Transfer of Fusarium Head Blight Resistance to Hard Red Winter Wheat

Fusarium head blight (FHB; caused by Fusarium graminearum Schwabe) is a serious disease of hard red winter wheat (HRWW) in North Dakota. Current varieties are lacking in resistance. Many resistance quantitative trait loci (QTL) were discovered in spring wheat that can be employed in HRWW. The North Dakota State University breeding program aims to acquire and pyramid useful FHB resistance QTL into its breeding population. Therefore, hybrid populations derived from CM82036 (Fhb1 and Qfhs.ifa-5A), PI277012 (Qfhb.rwg-5A.1 and Qfhb.rwg-5A.2), Frontana (Qfhs.ifa-3A), and TA5660 (Fhb6) were tested for type II resistance to: derive new FHB resistant HRWW lines with pyramided QTL (Fhb1+) using molecular marker-assisted selection; evaluate the ability of the different QTL to complement Fhb1. A second project objective was to assess FHB resistance in Thinopyrum distichum (wheat wild relative), random Thinopyrum single chromosome additions to wheat and triticale, and a triticale-Th. distichum secondary hybrid population segregating for a small translocation from Th. distichum. Useful winter wheat lines carrying Fhb1 with 1-2 additional resistance QTL were developed; however, transfer of Qfhb.rwg-5A.2 was not completed as it was not in the spring wheat intermediate, RWG21. Loci Qfhs.ifa-5A and Qfhb.rwg-5A.1 are probably alleles of the same locus with similar additive effects relative to Fhb1 on the overall resistance. Addition of Qfhs.ifa-3A to Fhb1 plants resulted in no convincing improvement in type II resistance. Combining either Qfhs.ifa-5A or Fhb6 with Fhb1 improved type II resistance; however, pyramiding of three QTL did not give further symptom reduction. No associated, detrimental phenotypic and yield effects were detected in a greenhouse assessment of the alien-derived Fhb6 resistance. The pyramids will be used in crosses to initiate full integration of the new QTL in the breeding germplasm. A select group of pyramids will be evaluated in field trials to better assess the full resistance. Strong FHB resistance was found in triticale-Th. distichum addition lines and secondary hybrid population (W1423). However, the W1423 lineage showed a high incidence of aneuploidy ascribable to aberrant segregation of chromosome 7A and an unknown chromosome. It was not possible to select a translocation homozygote or to identify the translocation chromosome.USDA National Institute of Food and Agriculture, Hatch project number: 1011140; US Wheat and Barley Scab Initiative (allocation number FAR0026888