Study On Population Structure And Characteristics Of Gibberella Fujikuroi Species Complex In Different Cereals

Cereals are indispensable food crops for human survival and Fusarium,one of the important plant pathogens,especially Gibberella fujikuroi species complex can infect various crops and cause several important plant diseases like Fusarium head blight and rice bakanae.In addition,Fusarium can produce a variety of toxins,leading to serious economic losses and the increased risk of human and animal health.The aim of our study is to make clear the Fusarium species composition in the study area,genetic diversity and mycotoxic ability of Gibberella fujikuroi species complex.This will provide theoretical basis for developing new disease and mycotoxin control strategies.At the same time,we have established a simple and fast multi-toxin detection method that is of great significance for the research and detection of various toxin contents in cereals.The main findings are as follows:(1)We collected 1924 Fusarium isolates from from rice,wheat,soybean and corn seed and tissue in several provinces including Jiangsu,Anhui,and Shandong.The compositions of pathogens in different hosts were specified.Fusarium graminearum species complex dominated in wheat,the dominant population in maize was Gibberella fujikuroi species complex,and most strains isolated from rice and soybean belonged to Fusarium incarnatum-equiseti species complex.(2)The compound group of Gibberella fujikuroi species complex was selected as the research object.Based on Fum1 and EF1-?,phylogenetic analysis of GFSC strains was conducted.The results suggested four groups(F.verticillioides,F.proliferatum,F.fujikuroi,and F.andiyazi)with no correlation with host.(3)We established a simultaneous determination method for multi-toxins with high performance liquid chromatography-tandem mass spectrometry.The detection of the toxicity of the Gibberella fujikuroi species complex showed that,fumonisins were mainly produced by F.verticillioides and F.proliferatum.F.proliferatum and F.fujikuroi can produce moniliformin and beauverian at a certain level.The toxigenic ability of F.andiyazi was extremely low.(4)The pathogenicity of Gibberella fujikuroi species complex was analyzed and the results showed,all species can reduce seed germination and produce lesions on maize leaf.There was no significant difference among species.F.fujikuroi showed two kinds of different patterns of influencing the bud and root of rice seedling.