模拟酸雨对不同类型玉米种子萌发和幼苗生长的影响

Effects of simulated acid rain on seed germination and seedling growth of different type corn (Zea mays)

以普通玉米、糯玉米、爆裂玉米和甜玉米为材料,研究了不同模拟酸雨(pH6.0、5.0、4.0、3.0、2.0、1.0)对玉米种子萌发和幼苗生长的影响.结果表明:pH2.0～5.0模拟酸雨对玉米种子萌发和幼苗生长没有显著影响;pH1.0处理的普通玉米、糯玉米、爆裂玉米和甜玉米的种子发芽率分别为91.3%、68.7%、27.5%和11.7%.与pH6.0处理(CK)相比,pH1.0模拟酸雨显著降低了玉米种子的发芽率、发芽指数、活力指数、发芽速度、苗高、根长、苗和根干物质、贮藏物质运转效率,延长了平均发芽时间.pH1.0模拟酸雨对玉米幼苗生长阶段的影响大于发芽阶段,对幼苗地下部分的影响大于地上部分;受基因型的影响,普通玉米和糯玉米的抗酸雨能力最强,其次为爆裂玉米,甜玉米最差.玉米属于抗酸雨作物,酸雨抑制阈值介于pH1.0～2.0之间.酸雨地区可优先选择种植普通玉米和糯玉米.

Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain （pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0）. Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 （CK）, the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.