Identification of Stem Rust Resistance Quantitative Trait Loci in Durum Wheat Populations

Abstract

Stem rust (Puccinia graminis f. sp. tritici) negatively impacts durum wheat production worldwide. Resistance loci from four resistant landrace durum wheat lines were identified in biparental F¬5¬ recombinant inbred line (RIL) populations after crossing with the susceptible line ‘Rusty’. The populations were tested with foreign race of stem rust from Eastern Africa and Europe (JRCQC, TRTTF, TTRTF, and TTKSK) and local races from United States Upper Midwest (MCCF and RKQQ), followed by genotyping and linkage map construction to identify stem rust resistant quantitative trait loci (QTLs). At least one stem rust resistance QTL was identified in each population with a total of twelve QTLs identified overall. Seven of the identified QTL regions validated previously published stem rust resistance genes and the other five identified potentially novel stem rust resistance genes. Various resistance mechanisms were determined from QTL regions that provide stem rust resistance to the four durum wheat RIL populations.