Fusarium Head Blight (FHB) is a devastating disease of small cereal grains that affects all growing regions throughout the world. Apart from yield and economic losses associated with the disease, toxicity of the deposited mycotoxins in the infected grains impact human and animal health. Control of this disease involves spraying of costly, biologically, and ecologically hazardous chemicals, and identifying and deploying genetic resistance.

Several quantitative trait loci (QTLs) associated with Fusarium head blight (FHB) resistance have been identified, of which seven of them are well-characterized (Fhb1...Fhb7). Chinese spring wheat, Sumai3 is the source for three major QTLs for FHB viz., Fhb1, Fhb2 and Fhb5. Interestingly, this FHB-resistant cultivar was developed by crossing two moderately susceptible parents, “Funo” and “Taiwanxiaomai”, which suggests that the resistance was inherited by appropriate combinations for favorable haplotype blocks.

This study aims to decipher those specific combinations of haplotype blocks in Sumai3 and trace the movement of resistance-associated gene regions across various derivatives. The whole genome sequencing of the Sumai3 along with resequencing of thirty lines harboring Sumai3 background was carried out and the haplotype blocks were characterized.

Coupled with RNASeq information, we aim to explore expression patterns of resistance-associated genes and their conjugation to these defined haplotype blocks. Preliminary analysis has shown that the entire 3B chromosome in Sumai3 harboring Fhb1 was inherited by a single parent, Taiwanxiaomai. But contradictorily, Taiwanxiaomai possessing this chromosome is moderately susceptible, suggesting Funo-derived genes might be necessary for strong resistance.

Furthermore, Fhb1 introgression into adapted germplasm does not always result in lines with the expected level of resistance. Hence this study aimed for identification of those co-inherited gene regions. This comprehensive analysis of the genomes of these important sources of FHB-resistance will expand our knowledge on what is required to combat disease and help with the development of molecular markers to track important linkage blocks in breeding germplasm.