Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2005
Publication Date: 12/11/2005
Citation: Garvin, D.F., Dill-Macky, R. 2005. Evaluation of wheat lines near-isogenic for diverse Fusarium head blight resistance QTLs [abstract]. National Fusarium Head Blight Forum Proceedings. p. 29. Interpretive Summary:
Technical Abstract: To enrich hard red spring wheat (HRSW) with novel FHB resistance QTLs, a program to introgress FHB resistance QTL from diverse wheat genotypes and wheat relatives into HRSW has been initiated. The project is employing marker-assisted backcrossing to create HRSW lines near-isogenic for different FHB resistance QTLs (QTL-NILs). The QTL-NILs are being developed in three HRSW backgrounds (Norm, Wheaton, Apogee). In 2005, FHB resistance evaluations were conducted on the first set of completed QTL-NILs. This included NIL series in both Norm and Apogee that have either a marker for a FHB resistance QTL on Freedom (a soft red winter wheat) chromosome 2A, or for individual QTLs from Sumai 3 (Qfhs.ndsu-3BS, Qfhs.ifa-5A) that will serve as checks. Greenhouse FHB evaluations involved point inoculations to assess the spread of disease symptoms in the spike (type II resistance). Disease spread in Norm was 10.0. In the best Norm-Qfhs.ndsu-3BS NIL, disease spread was 4.7, while disease spread was limited to just 4.2 in the best Norm-Freedom 2A NIL. In the Apogee QTL-NIL series, the best Qfhs.ndsu-3BS line exhibited a disease spread of 3.4, compared in contrast to the disease spread in Apogee (9.0). Disease spread in the best Apogee-Freedom 2A NIL was limited to 5.1 spikelets. A replicated FHB field evaluation of the first set of NILs was also conducted. In the Norm QTL-NIL series, the best Qfhs.ndsu-3BS and Freedom 2A QTL-NILs exhibited FHB severities of 14.5 and 13.9, respectively. In contrast, Norm exhibited a FHB severity of 27.6. The best Norm-Qfhs.ifa-5A NIL exhibited a FHB severity of 18.9. Similarly, Apogee exhibited a FHB severity of 30.2, while the best Apogee-Qfhs.ndsu-3BS and Apogee-Freedom 2A NILs exhibited significantly lower FHB severities (10.7 and 11.3, respectively). The best Apogee-Qfhs.ifa-5A NIL exhibited a FHB severity of 22.4. These QTL-NILs will provide prebreeding resources as well as genetic stocks for quantifying gene pyramiding, examining the molecular basis of resistance, and exploring biological differences between resistance to initial infection (type I) and type II resistance.