Identification and Validation of a Microsatellite Marker for the Seedling Resistance Gene Lr24 in Bread Wheat

Abstract

The background of PBW343, the high yielding and widely cultivated bread wheat cultivar of the Indian subcontinent was utilized. We were able to identify specific microsatellite markers for Agropyron elongatum derived seedling resistance gene Lr24. The two markers, Xgwm114 and Xbarc71 were mapped at a distance of 2.4 cM from Lr24 locus. They can be unquestionably utilized as landmarks for identification of these genes. An F 2 population segregating for Lr24 and Lr48 in the background of PBW343 was utilized for this study. Though phenotypic reaction of the plants of the progeny populations to leaf rust infection was recorded in the seedling stage, it was difficult to perform the same in the adult plant stage as more than one gene effective against the same pathogen act mutually thus making it difficult to interpret and differentiate the resistance reaction of each of the two different genes. This is a major aspect of concern for many plant breeders in various gene pyramiding experiments since differentiating virulences of pathogens for each and every gene utilized cannot be available within all geographic locations. Molecular markers play a significant role in all such cases.