Accounting for heading date gene effects allows detection of small-effect QTL associated with resistance to Septoria nodorum blotch in wheat

PLoS One. 2022 May 19;17(5):e0268546. doi: 10.1371/journal.pone.0268546. eCollection 2022.

Abstract

In humid and temperate areas, Septoria nodorum blotch (SNB) is a major fungal disease of common wheat (Triticum aestivum L.) in which grain yield is reduced when the pathogen, Parastagonospora nodorum, infects leaves and glumes during grain filling. Foliar SNB susceptibility may be associated with sensitivity to P. nodorum necrotrophic effectors (NEs). Both foliar and glume susceptibility are quantitative, and the underlying genetics are not understood in detail. We genetically mapped resistance quantitative trait loci (QTL) to leaf and glume blotch using a double haploid (DH) population derived from the cross between the moderately susceptible cultivar AGS2033 and the resistant breeding line GA03185-12LE29. The population was evaluated for SNB resistance in the field in four successive years (2018-2021). We identified major heading date (HD) and plant height (PH) variants on chromosomes 2A and 2D, co-located with SNB escape mechanisms. Five QTL with small effects associated with adult plant resistance to SNB leaf and glume blotch were detected on 1A, 1B, and 6B linkage groups. These QTL explained a relatively small proportion of the total phenotypic variation, ranging from 5.6 to 11.8%. The small-effect QTL detected in this study did not overlap with QTL associated with morphological and developmental traits, and thus are sources of resistance to SNB.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ascomycota
  • Disease Resistance / genetics
  • Phenotype
  • Plant Breeding
  • Plant Diseases / genetics
  • Plant Diseases / microbiology
  • Quantitative Trait Loci* / genetics
  • Triticum* / genetics
  • Triticum* / microbiology

Supplementary concepts

  • Parastagonospora nodorum

Associated data

  • figshare/10.6084/m9.figshare.19372457

Grants and funding

This project was supported by the Agriculture and Food Research Initiative Competitive Grants 2017-67007-25939 and 2022-68013-36439 (WheatCAP) from the USDA National Institute of Food and Agriculture. The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript.