Characterization of Postharvest Fungicide-Resistant Botrytis cinerea Isolates From Commercially Stored Apple Fruit

• DOI: 10.1094/phyto-07-16-0250-r
• Publication Date: 2016-11-14T19:18:59Z
• Authors: Wayne M. Jurick; Otilia Macarisin; Verneta L. Gaskins; Eunhee Park; Jiujiang Yu; Wojciech Janisiewicz; Kari A. Peter
• Keywords: Fludioxonil; Pyrimethanil

Botrytis cinerea causes gray mold and is an economically important postharvest pathogen of fruit, vegetables, ornamentals. Fludioxonil-sensitive B. isolates were collected in 2011 2013 from commercial storage Pennsylvania. Eight had values for effective concentrations inhibiting 50% mycelial growth 0.0004 to 0.0038 μg/ml fludioxonil dual resistant pyrimethanil thiabendazole. Resistance was generated vitro, following exposure a sublethal dose fludioxonil, seven eight dual-resistant isolates. Three vigorously growing with multiresistance fungicides further characterized found be osmosensitive retained resistance the absence selection pressure. A representative multiresistant strain caused decay on apple fruit treated fungicides, which confirmed vitro results. The R632I mutation Mrr1 gene, associated cinerea, not detected multipostharvest fungicide-resistant isolates, suggesting that fungus may using additional mechanisms mediate resistance. Results this study show first time thiabendazole can also rapidly develop pose control challenges packinghouse environment during long-term storage.