Sensitivity of Botrytis cinerea from vegetable greenhouses to boscalid |
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Authors: | C Q Zhang S K Yuan H Y Sun Z Q Qi M G Zhou G N Zhu |
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Institution: | Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029;;Center of Agrochemicals for Biological and Environmental Technology, Institute for the Control of Agrochemicals, Ministry of Agriculture, Beijing 100026;and;College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China |
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Abstract: | Between 2004 and 2006, 228 isolates of Botrytis cinerea from two regions in China were characterized for baseline sensitivity to boscalid, a new active ingredient that interferes with succinate ubiquinone reductase in the electron transport chain. The isolates showed similar sensitivity in different years and regions. Baseline sensitivities were distributed as unimodal curves with mean EC50 values of 1·07 (± 0·11) and 0·42 (± 0·05) mg L?1 for inhibition of mycelial growth and conidial germination, respectively. Laboratory studies were conducted to evaluate the risk of development of resistance to boscalid. Boscalid-resistant mutants were obtained by UV-treatment at lower frequencies and with smaller resistance factors than pyrimethanil-resistant mutants. All boscalid-resistant mutants were also significantly more sensitive to Qo inhibitors than their wild-type parents and showed reduced sporulation in vitro and pathogenicity on aubergine leaves. The results suggested that the risk of resistance developing for boscalid was lower than for pyrimethanil. However, as B. cinerea is a high-risk pathogen, appropriate precautions against resistance development should be taken. Synergism between the activity of boscalid and that of kresoxim-methyl was observed. |
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Keywords: | Botryotinia fuckeliana fungicide resistance grey mould kresoxim-methyl pyrimethanil |
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