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Analysis of β ‐tubulin Gene Fragments from Benzimidazole‐sensitive and ‐tolerant Cercospora beticola
Author(s) -
Davidson R. M.,
Hanson L. E.,
Franc G. D.,
Panella L.
Publication year - 2006
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/j.1439-0434.2006.01080.x
Subject(s) - cercospora , biology , sugar beet , benzimidazole , fungicide , fungus , leaf spot , mutant , mutation , gene , botany , microbiology and biotechnology , genetics , horticulture , chemistry , organic chemistry
Cercospora leaf spot of sugar beet, caused by the fungus Cercospora beticola , is a major foliar pathogen on sugar beet. Fungicide sprays have been used extensively to manage Cercospora leaf spot, including the benzimidazole fungicides. Resistance to benzimidazoles has been observed in isolates of C. beticola . The precise genetics of this resistance is not known in this fungus. We tested benzimidazole‐tolerant and ‐sensitive isolates and found a single mutation in the β ‐tubulin gene of benzimidazole‐tolerant isolates that corresponds to a mutation known to confer benzimidazole tolerance in other ascomycetes. This mutation is predicted to cause a change from glutamic acid to alanine in the protein product. Isolates containing this mutation further show an increased sensitivity to an N ‐phenylcarbamate, as would be predicted based on the mutant phenotype found in other filamentous fungi. Only a single mutation was found in isolates from different regions of the United States, isolated in different growing seasons.