硼胁迫对不同基因型西瓜部分生理指标的影响

为了研究硼胁迫对不同基因型西瓜细胞壁、细胞膜以及碳氮代谢的影响，以籽瓜、‘黑美人’西瓜和野生西瓜为材料，设4个硼浓度，测定3种类型西瓜细胞膜透性、游离脯氨酸、可溶性糖、可溶性蛋白含量及PAL和PPO活性。结果表明：3种类型西瓜在硼胁迫下的PPO活性上升，细胞膜透性与游离脯氨酸含量上升，可溶性糖和可溶性蛋白含量有所减少。PAL活性在缺硼胁迫时下降，在高硼胁迫时应激上升。硼胁迫破坏了3种类型西瓜细胞壁结构，产生醌等大量次生产物损伤细胞膜，使细胞膜透性增强，细胞内离子浓度失衡脱水。进而阻碍了细胞正常功能运转，间接削弱西瓜碳代谢系统与氮代谢系统，减少了可溶性糖与可溶性蛋白质等代谢产物的生成。

Boron Stress on Some Physiological Indexes of Different Watermelon Genotypes

In order to study the effect of boron stress on cytoderm, cell membrane and carbon-nitrogen metabolism of different watermelon genotypes, seed-used watermelon, ‘Heimeiren’ and wild watermelon were used in this test, cell membrane permeability, free proline content, soluble sugar content, soluble protein content and PAL, PPO activity were measured under four boron concentrations. The results showed that the PPO activity, cell membrane permeability and free proline content increased under boron stress, soluble sugar and soluble protein content decreased. PAL activity decreased when boron was deficient, while it increased under boron stress. Boron stress destroyed cytoderm structure of these three varieties, and the secondary production such as quinone could damage cytomembrane, which could increase cell membrane permeability and lead to dehydration, then the normal motion function was blocked, weakening the carbon and nitrogen metabolic system, and reducing the production of metabolites such as soluble sugar and soluble protein.