1. High-density genetic mapping of a major QTL for resistance to multiple races of loose smut in a tetraploid wheat cross
- Author
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Julio Isidro-Sánchez, Curtis J. Pozniak, Asheesh K. Singh, R. M. DePauw, Heather L. Campbell, George Fedak, Sachin Kumar, Andrew G. Sharpe, Fran R. Clarke, Daryl J. Somers, Richard D. Cuthbert, Brad Meyer, Amidou N’Daye, Yuefeng Ruan, and Ron Knox
- Subjects
0106 biological sciences ,0301 basic medicine ,Loose smut ,lcsh:Medicine ,01 natural sciences ,lcsh:Science ,Triticum ,education.field_of_study ,Multidisciplinary ,biology ,food and beverages ,Eukaryota ,Chromosome Mapping ,Plants ,Wheat ,Microsatellite ,Research Article ,Genotyping ,Population ,Quantitative Trait Loci ,Plant disease resistance ,Quantitative trait locus ,Research and Analysis Methods ,Polymorphism, Single Nucleotide ,Molecular Genetics ,Polyploidy ,03 medical and health sciences ,Genetics ,Ustilago ,Ustilago tritici ,Grasses ,education ,Molecular Biology Techniques ,Molecular Biology ,Alleles ,Crosses, Genetic ,lcsh:R ,Gene Mapping ,Organisms ,Biology and Life Sciences ,biology.organism_classification ,Tetraploidy ,030104 developmental biology ,Agronomy ,Genetic marker ,Genetic Loci ,Doubled haploidy ,lcsh:Q ,Departures from Diploidy ,010606 plant biology & botany - Abstract
Loose smut, caused by Ustilago tritici (Pers.) Rostr., is a systemic disease of tetraploid durum wheat (Triticum turgidum L.). Loose smut can be economically controlled by growing resistant varieties, making it important to find and deploy new sources of resistance. Blackbird, a variety of T. turgidum L. subsp. carthlicum (Nevski) A. Love & D. Love, carries a high level of resistance to loose smut. Blackbird was crossed with the loose smut susceptible durum cultivar Strongfield to produce a doubled haploid (DH) mapping population. The parents and progenies were inoculated with U. tritici races T26, T32 and T33 individually and as a mixture at Swift Current, Canada in 2011 and 2012 and loose smut incidence (LSI) was assessed. Genotyping of the DH population and parents using an Infinium iSelect 90K single nucleotide polymorphism (SNP) array identified 12,952 polymorphic SNPs. The SNPs and 426 SSRs (previously genotyped in the same population) were mapped to 16 linkage groups spanning 3008.4 cM at an average inter-marker space of 0.2 cM in a high-density genetic map. Composite interval mapping analysis revealed three significant quantitative trait loci (QTL) for loose smut resistance on chromosomes 3A, 6B and 7A. The loose smut resistance QTL on 6B (QUt.spa-6B.2) and 7A (QUt.spa-7A.2) were derived from Blackbird. Strongfield contributed the minor QTL on 3A (QUt.spa-3A.2). The resistance on 6B was a stable major QTL effective against all individual races and the mixture of the three races; it explained up to 74% of the phenotypic variation. This study is the first attempt in durum wheat to identify and map loose smut resistance QTL using a high-density genetic map. The QTL QUt.spa-6B.2 would be an effective source for breeding resistance to multiple races of the loose smut pathogen because it provides near-complete broad resistance to the predominant virulence on the Canadian prairies.
- Published
- 2018