硼胁迫对不同类型西瓜活性氧代谢与抗氧化系统的影响

【目的】为了研究硼对不同类型西瓜活性氧代谢与抗氧化系统的影响。【方法】以籽瓜、“黑美人”西瓜和野生西瓜为材料,设0.00,0.05,0.20,0.60 mmol/L 四个硼浓度,测定三种类型西瓜O2.?、H2O2和MDA含量及SOD、POD和CAT活性。【结果】结果表明：三种类型西瓜的O2和H2O2产生速率在硼胁迫下均显著提高,且高硼胁迫的西瓜O2.?和H2O2产生速率都大于缺硼胁迫,并导致MDA的积累。硼胁迫使三种类型西瓜的POD活性上升,CAT活性下降。籽瓜和“黑美人”的SOD活性下降,野生西瓜SOD活性上升。【结论】硼胁迫引起西瓜的活性氧爆发,并启动了西瓜的抗氧化系统,但仍然无法完全抵御硼胁迫带来的活性氧伤害,野生西瓜对硼胁迫的抗逆最强。

Effects of Boron Stress on Active Oxygen Metabolism and Antioxidant System of Different Genotypes of Watermelon Cultivars

The paper aims to study the effects of boron stress on active oxygen metabolism and antioxidant system of different genotypes of watermelon cultivars. Seed- used watermelon, watermelon cultivars ‘Heimeiren’and wild watermelon were used to test the activities of SOD, POD, CAT and the content of O2·-, H2O2, MDA under 0.00, 0.05, 0.20, 0.60 mmol/L boron concentration. The results showed that lots of ROC (O2 ·- and H2O2) were produced in watermelon under boron stress, ROC led to MDA accumulation. The high boron stress led to more ROC accumulation in the leaf of three watermelon cultivars. Under boron stress, POD activities were increased in watermelon, CAT activities were decreased. The SOD activities of seed- used watermelon and‘Heimeiren’were reduced. The SOD activities of wild watermelon were increased. Boron stress led to ROC accumulation. ROC accumulation activated the antioxidant system of watermelon. But the antioxidant system of watermelon could not completely resist active oxygen damage under boron stress. Stress resistance of seed-used watermelon was the strongest.