水分胁迫对玉米雌穗的伤害作用

玉米在孕穗期遭受不同强度水分胁迫处理后，雌穗超氧物歧化酶（ＳＯＤ）活性下降，丙二醛（ＭＤＡ）含量增加，膜脂过氧化作用增强，细胞质相对电导率增大，对生物膜系统产生直接伤害，电镜下可观察到线粒体、细胞质膜破坏，胞间连丝膨大变形，甚至断裂，进而引起生理代谢紊乱，使可溶性糖和游离氨基酸含量增加，淀粉和蛋白质含量下降，阻碍雌穗发育，减少穗粒数，引起减产。

Injurious Effect of Water Stress at Booting Stage on the Female Inflorescence of Maize

The results showed that water stress at this stage could cause decreased superoxide dismutase (SOD) and increased membrane lipid perioxidation in the female inflorscence of maize. Leading to direct injury on the biological membrane system and a sharp increment of eletrolyte leakage in the tissue, under the electronic microscape, it could be seen that the mitochondria and the protoplasmic membrane were damaged, the plasmodesmata swelled, deformed or even ruptured, these ultrastructural changes would lead to disordered metabolism, including increased soluble sugar and free amino acids, decreased starch and protein contents. As the results, the development of the female inflorscence was hindered, the number of kernels per ear reduced, and finally, the kernel yield decreased.