Exploitation and Application of a New SCAR Marker Linked to Strip Rust Resistance Gene Yr17 in Wheat

To further clarify the composition of stripe rust resistance gene in the newly developed wheat cultivars(lines) of Sichuan and establish molecular marker-assisted breeding system for rust resistance,the Thatcher Yr17 near isogeneic lines(NILs) and a F2 population derived from a cross between developed resistant line L15 and susceptible line SY95-71 were used to screen the SSR markers by bulked segregation analysis(BSA).A PCR product amplified by Xgwm415 was linked to resistance gene to strip rust resistance gene Yr17.The 390bp sequence of the PCR fragment had 90% identity to one EST of barley and 70% identity to the CDS of a NBS-LRR disease resistance protein in rice.Basing on this sequence,a pair of sequence-characterized amplified region(SCAR) primers were designed,and the SCAR marker,named SC-372,was able to target 15 resistant cultivars(lines) in all 54 wheat cultivars of newly developed in Sichuan Province.Compared with the amplification of marker VENTRUP/LN2 linked to Yr17,the SC-372 marker showed a higher detection efficiency to Yr17 when a set of NILs and Aegilops ventricosa were amplified.It was therefore to conclude that the new SCAR marker for Yr17 gene and the identified resistant lines could be used in wheat breeding for stripe rust resistance.