不同抗性种子萌发对酸雨胁迫时间的响应Ⅲ——酸雨持续胁迫对3类种子4项萌发指标的影响

Effect of Acid Rain on Seed Germination of Three Plants Ⅲ :Continuous Acid Rain Stress on the Physiological Index During Seed Germination

以pH3.0、3.5、4.0模拟酸雨处理水稻、小麦和油菜种子,研究酸雨胁迫时间对3类种子萌发的影响。试验表明,随酸雨胁迫时间t延长,水稻与小麦的消耗(运转)率变化幅度<CK,油菜消耗率>CK,且t=7d时,不同胁迫强度下消耗(运转)率增幅及与CK的差值是水稻<小麦,达到差异显著水平的胁迫时间是水稻>小麦>油菜;不同胁迫强度下根(芽)抑制指数与抑制指数增(减)幅的变化规律是水稻<小麦<油菜,说明3类种子萌发耐酸雨胁迫能力存在胁时上的明显差异,表现为水稻>小麦>油菜。

Seeds of rice, wheat and rape were subjected to a simulated acid rain with pH value of 3.0, 3.5, 4.0, and 6.5 (the control) to investigate the effects of acid rain stress time on seed germination of various acid- fast plants. The results indicated that the loss and transformation rate of storage reserve of rice and wheat were lower than that of the control, but the loss rate of rape was higher than that of the control with prolonged stress time. When stress time was 3～ 7d, the increase of loss rate of storage reserve of rice was 11.03% , 12.44% and 13.14% at pH value of 3.0, 3.5, 4.0, respectively, lower than that of wheat, being 15.69% , 23.47% , 23.81% , respectively. The increase of the transformation rate of storage reserve was lower in rice (being 24.80% , 29.37% and 29.72% at pH value of 3.0, 3.5, 4.0, respectively) than in wheat (being 6.33% , 37.87% and 38.87% , respectively). The loss and transformation rate of storage reserve in rape remarkably changed after 3～ 4 days of stress, but that happened in wheat and rice after 6 and 7 days of stress. The order of response to acid stress time was: rice>wheat>rape. After 7 days of stress, the inhibition index of root length of rice was lowest, being 67.86% , 36.49% , 0.92% , at pH value of 3.0, 3.5, 4.0, respectively, that of rape was biggest, being 88.26% , 44.32% , 17.8% , and that of wheat was 84.43% , 43.38% , 3.15% , respectively. The inhibition index of shoot length changed similarly, with the index of rice 16.37% , 11.63% and 0.84% , respectively, lower than that of wheat (46.49% , 15.43% , 3.72% ) and that of rape (58.5% , 17.51% , 5.76% ). The order of amplitude variation of inhibition index of root, shoot and length was rape>wheat>rice at different acidity levels under stress time from 3 to 7 days. These evidenced that plants could display different sensitivity to acid rain stress, rice had stronger resistance than wheat, and responses of rice and wheat to aid rain stress were faster than that of rape.