High-density genetic mapping of a major QTL for resistance to multiple races of loose smut in a tetraploid wheat cross

Sachin Kumar; Ron E Knox; Asheesh K Singh; Ron M DePauw; Heather L Campbell; Julio Isidro-Sanchez; Fran R Clarke; Curtis J Pozniak; Amidou N'Daye; Brad Meyer; Andrew Sharpe; Yuefeng Ruan; Richard D Cuthbert; Daryl Somers; George Fedak

doi:10.1371/journal.pone.0192261

High-density genetic mapping of a major QTL for resistance to multiple races of loose smut in a tetraploid wheat cross

PLoS One. 2018 Feb 27;13(2):e0192261. doi: 10.1371/journal.pone.0192261. eCollection 2018.

Authors

Affiliations

¹ Department of Genetics and Plant Breeding, Chaudhary Charan Singh University, Meerut, Uttar Pradesh, India.
² Swift Current Research and Development Centre, Agriculture and Agri-Food Canada, Swift Current, Saskatchewan, Canada.
³ 1501 Agronomy Hall, Iowa State University, Ames, Iowa, United States of America.
⁴ Advancing Wheat Technology, Swift Current, Saskatchewan, Canada.
⁵ School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland.
⁶ Department of Plant Sciences and Crop Development Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁷ Global Institute of Food Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁸ Vineland Research and Innovation Centre, Vineland Station, Ontario, Canada.
⁹ Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada.

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Crosses, Genetic*
Polymorphism, Single Nucleotide
Polyploidy*
Quantitative Trait Loci*
Triticum / genetics*
Triticum / microbiology
Ustilago / pathogenicity*

Grants and funding

This work was supported by the Agriculture and Agri-Food Canada (to REK); Western Grains Research Foundation (to REK); Genome Canada (to REK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.