酸雨胁迫对玉米种子萌发及其生理机制的影响

Effects of Acid Rain Stress on the Germination and Physiological Mechanism of Maize Seed

采用人工配制pH=2.0、3.0、4.0、5.0、6.0和7.0(对照组,CK)的人工模拟酸雨培养玉米种子,通过对种子发芽率、发芽势、发芽指数以及种子萌发后贮藏物质消耗率、运转效率等数据的分析,探明酸雨胁迫对玉米种子萌发及其生理机制的影响。结果表明:pH=5.0人工模拟酸雨胁迫处理组玉米种子的发芽指标、贮藏物质消耗率和运转效率均较对照组显著提高,而其他pH值人工模拟酸雨胁迫处理组玉米种子的发芽率、发芽势和发芽指数均显著下降;在萌发过程1-7 d内,所有人工模拟酸雨胁迫处理组玉米种子的呼吸强度均呈“先增后降”的趋势,而细胞质膜透性均呈“持续增加”的趋势;酸雨胁迫显著抑制玉米种子发芽率的pH阈值为3.0,显著抑制玉米种子发芽势、发芽指数、贮藏物质消耗率、贮藏物质运转效率和呼吸强度的pH阈值均为4.0,显著提高玉米种子细胞质膜透性的pH阈值为4.0。

Maize seeds were cultured using artificially simulated acid rain with pH=2.0,3.0,4.0,5.0,6.0,7.0(control group,CK).The effects of acid rain stress on maize seed germination and its physiological mechanisms were explored by analyzing data such as seed germination rate,germination potential,germination index,as well as storage material consumption rate and operational efficiency after seed germination.The results showed that the germination index,storage material consumption rate,and operational efficiency of maize seeds in the pH=5.0 artificial simulated acid rain stress treatment group were significantly improved compared to the control group,while the germination rate,germination potential,and germination index of maize seeds in the other pH artificial simulated acid rain stress treatment groups were significantly reduced.Within 1-7 days of germination,the respiration intensity of all artificially simulated acid rain stress treated seeds showed a trend of"first increasing and then decreasing",while the cytoplasmic membrane permeability showed a trend of"continuous increase".The pH threshold for significant inhibition of maize seed germination rate by acid rain stress was 3.0,and the pH threshold for significant inhibition of maize seed germination potential,germination index,storage material consumption rate,storage material transport efficiency,and respiratory intensity was 4.0.The pH threshold for significantly improving the cytoplasmic membrane permeability of maize seeds was 4.0.