Location: Cereal Crops ResearchTitle: Genomic analysis of a novel gene conferring resistance to Ug99 stem rust in Triticum turgidum ssp. dicoccum Author
|Saini, Jyoti - North Dakota State University|
|Rouse, Matthew - Matt|
|Long, Yunming - North Dakota State University|
|Mcclean, Phillip - North Dakota State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/14/2016
Publication Date: 11/2/2016
Citation: Saini, J., Xu, S.S., Rouse, M.N., Chao, S., Long, Y., Mcclean, P., Faris, J.D. 2016. Genomic analysis of a novel gene conferring resistance to Ug99 stem rust in Triticum turgidum ssp. dicoccum [abstract]. Durable Wheat Resistance Meeting, November 2-3, 2016, Minneapolis, MN.
Technical Abstract: Wheat production is threatened by the disease stem rust, which is caused by the biotrophic fungal pathogen Puccinia graminis Pers.:Pers. f. sp. tritici (Pgt). Among all known Pgt races, TTKSK (Ug99) and TRTTF are significant threats to North American wheat production due to their virulence against frequently deployed stem rust resistance (Sr) genes. In the current study, a population consisting of 190 recombinant inbred lines (RP883) derived from a cross between the stem rust susceptible durum wheat line Rusty and the resistant cultivated emmer (T. turgidum ssp. dicoccum) accession PI 193883 was used for the mapping of stem rust resistance genes. Linkage maps consisting of ~9000 markers were developed by using the Illumina 90K SNP beadchip and simple sequence repeat (SSR) markers. QTL analysis revealed two major stem rust resistance loci on chromosome arms 2BL and 6AL associated with TTKSK, TRTTF, and the North America race TMLKC. The 2BL QTL explained 60-80% of the phenotypic variation for TTKSK and TRTTF, but for TMLKC it explained only ~18% of the variation. However, the 6AL QTL explained ~46% of the variation for TMLKC, whereas it explained 8-11% of the variation for TTKSK and TRTTF. The 6AL QTL may be an allele of Sr13, but the 2BL gene is novel based on location and race specificity. Markers flanking the 2BL QTL were located on a wheat whole-genome sequence scaffold, and the intervening sequence was used to develop additional markers for marker-assisted selection. The novel gene from cultivated emmer wheat will be used to improve stem rust resistance in durum and common wheat varieties.