小麦种子内携真菌多样性研究

Diversity of fungi in wheat seeds

为揭示小麦种子所携带真菌的种类和多样性,丰富小麦相关微生物的可利用资源,我们对来自俄罗斯、澳大利亚、哈萨克斯坦、加拿大以及中国的57份小麦种子样品进行内携真菌分离并对其中的21份种子利用高通量测序进行多样性分析。结果显示,分离获得564株真菌,经ITS序列分析结合形态观察鉴定为31属69种,其中菌株数量相对多度最高的5个属为链格孢属Alternaria(51%)、核腔菌属Pyrenophora(6%)、附球菌属Epicoccum(6%)、镰刀菌属Fusarium(5%)和青霉菌属Penicillium(5%);同时有节菱孢属Arthrinium、烟管菌属Bjerkandera、毛壳属Chaetomium和小鬼伞属Coprinellus等17个属的真菌是首次从小麦种子内获得分离培养;此外还从小麦种子中分离得到多种潜在的重要植物病原菌,如互隔链格孢Alternaria alternata、麦根腐平脐蠕孢Bipolaris sorokiniana和禾谷镰刀菌Fusarium graminearum等。根据高通量测序结果进行的多样性分析表明来自中国的样品仅与来自俄罗斯样本存在显著差异。高通量测序获得的小麦种子内携真菌的优势属为链格孢属Alternaria、枝孢属Cladosporium和附球菌属Epicoccum,相对多度分别为23.95%、18.91%、13.32%;对小麦种子内携真菌OTU的营养类型进行注释后发现植物病原菌类型的相对多度占到71.36%。本研究结果初步揭示了小麦种子内携真菌的组成和多样性,结果显示小麦种子是多种种传病害病原菌的潜在载体,内携多种潜在的植物病原真菌,有可能在后续生产中条件适合的情况下发生病害,本文为小麦种传病害的防治和研究提供了重要的材料和科学依据。

Diversity of fungi colonized in wheat seeds was investigated.Fifty-seven wheat seed samples from China and those imported from Australia,Canada,Kazakhstan,Russia were subjected to strain isolation,of which 21 samples were analyzed by high-throughput sequencing.In total 564 fungal strains were isolated,and 69 species in 31 genera were identified based on ITS sequence analyses and morphological observations.Species of Alternaria(with relative abundance of 51%),Pyrenophora(6%),Epicoccum(6%),Fusarium(5%),and Penicillium(5%)were the most abundant,and 17 genera were isolated from wheat seeds for the first time.In addition,several potentially important phytopathogens,e.g.Alternaria alternata,Bipolaris sorokiniana,Fusarium graminearum were also isolated.The diversity analysis of high-throughput amplicon sequences showed that only the samples from Russia were significantly different from those from China.The dominant genera revealed by high throughput sequencing were Alternaria,Cladosporium and Epicoccum,with relative abundances of 23.95%,18.91%and 13.32%respectively.FUNGuilds analysis suggested that pathotrophs accounted for the highest portion of wheat seed fungi,and these potential phytopathogens may develop diseases under suitable conditions.