Abstract: Fusarium head blight (FHB) or scab disease, caused by Gibberrella zeae (Schw.) Petch, is a serious disease in many wheat (Triticum aestivum L.) growing regions worldwide. To study the inheritance of scab resistance against fungal penetration (type I resistance), an 198 lines “immortalized F₂”population was constructed by crossing between recombinant inbred lines chosen by random permutation of 132 RILs from the RIL population derived from the cross between scab-susceptible cultivar Nanda 2419 and scab-resistant cultivar Wangshuibai. The population were then evaluated for percentage of infected spikes (PIS) across two years and six chromosome regions were detected for their association with type I resistance through interval mapping, among which Qfhi.nau-4B and Qfhi.nau-5A with the resistance alleles originated from Wangshuibai and Qfhi.nau-2B with the resistance allele from Nanda 2419 were consistently detected. Qfhi.nau-4B and Qfhi.nau-5A had the largest effects among the detected QTLs and both showed mainly the additive allelic effects, the former also had partial dominance. In addition, four pairs of significant interaction loci were identified. These results further demonstrate that wheat scab resistance are under complex genetic control and also imply that early generation selection for type I resistance in scab resistance breeding is feasible with Wangshuibai as the parent.

Key words: Fusarium head blight, Wangshuibai, “Immortalized F₂” population, Type I resistance