The Acquisition of Useful Disease Resistance Genes for Hard Red Winter Wheat Improvement

Abstract

This study was part of a larger pre-breeding effort to develop new parental materials carrying useful genes for disease resistance and adaptation. Firstly, marker-assisted backcrosses were employed to transfer and pyramid combinations of disease resistance genes (Fhb1, Lr34, Lr53, Sr2, Sr26, Sr39, and Sr50) and a reduced height gene (Rht-B1b) into the variety Norstar. Following the third backcross to Norstar, the various backcrossed progenies were inter-mated to derive progenies having combinations of Fhb1 and Rht-B1b plus the targeted leaf and/or stem rust resistance genes. Five NILs (each carrying Fhb1 and Rht-B1b) that differ for the leaf and stem rust resistance genes they possess were recovered. Secondly, a mapping study using the 9K Illumina Infinium iSelect wheat assay was conducted with a F2 mapping population developed by crossing Lr59-25 (0306/2*CSph1b//CSN1AT1B/3/Thatcher) and Superb. Lr59 was mapped 0.5cM distally from the co-segregating SNPs IWA1495, IWA6704, IWA2098 and IWA969 on wheat chromosome arm 6BS.