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This test uses SSR the SCAR marker technology containing M. grisea of ??Heilongjiang Province, part of the city (county), avirulence gene AVR-pita, the AVR-CO39 PWL2 PWL3 AVR-pit, the AVR-PIAs PRE1 and AVR-pikm the case detection analysis to clarify the eight avirulence gene distribution Blast Fungus Population in Heilongjiang Province, and then analyzes the Blast Fungus Population pathogenicity of Heilongjiang Province. The Magnaporthe grisea SSR-PCR reaction system factors (Taq DNA polymerase, Mg2, template DNA, dNTP, primers) to optimize the test on four levels, screened various reaction factors using orthogonal design L16 (45) best level of the rice blast fungus SSR-PCR reaction system (20 μL): Taq DNA polymerase 1.0U, Mg2 2.0 mmol · L-1, DNA 100 ng of · μL-1, dNTP 50μmol · L-1, primers (ms355-356) 0.4μmol · L-1. Temperature gradient test to determine the best annealing temperature for each pair of primers in the reaction system of the SSR-PCR. In this study, not only four have been cloned avirulence gene AVR-pita AVR-CO39 PWL2 and the PWL3 specific primers, also uses three avirulence gene closely linked SSR markers and avirulence gene AVR-pikm SCAR markers tightly linked, Heilongjiang Province, 19 cities (counties) 204 M. grisea genomic DNA for PCR amplification, the test results show that different non-toxic gene is a significant difference in the frequency of occurrence of Heilongjiang Province, and non-toxic gene PWL2 is the most widely distributed in Heilongjiang Province, the frequency of occurrence of 52.94%; followed avirulence gene AVR-pit, the occurrence frequency of 43.14%; avirulence gene AVR-pita, AVR-pia, AVR1-CO39 PRE1 and AVR-pikm the The frequency of occurrence of 39.22%, 38.24%, 37.75%, 28.92% and 25.98%; non-toxic gene PWL3 not detected in all the strains tested. Heilongjiang Province, 204 tested isolates non-toxic results of genetic testing, the number of avirulence genes of different strains detected some differences. Two strains detected six avirulence genes; avirulence genes of 12 strains detected 5; 37 the strain detected four non-toxic gene; 55 strains detected three avirulence genes; 57 strains detected two non-toxic gene; 36 strains detected a non-toxic gene; five strains does not detect non-toxic gene. Detected strains of two and three non-toxic gene proportion These strains were detected by the gene, while the same number, but the types of genes having a not necessarily identical; the genetic background of the different strains and pathogenic differences. Larger differences in the frequency of occurrence of different non-toxic gene in the same region as the Fujin nontoxic gene PWL2 frequency of occurrence of 80%, while the non-toxic gene of AVR-pikm the frequency of occurrence of 0; Jidong avirulence gene AVR- The pia frequency of occurrence of 75%, while avirulence gene PWL2, PRE1, AVR-pikm appears frequency but had to 0. The distribution of the same non-toxic gene in different regions there are big differences avirulence gene AVR-pia in Jidong County, Baoqing and two hundred ninety-one,, the frequency of occurrence of the farms was 75.00%, 60.00% and 62.50%, respectively; in Tieli City, in Zhaoyuan County and Founder County's frequency of occurrence were 25.00%, 22.22% and 16.67%; frequency of occurrence in the Hulan County 0. This shows that the population structure of M. grisea in Heilongjiang Province is complex and non-toxic strains of the same region, and even in different regions have obvious differences in the presence of a gene.
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