水稻与油菜种子萌发对酸雨的胁迫反应

Effect of acid rain on germination of Rice and Rape

采用pH值为2.0、2.5、3.0、3.5、4.0、5.0的模拟酸雨处理水稻、油菜种子的试验结果表明,在pH2.0时两者均不发芽,在pH2.5时只有水稻异状发芽,pH≥3.0时,水稻和油菜种子的发芽率、发芽势、发芽指数、活力指数都与pH值显著正相关,水稻异状发芽率则随pH值上升而降低.部分生理指标的试验结果表明,水稻和油菜的吸水值、呼吸速率、贮藏物质运转效率也与pH值显著正相关,水稻贮藏物质消耗率与pH值显著正相关而油菜与pH值显著负相关;水稻和油菜的芽、根长抑制指数都与pH值显著负相关。酸雨胁迫下,水稻种子各项指标变幅低于油菜的事实表明,水稻抗酸雨胁迫能力强于油菜。

s: Rice and rape seeds were subjected to a simulated acid rain adjus t ed to pH value of 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, and to pH values of 6.5 (the con trol) for 7 days in order to understand the effects of acid rain on seed germina tion of various acid-fast plant. The germination test showed that seed germina tion was remarkably inhibited by pH 2.0 treatments for the two species. Rice see ds germinated abnormally at pH 2.5. Rape seeds didn’t germinated at pH 2.5. Fr om pH 2.5 to pH 5.0, the percentage of abnormal germination of rice decreased in relation with decreased acidity levels. When pH values above3.0, percentage ger mination, germination energy, germination index and vigor index of rice and rape seeds increased in relation with decreased acidity levels. The positive correla tion between each index and pH value was remarkable. From pH3.0 to pH5.0, the am plitude differences of these indexes of rice seeds were 4.00%, 4.67%, 3.60% , 35.90%, respectively. In the same acidity levels, the amplitude differences of rape seeds were 16.67%, 10.67%, 21.44%, 52.99%, respectively. These data evidenced that the amplitude differences of these indexes of rice seeds wer e remarkably lower than those of rape. The experiment data about physiological a spect demonstrated that water absorption rate, respiratory rate and the transfor mation rate of storage reserve of rice and rape seeds also increased with increa sed pH values. The positive correlation between these indexes and pH value was r emarkable. The loss rate of storage reserve of rice increased with increased pH values but that of rape decreased. Inhibition index of shoot and root length of two kinds of seeds decreased in relation with increased pH values. The negative correlation between inhibition index and pH value also was remarkable. From pH2. 0 to pH5.0, the amplitude differences of water absorption rate, respiratory rate of rice seeds were 4.84%, 73.07%, respectively. The amplitude differences o f rape seeds were 10.38%, 87.50%, respectively. From pH3.0 to pH5.0, the los s rate of storage reserve, the transformation rate of storage reserve, inhibitio n index of root length, inhibition index of shoot length of rice seeds were 3.39 %, 9.21%, 77.74%, 12.00%, respectively. The amplitude differences of rap e seeds were 7.55%, 15.70%, 81.61%, 55.87%, respectively. The amplitude differences of index of rice seeds were lower than those of rape. The experiment data suggested that rice had stronger fastness than rape under acid rain stress .