Development and Molecular Characterization of Wheat-Aegilops peregrinaIntrogression Lines with Resistance to Leaf Rust and Stripe Rust

Abstract

A wild non-progenitor species from wheat tertiary gene pool Aegilops peregrina accession pau3519 (UUSS) was used for introgression of leaf rust and stripe rust resistance in bread wheat. It was crossed and backcrossed with hexaploid wheat line Chinese Spring Ph I to develop two homozygous BC 2 F 6 wheat-Ae. peregrina introgression lines (ILs) viz. IL pau16058 and IL pau16061 through induced homoeologous recombination. Homozygous lines were screened against six Puccinia triticina and two Puccinia striiformis f. sp. tritici pathotypes at the seedling stage and a mixture of prevalent pathotypes of both rust pathogens at the adult plant stage. IL pau16061 showed resistance to leaf rust only while IL pau16058 was resistant to both leaf and stripe rust pathotypes throughout plant life. Molecular characterization of these ILs aided in defining the introgressed regions. Identification of linked markers with advance genomic technologies will aid in marker assisted pyramiding of alien genes in cultivated wheat background.

Discovery and characterisation of a new leaf rust resistance gene introgressed in wheat from wild wheat Aegilops peregrina

“…Previously, transfer of one stripe rust and two leaf rust resistance genes from Ae. peregrina accession pau3519 to cultivated wheat have been reported 21 . The present study describes the cytogenetic characterisation and genetic mapping of the leaf rust resistance gene in the wheat-Ae.…”

“…peregrina. Because the introgression lines were developed through induced homoeologous pairing 21 , most likely it is a compensating translocation from chromosome 6U P L.…”

“…'WL711' . The strategy for developing introgression lines has been previously described in detail 21 . To study the inheritance pattern of rust resistance, IL pau16061 was crossed with WL711 (NN).…”

“…A leaf rust resistant introgression line (IL) pau16061, was developed previously from the hybridisation of the wild species Ae. peregrina (U p U p S p S p ) with the wheat line WL711 (vulnerable to rust) 21 . In the present study, the wheat-Ae.…”

Phenotypic response of a core collection of Aegilops triuncialis accessions to wheat leaf rust and expression pattern of genes involved in resistance

“…In addition, 249 quantitative trait loci (QTLs) associated with resistance to this disease have been identified in wheat and its wild relatives (Pinto da Silva et al., 2018; Kumar et al., 2021). However, most Lr genes, although initially effective in the host, are defeated in a short time after deployment due to the emergence of new races in the Pt population as a result of mutation, genetic plasticity and migration (Narang et al., 2018). Therefore, it is necessary to identify new sources of resistance genes and clarify their interactions for use in wheat breeding programs to confront the constantly evolving races.…”