Identification of QTLs linked to partial resistance to foot and root rot caused by Fusarium avenaceum and Fusarium oxysporum in faba bean (Vicia faba)

Foot and root rot, caused by a complex of soil-borne fungal and oomycete pathogens, including several Fusarium spp., can cause serious yield losses in faba bean. Current control strategies rely largely on agronomic practices and limited varietal resistance. Identifying novel sources of genetic resistance is of great potential value for breeding elite varieties with improved foot rot resistance. A partially resistant Vicia faba accession ig124213 (NV490) was crossed with a moderately susceptible ig124301 (NV512) and a mapping population comprising 198 F3 families was developed. This was screened for resistance to a mixture of seven UK field isolates of Fusarium avenaceum and Fusarium oxysporum under glasshouse conditions. Several F3 families with moderate to high levels of resistance to both Fusarium species were identified, and a high-density linkage map of the V. faba genome including 6755 SNP-markers in seven linkage groups (LG) was generated using the Vfaba_v2 Axiom SNP array. Quantitative trait loci associated with improved resistance to Fusarium foot and root rot were identified, including one major QTL on LG4, corresponding to the chromosome 4 of V. faba. Key messageThe first QTL associated with partial resistance to Fusarium foot and root rot has been identified using a biparental mapping population of Vicia faba.