Effects of barley yellow dwarf disease on wheat grain quality traits

Abstract

AbstractBackground and objectivesBarley yellow dwarf (BYD) is an important aphid‐vectored viral disease of wheat. Grain samples were obtained from a previously reported integrated pest management (IPM) field plot experiment that was designed to test the effects of planting dates, cultivars, and insecticide treatments on BYD incidence and wheat yields over 4 years in Kansas, USA. In the current study, the effect of BYD on grain quality traits was estimated by comparing untreated plots that had varying levels of BYD to healthy control plots that received repeated insecticide treatments. Additional grain samples were compared from Tagged Tillers of visually healthy and symptomatic plants.FindingsFor IPM Plots, interactions between insecticide treatments and cultivars were not significant (α = 0.05). The effect of BYD on protein content (PC), starch content (SC), average kernel weight (AKW), and yield was a relative percent gain or loss of +3.7%, −1.0%, −6.4%, and −12.6%, respectively, averaged over all experimental factors and years. Linear critical point models were developed to estimate the percent gain or loss relative to healthy controls as a function of BYD incidence. For each percentage of BYD incidence, BYD increased PC by 0.284%, decreased SC by 0.063%, decreased AKW by 0.314%, and decreased grain yield by 0.664%. Similar magnitudes of effects of BYD were estimated from Tagged Tiller samples. There were distinct, non‐overlapping distributions for healthy versus symptomatic Tagged Tillers for PC and SC for four of six cultivars. However, two cultivars had overlapping distributions for healthy versus symptomatic samples, suggesting they had resistance or physiological tolerance to BYD.ConclusionsNatural infection with BYD significantly increased PC and decreased SC, AKW, and yields of wheat. The increase in PC was probably due to the concentrating effect of decreased SC and AKW. Critical point models were developed to predict the impact of varying levels of BYD on these parameters. Near‐infrared spectroscopy (NIRS) measurement of PC and SC of diseased versus healthy samples has potential to identify wheat lines with resistance or tolerance to BYD.Significance and noveltyThis is the first report of the effect of BYD on wheat starch content and confirms the effect on average kernel weight and protein content. This is the first report of simple models to predict grain quality changes as a function of BYD incidence. Near‐infrared spectroscopy (NIRS) measurement of grain PC and SC from plants with BYD may offer wheat breeding programs a rapid and objective selection method for improved resistance or physiological tolerance to BYD.