氮锌复合作用对白三叶叶片叶绿体超微结构的影响

在砂培条件下，研究了不同水平氮锌配施对白三叶生长、叶片叶绿素含量和叶绿体超微结构的影响。结果表明，在缺锌条件下，随供氮水平增加，植株干物重、叶片叶绿素含量显著下降，氮锌配施表现为拮抗效应。在足量供锌条件下，中量供氮，植株干物重、叶片叶绿素含量高于低量供氮，氮锌配施表现为协同效应；与低水平供氮相比，当高水平供氮时，白三叶各组分干物重、叶片叶绿素含量显著下降，氮锌配施表现为拮抗效应。白三叶叶片超显微结构表明，低锌条件下，随供氮水平增加，叶绿体结构变差，基粒及基粒片层、基质片层数量下降甚至解体，光合能力显著下降。足量供锌时，以中量供氮叶绿体基粒及基粒片层、基质片层数量最多，内部结构有序性最高，光合能力最强。叶绿体超显微结构变化与白三叶干物重、叶绿素含量变化趋势相一致。

The Compound Effects of N and Zn on Chloroplast Ultrastructure of White Clover Leaves

Sand culture experiment were carried out to investigate the compound effects of N and Zn on chloroplast ultrastructure of white clover leaves. The main findings showed that the dry matter weight, chlorophyll content of leaves significantly decrased with the increased N rate in Zn deficiency. Therefore, N and Zn combined application showed antagonism effect in the condition of Zn deficiency. However, in the condition of Zn sufficiency, the dry matter weight, chlorophyll content of leaves were higher in middle N rate than in high and low N rate. Consequently, N and Zn combined application showed synergism effect. Nevertheless, when high amount of N supply, the dry matter weight, chlorophyll content of leaves significantly decrased compared with middle and low N rate. Therefore N and Zn combined application showed antagonism effect. The ultrastructure of chloroplast of mesphyll cell of white clover leaves showed that in the condition of Zn deficiency, with the increasing rate of applied N, the inner structure of chloroplast ruined, in which the number of the grana and grana lamellae as well as stroma lamellae decreased and disintegrated, which resulted in the declination of photosynthesis capacity of chloroplast. In the condition of sufficient supply of Zn, the number of the grana, grana lamellae and stroma lamellae as well as the order of the combination of them in chloroplast were the highest at middle rate of N applied. However, the volume of chloroplast reduced and the system of lamellae swelled and couldn'n form grana when high rate of applied N. The changes of ultrastructure of chloroplast were correspondence with the changes of chlorophyll content and dry matter weight.