Fusarium head blight (FHB) disease of wheat caused by Fusarium spp. deteriorates both quantity and quality of the crop. Manipulation of susceptibility factors, the plant genes facilitating disease development, offers novel and alternative strategy for enhancing FHB resistance in plants. In this study, a major effect susceptibility gene for FHB was identified on the short arm of chromosome 7A (7AS). Nullisomic-tetrasomic lines for homoeologous group-7 of wheat revealed dosage effect of the gene, with tetrasomic 7A being more susceptible than control Chinese Spring wheat, qualifying it as a genuine susceptibility factor. The gene locus was found to be conserved in five chromosome 7A inter-varietal wheat substitution lines of diverse origin and a tetraploid Triticum dicoccoides genotype. The susceptibility factor was named as Sf-Fhb-7AS and mapped on chromosome 7AS to a 48.5-50.5 Mb peri-centromeric region between del7AS-3 and del7AS-8. Our results show that deletion of Sf-Fhb-7AS imparts 50-60% type-2 FHB resistance. Further work on mapping of Sf-Fhb-7AS is in progress. Identification and manipulation of Sf-Fhb-7AS will be useful for enhancing genetic resistance against FHB in wheat.
ACKNOWLEGEMENT AND DISCLAIMER:
This material is based upon work supported by the U.S. Department of Agriculture, under Agreement No. 59-0206-0-179, 59-0200-6-018, and 59-0206-4-0203 as cooperative projects with the U.S. Wheat & Barley Scab Initiative. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.