Mapping stripe rust resistance in soft red winter wheat

Stripe rust, caused by Puccinia striiformis, is an important foliar disease of soft red winter wheat (SRWW) in the eastern region of the U.S. and globally.  However, very few resistance genes have been characterized in this germplasm pool.  The SRWW lines VA96W-270 and VA96W-270V (a variant of VA96W-270) are known to be resistant to stripe rust race PST-100.  To understand the genetic basis of this resistance, each resistant line was crossed to a susceptible cultivar, Coker 9835. The two recombinant inbred line (RIL) populations (VA96W-270 x Coker 9835 and VA96W-270V x Coker 9835) were evaluated for stripe rust resistance in field experiments over three years and resistance was estimated to be controlled by at least two race-specific, adult plant resistance genes. Molecular marker analysis is being performed on these RILs with an aim to construct genetic linkage maps and to identify quantitative trait loci (QTL) responsible for stripe rust resistance in these SRWW populations. Simple sequence repeat (SSR) marker analysis is being carried out using a high-throughput capillary electrophoresis platform with LED-based fluorescence detection (AdvanCE FS96 system, Advance Analytical, Ames IA). The presentation outlines preliminary findings from this study.