引起我国甜樱桃叶斑病的间座壳菌种类鉴定

Identification of Diaporthe species associated with cherry leaf spot in China

为明确引起我国甜樱桃叶斑病的病原菌种类,于2019年在北京市、四川省、山东省和辽宁省对与已报道的其他叶斑病症状明显不同的一种甜樱桃叶斑病进行调查并采集病叶,通过组织分离法进行病原菌分离纯化,结合形态学特征和多基因(ITS、EF1-α、TUB2和CAL)系统发育分析对病原菌的种类进行鉴定,并采用离体叶片接种法进行致病性测定。结果显示,新发现的这种甜樱桃叶斑病通常从叶边缘产生圆形或不规则灰褐色病斑,病斑周围具黄色晕圈,有时形成穿孔。从病样中共分离纯化得到10株单孢系菌株,结合其菌落形态、分生孢子形态和大小等,以及多基因系统发育分析结果,最终将10株菌株鉴定为甜樱间座壳Diaporthe eres(5株)和大豆间座壳D.sojae(5株),致病性测定结果显示甜樱间座壳和大豆间座壳对甜樱桃叶片均具有致病性,完成柯赫氏法则验证。

In order to determine the pathogens causing cherry leaf spot disease in China,a new type of cherry leaf spot,samples were collected from Beijing,Sichuan,Shandong and Liaoning in 2019.Disease associated fungi were isolated from diseased tissues,and identified through morphological characteristics and multi-gene(ITS,EF1-α,TUB2 and CAL)phylogenetic analysis.Pathogenicity assays were also conducted on detached cherry leaves.The results showed that the disease caused brownish-grey lesions surrounded by yellowish halo rings developed on leaf margins.Ten purified fungal isolates were obtained and then identified as Diaporthe eres(five isolates)and D.sojae(five isolates),respectively,based on morphological characteristics(colonial morphology,spore morphology and size)and multi-gene phylogenetic analysis.Pathogenicity test confirmed that both D.eres and D.sojae were pathogenic to cherry leaves and the Koch’s postulate was fulfilled.This is the first report of D.sojae causing cherry leaf spot in China.