甘肃地区梨树腐烂病的病原种类鉴定

Identification of the pathogen of pear Valsa canker in Gansu area

明确甘肃省梨树腐烂病病菌的分布、组成及其亲缘关系,为有效防治腐烂病及筛选抗病种质资源提供理论依据。以甘肃省8个市州主要梨产区不同品种梨树上典型腐烂病症状的枝干为材料,采用常规组织分离法分离纯化得到53株梨树腐烂病病菌,经柯赫氏法则验证,通过形态学及多基因序列(rDNA-ITS、EF-1α和tub2)构建系统发育树,明确致病菌种类及分类地位。结果表明,分离得到的53株菌株均与模式菌株Valsapyri聚为一支,支持率为99%,确定引起甘肃省梨产区梨树腐烂病的病原只有1种,即V.pyri(无性型为Cytosporamali),且菌株在PDA培养基上表现出不同类型的培养性状。

To clarify the distribution,composition and genetic relationship of pear Valsa canker pathogens in Gansu Province,to provide theoretical basis for effective control of pear Valsa canker and screening of disease-resistant germplasm resources.Using the typical rots symptomatic branches on pear trees of different varieties in the main pear producing areas of eight cities and states in Gansu Province as materials,53 strains of pear Valsa canker were isolated and purified by conventional tissue isolation method,and the phylogenetic tree was constructed by Koch’s postulates of evidence,morphology and multi-gene sequences(rDNA-ITS,EF-1αand tub2)to clarify the species and taxonomic status of pathogenic.The results showed that all the 53 strains isolated were clustered with the model strain Valsapyrias one with 99%support,and only one pathogen causing pear Valsa canker in pear producing areas of Gansu Province was identified,namely V.pyri(anamorph Cytosporamali),and it showed different types of culture traits on PDA medium.