洋葱贮藏期干腐病致病镰刀菌的鉴定及室内药剂毒力测定

Identification and fungicide test in vitro of fusarium pathogens of onion dry rot disease

【目的】明确洋葱贮藏期干腐病致病镰刀菌的病原菌.【方法】采用形态学与分子生物学方法对洋葱干腐病病原种类进行了鉴定,在CLA培养基上对两株典型菌株的菌落形态和培养特征进行了观察和描述.【结果】rDNA-ITS序列测定和同源性比对结果表明,两菌株的ITS序列分别与GenBank数据库已知尖孢镰刀菌(Fusarium oxysporum)和层出镰刀菌(Fusarium proliferatum)的同源性均达99%,其片段大小分别为519bp和521bp.致病性测定结果表明,两种菌均能引起洋葱干腐病,其中尖孢镰刀菌的致病力强于层出镰刀菌.室内药剂毒力测定结果表明,43%戊唑醇对两种镰刀菌的抑菌效果最好.【结论】尖孢镰刀菌(F.oxysporum)和层出镰刀菌(F.proliferatum)是洋葱贮藏期干腐病的病原菌,由层出镰刀菌引起的洋葱干腐病属首次报道.

【Objective】In order to identify pathogenic Fusarium of onion dry rot during storage.【Method】The pathogen species were identified through morphological and molecular biological methods.Two typical colony morphology and cultural characteristics were observed and description in the CLA medium.【Result】With rDNA-ITS sequence analysis and homology comparison,the results showed that the rDNAITS sequence of two pathogenic shared 99%similarity with that of F.oxysporumand F.proliferatum,and their fragments were 519 bp and 521 bp.Pathogenicity test showed that two pathogenic caused onion dry rot,and F.oxysporum was stronger than F.proliferatum.Toxicity testing results showed that 43% of Tebuconazole displayed more strongly inhibitive to the mycelium growth of the two pathogens than fungicides.【Conclusion】F.oxysporumand F.proliferatum were major pathogens of onion dry rot during storage.F.proliferatumcaused onion dry rot was the first reported.