Study On Diversity Of Population Genetics And Resistance Of Magnaporthe Grisea In Guizhou Province

Rice blast caused by the fungus Magnaporthe grisea is one of the most widespread and destructive diseases of rice in the global. Magnaporthe grisea has occurred widely area in recent years and damaged greatly in our province. This study focuses on the composition and the relation between physiological race and genetic lineage of Magnaporthe grisea, the relations with the host acquisition, and the resistance tricyclazole in Magnaporthe grisea.This study utilized the rep-PCR molecular fingerprint technology, collected the blast strains more than 20 counties and cities and carried out DNA fingerprinting analysis in Guizhou. The results show 2～15 DNA bands among 0.4Kb～23Kb for each isolate were amplified. 200 isolates are classified into nineteen genetic lineages and composed of 141 haplotypes at a genetic similarity of 0.774 in clustering analysis of outweighed pair-group method using arithmetic average (UPGMA).Of these lineages, GZL7 and GZL6 are the predominant lineages . The results indicate that genetic structure of M.grisea population in Guizhou province tends to be multiplicity and complexity, and also reveals that genetic lineage isolates are directly relationship between variety and environment physiology. It is obviously related among the genetic lineage and the hosts, collecting places.According to fingerprint and pedigree analysis, isolates collect from 86 strains selected for the identification of physiological, The 86 isolates are divided into 7 groups, 20 races .The results also show there have no certain corresponding relationships between genetic lineage and physiological race. The same lineage can be composed of several different physiological races, and the same physiological race can belong to different lineage. Japan, in addition to the use of 13 varieties of this single gene toxicity and 76 strains of group structure. The research shows that a single gene varieties K3 Frequency of infection was low. So Pi-k~h Gene in Guizhou Province will use in breeding resistance.At the same, to make it clear whether there is resistance to Magnaporthe grisea to tricyclazole. Authors in the room with PDA culture medium treated with Tricyclazole found: With the generation induced by the increase, the sensitivity of rice blast pathogen to the fungicide tricyclazole gradually decreased and the resistance to tricyclazole was stronger and atronger. It shows that Magnaporthe grisea to tricyclazole veins have produced a resistance.