Sensitivity of Botrytis cinerea From Nectarine/Cherry in China to Six Fungicides and Characterization of Resistant Isolates

Abstract

Botrytis cinerea, the causal agent of gray mold, can result in considerable preharvest and postharvest losses in many economically valuable plant species. Fungicides were widely used to minimize such losses, but fungicide resistances were detected frequently. In the present study, we collected 164 isolates from nectarine and cherry in China and tested the sensitivity to six fungicides. Among the tested isolates, 71 (43.3%) were resistant to azoxystrobin, 14 (8.5%) to cyprodinil, 7 (4.3%) to boscalid, 4 (2.4%) to carbendazim, 1 (0.6%) to iprodione, and no isolates were found to be resistant to fludioxonil. The EC50 value and resistance factor (RF) of resistant isolates were determined. Fitness analysis showed that there were no significant differences between sensitive and resistant isolates for osmotic stress and pathogenicity, while more conidia production was observed for some resistant isolates. Control efficacy of fungicides showed that the resistant isolates could not be controlled efficiently by using corresponding fungicides. The point mutation G143A was detected in the Cyt b gene of the isolates resistant to azoxystrobin, while the point mutation H272R of SdhB gene was confirmed in boscalid-resistant isolates, and mutations E198V/A of TUB2 gene and mutation I365S of BcOs1 occurred in carbendazim-resistant and iprodione-resistant isolates, respectively. These results indicate that the occurrence of fungicide resistance greatly threatens the management of gray mold on stone fruits nectarine and cherry.

Two Point Mutations on CYP51 Combined With Induced Expression of the Target Gene Appeared to Mediate Pyrisoxazole Resistance in Botrytis cinerea

“…Control of gray mold is based on integrated management strategies, including cultivar resistance, physical factors, and inoculum reduction. Nevertheless, chemical control remains the main approach for the management of B. cinerea diseases ( Leroux, 2007 ; Hahn, 2014 ; Fan et al, 2017 ; Yin et al, 2018 ). Several site-specific fungicides with different modes of action are available for gray mold management, including methyl benzimidazole carbamates (MBCs), anilinopyrimidines (APs), dicarboximides (DCFs), quinone outside inhibitors (QoIs), succinate dehydrogenase inhibitors (SDHIs), and phenylpyrroles (PPs).…”

“…Unfortunately, according to the Fungicide Resistance Action Committee (FRAC) 1 , B. cinerea has been categorized as a high-risk pathogen due to the development of fungicide resistance. Over the last 30 years worldwide, the resistance of B. cinerea to these types of fungicides was frequently reported soon after their introduction for gray mold control ( Moyano et al, 2004 ; Myresiotis et al, 2007 ; Zhang et al, 2009 ; Fernández-Ortuño et al, 2012 ; Chen et al, 2016 ; Yin et al, 2018 ). Resistance of B. cinerea often compromises the efficacy of fungicide and results in disease control failure.…”

Sesquiterpenes and Cyclodepsipeptides from Marine-Derived Fungus Trichoderma longibrachiatum and Their Antagonistic Activities against Soil-Borne Pathogens

“…The novel norsesquiterpene 1 showed significant antifungal activities against two Colletotrichum species and two carbendazim-resistant strains of B. cinerea with MIC values ranging from 8 to 64 µg/mL. These results are better than those from the commonly used carbendazim, a benzimidazole fungicide which binds to the β-tubulin proteins and then inhibits cell division [36]. Therefore, although there are almost no reports concerning antifungal mechanisms of norsesquiterpenes, the novel 1 could show multiple-target potential.…”

Beneficial Microorganisms to Control the Gray Mold of Grapevine: From Screening to Mechanisms

“…Until lately, the use of chemical fungicides to protect plant was thought to be fairly safe. Nevertheless, more than ever before, chemical fungicides use faces multiple challenges namely the development of resistance to fungicides resulting in the decline or even failure of control effect [ 13 , 14 , 15 , 16 ], increased consumers desire of food free of pesticide residues [ 17 ], enhanced concern regarding environmental pollution, and stricter regulatory policies are being imposed on the use of synthetic chemical fungicides [ 17 , 18 ].…”