号为试材,分析短期高温条件下不同生育期其气孔导度(Gs)、蒸腾速率(Tr)、叶室内外CO2浓度差、净光合速率(Pn)以及叶片光合水分利用效率(WUE)的变化。[结果]出苗期高温胁迫下的马铃薯净光合速率和叶室内外CO2浓度差均出现滞后性,而气孔导度和蒸腾速率的变化趋势与常温下相一致,但数值均高于常温下;其中对净光合速率影响最大的因子是叶室内外CO2浓度差。分枝期高温胁迫下净光合速率、叶室内外CO2浓度、气孔导度和蒸腾速率虽然变化趋势与常温下相近,但是均在中午出现一次突变,达到峰值,而水分利用率变化与常温下基本一致;其中对净光合速率影响最大的因子也是叶室内外CO2浓度差,其次是蒸腾速率。[结论]高温胁迫对不同生育期马铃薯光合作用均有影响,且分枝期大于出苗期,其中叶室内外CO2浓度差是对净光合速率影响最大的因子。
[Objective] The research aimed to study the effects of short-term high temperature stress on photosynthesis of potatoes at different growth stages. [Method] The potato cultivars Longshu No.3 widely planted in Ningxia were selected to study the effects of short-term high temperature on stomatal conductance (Gs), transpiration rate (Tr) Photosynthetic rate (Pn) and leaf photosynthetic water use efficiency (WUE). [Result] The net photosynthetic rate of potato under the high temperature stress and the difference of CO2 concentration inside and outside the leaf appeared lag, while the change trend of stomatal conductance and transpiration rate was consistent with that under normal temperature, but the values were higher than those under normal temperature The most important factor affecting the net photosynthetic rate is the difference in CO2 concentration inside and outside the leaf chamber. The net photosynthetic rate, leaf CO2 concentration, stomatal conductance and transpiration rate were similar at room temperature under the high temperature stress in the branching stage, but both had a mutation at midday, reaching the peak value. However, the change of water use efficiency was similar to that at room temperature Among them, the most significant factor affecting the net photosynthetic rate was also the difference of CO2 concentration inside and outside the leaf chamber, followed by the transpiration rate. [Conclusion] The effects of heat stress on the photosynthesis of potatoes at different growth stages were affected, and the branching stage was larger than that at the seedling stage. The difference of CO2 concentration inside and outside the leaf chamber was the most important factor affecting the net photosynthetic rate.