短期高温胁迫对不同生育期马铃薯光合作用的影响

Effects of Short-term High Temperature Stress on the Photosynthesis of Potato in Different Growth Stages

[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 aim was to study the effects of short-term high temperature stress on the photosynthesis of potato in different growth stages. [ Method ] Choosing powder potato named Longshu No. 3 widely cultivated in Ningxia as test material, the change of stomata conduct- ance （ Gs）, transpiration rate （Tr） and CO2 concentration difference between internal and external leaf chamber, net photosynthetic rate （Pn） and photosynthetic water use efficiency （WUE） in different growth stages under short-term high temperature were analyzed. [ Result] During seeding stage, the hysteretic nature of net photosynthetic rate and CO2 concentration difference between internal and external leaf chamber of potato could be found under high temperature stress, while the change trend of stomata conductance and transpiration rate under high tempera- ture stress was consistent to that under normal temperature, but its stomata conductance and transpiration rate were higher than that under nor- mal temperature, and CO2 concentration difference between internal and external leaf chamber affected net photosynthetic rate mostly. During branching stage, the change trend of net l^hotosynthetic rate, CO2 concentration difference between internal and external leaf chamber, stomata conductance and transpiration rate under High temperature stress and normal temperature were similar, but they changed abrupflfly and reached peak value at noon under high temperature stress, while there existed consistent variation of water use efficiency under high temperature stress and normal temperature, and CO2 concentration difference between internal and external leaf chamber also affected net photosynthetic rate mostly, next came transpiration rate. [ Conclusion ] High temperature stress affected the photosynthesis of potato in different growth stages, and it was more obvious during branching stage than seeding stage, while CO2 concentration difference between internal and external leaf chamber had the most important influence on Pn.