Poster # 303

Simran Goyal ¹, Bhavit Chhabra ¹, Vijay Tiwari ¹, Bikram S. Gill ², Yanhong Dong ³, and Nidhi Rawat ¹
1. Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742
2. Department of Plant Pathology, Kansas State University, Manhattan, Kansas 66506
3. Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota 55108
Corresponding Author: Nidhi Rawat, nidhirwt@umd.edu

Goyal, Simran

sgoyal13@umd.edu

Fusarium head blight (FHB), caused by Fusarium graminearum, severely impacts wheat yield and grain quality worldwide. Manipulation of plant susceptibility factors, genes that facilitate pathogen infection, offers a novel strategy for enhancing FHB resistance. In this study, we refined the genomic location and validated the role of a major susceptibility factor on the short arm of chromosome 7A (Sf-Fhb-7AS) in the wheat cultivar Chinese Spring. Nullisomic-tetrasomic analysis of group 7 chromosomes confirmed the dosage effect of the gene, with tetrasomic 7A lines showing enhanced susceptibility relative to wild-type Chinese Spring. The conserved nature of this susceptibility factor was further supported by its presence across diverse wheat backgrounds. Using recombination-independent approaches, including seed and pollen irradiation-derived deletion panels, we delimited Sf-Fhb-7AS to a shorter interval on chromosome 7AS. Screening of over 300 irradiated Chinese Spring and Jagger lines revealed that deletions spanning this interval imparted 50–60% Type II FHB resistance without any effect on plant development. Transcriptomic analysis of the 48 high-confidence genes in this region revealed differential expression of multiple candidate genes upon F. graminearum infection. Our findings establish the potential of Sf-Fhb-7AS as a promising target for novel FHB resistance breeding strategies in wheat. Keywords: Fusarium graminearum; Fusarium Head Blight; Susceptibility Factor; Sf-Fhb-7AS

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