Distribution Of Resistance Genes In Rice And Avirulence Genes In Rice Blast Fungus And Molecule Detection Of Magnaporthe Oryzae

Rice is the important food crop in world, and it is very extensive of the plantingarea in China, too. There are many factors for affecting the rice yield and quality,and the rice blast is one of them. In Jilin Province, the pathogenesis of rice blast hasintensified trend with years of rice planting. The distribution of the resistance genewas not very clear in this area of rice varieties, and because rice blast variation fast,it cause a great difficulty in field layout and resistance breeding of rice. So it hasvery important significances of distribution research of rice resistance genes and riceblast avirulence genes in Jilin Province. It is helpful for prophylaxis and treatment ofrice blast by using the condition forecasting. But the methods of rice blastforecasting now have some faults, such as complex operation, not exactly, big error,not in time and so on. So we need a rapidly, accurately and simplify method todetect the fungi before the disease show symptom in the same year. And it is helpfulfor reduce distance spread by man by using the method on rice seeds.In this study, the primers were designed in the specificity of the conservativeregions of9cloned rice resistance genes, there are pi-d2、pik^h、pid3、pi36、pita、pib、pi37、pik and pi5. The Polymerase Chain Reaction （PCR） was used in this studywith62kinds of rice in Jilin Province. It found that the distribution frequency of pik^h,pi-d2and pid3genes were all100%, pi36gene was98.39%, pita gene was96.77%,pi37gene was88.71%, pib gene was40.32%, pik gene was46.77%and pi5genewas20.97%. The results showed that pib、pik and pi5were serious lacking. Byfingerprint, the distribution of resistance genes was cleared in Jilin Province.In the study of rice blast avirulence genes, the primers were designed ofAvr-Pita and AvrPiz-t genes and amplification with103strains of Magnaportheoryzae collected in Jilin Province. The results showed that the distribution frequency of the two genes were86.41%and62.13%. By Jin Chunpeng’s results, thefingerprint was structured of6avirulence genes by85strains of rice blast. It showedthat the type1was the major type and it was40.00%in all types. Type1containedall6genes. It can be used for resistance breeding reference results of the fingerprintto induce the loss that could be brought by Magnaporthe oryzae.In the study of Magnaporthe oryzae, a kind of mycovirus was found in the040101-3strain. Compare with the healthy one, the strain with mycovirus has nosporulation, no pigmentation and affect the host hypha. These can prevent the fungiintrude into its host and spread in host. So it is a good material for the Bio-control ofMagnaporthe oryzae.The primers were designed in the rDNA region and the Magnaporthe oryzaewas detected by the Real Time PCR （QPCR）. The results showed that the DNA ofthe Magnaporthe oryzae was detected as low as6.9×10^-5ng. By using the relativeQPCR, the Tublin gene was the housekeeping gene. And the methods of thedetection and quantification the Magnaporthe oryzae before the disease showsymptom was constructed. This method can be used in condition forecasting and ricequarantining.