中文摘要：

【目的】稻瘟病是水稻生产主要的病害之一，每年造成严重的产量损失。研究表明，施用硅肥作为一种环境友好型病害防治措施，在增强植物抗病性中起重要作用，但其作用机理还不完全清楚。本文旨在探讨硅处理对水稻稻瘟病的抗性效应及生理作用机理，为稻瘟病的有效防治提供理论依据和实践指导。【方法】选用稻瘟病广谱感病品系C039（不含已知抗稻瘟病基因）及其近等基因系C101LAC（丹卸（抗病品系）为试验材料，设置（1）不加硅不接种（Si_M一）、（2）加硅不接种（si＋M一）、（3）不加硅接种（Si—M＋）和（4）加硅接种（Si＋M＋）等4个处理，通过光照培养箱控制生长条件，用Hoagland营养液进行水培试验，研究施硅对稻瘟病的控制效果，以及对水稻根系和叶片中硅、酚类物质、水杨酸、乙烯及H2O2含量的影响。【结果】施硅显著降低两个水稻品系的稻瘟病的发病率和病情指数。抗病品系C101LAC（Pi-1）的稻瘟病的发病率和病情指数明显低于感病品系C039。施硅后，两个水稻品系的根、茎、叶中的硅含量都显著增加，地上部的硅含量明显高于根部。稻瘟病菌侵染条件下，加硅显著降低两个材料叶片中的总酚含量，对根系中的总酚含量没有显著影响。不接种稻瘟病菌情况下，加硅对第3天叶片中总酚含量没有显著影响，而显著降低了第7天叶片中的总酚含量，两个水稻品系表现一致。对两个品系水稻品种来说，根系中的总酚含量明显低于叶片中的总酚含量。稻瘟病菌侵染条件下，加硅显著降低两个材料叶片中的木质素含量，对根系中的木质素含量没有显著影响。不接种稻瘟病菌情况下，加硅显著增高了C039叶片中的水杨酸含量，而对于C101LAC（用一D，加硅只在第3天显著增高了叶片中的水杨酸含量。接种稻瘟病菌后，施硅使C039在第3?

英文摘要：

[Objective] Rice blast is one of the major diseases in rice production and cause serious yield losses every year. As a kind of environment friendly disease control measures, silicon fertilizer application plays an important role in enhancing plant disease resistance, but the mechanism is not totally clear. The purpose of this study was to investigate the physiological mechanismof silicon-enhanced resistance of rice to blast, and to provide a theoretical foundation and methods of controlling rice blast. [Method] Two rice near-isogenic lines（NILs） with different resistances to blast, i.e. CO39 （susceptible） and C101LAC （Pi-1） （resistant） were used in the experiments. There were four treatments： no silicon added and no inoculation with M. oryzae（Si-M-）; silicon added but no inoculation with M. oryzae（Si＋M-）; no silicon added but inoculation with M. oryzae（Si-M＋）; silicon added and inoculation with M. oryzae（Si＋M＋）. Using a grown chamber to control the growing conditions, the hydroponic culture experiments with Hoagland＇s nutrient solution were conducted to clarify the effects of silicon on disease incidence, content of silicon, phenolics, SA, ethylene and H202 in roots and leaves of rice. [Result] Si application significantly reduced the blast incidence and disease index for both two rice lines. And the blast incidence and disease index of C101LAC （Pi-1） were obviously lower than CO39. Si concentration increased significantly in all leaf, stem and root tissues of both two rice lines by Si treatment regardless of inoculation. While Si concentrations in leaves and stems were obviously higher than that in roots. After inoculation with M. oryzae, Si treatment significantly reduced the total phenolic content in leaves of CO39 and C I 01LAC （Pi-1）. In roots of two rice lines, Si application had no significant effect on the total phenolic content. Without inoculation, Si application had no significant impact on the total phenol content in leaves 3 d after inoculation, bu