Abstract:

The main aim of this study was to develop closely linked markers for rust resistance genes Lr48, Lr49 and Sr48. In addition, mapping of adult plant stripe rust resistance in a landrace Aus27284 was also performed. Close SNP-Ar45 associations were identified using the iSelect 90K. Infinium array, five SNP markers co-segregated with Lr48 and IWB70I47 mapped 0.3 cM proximal to this gene. Kompetitive allele-specific PCR (K.ASP) assays were developed for linked SNPs. In contrast, the K.ASP markers developed from the iSelect 90K Infinium SNP array for Lr49 did not result in close marker-trail association. Sequence comparison of How sorted chromosome 4B from parents VL404 (Lr49) and WL711 (Jr49) resulted in dose association of sunKASP_21 (0.4 cM) with Lr49. The Arina/Cezanne RIL population was used to develop markers linked with Sr48 using the DArTseq platform and the iSelect 90K Infinium SNP array. DArTseq based linkage map located Sr48 on the short arm of chromosome 2D. Marker siin590 derived from a DArTseq marker mapped 0.4 cM distal to Sr48. Sr48 was earlier mapped in the long ami of chromosome 2A in the Arina/Fomo RIL population based on repulsion linkage with Yrl. The detection of 2AL-2DS translocation in Fomo through genomic in-situ hybridisation (GISH) appears to have resulted in pseudo-linkage to locate Sr48 in chromosome 2AL. Aus27284 was susceptible to stripe rust at the seedling stage and exhibited resistance in field experiments. Genetic analysis showed monogenic segregation and the resistance gene was temporarily designated YrAlVH. YrAWll was located on chromosome 3 BL near the centromere KASP 53113 flanked this locus. and KASP 65624/KASP 58449 and The closely linked markers identified in this study were tested on a set of Australian and/or Nordic wheat genotypes to validate their suitability for marker assisted selection (MAS). The results indicated that IWB70147, simKASP_21, sun590 and KASP 53113 can be used for MAS of Lr48, Lr49, Sr48 and YrA W11. respectively.