Development of Winter Common Wheat Lines with the Stem Rust Resistance Gene Sr33

Abstract

Stem rust caused by the fungus Puccinia graminis Pers. is a dangerous disease of wheat that occurs in all regions of its cultivation. New highly virulent races causing severe yield losses have appeared in recent decades. Sr33 introgressed from Aegilops tauschii is one of the genes conferring resistance against most races of stem rust, including Ug99. To develop winter common wheat lines with the gene Sr33 and evaluate a possible effect of the gene on yield traits, the authors made a cross between the spring line DH31 carrying the Sr33 gene and the winter cultivar Myrkhad followed by marker-assisted selection of winter genotypes with Sr33 starting from F₃. To identify the Sr33 gene, PCR with the gene-specific marker Sr33A was used. Alleles at the storage protein loci of the parental forms were identified using acid polyacrylamide gel electrophoresis and SDS-electrophoresis as well as the molecular marker MAR for Glu-Blal. As a result of marker-assisted selection, winter F₅ lines with the Sr33 gene were developed from the cross DH31 × Myrkhad. The yield traits of F₅ spikes of families derived from single F₃ spikes with and without Sr33 were analyzed considering that the line DH31 has a specific allele at Gli-D1 from Ae. tauschii, dark glumes, and high molecular weight glutenin subunit alleles associated with high dough strength, in particular, Glu-Blal. Comparison of means of yield traits of spikes from families with Sr33 and without it did not reveal significant differences between these two groups. Thus, winter F₅ lines with the Sr33 gene from the cross DH31 × Myrkhad may be used in the breeding practice to develop cultivars with high bread-making qualities of flour and stem rust resistance.