Identification of a Major QTL-Controlling Resistance to the Subtropical Race 4 of f. sp. in ssp. .

Vascular wilt caused by the ascomycete fungal pathogen f. sp. () is a major constraint of banana production around the world. The virulent race, namely Tropical Race 4, can infect all Cavendish-type banana plants and is now widespread across the globe, causing devastating losses to global banana production. In this study, we characterized Subtropical Race 4 (STR4) resistance in a wild banana relative which, through estimated genome size and ancestry analysis, was confirmed to be ssp. . Using a self-derived F population segregating for STR4 resistance, quantitative trait loci sequencing (QTL-seq) was performed on bulks consisting of resistant and susceptible individuals. Changes in SNP index between the bulks revealed a major QTL located on the distal end of the long arm of chromosome 3. Multiple resistance genes are present in this region. Identification of chromosome regions conferring resistance to can facilitate marker assisted selection in breeding programs and paves the way towards identifying genes underpinning resistance.