Marker-assisted selection for pre-harvest sprouting tolerance and leaf rust resistance in bread wheat

Abstract

The present study was undertaken for developing a pre-harvest sprouting (PHS) tolerant and leaf rust resistant wheat genotype using marker-assisted selection (MAS). A major quantitative trait locus (QTL) (QPhs.ccsu-3A.1) for PHS tolerance (PHST) identified by us earlier was introgressed into HD2329, which is an elite but PHS susceptible cultivar, and carried two Lr genes (Lr24 + Lr28) earlier introgressed by us using MAS. In each backcross generation, foreground selection for PHS QTL was exercised using flanking markers (gwm155 and wmc153), and background selection was performed using 61 simple sequence repeat loci spread over the whole genome. During backcrossing, the desirable alleles of Lr24 and Lr28, were also tracked using linked SCAR markers. Seven BC₃F₃ progenies having desirable PHST QTL and Lr genes, and showing up to 93.44% genetic similarity with the recipient parent were selected. These lines exhibited high level of PHST (PHS score 2-4) and resistance against leaf rust under artificial conditions. The study demonstrated successful application of MAS for targeted pyramiding of QTL/genes for more than one trait into an improved wheat cultivar.