Characterization of the Genetic Architecture for Fusarium Head Blight Resistance in Durum Wheat: The Complex Association of Resistance, Flowering Time, and Height Genes.

Yuefeng Ruan,Maria Antonia Henriquez,Brittany Polley,Heather L Campbell,Hermann Buerstmayr,Wentao Zhang,Andrew Burt,Kerry Boyle,Pierre R Fobert,Santosh Kumar,Ron M Depauw,Samia Berraies,Richard D Cuthbert,Ron E Knox,Raja Ragupathy

doi:10.3389/fpls.2020.592064

Abstract

Durum wheat is an economically important crop for Canadian farmers. Fusarium head blight (FHB) is one of the most destructive diseases that threatens durum production in Canada. FHB reduces yield and end-use quality and most commonly contaminates the grain with the fungal mycotoxin deoxynivalenol, also known as DON. Serious outbreaks of FHB can occur in durum wheat in Canada, and combining genetic resistance with fungicide application is a cost effective approach to control this disease. However, there is limited variation for genetic resistance to FHB in elite Canadian durum cultivars. To explore and identify useful genetic FHB resistance variation for the improvement of Canadian durum wheat, we assembled an association mapping (AM) panel of diverse durum germplasms and performed genome wide association analysis (GWAS). Thirty-one quantitative trait loci (QTL) across all 14 chromosomes were significantly associated with FHB resistance. On 3BS, a stable QTL with a larger effect for resistance was located close to the centromere of 3BS. Three haplotypes of Fhb1 QTL were identified, with an emmer wheat haplotype contributing to disease susceptibility. The large number of QTL identified here can provide a rich resource to improve FHB resistance in commercially grown durum wheat. Among the 31 QTL most were associated with plant height and/or flower time. QTL 1A.1, 1A.2, 3B.2, 5A.1, 6A.1, 7A.3 were associated with FHB resistance and not associated or only weakly associated with flowering time nor plant height. These QTL have features that would make them good targets for FHB resistance breeding.

Highlights

Fusarium head blight (FHB), known as scab and mainly caused by Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schwein.) Petch] (Bai and Shaner, 1994; McMullen et al, 1997), is a devastating fungal disease of smallgrain cereals including durum and common wheat and barley, resulting in severe yield and quality losses (Gilbert and Tekauz, 2000; McMullen et al, 2012)
All of the inbreeding lines derived from introgression of FHB resistance genes from Sumai 3 into European durum wheat cultivars were contained in subpopulation 2, as were the majority of T. dicoccoides introgression lines
With genome wide association analysis we identified 31 quantitative trait loci (QTL) for FHB resistance

Summary

Introduction

Fusarium head blight (FHB), known as scab and mainly caused by Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schwein.) Petch] (Bai and Shaner, 1994; McMullen et al, 1997), is a devastating fungal disease of smallgrain cereals including durum and common wheat and barley, resulting in severe yield and quality losses (Gilbert and Tekauz, 2000; McMullen et al, 2012). As food for humans and feed for animals, FHB infected grain creates health risks due to contamination with mycotoxins. This is a particular concern for durum wheat, as its main purpose is for human consumption (Bai and Shaner, 2004; Zhao et al, 2018; Haile et al, 2019; He et al, 2019). Since the early 1990s, FHB has become the major disease threatening durum production in Canada and has caused major economic losses for producers (Gilbert and Tekauz, 2000). It is a priority to develop durum wheat with desirable FHB resistance to protect it from losses

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