Assessing non-specificity of resistance in wheat to head blight caused by inoculation with European strains of Fusarium culmorum, F. graminearum and F. nivale using a multiplicative model for interaction

Abstract

To determine whether resistance to Fusarium head blight in winter wheat is horizontal and non-species specific, 25 genotypes from five European countries were tested at six locations across Europe in the years 1990, 1991, and 1992. The five genotypes from each country had to cover the range from resistant to susceptible. The locations involved were Wageningen, Vienna, Rennes, Hohenheim, Oberer Lindenhof, and Szeged. In total, 17 local strains of Fusarium culmorum, F. graminearum, and F. nivale were used for experimental inoculation. One strain, F. culmorum IPO 39-01, was used at all locations. Best linear unbiased predictions (BLUPs) for the head blight ratings of the genotypes were formed within each particular location for each combination of year and strain. The BLUPs over all locations were collected in a genotype-by environment table in which the genotypic dimension consisted of the 25 genotypes, while the environmental dimension was made up of 59 year-by-strain-by-location combinations. A multiplicative model was fitted to the genotype by-environment interaction in this table. The inverses of the variances of the genotype-by-environment BLUPs were used as weights. Interactions between genotypes and environments were written as sums of products between genotypic scores and environmental scores. After correction for year-by-location influence very little variation in environmental scores could be ascribed to differences between strains. This provided the basis for the conclusion that the resistance to Fusarium head blight in winter wheat was of the horizontal and non-species specific type. There was no indication for any geographical pattern in virulence genes. Any reasonable aggressive strain, a F. culmorum strain for the cool climates and a F. graminearum strain for the warmer humid areas, should be satisfactory for screening purposes.

Relationship between cultivar height and severity of Fusarium ear blight in wheat

“…Most workers are of the opinion that resistance is not species dependent and is controlled by nonspecific genes (Van Eeuwijk et al, 1995). Studies of the inheritance of FEB resistance in wheat have suggested that it is a quantitatively controlled character effected by a number of genes.…”

Fusarium ratings in Ontario winter wheat performance trial (OWWPT) using an index that combines Fusarium head blight symptoms and deoxynivalenol levels

“…This could be explained by level of resistance in material tested, aggressiveness of isolates used for inoculation, inoculation techniques and different environments. Resistance to FHB is horizontal and non-species specific (Van Eeuwijk et al 1995). To obtain good differentiation among tested cultivars, we have been using a mixture of four highly DONproducing F. graminearum isolates and spray inoculation method with daily mist irrigation to promote fungal development.…”

Deoxynivalenol resistance as a component of FHB resistance

“…Resistance is horizontal, i.e. it is not considered Fusarium species-specific (Van Eeuwijk et al 1995), but it is quantitative, polygenic and can be affected by the environment (Bai and Shaner 2004). Several components or 'types' of FHB resistance have been described, but types I and II are most widely accepted.…”