High density mapping and haplotype analysis of the major stem-solidness locus SSt1 in durum and common wheat

Kirby T Nilsen; Amidou N'Diaye; P R MacLachlan; John M Clarke; Yuefeng Ruan; Richard D Cuthbert; Ron E Knox; Krystalee Wiebe; Aron T Cory; Sean Walkowiak; Brian L Beres; Robert J Graf; Fran R Clarke; Andrew G Sharpe; Assaf Distelfeld; Curtis J Pozniak

doi:10.1371/journal.pone.0175285

High density mapping and haplotype analysis of the major stem-solidness locus SSt1 in durum and common wheat

PLoS One. 2017 Apr 11;12(4):e0175285. doi: 10.1371/journal.pone.0175285. eCollection 2017.

Authors

Kirby T Nilsen¹, Amidou N'Diaye¹, P R MacLachlan¹, John M Clarke¹, Yuefeng Ruan^{1

2}, Richard D Cuthbert², Ron E Knox², Krystalee Wiebe¹, Aron T Cory¹, Sean Walkowiak¹, Brian L Beres³, Robert J Graf³, Fran R Clarke², Andrew G Sharpe⁴, Assaf Distelfeld⁵, Curtis J Pozniak¹

Affiliations

¹ Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, Canada.
² Swift Current Research and Development Centre, Agriculture and Agri-Food Canada, Swift Current, SK, Canada.
³ Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada.
⁴ Global Institute of Food Security, University of Saskatchewan, 110 Gymnasium Place Saskatoon, SK, Canada.
⁵ Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, Israel.

Abstract

Breeding for solid-stemmed durum (Triticum turgidum L. var durum) and common wheat (Triticum aestivum L.) cultivars is one strategy to minimize yield losses caused by the wheat stem sawfly (Cephus cinctus Norton). Major stem-solidness QTL have been localized to the long arm of chromosome 3B in both wheat species, but it is unclear if these QTL span a common genetic interval. In this study, we have improved the resolution of the QTL on chromosome 3B in a durum (Kofa/W9262-260D3) and common wheat (Lillian/Vesper) mapping population. Coincident QTL (LOD = 94-127, R2 = 78-92%) were localized near the telomere of chromosome 3BL in both mapping populations, which we designate SSt1. We further examined the SSt1 interval by using available consensus maps for durum and common wheat and compared genetic to physical intervals by anchoring markers to the current version of the wild emmer wheat (WEW) reference sequence. These results suggest that the SSt1 interval spans a physical distance of 1.6 Mb in WEW (positions 833.4-835.0 Mb). In addition, minor QTL were identified on chromosomes 2A, 2D, 4A, and 5A that were found to synergistically enhance expression of SSt1 to increase stem-solidness. These results suggest that developing new wheat cultivars with improved stem-solidness is possible by combining SSt1 with favorable alleles at minor loci within both wheat species.

MeSH terms

Genes, Plant*
Haplotypes*
Quantitative Trait Loci
Species Specificity
Triticum / classification
Triticum / genetics*

Grants and funding

This research was carried out under the Canadian Triticum Applied Genomics (CTAG2) project. We are grateful for the funding provided by Genome Canada, and project support provided by Genome Prairie. We also acknowledge financial support provided by the Saskatchewan Ministry of Agriculture, Western Grains Research Foundation, and the Saskatchewan and Alberta Wheat Development Commissions. The financial support provided through the AgriFlex Program of Agriculture and Agri-Food Canada is also acknowledged. K. Nilsen acknowledges funding provided by the Robert P. Knowles scholarship administered by the University of Saskatchewan.