Broad-spectrum resistance loci for three quantitatively inherited diseases in two winter wheat populations

Thomas Miedaner,Lorenz Hartl,Beat Keller,Sophie Paillard,Thorsten Schnurbusch,Viktor Korzun,Josef Holzapfel,Erhard Ebmeyer,H Friedrich Utz,Peter Risser

doi:10.1007/s11032-011-9586-6

Abstract

Septoria tritici blotch (STB), caused by S. tritici, Stagonospora glume blotch (SGB), caused by S. nodorum, and Fusarium head blight (FHB), caused by F. graminearum and F. culmorum, are the most important diseases of wheat (Triticum aestivum L.) in temperate growing areas. The main goals of this study were to detect (1) new quantitative trait loci (QTL) for STB resistance in two adapted European biparental populations (Arina/Forno, History/Rubens) and (2) QTL regions for broad-spectrum resistance (BSR) to the above-mentioned diseases during the adult-plant stage in the field. The three resistances were phenotyped across 4–7 field environments and phenotypic data revealed significant (P < 0.01) genotypic differentiation in all cases. Entry-mean heritabilities (h²) ranged from 0.73 to 0.93. For STB resistance, correlations between disease ratings and heading date were significant (P < 0.01), but moderate (r = −0.23 to −0.30) in both populations. Correlations between STB and plant height were higher in Arina/Forno (r = −0.45) and History/Rubens (r = −0.55), the latter population segregating at the Rht-D1 locus. During the initial QTL analysis, 5 QTL were detected for STB resistance in each of the populations, amounting to an explained genotypic variance of 45–63%, thus, showing the same ranges as FHB and SGB resistances in Arina/Forno and FHB resistance in History/Rubens. In total, 7 BSR QTL were found in the meta-analysis with the raw data, including the QTL on chromosome 4D at the Rht-D1 locus. A BSR QTL for all three diseases was not found but several BSR QTL for combinations with two diseases were detected. Combining the BSR QTL detected in the present breeding material by applying marker-assisted selection seems a promising approach.

Highlights

Wheat (T. aestivum L.) is one of the most important food crops worldwide, covering more land area than any other crop (FAOSTAT 2010)
Arina is quantitatively resistant to Septoria tritici blotch (STB), Fusarium head blight (FHB), and Stagonospora glume blotch (SGB), History to FHB and STB; Forno and Rubens are the susceptible parents with the latter including the dwarfing allele Rht-D1b
Entry-mean heritability was higher for the former population

Summary

Introduction

Wheat (T. aestivum L.) is one of the most important food crops worldwide, covering more land area than any other crop (FAOSTAT 2010). In Germany, arable land comprises about 12 million hectares including 3.2 million hectares of wheat. In comparison to other wheat-growing regions worldwide with an average yield of 1–3 t/hectare, Germany is one of the highest yielding areas with an average yield of 7–8 t/hectare (FAOSTAT 2010), with winter wheat being predominant. Several fungal diseases restrict maximum grain yield, among which Septoria tritici blotch (STB), caused by S. tritici (teleomorph M. graminicola), Stagonospora glume blotch (SGB), caused by S. nodorum (teleomorph P. nodorum), and Fusarium head blight (FHB), caused by Mol Breeding. F. graminearum (teleomorph G. zeae) and F. culmorum, are the most important fungal pathogens. FHB affects grain quality and leads to mycotoxin contamination. Cultivation of resistant varieties is the most environmentally friendly and cost-effective strategy for controlling these diseases

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Conclusion