小豆白粉病菌的鉴定与小豆品种抗白粉病评价

Identification of powdery mildew isolates from adzuki bean and resistance assessment of adzuki bean varieties in China

为明确小豆白粉病病原菌的种类以及小豆种质资源对白粉病的抗性,采用形态学和系统发育学方法对近年来在北京市发生的小豆白粉病病原菌种类进行鉴定,并采用室内苗期人工接种法评价小豆常见栽培品种(系)对白粉病的抗性。结果表明,从北京市采集的感白粉病小豆病样中培养获得病原菌BJ1,该菌能在小豆叶片和茎上产生明显的白色粉斑,分生孢子梗直立,不分枝,分生孢子单细胞,成链状着生于分生孢子梗上,呈椭圆形或卵圆形。通过rDNA-ITS序列系统发育分析,小豆白粉病菌BJ1被鉴定为白粉菌目白粉菌科的苍耳叉丝单囊壳Podosphaera xanthii。室内苗期人工接种条件下,19个供试小豆品种(系)接种小豆白粉病菌BJ1后均可发病,其中9个审定品种均表现为中度感病或高度感病,10个优良品系发病略轻。

In order to explore the causal agent of adzuki bean powdery mildew and evaluate adzuki bean varieties(lines)for resistance to powdery mildew,morphology and phylogenetic analyses were carried out to identify the pathogen species of adzuki bean powdery mildew isolates collected in Beijing in recent years,and indoor artificial inoculation at seedling stage were adopted for evaluating adzuki bean common varieties(lines)for resistance to powdery mildew.The results showed that isolate BJ1,derived from the adzuki bean samples collected from Beijing,could produce obvious white powdery mildew on leaves and stems of adzuki beans.The conidiophores were erected and unbranched.Conidia,produced in chains on conidiophores,were unicellular and ellipsoidal or ovoidal in shape.Subsequently,BJ1 was identified as Erysiphales,Erysiphaceae,Podosphaera xanthii based on phylogenetic analysis of rDNA-ITS sequences.Under the conditions of indoor artificial inoculation at seedling stage,all the 19 tested varieties(lines)of adzuki bean were susceptible to BJ1,with nine varieties moderately or highly susceptible,and ten lines slightly less susceptible.