title: A New Map Location of GeneStb3for Resistance to Septoria Tritici Blotch in Wheat.
abstract: Septoria tritici blotch (STB), caused byMycosphaerella graminicola(synonym:Zymoseptoria tritici; asexual stage:Septoria tritici), is an important disease of wheat worldwide. Management of the disease usually is by host resistance or fungicides. However,M. graminicolahas developed insensitivity to most commonly applied fungicides so there is a continuing need for well-characterized sources of host resistance to accelerate the development of improved wheat cultivars. GeneStb3has been a useful source of major resistance, but its mapping location has not been well characterized. Based on linkage to a single marker, a previous study assignedStb3to a location on the short arm of chromosome 6D. However, the results from the present study show that this reported location is incorrect. Instead, linkage analysis revealed thatStb3is located on the short arm of wheat chromosome 7A, completely linked to microsatellite (SSR) locusXwmc83and flanked by lociXcfa2028(12.4 cM distal) andXbarc222(2.1 cM proximal). Linkage betweenStb3andXwmc83was validated in BC1F3progeny of other crosses, and analyses of the flanking markers with deletion stocks showed that the gene is located on 7AS between fraction lengths 0.73 and 0.83. This revised location ofStb3is different from those for other STB resistance genes previously mapped in hexaploid wheat but is approximately 20 cM proximal to an STB resistance gene mapped on the short arm of chromosome 7AminTriticum monococcum. The markers described in this study are useful for accelerating the deployment ofStb3in wheat breeding programs.
authors.affiliation: Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Department of Botany and Plant Pathology, 915 West State Street, Purdue University, West Lafayette, IN 47907-2054, USA.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Goodwin
authors.affiliation: Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Department of Botany and Plant Pathology, 915 West State Street, Purdue University, West Lafayette, IN 47907-2054, USA.
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Cavaletto
authors.affiliation: Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
authors.forename: Iago L
authors.initials: IL
authors.lastname: Hale
authors.affiliation: Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Department of Botany and Plant Pathology, 915 West State Street, Purdue University, West Lafayette, IN 47907-2054, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Thompson
authors.affiliation: USDA-ARS, Northern Crop Science Laboratory, 1307 18th Street North, Fargo, ND 58105-5677, USA.
authors.forename: Steven X
authors.initials: SX
authors.lastname: Xu
authors.affiliation: Department of Plant Pathology, North Dakota State University, 306 Walster Hall, Fargo, ND 58105-5012, USA.
authors.forename: Tika B
authors.initials: TB
authors.lastname: Adhikari
authors.affiliation: Department of Plant Sciences, University of California, Davis, CA 95616-8515, USA, and Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Dubcovsky