Breeding for resistance to head blight caused by Fusarium spp. in wheat

Fusarium diseases of cereals, particularly wheat, are a persistent threat to food and feed safety andsecurity. Apart from yield losses, the contamination of the crop with Fusarium mycotoxins is ofgreat concern. Among other measures, the deployment of Fusarium-resistant cultivars plays a keyrole in integrated Fusarium control and the reduction of mycotoxin contamination in feed andfood. In this review, genetic diversity for Fusarium resistance in wheat and its close relatives,evaluation methods for assessing quantitative resistance and tools for breeding Fusarium-resistantcultivars are presented and critically discussed.Keywords: Fusarium head blight, Fusarium crown rot, Resistance breeding, Genetic diversity, Phenotypicselection, Marker-assisted selection, Genomic selection.Purpose of This ReviewFungal diseases of crops are a continuing threat for foodand feed security, possibly since domestication of agri-cultural plants. Plant diseases may lead to devastatingepidemics on food crops, such as the potato late blightepidemic in Ireland in the 1840s71850s. Although suchdramatic occurrences are rare, also less extreme butregular incidence of crop plant diseases leads to yieldlosses and reduces food and feed quality.This review summarizes published reports and somenot-yet published experiences and personal opinions onbreeding for Fusarium head blight (FHB) resistance inwheat. For many of the discussed aspects earlier articlesare available each with specific emphases. Phytopatho-logical aspects have been reviewed by Parry et al. [1].Reviews on conventional breeding for FHB resistancehave been published [2–4]. Placinta et al. [5] documentedthe worldwide occurrence and significance of Fusariummycotoxins. The first review on molecular markers forFHB resistance in wheat by Kolb et al. [6] summarized theearly findings in this field and later Anderson et al. [7]listed some of the more stable FHB resistance quantitativetrait loci (QTL). Bai and Shaner [8] reviewed the man-agement and resistance to FHB in wheat and barleyincluding knowledge on the genetics of FHB resistancemainly from a North American perspective. A compre-hensive overview about genetics and breeding for FHBresistance was provided by Buerstmayr et al. [9], whosummarized the findings of 52 QTL mapping studies, nineresearch articles on marker-assisted selection and sevenon marker-assisted germplasm evaluation. Two indepen-dently published QTL meta-analyses on this topic areavailable [10, 11] as well as an overview of FHB resistanceQTL found in European winter wheat [12]. A review byGoswami and Kistler [13] covers the most importanthead blight causing pathogen Fusarium graminearum.In addition, books and book chapters on Fusarium areavailable to the attentive reader. The monograph editedby Leonard and Bushnell [14] reports in 18 book chaptersa range of aspects on Fusarium diseases of small graincereals, including a characterization of the pathogen, theassociated mycotoxins, resistance breeding and othercontrol measures as well as the social and economicimpact of the disease. Brown and Proctor [15] edited arecent book describing the molecular biology of Fusariumfungi. Buerstmayr et al. published a recent book chapterabout breeding for FHB resistance in wheat [16] andabout genomics of FHB resistance [17]. A book chapterby Becher et al. [18] covers different aspects of FHB