Resistance Gene Analog Polymorphism (RGAP) Markers Co-Localize with the Major QTL of Fusarium Head Blight (FHB) Resistance, Qfhs.ndsu-3BS in Wheat

Resistance gene analog polymorphism (RGAP) markers linked to Fusarium head blight resistance (FHB) and co-localize with Qfhs.ndsu-3BS were identified using F3 plants and F3:5 lines derived from a ‘Wangshuibai’ (resistant) / ‘Seri82’ (susceptible) cross. The mapping populations were genotyped using 50 degenerate primers designed based on the known R genes. Out of the 50 designed primer combinations, eight showed polymorphism and produced 16 RGAP markers. Out of the 16 RGAP markers, two were integrated into the major QTL for FHB resistance, Qfhs.ndsu-3BS. Composite interval mapping (CIM) analysis detected two QTLs in a genomic region that were coincident with Qfhs.ndsu-3BS, thus explaining up to 12.5% of the phenotypic variations. The nucleotide sequence analysis of the positive subjected RGAP markers showed that known R-genes, namely Pto and Pto-like genes, may be considered as FHB candidate resistance genes underlying Qfhs.ndsu-3BS and may be used in future studies.