Open AccessA PCR‐based method to characterise and identify benzimidazole resistance in Helminthosporium solani 1
Author(s) -
MKay Gareth J,
Cooke Louise R
Publication year - 1997
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1997.tb10454.x
Subject(s) - biology , benzimidazole , gene , point mutation , fungicide , restriction enzyme , polymerase chain reaction , microbiology and biotechnology , rhizoctonia solani , genetics , mutation , botany , chemistry , organic chemistry
Control of Helminthosporium solani , the cause of silver scurf in potato tubers, has been impaired by selection of benzimidazole‐resistant strains as a result of repeated use of the fungicide thiabendazole. Identification of thiabendazole‐resistant strains of H. solani by conventional techniques takes several weeks. Primers designed from conserved regions of the fungal β‐tubulin gene were used to PCR amplify and sequence a portion of the gene. A point mutation was detected at codon 198 in thiabendazole‐resistant isolates causing a change in the amino acid sequence from glutamic acid to alanine or glutamine. Species‐specific PCR primers designed to amplify this region were used in conjunction with a restriction endonuclease to cause cleavage in sensitive isolates only and thus provide a rapid diagnostic test to differentiate field isolates.