Chhuneja, ParveenJose, Alin Maria2022-12-032022-12-032021Jose, Alin Maria (2021). Identification and Molecular mapping of leaf rust and stripe rust resistance genes introgressed from wild progenitor species in cultivated wheat (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810190292Wild emmer wheat, Triticum dicoccoides, the tetraploid progenitor of wheat and Einkorn wheat, Triticum monococcum, diploid progenitor of modern hexaploid wheat, are important sources of novel disease resistance genes. T. dicoccoides acc pau 14716, which showed resistance to most common leaf rust and stripe rust races in India, was used to develop introgression line (ILdic) in the background of T. aestivum cultivar WL711(NN). An F4 mapping population was developed by crossing ILdic with T. aestivum cultivar HD2967 and the population was screened against highly virulent Pt leaf rust pathotypes at seedling and adult plant stage and Pst stripe rust pathotypes at the adult plant stages. The population segregated for a single all-stage resistance gene (ASR) against leaf rust and single gene for stripe rust resistance, according to inheritance analyses. Similarly, T. monococcum G1277 showed resistance to the most prevalent Pst stripe rust pathotypes in India. Therefore it was used to create a stable introgression line ILmono into hexaploid wheat background. T. aestivum cultivar HD2967 was used to develop F6 mapping population. ILmono mapping population upon screening against Pst stripe rust pathotypes at adult plant stage segregated for a single gene for stripe rust resistance. For mapping, leaf rust and stripe rust resistance genes in the F4 mapping population derived from HD2967-ILdic, bulk segregant analysis in combination with whole-genome resequencing (BSA-seq) was conducted. Two resistant bulks (RB) and two susceptible bulks (SB) were prepared separately for performing BSA-seq for mapping leaf rust and stripe rust resistance genes. A 10Mb candidate region on chromosome 7A with three highly significant SNPs linked to leaf rust resistance and 61 annotated genes was identified. It was observed that out of 61 annotated genes, 12 genes were involved in the defense mechanism against diseases and considered as candidate putative genes for leaf rust resistance gene in ILdic. Similarly, a 20Mb region with two highly significant SNPs was identified on chromosome 3A to be associated with stripe rust resistance and was identified to carry 49 annotated genes. Out of 49 annotated genes, four genes were found to be involved in defense mechanisms against diseases in which one gene had an NBS-LRR domain and therefore considered as candidate putative genes. The current study discovered useful leaf rust and stripe rust resistance genes that are effective against several rust races and can be deployed in the wheat breeding program.EnglishThesis