Combining Wheatgrass-derived Resistance to Yellow Dwarf Virus and Fusarium Head Blight in Common Wheat.

The objective of this research is to combine Bdv3 that conditions resistance to yellow dwarf virus (YDV) and Qfhs.pur-7EL that conditions resistance to fusarium head blight (FHB). Bdv3 was introgressed into wheat (Triticum aestivum L.) chromosome 7D from intermediate wheatgrass (Thinopyrum intermedium) and is located subterminal on the 7E segment that was translocated into 7DS.7DL-7EL.  Qfhs.pur-7EL was introgressed from tall wheatgrass (Thinopyrum ponticum) and was mapped to the distal region of chromosome 7DS.7DL-7EL in wheat.  Bdv3 is located more proximal to the centromere of chromosome 7DS.7DL-7EL than Qfhs.pur-7EL.  The wheat line, 216-67, was developed in which the introgressed 7E segment replaced the distal approximately 1/3 of 7DL.  The wheat line, 275-4, was developed in which the introgressed 7E segment containing Qfhs.pur-7EL replaced the distal approximately 1/3 of 7DL.  The wheat lines 216-67 and 275-4 were crossed resulting in plants heterozygous for the introgressed 7E segments.  A large population of F₂ individuals will be grown in order to identify plants in which a recombination occurred, resulting in the combination of Bdv3 and Qfhs.pur-7EL on the same chromosome.  Plants resistant to both YD and FHB will be identified by genotyping with respective associated SSR markers and verified by testing putative recombinant plants to YDV and FHB.