Haplotype analysis of loci associated with Fusarium head blight resistance in a collection of Brazilian spring wheat: An Update.

G. HUMPHREYS, L. LANGILLE, X. WANG, C. MCCARTNEY, S. KHANIZADEH and H. VOLDENG. Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, ON, Canada, K1A 0C6; and (C.M.)Morden Research and Development Centre, Agriculture and Agri-Food Canada, 101 Route 100, Morden, MB, Canada, R6M 1Y5
Fusarium head blight (FHB) is the most important disease of wheat reducing grain yield, crop grade and end-use quality. FHB can be caused by various Fusarium spp., but F. graminearum is the most economically important in North America due in part to the production of mycotoxins such as deoxynivalenol (DON) during infection. Food and feed safety can be compromised because mycotoxin content can make the wheat grain unsuitable for food or feed. A collection of 79 wheat lines from various Brazilian breeding institutions were genotyped using DNA markers at four FHB quantitative trait loci (QTL). These QTL were previously reported on chromosomes 3BS, 5AS and 6BS in the cultivar Sumai 3, and 3A in the cultivar, Frontana. Visual Ratings Index (VRI) for reactions to FHB were evaluated in the Ottawa inoculated FHB nursery in 2016, and deoxynivalenol (DON) content was determined from 2016 harvested nursery samples. None of the Brazilian lines possessed the Sumai 3 haplotype for FHB resistance QTL on 3BS (Fhb1) or 6BS (Fhb2). While 63% of the lines amplified the Sumai 3 allele at gwm415 on 5AS, none amplified the Sumai 3 alleles for adjacent SSR markers. Nevertheless, 2016 FHB ratings ranged from 13.3 to 95.0, and DON levels ranged from 1.8 to 30.5 ppm. Some lines in the Brazilian collection appear to possess FHB resistance that is not associated with the three major Sumai 3 FHB QTL which would make these lines useful sources of Fusarium head blight resistance for wheat breeding and research.