ARS | Publication request: Marker-Assisted Selection for FHB at the Eastern Regional Small Grains Genotyping Lab

Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 5, 2008
Publication Date: N/A

Technical Abstract: Head scab of wheat, caused by Fusarium graminearum, is a disease that affects wheat production in the Eastern soft wheat growing region of the U.S.A.. Genotyping and marker-assisted selection (MAS) are being applied in the Eastern wheat growing region to develop resistant wheat varieties and to characterize germplasm. Since 2005, the Eastern Regional Small Grains Genotyping Lab has worked with breeders in eastern region to conduct MAS for FHB resistance. During 2008, samples for screening with markers linked to FHB resistance QTL were received from 13 soft wheat breeding programs. The Fhb1 resistance gene is by far the most frequent gene being deployed by MAS. However, marker-assisted selection has also been conducted for resistance QTL on chromosomes 5A, 2D, 4B, 6B, 2B, and 3BS near the centromere. In addition to MAS, genotyping with markers linked to FHB resistance is also done on collaborative regional nurseries. The 2007 and 2008 Uniform Southern Fusarium Head Blight Nursery and Northern and Preliminary Northern Uniform Winter Wheat Scab Nurseries, were screened for SSR markers linked FHB resistance QTL on chromosome 3BS (Fhb1), 5AS, and 2DL using SSR markers. The 2008 nurseries were also screened with markers linked to the 3BS centromere QTL mapped in Ernie, as well as markers associated with genes for resistance to leaf, stripe and stem rust, the Hessian fly, and barley yellow dwarf virus. Markers for the Bx7oe allele for gluten strength, reduced height genes Rht-B1 and Rht-D1 and the short arm of rye chromosome 1R were also evaluated. No lines were found in any nursery evaluation to contain all the scab resistance QTL evaluated. In 2007, seven lines evaluated had at least one scab resistance QTL in the NUWWSN, while the USFHBN had six lines with at least one QTL. In 2008, the number of lines postulated to have a mapped resistance QTL increased to 12 lines and 11 lines in the NUWWSN and USFHBN, respectively.