Executive Summary : | shoot fly (Atherigona soccata Rondani) is the most destructive pest of sorghum seedlings in Africa and Asia during the early stages (7 to 30 days after seedling emergence). shoot fly resistance in sorghum is a quantitative complex trait that results from the interaction of various interdependent characters leading to resistance sorghum genotypes. Quantitative trait loci (QTL) for the component traits imparting shoot fly resistance in sorghum had been identified for Trichome density on the upper and lower leaf surface, and leaf glossiness (sathis et al., 2012). Marker-assisted breeding has a great challenge in developing sorghum shoot fly resistance lines using the component traits like leaf glossiness and trichome density. The present study focuses on the fine mapping of major QTLs region of leaf glossiness viz., leaf glossiness (QGs.dsr-10.1,10.2, 10.3), seedling vigour (Qsv.dsr-10), number of eggs per plant at 21 DAE (QEg21.dsr-10.1, 10.2), number of eggs per plant at 28 DAE (QEg28.dsr-10.2, 10.3), deadheart (QDh.dsr-10.3, 10.5), trichome density on upper side (QTdu.dsr-10.1, 10.2) and trichome density on lower side (QTdl.dsr-10.1, 10.2). New set of breeder-friendly Kompetitive Allele specific Polymerase Chain Reaction (KAsP) assays markers for the sNPs tightly linked to shoot fly resistance in multiple breeding populations will be take up for fine mapping and selection of resistance progenies. Development and validation of KAsP markers into high throughput genotyping platform is cost effective in mapping and marker assisted breeding programme of complex traits in sorghum. The identified KAsP marker linked to leaf glossiness and trichome density for shoot fly resistance trait will be used to pyramid for shootfly resistance traits . Mapping population used for the KAsP marker assay design and fine mapping are K8 X Is 2205 (F6), K8 X Is 18551 (F6) families and CO(s) 28 x Is18551 (BC3F4) populations. Present study will demonstrate the effectiveness of newly developed KAsP assays for selection of major QTLs governing the shoot fly component traits and also finding novel genomic regions controlling the shootfly resistance for future sorghum breeding programme. |
Co-PI: | Dr. Murugan Marimuthu, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu-641003, Dr. Kavithamani Duraisamy, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu-641003 |