Identification, Distribution And Genetic Diversity Of Rice Seedling Blight Pathogen In Heilongjiang Province

Rice is one of the main food crops in China and occupies an important position in the wholeagricultural production in China. Heilongjiang province is the main rice production area, and riceproduction increased year by year. In recent years, an aggravating trend of rice seeding blight inHeilongjiang. Study for the pathogen species dientification of rice seeding blight in Heilongjiangprovince are very few, only Zheng Wen etc. The study carried out samples of rice seeding blighting in16cities or towns in Heilongjiang province in2010~2012years and separation the pathogens, withmorphological and molecular methods of pathogens, pathogenicity identification, distribution anddiversity research to clear about the pathogen species, distribution and genetic diversity of rice seedingblight in Heilongjiang province and set an important basis for the prevention and the control of riceseeding blight.351strains of fungi were isolated from samples of rice seedling blight and these strains belonged toseven species according to the identification, which were F. Oxysporum for119plant,33.9%, F.Avenaceu for10plant,2.8%, F. equiseti for31plants,8.9%, F. solani for30plants,8.5%, F. Communefor14plants,4.0%, F. verticillioides for138plants,39.3%, F. Proliferatum for9plants,2.6%.According to the identification the main spieces of pathogen are F. Oxysporum and F. Verticillioides for73.2%and others totally26.8%.According to the results of identification: F. Oxysporum and F. Verticillioides are distributed in16cities or towns, has universal distribution; F. Avenaceum only isolated in Wuchang, Ningan, Fuyu andFangzheng; F. equiseti isolated in Hailin, Huanan, Fujin, Wuchang, Yian, Fangzheng and Jixi; F. Solaniisolated in Hailin, Mishan, Wuchang,852farm, Ningan, Dumeng and Mudanjiang; F.commune isolatedin Hailin, Qingan, Huanan, Fujin and852farm; F. Proliferatum only isolated in Mishan, Ningan,Mudanjiang and Fangzheng. According to the results of pathogen, we know that the pathogens havedifference in pathogenicity isolated from different areas. F. Oxysporum and F. Verticillioides have astronger pathogenicity than others. F. commune has no pathogenic, it’s just a kind of saprophyticbacteria. The genetic diversity of the populations of Fusarium was detected by amplified restrictionfragment polymorphism (AFLP) analysis. Among99combinations of primer pair screened,12combinations could generate consistent polymorphic bands. The16combinations were used to amplifythe genomic DNA of351Fusarium. Cluster analysis using the unweighted pair-group method witharithmetic averages (UPGMA) separated351Fusarium isolates into seven AFLP groups. The genetic diversity level of pathogens isolated form rice seedling blight in Heilongjiang province was high.