旱后复水对不同倍性小麦光合及抗氧化特性的影响

利用盆栽控水试验方法,在干旱和复水条件下,于拔节期对不同倍性小麦叶片的光合参数以及抗氧化指标进行测定.结果表明:(1)与干旱处理相比,拔节期恢复供水可使受旱小麦叶片的光合参数增大,叶水势、超氧化物歧化酶(SOD)活性、细胞膜透性以及质膜过氧化程度都有所降低,其中净光合速率(Pn)和蒸腾速率(Tr)的增加超过对照,叶水势和细胞膜透性的降低也超过对照,产生了生理补偿效应;(2)旱后复水条件下,叶水势很快恢复到正常水平,Pn显著提高且高于正常对照水平,其中野生一粒和小偃6号,在干旱条件下,SOD酶活性高,具有较强的活性氧清除能力,复水后,MDA的积累减少,膜透性迅速恢复,抗氧化系统更好地保护和修复了光合机制,表现出较强的光合优势.

Effect of Post-drought Rewatering on Leaf Photosynthetic Characteristics and Antioxidation in Different Wheat Genotypes

The response of leaf photosynthetic characteristics and antioxidation were studied with Pot experiment under drought and rewatering condition in six wheat genotypes.Compared with drought treatment after rewatering wheat at erect seedling stage,the photosynthetic parameters were increased;but the water potential,SOD activities,MDA contents,and plasma membrane penetration declined in the leaf;the leaf water potential,Pn,Tr and plasma membrane penetration recovered rapidly,which brought the physiological compensatory and "over-compensatory" effects.The higher Pn potential was shown both in wild einkorn and Xiaoyan No.6.The possible reasons are as follows,(1)under drought condition,the high SOD activities can increase scavenging capacity for ROS;and(2)under rewatering condition,the decreasing of MDA accumulation results in the quickly recovery of plasma membrane penetration,and the photosynthetic mechanisms were well protected and recovered by antioxidant system.