A real-time PCR assay for quantification of the Y136F allele in the CYP51 gene associated with Blumeria graminis f.sp. tritici resistance to sterol demethylase inhibitors

A single point mutation resulting in the replacement of TAT by TTT at codon 136 (Y136F) in the 14α-demethylase (CYP51) gene was detected from triadimefon-resistant Blumeria graminis f.sp. tritici (Bgt) isolates collected from different locations in China. Based on this point mutation, a pair of PCR primers Bgt136-F + Bgt136-R was developed for the specific detection of Y136F mutation. Additionally, based on the sequence of introns of the CYP51 gene from Bgt, another pair of PCR primers Bgt-F + Bgt-R was developed for specific detection of Bgt. Using these two primer pairs, a real-time PCR method was developed for rapid quantification of DMI-resistant Bgt populations from field samples.