云南葡萄产区葡萄炭疽病病原鉴定及致病力分析

为了明确引起云南葡萄产区炭疽病的病原种类,利用形态鉴定和特异性引物分子检测相结合的方法对从云南省主要葡萄产区采集的60株炭疽病菌菌株进行了鉴定。葡萄炭疽病菌菌株的菌落形态和生长速率与对照菌株尖孢炭疽菌Colletotrichum acutatum差异不明显,但其分生孢子大小显著小于尖孢炭疽菌,附着胞深褐色,球形或不规则形。胶孢炭疽菌Colletotrichum gloeosporioides特异性引物CgInt/ITS4从供试葡萄炭疽病菌菌株基因组DNA中扩增出1条约500 bp的特异性条带,而尖孢炭疽菌特异性引物CaInt2/ITS4对葡萄炭疽病菌无扩增条带。研究表明,引起云南葡萄主产区炭疽病的病原为胶孢炭疽菌;供试胶孢炭疽菌对红提葡萄均有致病力,但菌株致病力差异较大,对番茄和草莓存在交叉侵染的能力,且对多菌灵的敏感性较尖孢炭疽菌高。

Identification of the pathogen causing grape anthracnose in Yunnan and its pathogenicity

A total of 60 Colletotrichum spp. isolates from anthracnose rot lesions of grapes collected from main grape-growing areas in Yunnan were identified using morphological method and species-specific primers in order to make sure of the pathogen causing grape anthracnose. There was no significant difference in colony morphotype and colony growth rate between strains from grapes and Colletotrichum acutatum J. H. Simmonds ex J. H. Simmonds strains, but the conidial size of grape anthracnose strains significantly smaller than that of C.acutatum strains. The conidial appressoria of Colletotrichum spp. isolates from grapes were brown, spherical and irregularly lobed. The genome of 60 isolates had been amplified to produce DNA fragments of 500 bp with species-specific primers CgInt/ITS4 for Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., while no fragments for primers CaInt2/ITS4 of C.acutatum. These results indicated that the pathogen of grape anthracnose in Yunnan was C.gloeosporioides. Additionally, significant differences were found in pathogenicity of the strains which were all pathogenic to Vitis vinifera cv. Red Globe. These isolates could also infect fruits of tomato and strawberry, suggesting that the potential for cross-infection existed among grape, tomato and strawberry. All isolates were more sensitive to carbendazim than that of C.acutatum strains.