Mapping of Novel Leaf Rust and Stem Rust Resistance Genes in the Portuguese Durum Wheat Landrace PI 192051.

Leaf rust caused by Erikss. () and stem rust caused by f. sp. i Erikss. & E. Henn () are serious constraints to production of durum wheat ( L). The objective of this study was to identify leaf rust resistance () and stem rust resistance () genes/QTL in Portuguese durum landrace PI 192051. Four -isolates, representing three virulence phenotypes (BBBQJ, BBBSJ & EEEEE) and six -races TTKSK, JRCQC, TKTTF, QFCFC, TPMKC and TMLKC were used to evaluate 180 recombinant inbred lines (RILs) derived from the cross Rusty (rust susceptible) × PI 192051-1 (rust resistant) at the seedling stage. The RILs were also phenotyped at the adult-plant stage in a stem rust nursery in Ethiopia in 2017. The RILs were genotyped using the Illumina iSelect 9K wheat SNP array. PI 192051-1 carries a previously unidentified major gene designated as on chromosome arm 7AS and gene in the pericentromeric region of chromosome 4A. In addition, three minor QTL , and were mapped in PI 192051-1 on chromosomes 1AL, 2BL, and 4A, respectively could be co-located or tightly linked to Markers linked to the identified QTL/genes can be used for marker assisted selection. These findings enrich the genetic basis of rust resistance in both durum and common wheat.