抗旱性不同的玉米品种在土壤干旱及复水过程中的生理差异

Physiological differences between desication-tolerent and desication-sensitive varieties of maize ( Zea mays L.) during soil draught stress and rehydration

通过对玉米的两个品种 (抗旱性强的丹玉 13和抗旱性弱的山农 3号 )在土壤干旱及复水过程中的几种生理参数 (渗透调节、弹性调节、气孔导度、光合速率、PS 光化学效率、ABA浓度 )的测定和对这些生理参数在干旱及复水过程中的变化规律的分析发现 :抗旱性弱的山农 3号在干旱过程中渗透调节能力和细胞壁弹性调节能力差 ,气孔导度下降慢 ,光合速率和 PS 光化学效率下降快 ,ABA浓度升高慢 ;而抗旱性强的丹玉 13则与之相反。在复水过程中 ,山农 3号的气孔导度恢复慢 ,光合速率和 PS 光化学效率恢复慢 ,ABA浓度降低慢 ;而丹玉 13的气孔导度、光合速率和 PS 光化学效率则短时间内恢复 ,ABA浓度降低快。由此看出 ,1在干旱及复水过程中 ,丹玉 13伤害程度小 ,代谢能力强 ;2抗旱性强弱主要体现在生理上的差异 ;

To determine the physiological differences between the drought tolerant variety Danyu No.13 and drought sensitive variety Shannong No.3 of maize during soil draught and following rewatering, physiological characteristics, including osmoregulation, cell elasticity regulation, stomatal conducance, photosynthetic rate, PSⅡphotochemical efficiency and ABA concentration in leaf were studied. During soil draught the drought sensitive Shannong No.3 showed less capabilities in osmoregulation and cell elasticity regulation, slower decrease in stomatal conducanc, and increase in ABA concentration, more rapid decline in photosynthetic rate and PSⅡphotochemical efficiency compared with drought tolerant Danyu No.13. After watering, Danyu No.13 regained its prestress stomatal conducance, photosynthetic rate, PSⅡphotochemical efficiency faster than Shannong No.3.So the conclusions can be drawn that: ①less damage occurred and more persistant capability of metabolism maintained with the more tolerant Danyu No.13 during soil draught stress and after rewatering; ②differences in drought tolerance was reflected in physiological difference; ③ABA concentration may act as a physiological index for measuring drought tolerance of maize.