汞胁迫对小麦种子萌发、幼苗生长及生理生化特性的影响

Effects of Hg on Seed Germination,Seedling Development and Physiological and Biochemical Characteristics of Wheat

利用水培试验方法研究了Hg对小麦种子萌发、幼苗生长及生理生化特性的影响。结果表明,随Hg浓度的增加,Hg对小麦种子萌发、芽和根的伸长的抑制作用加强。高浓度的Hg胁迫下,幼苗叶片内的叶绿素含量、根系活力显著下降,丙二醛和游离脯氨酸含量大量增加,说明膜脂过氧化作用加强;随胁迫强度增加,POD和CAT活性呈现先上升后下降的趋势;叶片净光合速率和单株生物量显著降低,特别是在50.0μmol.L-1Hg2+浓度下,植株生长受到极大抑制。相关分析表明,净光合速率与叶绿素含量、干物质积累显著正相关。

Effects of heavy metal Hg on seed germination,seedling development and physiological and biochemical characteristics of wheat were examined in a solution-culture experiment.The results showed that seed germination,bud and root growth decreased with the increasing concentration of Hg.The chlorophyll content in seedling leaves and the root activity dropped dramatically in the treatment of 50.0 μmol·L^(-1)Hg^(2+),while,the content of MDA and free proline increased significantly;under low concentration of Hg^(2+),the activity of POD and CAT increased,but decreased at the high concentration.The net photosynthesis rate of leaf and the biomass changed with Hg^(2+)similarly to that of the content of chlorophyll in wheat leaf,and there was a significant positive correlation between the photosynthesis rate with the content of chlorophyll and the biomass(P<0.05).