重茬胁迫下硒对大豆叶绿体超微结构和叶片中微量元素含量的影响

采用盆栽试验和田间小区试验方法，研究了低浓度施Se对重茬胁迫下大豆叶绿体超微结构及大豆叶片中Mg、Fe、Mn含量的影响．结果表明，当盆栽试验施Se量小于0．50mg.kg^-1，田间小区试验施Se量小于300g.hm^-2时，施Se都不同程度地提高了大豆叶片的Mg、Fe和Mn含量．在盆栽试验中，施Se量与大豆叶片中Mg、Fe的含量呈正比，而施Se量与大豆叶片中Mn含量之间的关系很难确定．同时，透射电镜照片显示，盆栽试验中重茬胁迫下，施se可使大豆叶绿体膜结构保持完好，而不施se对照的叶绿体发生膨胀，基粒消失，甚至转化成了黄化体．可以认为，低浓度施Se能缓解大豆重茬胁迫所造成的过氧化损伤，使大豆生长较为正常．

Effects of selenium on soybean chloroplast ultra-structure and microelement content of soybean leaves under continuous cropping stress

Pot and field experiments were carried out to study the effect of low Se concentration on soybean chloroplast ultra-structure and on Mg, Fe, Mn and contents in soybean leaves under continuous cropping stress. The results showed that Se could certainly increase the contents of Mg, Fe and Mn in soybean leaves when the application rate of Se was below 0.50 mg.kg-1 in pot experiment, and below 300 g.hm-2 in field experiment. In pot experiment, Se concentration positively correlated with Mg and Fe contents in soybean leaves, but the relationship between Mn and Se was hardly to be quantified. Transmission electron microscopic observation indicated that under continuous cropping stress, application of Se could hold the soybean chloroplast membrane structure in good condition. When Se was not applied, the chloroplast swelled, and its grana disappeared, and even, transformed into etioplast. These experiments indicated that application of low Se could alleviate peroxidative stress resulting from continuous cropping, and keep the soybean grow normally.