Evaluation for new sources of Fusarium head blight resistance in hexaploid and tetraploid wheat.

Fusarium head blight (FHB) is a devastating disease of bread (Triticum aestivum L.) and durum (Triticum durum L.) wheat, which can cause significant grain yield losses, reduce wheat quality, and result in the accumulation of harmful mycotoxins in the grain. The deployment of resistant cultivars is the most effective, economical and environmentally friendly means to control the disease. However, breeding for FHB resistance in Canadian wheat breeding programs has been challenging due to limited sources of resistance. The objective of this study was to identify new sources of FHB resistance for use in wheat improvement. We evaluated 107 genotypes of hexaploid wheat including common wheat as well as Triticum species: spelta, macha, spherococcum, compactum plus T. aestivum synthetics, and 106 accessions of tetraploid wheat, including Triticum durum and species turgidum, dicoccon, polonicum and carthlicum, in an artificially inoculated field FHB nursery in 2017 and 2018. Results indicated significant variation among entries for FHB reaction. FHB index, Fusarium damaged kernel (FDK) and deoxynivalenol (DON) content ranged from 1.5 to 78.6%, 2.4 to 61.7% and 1.6 to 139 ppm, respectively. Pearson correlation coefficients (P< 0.0001) were 0.63, 0.42 and 0.57 between DON and FDK, DON and FHB index, and FHB index and FDK, respectively. We identified 19 accessions with DON content as low as the resistant check ‘Sumai3’. This group consisted of 15 hexaploid genotypes including Triticum spelta accession ‘CN1849’ and four tetraploid wheat accessions, and are promising germplasm for improvement of FHB resistance in wheat breeding programs.