The Research Of Nano Silicon Strengthen Resistance Of Rice Against Rice Blast

Silicon can significantly improve the rice's resistance to many diseases, especially has the vital resistantly role to the blast. But now the domestic public comments on rice silicon nutrition research, its resistance to blast mechanism has been unclear, long-standing controversy, and nano silica on the growth and development of biological stress and resistance mechanism were seldom studied. Therefore, this study with two rice varieties for research object, there were "NongDa18" for high resistance to rice blast and "Mongolian rice" for high disease. After application nano silica, researched the mineralization silicon's role in the rice, Illustrates that the effect of nano silica's role in rice disease and growth, and particularly discussed the application of nano silica can enhance the rice's structure to resistant magnaporthe grisea, physiological and biochemical resistance. The main research results are as follows:1. The effects of resistance to rice blast and the influence of rice growthExperimental results from water planting show that the disease index of the disease-resistant varieties and susceptible varieties which with nano silica treatment more tinier than without silicon processing, respectively decrease 30.98% and 51.03%. The relative control effect of disease-resistance varieties to 54.93%, and the susceptible varieties reached 73.47%. It's reduced the disease level and disease index of rice leaves with silicon application, and strengthened the resistance to rice blast, and particularly significant strengthened the Mongolian rice's resistance. After application of nano silica in rice, it not only significant improvement the content of chlorophyll, increase net photosynthetic rate, stomatal conductance and intercellular carbon dioxide concentration, but also enhanced the photosynthesis of rice leaf, and it can increase the roots number and new roots'length, and raising the longest root's length of root active absorption area, make the root vigor enhanced. And it also can increase the contact angle of rice, and reduce the angleofincliation of leaf, make the rice plant forceful, reduce the fungi attached to the rice leaves, and it's good for rice growth.2. Strengthen structure resistance to rice blast for riceResearch by scanning electron microscopy, The silicified cells of the rice within silicon application processing number to more than without silicon processing and the area is larger, the gaps between silicified cells much smaller than without silicon processing. Through the X-ray spectrometry analysis of silicon application processing that the silicon contents in silicified cells, mastoid and other microarea was significantly more than that without silicon application processing. After magnaporthe grisea inoculated, only a minority of magnaporthe grisea hyphae exist in the rice leaves surface with silicon processing, and its grisea hyphae's quantity much less than the rice which without silicon processing. Illustrate that application silicon can effectively restrain magnaporthe grisea dioperation, thereby it also enhancing the rice's resistance to rice blast. Also observed the rice leaves surface which with silicon application processing, the grisea hyphae intertraversing the silicification cells, illustrate that the silicon on magnaporthe grisea non-toxic. Research the rice leaves's health department disease by transmission electron microscopy, each cell of rice leaves all existing mineralization silicon substance, there was existing only a small amount of mineralization silicon in epidermal cells and mesophyll cells in the rice leaves of susceptible varieties. Each cell of the rice leaves of disease-resistant varieties all existing a great quantity and tightly mineralization silicon substance around the grisea hyphae, and the magnaporthe grisea hyphae were surrounded by these substance, even some hyphae were empty by this substance. Illustrate that when the rice with silicon processing, it can formation a kind of mineralization silicon substance, and this substance can prevent the magnaporthe grisea disoperating the rice leaves more, it even can clear away the magnaporthe grisea from rice, so as to strengthen the structure resistance to rice blast.3. The effects of rice membrane lipid peroxide and ros removal systemsUninoculated with magnaporthe grisea, the POD and SOD activity of two rice, silicon application processing are higher than without silicon application processing, and the CAT activity has no significant change. Explain that the rice with silicon application can significantly increased the POD and SOD activity. Inoculated with magnaporthe grisea, silicon application processing of rice could significantly reduce the accumulation of reactive oxygen species in the system, and improve the POD and SOD activity, and reduce the rice membrane lipid peroxide caused by magnaporthe grisea, enhanced rice resistance to magnaporthe grisea, and the susceptible varieties with silicon enhanced role better than disease-resistant varieties.4. The effects of the phenolic compounds metabolic in rice leavesUninoculated with magnaporthe grisea, the PPO and PAL activities, and the contents of flavonoids and lignin in two kinds of rice leaves with silicon processing had no significant differences from without silicon processing, explain that them was no apparent effect with silicon. The total of phenols content in rice leaves with silicon processing was not significant higher than without silicon processing,explain thant it can significantly improve the total content of polyphenols in rice leaves with silicon processing. Inoculated with magnaporthe grisea, the PPO and PAL activities, and the contents of flavonoids and lignin in two kinds of rice leaves with silicon processing were higher than that without silicon processing, the PPO activity of disease-resistant varieties were higher than susceptible varieties. Illustrate that the rice after magnaporthe grisea dioperation, silicon application can enhance the phenolic compounds metabolic enzymes activities, improve the resistance function (phenolic flavonoids, lignin, etc.), thereby increasing the resistance of the rice to magnaporthe grisea, and the effect of susceptible varieties is preceder than disease-resistant varieties.5. The effects of rice leaves duration related proteins activityUninoculated with magnaporthe grisea, two kinds of rice with silicon processing, the chitinase enzyme andβ-1,3-glucan enzyme activities were significantly greater than without silicon processing, and after silicon application that the protein content was also significantly higher than without silicon application processing. Inoculated with magnaporthe grisea, the (3-1,3-glucan enzyme activities of two kinds of rice were fell after the first rise up and fell again. For disease-resistant varieties, the chitin enzyme activity of leaves rise rapidly, and inoculated with magnaporthe grisea after 48h, the chitin enzyme activity reached peak value, and fell. The chitin enzyme activity with silicon application processing has been significantly higher than without silicon processing. Inoculated with magnaporthe grisea, the chitin enzyme activity of sueceptible varieties was also rise up rapidly. Early inoculated with magnaporthe grisea, the silicon application processing was significant higher than without silicon processing, the chitin enzyme activity without silicon processing reached peak value when inoculated with magnaporthe grisea 48h, and fell. And the silicon application processing continue to rise until inoculated with magnaporthe grisea 72h and it reached peak. Illustrate that the chitin enzyme activity of susceptible varieties with silicon processing which infect with magnaporthe grisea can maintain higher levels, and more lasting, help to improve rice resistance to rice blast.In conclusion, The results of this study are proof nano silica can not only enhance the structure of rice to magnaporthe grisea resistance, but also can adjust the rice to enhance the physiological functions to resistance magnaporthe grisea.