进境澳大利亚大麦上葡萄茎枯病菌的检疫鉴定

自进境澳大利亚大麦样品上,采用常规平板分离法获得1株疑似葡萄茎枯病菌菌株74919。通过形态学特征观察、β-tubulin和actin序列比对分析以及致病性测定,对该菌株进行了种类鉴定。结果表明:菌株74919在PDA培养基上生长良好,可产生大量分生孢子器和厚垣孢子;基于β-tubulin和actin序列构建的系统发育树中,菌株74919和其他葡萄茎枯病菌相关序列划分在同一分支;菌株74919接种大麦叶片,在接种部位引起叶斑症状。根据上述实验结果,将菌株74919鉴定为葡萄茎枯病菌(Didymella glomerata),这是我国口岸首次从进境澳大利亚大麦中截获葡萄茎枯病菌。

Quarantine identification of Didymella glomerata on barley imported from Australia

The fungal strain 74919 was isolated from the barley imported from Australia by traditional PDA method.The morphological observation,sequences analysis and pathogenicity test were carried out to identify the strain 74919.The morphological results showed that the isolate 74919 grew well on PDA producing abundant pycnidia and chlamydospores.Its β-tubulin and actin sequences were sequenced.Analysis of these sequences with the related sequences in NCBI showed that the strain 74919 clustered into Didymella glomerata clade.The pathogenicity test showed that the strain 74919 could cause leaf spot on barley leaves.Based on these results,the isolate 74919 was identified as D.glomerata.To our knowledge,this is the first interception report of D.glomeratain on barley imported from Australia in China.