Si在燕麦籽粒中的富集及其与其它8种元素的关系

通过环境扫描电镜结合X射线电子探针显微分析技术,对22个基因型的燕麦籽粒皮层、糊粉层、近糊粉层和颖果中部的Si含量进行测定.结果表明,Si元素在燕麦籽粒不同部位的含量有明显差异,皮层和糊粉层Si含量较高,近糊粉层和颖果中部含量较低,在颖果中Si主要富集在糊粉层中;而且不同基因型燕麦籽粒同一部位或不同部位Si的积累量也有较大差异,这可能是由遗传差异引起的.糊粉层中的Si含量影响着近糊粉层和颖果中部的Si含量.另外,籽粒不同部位Si含量与P、Ca、Mg、S、Al、Pb含量之间存在显著或极显著的非线性关系,颖果中部的Si含量与K、Cd含量之间不存在显著的非线性关系.说明Si在燕麦籽粒中富集的同时也影响着P、Ca、Mg、S、Al、Pb等元素的富集.

Accumulation of silicon in different genotypes of oat grains and its relationship with other eight elements

Silicon (Si) is the second most abundant element in the earth's crust, the beneficial effects of this element on the growth, development, yield and disease resistance have been observed in a wide variety of plant species. However, the precise distribution of silicon, and its relationship with some heavy metals in oat grain are largely unexplored. In the present study, the Si levels of 22 oat genotypes in 4 different grain parts (the cortex, aleuronic layer, near aleuronic layer and center of caryopsis) were determined by environmental scanning electron microscopy combining with X-ray electron probe microanalysis, and its relevancy with the contents of other metals in the whole oat grain, including P, Mg, K, Ca, S, Cd, Al and Pb, were analysed. There was remarkable difference in Si levels among different portions of oat grain, with higher Si contents in the cortex and aleuronic layer, while less Si in the near aleuronic layer and center of caryopsis, which implied that Si predominantly deposited in the aleuronic layer for a whole oat caryopsis. Moreover, the considerable difference in Si level was also existed among the different oat genotypes, with a comparison of the same portion of different oat cultivars, suggesting that oat genotypes had a dominant effect on Si accumulation. Si content in aleuronic layer was closely related to that in near aleuronic layer and center of caryopsis. Furthermore, a significant non-linear correlation between the content of Si and that of P, Ca, Mg, S, Al, Pb in different parts of oat grains was observed, but no significant non-linear relationship existed between the content of Si and that of K、Cd in the center of caryopsis. The Si accumulation might facilitate the accumulation of P, Ca, Mg, S, Al and Pb.