Resistance to Fusarium head Blight and Deoxynivalenol Accumulation in Chinese Barley

Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe is a devastating barley disease world-wide, causing significant yield losses and contaminating cereal products with mycotoxins. Barley grain contaminated with deoxynivalenol (DON) is associated with gushing and may be rejected by the malting and brewing industry. Genetically inherited resistance is the most effective option for the control of the disease. A total of 266 barley cultivars and breeding lines originating from China were evaluated for FHB resistance and concentration of DON in grain. Plants were inoculated with isolates of F. graminearum under field conditions by injecting conidia into a single spikelet of each spike. FHB symptoms were evaluated by visual inspection, and DON content was analysed by HPLC. Significant differences in FHB ratings and DON levels were observed among cultivars. Visual symptoms of FHB varied from 4.88 to 71.75% of infected spikelets 21 days after inoculation and from 7.86 to 113.33 area under the disease progress curve units (AUDPC). Twenty-seven lines were more resistant to FHB than the control resistant cultivar Zhedar 2 and with fewer than 12% infected spikelets. Twenty-one of the above lines originated from the area in the mid to low valley of Yangtze River, where FHB epidemics are frequent. DON levels ranged from 0.05 to 24.39 mg/kg among the tested barley lines. Correlation coefficients were significant between FHB symptom ratings and DON levels. However, there was no significant correlation between symptom rating and plant height and no significant correlation between symptom rating and heading date.