进境棉籽中棉花枯萎病菌的检疫鉴定和监控策略

Identification and monitoring strategy of Fusarium oxysporum f.sp.vasinfectum from imported cotton seeds

对从澳大利亚进境的多批棉籽进行了病原菌分离,纯化培养后得到3株疑似棉花枯萎病菌的菌株FOV-093、FOV-130和FOV-245。形态学观察表明:菌株FOV-093、FOV-130和FOV-245均产生典型的棉花枯萎病菌大型分生孢子和小型分生孢子,前者呈镰状或椭圆形弯曲,后者呈假头状着生,多数为单孢,卵圆形;用通用引物ITS4/ITS5和特异引物FOV-F/R扩增,分别获得518 bp和354 bp的DNA片段,测序后通过BLAST比对表明,其与GenBank中Fusarium oxysporum f.sp.vasinfectum序列同源性为100%,;致病性测定表明:3个菌株均可侵染棉花并致其萎蔫死亡。根据上述试验结果,将分离获得的菌株FOV-093、FOV-130和FOV-245鉴定为棉花枯萎病菌Fusarium oxysporum f.sp.vasinfectum。加强进境棉籽的检疫和病害监控,是防止该真菌扩散和传播的有效方法。

FOV-093,FOV-130 and FOV-245 were isolated from imported cotton seeds of Australia by using traditional PDA isolation method.These isolates produced typical macroconidia and microconidia of Fusarium oxysporum f.sp.vasinfectum .Macroconidia were falciform,oval;microconidia gathered to head shape,single cell,spawn.The general primer ITS4/ITS5 and the specific primer FOV-F/R yielded PCR products of approximately 518 bp and 354 bp,respectively.Compared with the identity of rDNA sequence of Fusarium oxysporum f.sp.vasinfectum from NCBI GenBank databases by BLAST method,the results showed that its homology was up to 100%.Pathogenicity tests showed that cotton seedlings were infected,wilted to death by FOV-093,FOV-130 and FOV-245. Based on morphological characteristics,molecular and pathogenicity test results,FOV-093,FOV-130 and FOV-245 were identified as Fusarium oxysporum f.sp.vasinfectum （Atk.）Snyder ＆amp;Hansen.It was an effective way to prevent this fungus from proliferating and spreading by strengthening cotton seeds pest monitoring,inspection and quarantine.