一种大蒜叶枯病新病原菌鉴定与药剂敏感性测定.

[Objective] The present paper aimed to explore the new pathogens causing garlic leaf blight and its sensitivity to fungicides, so as to provide scientific basis for the control of garlic leaf blight in production. [Method] The pathogen strains were obtained by conventional tissue isolation method. The strains were identified by pathogen morphological characteristics, pathogenicity determination and molecular biological technology. The biological characteristics of hyphae and susceptibility of the strain to fungicides were studied by mycelial growth rate method. [Result] According to the morphological and molecular biological characteristics of the strain, it was determined that a new pathogen causing garlic leaf blight was Chaetomium globosum. The best medium for the pathogen was corn medium, the best carbon source was D-fructose, the best nitrogen source was yeast extract powder, the suitable pH was 7.0, and 72% metalaxyl-mancozeb WP 2400 mg/L, 70% thiophanate-methyl WP 700 mg/L, 500 g/L tebuconazole-carbendazim SC 330 mg/L, 50% procymidone WP 830 mg/L, 45% prochloraz ME 300 mg/L and 60% pyraclostrobine-metiram WG 600 mg/L exhibited good inhibition effects on the pathogen. The EC50 of pyraclostrobinemetiram, difenoconazole-azoxystrobin, tiezene, metalaxyl-mancozeb and propineb were 0.0053, 0. 1792, 0.5162, 3.0539 and 4.2175 mg/ L, respectively. [Conclusion] C. globosum is a new pathogenic fungus causing garlic leaf blight, which can infect garlic leaves and cause leaf withering and yellowing, the disease was named as C. globusum leaf blight of garlic; Six kinds of fungicides with good inhibition to the mycelium are selected, pyraclostrobine-metiram, difenoconazole-azoxystrobin, tiezene are highly toxic to the pathogenic fungi, so can be used as effective agents to control the new leaf blight in production. [ABSTRACT FROM AUTHOR]