模拟酸雨对农作物种子萌发和幼苗生长的影响

研究模拟酸雨对3种农作物种子萌发年和幼苗生长的影响。结果表明：不同pH值(2．5，4．5，5．6)的模拟酸雨对水稻和小麦的种子萌发没有影响，但明显抑制了玉米种子萌发。模拟酸雨条件下，3种农作物幼苗的生长受到抑制，生物量减少，叶绿素和类胡萝卜素含量下降，而叶绿素a/b的变化却不明显。pH4．5和5．6的模拟酸雨对玉米Fv／Fm、光化学猝灭(qP)的影响较小，非光化学猝灭(NPQ)却明显下降，表明酸雨伤害了植物PSⅡ天线对激发能的非辐射耗散能力。

Effects of Simulated Acid Rain on Seed Germination and Seedling Growth of Three Crops

The responses of seed germination and seedling growth of rice (Oryza sativa cv. Yueza 223), wheat (Triticum aestivum cv. Gaoyun 5) and maize (Zea mays cv. Shangyu 2) to simulated acid rain were investigated by dipping seeds into solution of pH2.5, 4.5 and 5.6 made from mixtures of H2SO4 and HNO3, and into distilled water (control). Different pH (2. 5, 4.5, 5.6) simulated acid rain showed no effect on seed germination of rice and wheat, but significant inhibition effect was found in the germination of maize. Seedling growth of rice , wheat and maize was inhibited by simulated acid rain. Biomass and contents of chlorophyll and ca rotenoids decreased to some extent in all the three crop species grown under simulated aci d rain, whereas no obvious changes in Chl a/b was exhibited in these crops. There was little effect on Fv/Fm and photochemical quenching of chlorophyll fluorescence (qP) in leaves of maize grown at pH 4.5 or 5.6 of simulated acid rain, but nonphotochemical quenching of chlo rophyll fluorescence (NPQ) decreased markedly, revealing that non-radiation energy dissi pation in the antenna of photosystem II was possibly damaged under acid rain condition.