广东怀集青心菊炭疽病病原菌的分子鉴定

Molecular Identification of Anthracnose Pathogen of Chrysanthemum in Huaiji,Guangdong Province

【目的】明确引起广东省怀集县青心菊炭疽病的病原菌及田间最佳防治药剂,为青心菊炭疽病的防治作出指导意见。【方法】对采集的菊花炭疽病病样(花朵和叶片)进行常规的组织分离培养;对分离所得真菌菌株Cg1-1、Cg1-2和Cg1-3进行致病性测定并在显微镜下观察其孢子大小和菌丝形态,同时选取核糖体转录间隔区(ITS)、大亚基(LSU)、几丁质合成酶(CHS1)和肌动蛋白(ACT)基因对菌株Cg1-1、Cg1-2和Cg1-3进行多基因分子鉴定;利用Mega7.0.18以最大自然法建立菊花炭疽病菌Cg1-1、Cg1-2和Cg1-3的进化系统发育树。在田间选用苯醚甲环唑、咪鲜胺、30%噻呋·嘧菌酯(良尊)、430 g/L戊唑醇悬浮剂(翠箭)及40%噻呋·肟菌酯(润秀)对菊花炭疽病进行药剂防治。【结果】通过对病原菌形态等生物学特性分析和多基因分子生物学鉴定,引起广东怀集青心菊炭疽病的病原菌为胶孢炭疽菌Colletotrichum gloeosporioides。田间药效试验结果表明,1500倍液苯醚甲环唑和1500倍液咪鲜胺对田间青心菊炭疽病的防治效果最佳,同时注意在雨后和菊花生长旺季进行有效的施药。【结论】引起广东怀集青心菊炭疽病的病原为C.gloeosporioides,1500倍液苯醚甲环唑和1500倍液咪鲜胺可作为田间防治推荐药剂。

【Objective】The study was conducted to identify the pathogen causing anthracnose of Chrysanthemum in Huaiji of Guangdong province,and to screen the best control agents in the field in order to provide guidance for the prevention and control of Chrysanthemum anthracnose.【Method】Diseased samples(flowers and leaves)of Chrysanthemum with anthracnose symptoms collected from Huaiji of Guangdong were isolated and cultured conventionally.Fungal strains Cg1-1,Cg1-2 and Cg1-3 were isolated and obtained.The pathogenicity of above strains were determined by the Koch’s postulates with in vivo and in vitro inoculation of conidial suspension on plants of Chrysanthemum.The spores sizes and myelium morphologies of Cg1-1,Cg1-2 and Cg1-3 were observed under microscope and polygene molecular identification was conducted with ribosomal transcription spacer(ITS),large subunit(LSU)、Chitin synthase(CHS1)and actin(ACT).Finally,Mega7.0.18 was used to construct the phylogenetic tree of Cg1-1,Cg1-2 and Cg1-3 with the maximum natural method.Difenoconazole,Prochloraz,30%Thifluzamide(Liangzun),430 g/L Tebuconazole(Cuijian)and 40%Thifluzamide·Trifloxystrobin(Runxiu)were used to control Chrysanthemum anthracnose in the field.【Result】Through the analysis of the biological characteristics of pathogen and the identification of polygene molecular biology,the anthracnose pathogen on Chrysanthemum in Huaiji of Guangdong Province is Colletotrichum gloeosporioides.The field efficacy test results showed that 1500 times Difenoconazole and 1500 times Prochloraz has the best control effects on the disease in the field.Attention should be paid to effective application of agents after the rain and in the rapid growing season of Chrysanthemum.【Conclusion】C.gloeosporioides is the causative agent of anthracnose on Chrysanthemum in Huaiji of Guangdong.1500 times Difenoconazole and 1500 times Prochloraz can be used as recommended agents for field control.