水稻施硅之抗虫机制的研究

Studies on Insect-Resistance Mechanism after Silicon Applied in Rice

从水稻施硅处理区和对照区分别采取叶片和叶鞘,进行相同部位的扫描电镜观察拍片,发现叶片上、下表皮之表面分布的硅粒,处理区明显比对照区突出而稍大;叶脉表面成对的硅化细胞扁平,排列紧密,在63.6μm长的视野内比对照的多出1对;表皮细胞外壁与硅化层、角质层的总厚度加厚O.6-O.7μm;叶脉维管束外的厚壁细胞壁较厚,排列行次及宽度均比对照的大。叶鞘切片也有类似的情况。因而处理区内稻纵卷叶螟和褐稻虱等害虫的种群密度分别比对照区下降5-6成。上述解剖形态的差异,也许就是水稻施硅后能抗虫的主要机制。

The structure of rice leaves and leaf sheathes collected from the plants treated with and without silicon were examined by means of scanning electron microscopy. It was found that the silicon particles accumulated on the surface of epiderm and subepiderm of treated leaves were thicker and bigger comparing with that of untreated leaves. The silicon cells arranged in a pair on the surface of leaf vein appeared flat and close in treated plants and one pair more than those untreated plants every 63. 6μm under the field of view. The total thickness of the epi-dermic outer cell wall including silicons layer and corneous layer increased by 0. 6-0. 7μm. With respect of thick-walled cells in vascular bundleS of leaf vein, it was observed that the cell wall thickened and the number of the cells increased after silicon treatment. The changes of structure of leaf sheathes were similar to that of leaves. In addition, the population density of some pests such as rice case worm and brown rice plant-hopper etc decreased by 50-60%in silicon-treated areas. It seems that the changes of anatomic structures of leaves and leaf sheathes after applied by silicon are the main insect-resistance mechanism.