Wednesday, November 15, 2006 - 9:00 AM

Transfer of FHB Resistance from Hexaploid Wheat to Tetraploid Wheat.

Suresh Bhamidimarri1, Elias Elias2, and Shahryar Kianian1. (1) North Dakota State Univ, Fargo, ND 58105, (2) Box 5051, North Dakota State University, North Dakota State University, Department of Plant Science, Fargo, ND 58105-5051

 Heavy economic losses of durum wheat due to Fusarium Head Blight (FHB) caused by Fusarium  graminearium Schwabe (telomorph Gibberella zea (Schw.) Petch have made it necessary to focus research on the development and release of resistant cultivars.  This investigation focuses on developing type II FHB resistant durum wheat using ‘Sumai3’ and ‘Wangshuibai’ as source of resistance.  Marker assisted selection is being used in two F2:4 populations of size 1,814 and 320 lines derived from a cross between Sumai3 and cultivars ‘Ben’ and ‘Lebsock’, respectively. These populations were screened with the microsatellite locus Xgwm533, linked to a region 3BS (Qfhs.ndsu-3B) associated with resistance. A total of 238 F2:5 lines from these populations were selected and of these, 153 lines that had the Xgwm533 allele and were resistant in greenhouse evaluations (64% efficiency of selection).  These lines were further tested for their resistance to FHB and agronomic performance in replicated field trials at two locations.  Significant differences were detected in FHB resistance, agronomic and quality traits among lines at both locations.  Superior lines will be selected and tested in advanced yield trials in summer 2006.  Efficiency of selection could potentially be improved by utilizing markers closely linked and flanking the Qfhs.ndsu-3B region.,A third population, consisting of 140 recombinant inbred lines (F2:6) derived from crossing Ben to Wangshuibai, is being analyzed to determine the location of important regions and their possible epistatic interactions in durum background.  So far, a total of 82 SSR loci have been mapped on the entire population.  Preliminary analysis shows that the FHB region on 3BS explains 18% of the phenotypic variation in this population.  More markers are being mapped on this population to provide complete genome coverage and identify other regions of importance.