广东省柑橘炭疽病病原菌的形态与分子鉴定

Morphological and molecular identification of citrus anthracnose pathogen from Guangdong Province

炭疽病是柑橘的主要真菌性病害之一。2007年春,广东省德庆县名优柑橘品种贡柑炭疽病暴发流行。为了明确该县及广东省其他地区柑橘炭疽病菌的种类,为防治提供依据,对采集自广东省6个地区柑橘属10个栽培品种上的炭疽病样本进行病原菌分离,共获得柑橘炭疽病菌单孢菌株75株,对其中10株代表性的菌株进行了种类鉴定。通过培养性状和形态学特征观测、核糖体DNA(rDNA)内转录间区(ITS)序列分析、ITS区特异性引物PCR检测和系统发育关系比较等方面的研究,结果表明:10个柑橘炭疽病菌菌株均为盘长孢状刺盘孢Colletotrichum gloeosporioides,未发现国际上其他国家报道的严重危害柑橘花器和幼果部位的柑橘花后落果病病原菌——尖刺盘孢C.acutatum。

Anthracnose is one of the major fungal diseases of citrus.A large-scale outbreak of anthracnose in Citrus sinensis cv.gonggan,the high-yield and high-quality cultivar of citrus,occurred in Deqing county,Guangdong Province in the spring of 2007.For identifying the pathogen so as to control this disease effectively,samples of citrus anthracnose were collected from ten cultivars of the genus Citrus in six areas of Guangdong Province,and a total of 75 single-conidial isolates were obtained,among them 10 representative single-conidial isolates were identified at the species level.Based on cultural and morphological characteristics,ribosomal DNA（rDNA） internal transcribed spacer（ITS） sequence analysis,ITS-specific primers PCR detection and phylogenetic relationships with other species of Colletotrichum,the 10 isolates were identified as Colletotrichum gloeosporioides,whereas C.acutatum,the causal agent of postbloom fruit drop of citrus seriously occurring in some countries in the world,was not yet found in this research.