Discovery and characterisation of a new leaf rust resistance gene introgressed in wheat from wild wheat Aegilops peregrina
Deepika Narang, Satinder Kaur, Burkhard Steuernagel, Sreya Ghosh, Urmil Bansal, Jianbo Li, Peng Zhang, Subhash Bhardwaj, Cristóbal Uauy, Brande B. H. Wulff, Parveen Chhuneja
Abstract
Abstract Wild wheat species Aegilops peregrina (U p U p S p S p ), harbours resistance to various diseases including leaf rust and stripe rust. Inheritance studies in a recombinant inbred line population of wheat -Ae. peregrina introgression line IL pau16061 revealed the transfer of a single major dominant gene conditioning all stage resistance, herein temporarily designated as LrAp . Genomic in situ hybridisation of IL pau16061, resistant and susceptible RILs with U- and S-genome DNA probes confirmed that the introgression with leaf rust resistance is from the U p genome of Ae. peregrina . Fluorescence in situ hybridisation using chromosome specific probes identified U p genome introgression to be on the long arm of wheat chromosome 6B. To genetically map LrAp , bulked segregant analysis was combined with r esistance gene en richment seq uencing (MapRenSeq). Five nucleotide binding leucine-rich repeat contigs distinguished resistant and susceptible bulks and single nucleotide polymorphism (SNP) markers from these contigs co-segregated with LrAp . All five RenSeq NB_ARC contigs showed identity with the long arm of wheat chromosome 6B confirming the introgression on 6BL which we propose is a compensating translocation from Ae. peregrina chromosome 6U p L due to homoeology between the alien and wheat chromosomes. The SNP markers developed in this study will aid in cloning and marker assisted gene pyramiding of LrAp .