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

• Published in: Guangdong nong ye ke xue Vol. 49; no. 1; pp. 87 - 93
• Main Authors: Yiping CUI, Yifang LI, Aitian PENG, Xiaobing SONG, Jinfeng LING, Feng HUANG, Xia CHEN
• Format: Journal Article
• Language: English
• Published: Guangdong Academy of Agricultural Sciences 01.01.2022
• Subjects: anthracnose; chrysanthemum; colletotrichum gloeosporioides; difenoconazole; field control
• ISSN: 1004-874X
• DOI: 10.16768/j.issn.1004-874X.2022.01.010

【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 1 500 times Difenoconazole and 1 500 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. 1 500 times Difenoconazole and 1 500 times Prochloraz can be used as recommended agents for field control.