Development of wheat genotypes possessing a combination of leaf rust resistance genes Lr19 and Lr24

Abstract

Endopeptidase allele Ep-D1c and DNA marker-assisted selection have been used for the incorporation of Lr19 + Lr24 leaf rust resistance genes combination into adapted commercial winter wheat cultivars. The first step was the transfer of the gene Lr19 from the donor cultivar Agrus into acceptor cultivars Simona and Lívia. The progenies possessing the null allele Ep-D1c linked to the gene Lr19 have been screened for their resistance to leaf rust by isolate 4332 SaBa. The plants homozygous properties at the Ep-D1c locus and resistant against leaf rust were used for crossing with NIL Thatcher/Lr24 – a donor of the gene Lr24. Plants possessing both Lr genes were selected from F₂ population by STS and isozyme markers linked to the Lr genes. Progenies of 18 F₂ plants have been selected by STS marker and tested for resistance against leaf rust. Results obtained with isozyme and STS markers corresponded with resistance testing. Altogether 6 progenies of F₃ generation possessing a resistance gene combination of Lr19 + Lr24 in a homozygous condition were developed.