灌浆期高温对小麦剑叶抗氧化酶及膜脂过氧化的影响

 采用人工气候室控温，研究弱筋小麦扬麦9号和中筋小麦扬麦12在灌浆最快时期（花后19～21 d）、温度（25℃、30℃、35℃、40℃）、大气相对湿度50%的条件下，对剑叶抗氧化酶及膜脂过氧化的影响。结果表明，随着温度升高，剑叶超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性呈下降趋势，膜脂过氧化产物（MDA）含量呈上升趋势。高温胁迫对中筋小麦扬麦12 SOD、CAT活性的伤害大于弱筋小麦扬麦9号，对扬麦9号POD活性的伤害大于扬麦12，扬麦12 MDA积累速率大于扬麦9号。高温胁迫导致千粒重下降。

Effects of High Temperature During Grain Filling Period on Antioxidant Enzymes and Lipid Peroxidation in Flag Leaves of Wheat

Based on the phytotron, the effects of high temperature (daily average temperature 25℃, 30℃, 35℃ and 40℃, respectively) at grain fastest filling stage 19-21 days after anthesis (DAA)] at 50% relative air moisture on antioxidant enzymes and lipid peroxidation in flag leaves were studied. The wheat varieties tested were Yangmai 9 with weak-gluten and Yangmai 12 with medium-gluten. Compared with 25℃, the higher the temperature was, the higher MDA content in flag leaves was, while the lower the SOD, POD, CAT activities were. SOD and CAT activities in Yangmai 12 appeared to be more sensitive to high temperature than those in Yangmai 9. But POD activity in Yangmai 12 was less sensitive to high temperature. MDA content in Yangmai 12 was higher than that in Yangmai 9. 1000-grain weight declined with the rising of temperature.