Fine Mapping and Expression Analysis of Stripe Rust Resistance Genes derived from Aegilops geniculata

Abstract

Wheat production in temperate area is significantly affected by rust diseases, among which stripe (or yellow) rust caused by Puccinia striiformis Westend f. sp. tritici and leaf (or brown) rust caused by Puccinia triticina Eriks. is major threat to production. Non-progenitor Aegilops species with substantial amount of variability for stripe rust resistance genes has been exploited to a limited extent. A tetraploid non-progenitor species (UUMM genome), namely Aegilops geniculata accession pau3549 is found to be resistant to stripe rust. A stripe rust resistant introgression line-ILT598 (BC 2 F 8 Ae. geniculata acc. pau3549/CSS//3*WL711) was already available. In the present investigation an F 5 population was derived from the cross of ILT598 with wheat cultivar WL711(NN). Inheritance studies in F 5 population revealed that stripe rust resistance is controlled by a single dominant gene, temporarily designated as YrAg. Mapping of YrAg was done by using SNP based KASper marker linked with two group of linked gene on chromosome 5DS viz Lr57-Yr40 and Lr76-Yr70 and one marker was designed from candidate gene of comp_121307_c0_seq4 derived from ILT598. Molecular mapping using F 5 population mapped YrAg at a distance of 3.3cM from KASP comp_121307_c0_seq4 towards distal end of chromosome 5D.