Analysis of Fusarium Head Blight Resistance in a Canadian Winter Wheat Doubled Haploid Population.

Fusarium head blight (FHB) is one of the most devastating diseases of wheat, causing significant reduction in grain yield and end-use quality. The Canadian winter wheat varieties, ‘AC Morley’ and ‘Emerson’ have shown notable FHB resistance in the field, but the genetic nature of FHB resistance in these varieties is not well understood. FHB resistance is a quantitative trait that is controlled by multiple genes, and it is affected by genotype (G), environment (E), and their interaction. Studies have reported a relationship between morphological traits such as plant height and anther extrusion/retention, and FHB resistance. To study the genetic basis of resistance in ‘AC Morley’ and ‘Emerson’, a F1-derived doubled haploid (DH) population was developed. The population was tested for FHB resistance both in the greenhouse using point inoculation and in inoculated field nurseries followed by mist irrigation along with checks. Indoor screening for FHB Type II resistance was performed in the summer 2017 at the Ottawa Research and Development Centre, and field evaluation for FHB visual rating index ((FHB incidence x FHB severity) /100) was conducted in 2017/18 cropping year at two locations, Ottawa and Elora, ON, Canada. In addition to FHB resistance-related data, morphological characteristics, such as plant height and anther extrusion, were also used in the analysis. Transgressive segregation for type II resistance and field resistance was detected in the ‘AC Morley’ and ‘Emerson’ DH population, and the lowest average disease index score was 5% from type II testing and less than 1% from field evaluation.