新病害—山核桃果实黑斑病病原菌的鉴定

2007年以来,浙江临安、淳安、桐庐和安徽部分地区山核桃主产区出现了一种果实新病害——山核桃果实黑斑病,该病严重影响山核桃果实的产量和品质。本研究从采集的病果中分离得到了一种真菌,离体幼果接种的症状与田间相似。病原菌在PDA培养基上形成白色轮纹状菌落,分生孢子长梭形,直或弯曲,(22.6～29.9)μm×(6.1～9.0)μm,5个细胞,中间3个有色孢(上部2个为黑褐色、下部1个为淡橄榄色),孢子顶生2～3根附属丝、多为3根。根据该病原菌的培养和形态特征及其ITS序列,将其鉴定为小孢拟盘多毛孢(Pestalotiopsis microspora)。

Identification of the pathogen causing a new disease-nut black spot on Carya cathayensis

A new disease, nut black spot, of Carya cathayensis has occurred in Anhui Province and Lin’an, Chun’an and Tonglu city of Zhejiang Province since 2007, which severely decreased the production and quality of nuts. This study was carried out to isolate and identify the pathogen. A fungus was isolated from all of the diseased nuts which could cause similar symptoms as in fields by artificial inoculation of the detached young nuts. This pathogen formed zonate colonies of whitish mycelia on potato dextrose agar (PDA). The conidia were 5 celled, fusiform and (22.6-29.9)μm×(6.1-9.0)μm in size. The three median cells consisted of two dark brown upper cells and one olivaceous bottom cell. The apical cell carried 2-3, mostly 3, appendages. According to the characteristics and DNA sequencing of the internal transcribed spacer (ITS) region, this pathogen was identified as Pestalotiopsis microspora.