水稻的主要养分组成和显微结构对灰飞虱取食选择性的影响

通过测定灰飞虱在12个不同类型水稻品种上的取食选择性和稻株的含水量、可溶性糖含量、蛋白质含量及粗纤维含量,激光共聚焦显微镜观察稻叶片和茎杆的结构及硅化细胞分布,从养分组成和显微结构两个方面研究灰飞虱对寄主的选择性及其影响因子.结果表明:在植株的养分组成中,对灰飞虱取食选择性起决定性作用的是粗纤维含量,它与虫口密度显著负相关,相关系数达-0.96;而蛋白质含量和含水量均与虫口密度显著正相关,相关系数分别为0.79和0.89,植株可溶性糖含量对灰飞虱取食选择性影响不显著.在显微结构方面,植株硅化细胞体积和密度大、叶脉间距小、叶脉宽的水稻品种对灰飞虱的非选择性强.

Effects of the major nutritional substances and micro-structure of rice plants on the host preference of the small brown planthopper, Laodelphax striatellus

The host preference and its factors of the small brown planthopper, Laodelphax striatellus (Homoptera: Delphacidae) on rice cultivars were studied in both aspects of plant nutrients and micro-structure of plant tissues. The planthoppers settled on rice plants and the water content, soluble sugars, protein content and crude fiber in 12 rice cultivars were measured. The micro-structure of rice leaves and stems and the distribution of silicon cells were observed using laser scanning microscopy. The results showed that crude fiber was the decisive factor that affected the preference of L.striatellus to its host. The insect density was significantly and negatively correlated with crude fiber (r=-0.96), and significantly and positively with protein content (r=0.79) and water content (r=0.89). Plant soluble sugar had no significant effect on the preference of L.striatellus. When observing the micro-structure of plant tissues, it was found that the cultivars with high density and volume of silicon cells, wider leaf venation and narrower venation intervals showed higher resistance against L.striatellus.