Morphological characterization of fungi associated with the ascochyta blight complex and pathogenic variability of Mycosphaerella pinodes on field pea crops in central Alberta

作     者：Hafiz Ahmed Kan-Fa Chang Sheau-Fang Hwang Heting Fu Qixing Zhou Stephen Strelkov Robert Conner Bruce Gossen 

作者机构：Crop Diversification Centre North Alberta Agriculture and Rural Development Department of Agricultural Food and Nutritional Science University of Alberta Agriculture and Agri-Food Canada (AAFC) Morden MB R6M 1Y5 Canada Agriculture and Agri-Food Canada (AAFC) Saskatoon SK S7N 0X2 Canada 

出 版 物：《The Crop Journal》 (作物学报（英文版）)

年 卷 期：2015年第3卷第1期

页      面：10-18页

核心收录：

学科分类：09[农学] 0904[农学-植物保护] 090401[农学-植物病理学] 090402[农学-农业昆虫与害虫防治] 

基　　金：funded in part by the ACAAF (Advancing Canadian Agriculture and Agri-Food) Program of the Agriculture and Food Council and the Alberta Pulse Growers Commission 

主　　题：Ascochyta Phoma Resistance Virulence Pathotype 

摘      要：Field pea crops in central Alberta were surveyed for ascochyta blight from 2011 to 2012 and fungal isolates were recovered from foliar lesions on selected plants. Cultural and microscopic characterization of the 275 isolates obtained revealed that 272 were of Mycosphaerella pinodes and three were of Phoma medicaginis var. pinodella. Ascochyta pisi or Phoma koolunga were not identified. Isolates of M. pinodes were divided into two groups,GI and GII, based on visual assessment of culture characteristics. GI isolates(light to dark, mostly gray colony color; pycnidial distribution radial and concentric; conidia10.5–14.5 × 4.2–6.2 μm most with one septum, occasionally two, constricted at the septum;spore mass light buff to flesh color) were predominant(83%), while GII isolates(dark to gray colony color; pycnidia abundant; conidia 8–16 × 3.5–6.2 μm most with 1 septum, constricted at the septum; spore mass light buff to flesh color) were less common(17%). The cultures of GII isolates were similar to recent descriptions of A. pisi, but they differed in spore color. In a host differential study, 13 pathotypes of M. pinodes were identified from 110 single-spore isolates. Pathotype I was predominant(88 isolates) and virulent on all nine differential genotypes. The other pathotypes(pathotypes II–XIII) were rare(1–6 isolates of each).Comparison of the present results with earlier studies suggests that pathotype I has been prevalent for many years, and that its aggressiveness on the host differentials has increased over time. Emphasis should be placed on breeding for resistance to M. pinodes in field pea cultivars intended for deployment in central Alberta.