Accelerating resistance breeding in wheat by integrating marker-assisted selection and doubled haploid technology

Abstract

Genetic resistance is the simplest and most cost-effective way to guard against disease in plants. The pyramiding of resistance genes is a useful practice in bringing about durable resistance. This study aimed to develop a series of doubled haploid (DH) wheat lines containing combinations of wild species genes for rust resistance. Rust resistance genes Lr19, Sr31/Lr26/Yr9/Pm8 and Lr54/Yr37 were combined by means of crossing. Breeders’ lines that have complex resistance, including Lr24/Sr24, Lr34/Yr18, Sr36 and Sr2, were used. Marker-assisted selection was used to type populations for selection of favourable combinations. A DH method was used to develop an inbred population from the selected lines, after which the lines were characterised for the resistance genes. The study produced 27 lines with diverse genetic profiles. Seven lines contained four translocations (Lr24/Sr24, Lr34/Yr18, Sr2 and Lr19 or Sr31) each, 11 lines contained three genes each, six lines contained two genes each and three lines contained a single translocation (Lr24/Sr24). The value of the integration of marker-assisted selection and DH in combination with conventional breeding practices in breeding programmes has already been illustrated internationally for increasing the rate of cultivar development and this is reaffirmed by this study.