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Silicon can significantly improve the resistance of rice to a variety of diseases has an important role, especially for rice blast. But at home and abroad published research on rice Silicon Nutrition resistance to blast mechanism has been unclear, long-standing controversy, and nano-SiO2 on rice growth and its biotic stress resistance mechanism of very little. Therefore, this study Blast CAU 18 disease resistance and high susceptibility Mongolia rice two rice varieties as the research object, the application of nano-SiO2 by study of biomineralization silicon role, clarify SiO2 nanoparticles rice disease resistance effect and the impact of growth and development, and in particular explore the nano-SiO2 to enhance the structure of rice rice blast fungus resistance and physiological and biochemical resistance. The main findings are as follows: 1, growth and development of rice blast disease effects and rice the hydroponic test results show that nano-SiO2 treatment of resistant varieties and susceptible disease index fell 30.98%, respectively, compared with no facilities for silicon processing the resistant varieties relative control effect of 54.93% and 51.03%, 73.47%, and the relative control effect of the susceptible cultivar. Applied silicon to reduce disease and disease index of enhanced rice resistance to rice blast, in particular, significantly enhanced resistance to the susceptible cultivar Mongolia rice. Rice in the application of nano-SiO2, not only can significantly improve the chlorophyll content, increase the net photosynthetic rate, stomatal conductance and intercellular CO2 concentration, so that the rice leaf photosynthesis enhanced, they can also increase the number of the root of the new root and the longest root length and improve the root active absorption area, enhanced root activity also increases the contact angle of Rice Leaf, and reduced leaf angle, the rice plants upright, reduce fungi attachment, is conducive to the normal growth of rice. 2, to enhance the resistance of Rice Blast structure by scanning electron microscopy analysis, the rice leaves applied to the silicon silicide cells than the number of silicon processing is not applied to more and larger, the gap between the silicide cells than not applied to silicon processing small much; analysis by X-ray spectroscopy shows that silicon application processing rice leaves silicide cells, mastoid and other micro-zone silicon content was significantly higher than that applied to silicon processing. The inoculated rice blast fungus, after the rice leaf surface of silicon application processing there is only a handful of rice blast fungus mycelium, and the number of hyphae than not applied much less silicon processing. Description of silicon application to effectively inhibit invasion of the rice blast fungus, to Rice Blast structure resistance. Also observed facilities silicon surface and yield of rice, the mycelium aspect through the silicide cells, silicon is not toxic to the rice blast fungus. By transmission electron microscopy analysis of rice leaves at the disease and health, found that the blade of intracellular mineralization of silicon material existence. There is only a small amount of mineralization silicon in susceptible cultivar rice leaf epidermal cells and mesophyll cells, but the cells of the leaves of resistant varieties hyphae surrounded by dense mineralization silicon material existence, and rice blast mycelium surrounded by this kind of material, even some mycelium is emptied. Rice after the silicon is applied, within the blades to form a mineralized silicon material, this material can prevent further violations of the rice blast fungus on rice leaves, and even to clear, thereby enhancing the structural resistance of Rice Blast. 3, rice membrane lipid peroxidation and active oxygen scavenging system unvaccinated rice blast fungus, disease-resistant varieties and susceptible rice leaves POD and SOD activity facilities than no facilities for processing silicon in silicon processing CAT activity did not change significantly, facilities silicon can significantly increase rice plants POD and SOD activity. Rice by the rice blast fungus infection of silicon application processing rice can significantly reduce the level of accumulation of reactive oxygen species within the system, to improve the POD and SOD activity, reduce due to rice blast fungus caused by rice leaf membrane lipid peroxidation, thereby enhancing rice resistance to rice blast fungus and disease-resistant varieties of silicon on an enhanced role of the susceptible variety is greater than. 4, phenolic metabolism in rice leaves inoculated with rice blast fungus conditions, the two rice leaves PAL and PPO activity, flavonoids and lignin content Shi silicon and silicon is not applied to deal with no significant difference, indicating no apparent effect of silicon on them; while the total phenolic content of silicon application in rice leaves was significantly greater than applied to silicon processing facilities silicon can significantly improve the total phenol content in the leaves. Inoculated with rice blast fungus, rice in silicon processing PPO, PAL activity, total phenolic content and lignin content significantly higher than that of silicon application processing; the overall PPO activity of disease-resistant varieties is greater than the susceptible cultivar. Rice by the rice blast fungus infestation facilities silicon to enhance rice phenolic metabolism in vivo enzyme activity and increased rice blast fungus resistant phenolic compounds (flavonoids, lignin, etc.), thereby enhancing rice Blast bacteria resistance, and the effect of the susceptible variety is superior to resistant varieties. 5, the rice leaves pathogenesis-related protein activity missed under aseptic conditions, two rice facilities silicon processing chitinase and beta-1, 3 - glucanase activity was significantly greater than silicon processing is not applied, and Application of Silicon protein content was also significantly higher than that of silicon application processing; inoculated with rice blast fungus, rice beta-1, 3 - glucanase activity increased first and then fall and then rise. Resistant varieties, leaves chitinase activity increased rapidly, and 48h after inoculation, the activity reached a peak and then decline, applied to silicon processing chitinase activity has been significantly higher than the non-silicon application processing; sense disease varieties of rice blast fungus after inoculation, the chitinase activity began to rise early in the inoculation, facilities silicon processing was significantly greater than silicon processing is not applied, and have no silicon processing, they begin to decline after the inoculation 48h peak, applied to silicon processing continues to rise and reached a peak after inoculation 72h. Applied to silicon enables the rice blast fungus infection of susceptible varieties chitinase activity remained higher concentrations in rice leaves, and more durable to help improve rice resistance to rice blast. In summary, the results of this study prove that nano-SiO2 not only to enhance the structural resistance of rice to rice blast fungus, and nano-SiO2 can also adjust the physiological function of rice plants to enhance the resistance of rice to rice blast fungus.
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