Genome-wide association analysis of Russian wheat aphid (Diuraphis noxia) resistance in Dn4 derived wheat lines evaluated in South Africa

PLoS One. 2020 Dec 28;15(12):e0244455. doi: 10.1371/journal.pone.0244455. eCollection 2020.

Abstract

Russian wheat aphid (RWA; Diuraphis noxia Kurdjumov) resistance on the 1D chromosome of wheat has been the subject of intensive research. Conversely, the deployment of the Dn4 derived RWA resistant varieties diminished in recent years due to the overcoming of the resistance it imparts in the United States of America. However, this resistance has not been deployed in South Africa despite reports that Dn4 containing genotypes exhibited varying levels of resistance against the South African RWA biotypes. It is possible that there may be certain genetic differences within breeding lines or cultivars that influence the expression of resistance. The aim of this study was to identify single nucleotide polymorphism (SNP) markers associated with resistance to South African RWA biotypes. A panel of thirty-two wheat lines were phenotyped for RWA resistance using four South African RWA biotypes and a total of 181 samples were genotyped using the Illumina 9K SNP wheat chip. A genome wide association study using 7598 polymorphic SNPs showed that the population was clustered into two distinct subpopulations. Twenty-seven marker trait associations (MTA) were identified with an average linkage disequilibrium of 0.38 at 10 Mbp. Four of these markers were highly significant and three correlated with previously reported quantitative trait loci linked to RWA resistance in wheat. Twenty putative genes were annotated using the IWGSC RefSeq, three of which are linked to plant defence responses. This study identified novel chromosomal regions that contribute to RWA resistance and contributes to unravelling the complex genetics that control RWA resistance in wheat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aphids*
  • Chromosomes, Plant / genetics
  • Disease Resistance / genetics*
  • Genes, Plant / genetics
  • Genetic Markers
  • Genome-Wide Association Study
  • Genotype
  • Plant Diseases / genetics
  • Plant Diseases / parasitology*
  • Sequence Analysis, DNA
  • South Africa
  • Triticum / genetics*
  • Triticum / parasitology

Substances

  • Genetic Markers

Grants and funding

Funding for the research undertaken in this manuscript were sourced from the following funders: 1. South African Winter Cereal Trust https://www.wintercerealtrust.co.za Grant WCT/W/2018/06 - Awarded to VT PhD bursary - Awarded to LK 2. National Research Foundation - Research and Technology Fund https://www.nrf.ac.za Grant RTF1505 2911 8466 - Awarded to VT 3. National Research Foundation - Professional Development Programme https://www.nrf.ac.za Block Grant PDP160318160924 - Awarded to VT via Jasper Rees PhD bursary - Awarded to LK 4. LongReach Plant Breeders Management Pty Ltd https://www.longreachpb.com.au Salary of SLS The funders [1-3] mentioned above had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funder (LongReach Plant Breeders Management Pty Ltd) provided support in the form of salaries for author SLS but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.