山东牡丹黑斑病的病原菌鉴定与ITS序列分析

The Identification and Analysis of ITS Sequence on Tree Peony Black Spot in Shandong

牡丹黑斑病的致病菌尚不明确。通过对泰安地区的牡丹病叶进行组织分离,利用分子生物学技术结合形态学方法对病原菌进行鉴定,并利用Mega5软件对链格孢属的22个种进行系统发育树分析,进一步明确其分类地位。结果表明:该病致病菌ITS序列与GenBank中登录的Alternaria alternata、A.tenuissima、A.metachromatica相似性均为100%,利用DNAMAN软件对核苷酸一致性进行比较,发现样品菌株与A.alternata的一致性最高,结合形态学方法鉴定该病致病菌为链格孢A.alternata(GenBank登录号为:KJ682317)。回接鉴定后分离得到的菌株,菌饼刺伤接种的病叶与无伤接种的病叶均发病,但刺伤叶片病斑扩展快。

The pathogens of tree peony black spot remained unclear. The aim of this research was to clarify its taxonomic status by identifying the pathogen of tree peony black spot. In this study,the pathogen was identified based on morphology and molecular identification,the ITS phylogenetic trees was generated with the soft of Mega 5. The result suggested that the pathogen of tree peony black spot was Alternaria alternate(Genbank Accession No. KJ682317). The homology between the sample strain and A. alternate was up to 100 percent. The wound leaves and the intact ones were both infected by the pathogen. However,the expansion rate of the disease spot on the wound leaves was faster than the intact ones.