Marker Assisted Selection of Fhb1 Gene for Scab Resistance (FHB) and Evaluation of FHB Resistance in Field in 4 Wheat F2 Populations Derived from H140-2

Abstract

Fusarium head blight (FHB), is a fungal disease threatening wheat production and food security. Fhb1, the most potent anti-FHB gene, is widely used in wheat breeding. However, few varieties are highly resistant to FHB. It is thus critical to develop FHB-resistant cultivars using the appropriate genes. In this study, we identified an FHB-resistant germplasm, H140-2 carrying Fhb1. Thereafter, to accelerate the development of the FHB-resistant cultivar, H140-2 was crossed with Chuannong 30, Chuannong 32, and Chuannong 42. The diagnostic marker, TaHRC-GSM, of Fhb1 was employed in the F₂ and F_2:3 populations obtained from the aforementioned three crosses to identify FHB-resistant germplasms. The results demonstrated that Fhb1 could reduce the percentage of Fusarium-damaged kernels (PFDK) and improve wheat FHB resistance. To screen FHB-resistant lines with greater yield potential, we also evaluated grain weight per spike (GWS) and overall FHB resistance in the F₂ and F_2:3 populations. Finally, we selected six FHB-resistant lines with the highest GWS values and Fhb1, especially L6 with a similar GWS and a lower PFDK value at 1.5% compared to CN32, which will play a key role in wheat breeding practice. These findings illustrated that the diagnostic marker, TaHRC-GSM, as well as the entire FHB resistance evaluation process can be used to successfully screen FHB-resistant wheat lines, laying the foundation for FHB resistance improvement.