水分胁迫下非气孔因素对葡萄叶片光合作用的影响

Effects of Nonstomatal Factors on Photosynthesis in Grape Seedling Leaves under Water Stress

水分胁迫使葡萄叶片Chl、Car含量下降,Pn、Gs下降,Ci先降后升,SOD、POD、CAT活性先升后降,O2-.、H2O2含量增高;水分胁迫下葡萄幼苗叶片的Pn与其Chl、O2-.、H2O2、Gs间均呈显著相关。表明水分胁迫对葡萄光合速率的影响除受气孔因素限制之外,在胁迫后期由活性氧代谢失调所诱导的非气孔因素成为限制光合速率的主导因子。

Effects of nonstomatal factors on photosynthesis in grape seedling leaves under water stress were studied. The results were as follows： Under water stress, the contents of chlorophyll （Chl）, carotenoid （Car） in leaves decreased. Photosynthetic rate （Pn）, stomatal conductance （Gs） decreased, intercellular CO2 concentration （Ci） increased, then decreased. The activities of SOD, POD, CAT increased in the early period, then decreased. The contents of O^-·, H2O2 decreased. Under water stress, there are high significant correlation between Pn and Chl, O^-· , H2O2, Gs in seedings. The results indicate that the decline of the photosynthetic rate was due to the stomatal limitation. With the duration of water stress, the excessive accumulation of O2^-·, H2O2, induced the nonstomatal limitation. It played key role in the decline of the photosynthetic rate.