Reaction of South African spring wheat cultivars to head blight caused by Fusarium graminearum

Abstract

Head blight caused by Fusarium graminearum (Schwabe) is an important wheat (Triticum aestivum L.) disease in the centrepivot irrigation areas of South Africa. Fifteen cultivars, Gamtoos, Inia, Kariega, Marico, Nantes, Palmiet, SST 38, SST 55, SST 57, SST 65, SST 66, SST 822, SST 825, SST 876, T4 and two breeding lines, Potch 92 and Potch 93 were evaluated in the greenhouse for their ability to resist the development of head blight (Type II resistance). Following inoculation of a single spikelet (growth stage 61) with a mixture of two F. graminearum isolates, disease progress in each cultivar was assessed over a 20 day period. Fourteen days after inoculation less than 29% of the spikelets of Gamtoos, T4 and Potch 93 were infected whilst Inia, Palmiet, SST 65, SST 825 and SST 876 had infection levels equal or above 58%. Kariega, Marico, Nantes, SST 38, SST 55, SST 57, SST 66, SST 822 and Potch 92 indicated an intermediate head blight response with disease severity differing between 36 and 48%, 14 days after inoculation. These results will be followed by evaluations for resistance to penetration (Type I) and ability to suppress toxin production (Type III).