Genome-wide association mapping of grain yield in a diverse collection of spring wheat (Triticum aestivum L.) evaluated in southern Australia

PLoS One. 2019 Feb 4;14(2):e0211730. doi: 10.1371/journal.pone.0211730. eCollection 2019.

Abstract

Wheat landraces, wild relatives and other 'exotic' accessions are important sources of new favorable alleles. The use of those exotic alleles is facilitated by having access to information on the association of specific genomic regions with desirable traits. Here, we conducted a genome-wide association study (GWAS) using a wheat panel that includes landraces, synthetic hexaploids and other exotic wheat accessions to identify loci that contribute to increases in grain yield in southern Australia. The 568 accessions were grown in the field during the 2014 and 2015 seasons and measured for plant height, maturity, spike length, spike number, grain yield, plant biomass, HI and TGW. We used the 90K SNP array and two GWAS approaches (GAPIT and QTCAT) to identify loci associated with the different traits. We identified 17 loci with GAPIT and 25 with QTCAT. Ten of these loci were associated with known genes that are routinely employed in marker assisted selection such as Ppd-D1 for maturity and Rht-D1 for plant height and seven of those were detected with both methods. We identified one locus for yield per se in 2014 on chromosome 6B with QTCAT and three in 2015, on chromosomes 4B and 5A with GAPIT and 6B with QTCAT. The 6B loci corresponded to the same region in both years. The favorable haplotypes for yield at the 5A and 6B loci are widespread in Australian accessions with 112 out of 153 carrying the favorable haplotype at the 5A locus and 136 out of 146 carrying the favorable haplotype at the 6A locus, while the favorable haplotype at 4B is only present in 65 out of 149 Australian accessions. The low number of yield QTL in our study corroborate with other GWAS for yield in wheat, where most of the identified loci have very small effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Australia
  • Chromosome Mapping
  • Edible Grain / genetics*
  • Genetic Association Studies / methods
  • Genome-Wide Association Study / methods
  • Genotype
  • Haplotypes / genetics
  • Linkage Disequilibrium / genetics
  • Phenotype
  • Polymorphism, Single Nucleotide / genetics
  • Quantitative Trait Loci / genetics
  • Seasons
  • Seeds / genetics
  • South Australia
  • Triticum / genetics*

Grants and funding

The authors thank DuPont Pioneer and the Australian Research Council Industrial Transformation Research Hub for Genetic Diversity and Molecular Breeding for Wheat in a Hot and Dry Climate (project number IH130200027) for financial support. Corteva AgriscienceTM provided support in form of salaries for authors (PW) and genotyping of the accessions used in this study but did not have any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.