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大豆腐霉菌是黑龙江省大豆根腐病菌群的重要组成部分,为了明确大豆腐霉菌的种类,从黑龙江省黑河市大豆根系土壤分离获得1株腐霉菌PSHH1,应用r DNA-ITS序列分析法对其进行菌种鉴定。Blast和系统进化树结果表明:PSHH1与Gen Bank上登录号为AB259316.1和AB512973.1等的Pythium sylvaticum亲缘关系最近,r DNA-ITS序列同源性大于99%,因此认定PSHH1为Pythium sylvaticum。为了考察PSHH1的致病性,选取了60份当前大豆主栽品种,应用种子腐烂法和下胚轴接种法进行回接试验,通过计算种子腐烂率和植株茎折率来评价PSHH1的致病性,结果显示,PSHH1仅对13.33%的大豆主栽品种表现出较强的致病力,而对61.67%的大豆主栽品种致病力较弱。
In order to clarify the types of Pythium, a strain of Pythium PSHH1 was isolated from soybean root soil in Heihe City, Heilongjiang Province. The rDNA-ITS sequence analysis For species identification. The results of Blast and phylogenetic tree showed that PSHH1 has the closest genetic relationship with Pythium sylvaticum with accession numbers AB259316.1 and AB512973.1 on GenBank, and the sequence homology of rDNA-ITS is more than 99%. Therefore, PSHH1 was identified as Pythium sylvaticum. In order to investigate the pathogenicity of PSHH1, 60 soybean cultivars were selected and the pathogenicity of PSHH1 was evaluated by the seed decay method and the hypocotyl inoculation method. The results showed that PSHH1 showed strong virulence only to 13.33% of soybean cultivars, but weak to 61.67% of soybean cultivars.