Mapping of novel leaf rust and stem rust resistance genes in the Portuguese durum wheat landrace PI 192051

Authors: AOUN, MERIEM - North Dakota State University; Kolmer, James; Rouse, Matthew; ELIAS, ELIAS - North Dakota State University; BREILAND, MATTHEW - North Dakota State University; BULBULA, WORKU - Ethiopian Institute Of Agricultural Research; Chao, Shiaoman; ACEVEDO, MARICELIS - North Dakota State University

Submitted to: G3, Genes/Genomes/Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/13/2019
Publication Date: 8/8/2019
Citation: Aoun, M., Kolmer, J.A., Rouse, M.N., Elias, E.M., Breiland, M., Bulbula, W.D., Chao, S., Acevedo, M. 2019. Mapping of novel leaf rust and stem rust resistance genes in the Portuguese durum wheat landrace PI 192051. G3, Genes/Genomes/Genetics. 9(8):2535-2547. https://doi.org/10.1534/g3.119.400292.
DOI: https://doi.org/10.1534/g3.119.400292

Interpretive Summary: Leaf rust and stem rust are two major diseases of wheat. Genes in wheat provide resistance to leaf and stem rust, however not all genes provide effective resistance, since there are many races of both rusts that are virulent to many of the resistance genes in wheat. Information on the chromosome location of genes for rust resistance is needed in order to add new resistance genes to wheat cultivars. The objective of this study was to determine the chromosome location of leaf and stem rust resistance genes in a durum wheat from Portugal. A gene for stem rust resistance was determined to be on the short arm of chromosome 7A, and a gene for leaf rust resistance was determined to be on chromosome 4A. Three genes with small effect for stem rust resistance were also found on chromosomes 1A, 2B, and 4A. These genes for leaf and stem rust resistance can be used by durum wheat breeding projects to improve rust resistance.

Technical Abstract: Leaf rust caused by Puccinia triticina Erikss. (Pt) and stem rust caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn (Pgt) are serious constraints to production of durum wheat (Triticum turgidum L). The objective of this study was to identify leaf rust resistance (Lr) and stem rust resistance (Sr) genes/QTL in Portuguese durum landrace PI 192051. Four Pt-isolates, representing three virulence phenotypes (BBBQJ, BBBSJ & EEEEE) and six Pgt-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 (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 Sr gene designated as QSr.ace-7A on chromosome arm 7AS and Lr gene Lr.ace-4A in the pericentromeric region of chromosome 4A. In addition, three minor Sr QTL QSr.ace-1A, QSr.ace-2B and QSr.ace-4A were located on chromosomes 1AL, 2BL, and 4A, respectively. Lr.ace-4A could be co-located or tightly linked to QSr.ace-4A. Markers linked to the identified QTL are potential candidates for use in marker assisted selection. These findings enrich the genetic basis of rust resistance in both durum and common wheat.