Genetic basis of resistance against powdery mildew in the wheat cultivar Tabasco

European winter wheat cultivar Tabasco was reported to have resistance to powdery mildew disease caused by Blumeria graminis f. sp. tritici (Bgt) in China. In previous studies, Tabasco was reported to have the resistance gene designated as Pm48 on the short arm of chromosome 5D when a mapping population was phenotyped with pathogen isolate Bgt19 collected in China and was genotyped with simple sequence repeat (SSR) markers. In this study, single-nucleotide polymorphism (SNP) chips were used to rapidly determine the resistance gene by mapping a new F-2 population that was developed from Tabasco and a susceptible cultivar Ningmaizi119 and inoculated with pathogen isolate NCF-D-1-1 that was collected in the USA. The segregation of resistance in the population was found to link with Pm2 which was identified in Tabasco. Therefore, it was concluded that the previously reported Pm48 on chromosome arm 5DS in Tabasco should be the Pm2 gene on the same chromosome. The Pm2 was also found in European cultivars Mattis and Claire but not in any of the accessions from diploid wheat Aegilops tauschii or modern cultivars such as Gallagher, Smith's Gold, and OK Corral being used in the Great Plains in the USA. A KASP marker was developed to track the resistance allele Pm2 in wheat breeding.

Automated summary

European winter wheat cultivar Tabasco was found to be resistant to powdery mildew disease caused by Blumeria graminis f. sp. tritici (Bgt) in China. Through mapping a new F-2 population, it was discovered that the resistance in Tabasco is linked to the Pm2 gene. A KASP marker was developed to track the resistance allele Pm2 in wheat breeding.