在甘肃榆中大田条件下，研究了水分胁迫对全膜双垄沟播玉米叶片保护酶系活性、膜脂过氧化、根系活力、光合速率及产量的影响。结果表明，玉米生育前中期水分胁迫使超氧化物歧化酶（SOD ）、过氧化氢酶（CAT ）、过氧化物酶（POD ）活性大幅度增加，随干旱持续和强度加剧，使SOD、CAT、POD活性降低，叶片丙二醛（MDA ）含量增加。播后126 d ，严重水分胁迫处理的SOD、CAT、POD活性分别降低到充分供水处理的61．2％、62．5％和76．1％， MDA含量较充分供水处理增加18．4％。短期水分胁迫能提高玉米根系活力，但随着受旱时间延长根系活力迅速下降。水分胁迫使玉米光合产物合成与转运量显著下降，致使百粒重、穗粒数和收获指数分别降低15．1％、54．1％和47．4％，减产达45．7％。%A field research was conducted in Yuzhong ,Gansu ,to investigate the influences of different levels of moisture on protective enzyme activities , lipid peroxidation , root activity , photosynthetic rate and yield . The results showed that the activities of superoxide dismutase (SOD ) ,catalase (CAT ) ,and peoxidase (POD ) in leaves were in-creased during early and middle growth stages under water stress .With the pretension and enhanced levels of drought stress ,activities of SOD ,CAT ,and POD were decreased rapidly ,while the content of malondialdehyde (MDA ) in leaves became increased .After 126 days since sowing ,compared to full water supply (FW) ,SOD ,CAT and POD activities under serious water stress (SW ) treatment were decreased to 61 .2% ,62 .5% and 76 .1% ,respectively ,and the con-tent of MDA was increased by 18 .4% .Root activity of maize was improved under short-term water stress .With the dura-tion of water stress continued ,root activity went decreased rapidly .Synthesis of photosynthate and transportation level be-came decreased significantly under water stress ,which led to the decreases of 100-grain weight ,number per spike ,har-vest index and grain yield by 15 .1% ,54 .1% ,47 .4% ,respectively resulting in yield loss of 45 .7% .
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