温度与水分双重胁迫下豇豆种子萌发的生理变化

Physiological Changes during Asparagus Bean Seed Germination under Dual Stresses of Temperature and Water

通过6个处理组合研究温度与水分逆境互作下豇豆种子萌发的生理指标变化。结果表明:25℃和常湿适于种子萌发;双重胁迫比单因子胁迫对种子萌发的影响严重;35℃高温比10℃低温与水分胁迫互作效应明显;低温和高温影响萌发的机制有所不同。低温引起发芽程序难以启动;高温引起呼吸速率和α-淀粉酶活性高峰提早,子叶贮藏蛋白质降解加速,早期发芽较快,但随着胁迫时间的延长,导致种芽坏死,尤其是高温过湿条件。逆境条件下SOD先升高,但在幼芽受损伤后又极显著降低。

The physiological changes during asparagus bean （ Vigna unguiculata （L.） ssp. sesquipdalis Verde. ） seed germination under dual stresses of temperature and water were studied by six treatment combinations. The results show that the optimum seed germination condition is at 25 ℃ with suitable water supply. The physiological changes during seed germination are more prominent under dual stresses than single stress, and the interaction of high temperature （35 ℃ ） is more remarkable than that of low temperature （ 10 ℃ ） while mating with waterlogging. Moreover, the high and low temperature affects the seed germination in a different way. The germinative procedure can hardly initialize under low temperature. Conversely, the decomposition of stored proteins in cotyledons and germination are accelerated under high temperature. It also makes the respiration rate and α- amylase activity arrive the peak ahead of the control. However, their germinated sprouts become necrotic as the stress time lengthening, especially when high temperature mating with waterlogging. The SOD activity rises up when seeds germinate under stresses, and then it is drop-off as the sprouts injured.