Identitification ot an bite Wheat-Rye TIRS-1BL UL Translocation Line conterring High Resistance to Powdery Mildew and Stripe Rust

Abstract

Wheat-rye T1RS- IBL translocations have been widely used worldwide in wheat production for multiple disease resistance and superior yield traits. However, many TIRS-IBL translocations have successively lost their resistance to pathogens due to the coevolution of pathogen virulence with host resistance. Because of the extensive variation in rye (Secale cereale L.) as a naturally cross-pollinating relative of wheat, it still has promise to widen the variation of IRS and to fully realize its application value in wheat improvement. In the present study, the wheat-rye breeding line R2207 was characterized by comprehensive analyses using genomic in situ hybridization (GISH), multicolor fluorescence in situ hybridization with multiple probes, multicolor GISH, and molecular marker analysis, and then was pmven to be a cytogenetically stable wheat-rye T IRS-I BL translocation line. Based on the disease responses to different isolates of powdery mildew and genetic analysis, R2207 appears to possess a novel variation for resistance, which was confirmed to be located on the rye chromosome arm IRS. Line R2207 also exhibited high levels of resistance to stripe rust at both seedling and adult stages, as well as enhanced agronomic performance, so it has been transferred into a large number of commercial cultivars using an efficient iRS-specific kompetitive allele specific PCR marker for marker- assisted selection.