摘要
Current efforts in sorghum breeding programs are exploiting genotyping-by-sequencing (GBS) data to provide full-genome scans for desired traits. The aim of this study was to utilize GBS approach for the identification of genomic regions associated with stress response in sorghum (Sorghum bicolor L. Monech) accessions. DNA samples of twenty sorghum accessions, having different response to drought, were used to prepare GBS libraries for sequencing. SNPs were called using the TASSELGBS pipeline and the tags that present at least 10 times in the dataset were considered and aligned to the reference genome of Sorghum bicolor. The identified SNPs were all compared with the published sorghum transcript related to stress response gene activity. Overall;94.40% tags were aligned and 69,736 putative SNPs positions were identified. Blast search revealed homology to annotated heat and drought–tolerance associated genes which code for ATPases, Peroxidase, Hydrophobic protein LTI6A, Aquaporin SIP2-1, Aconitate hydratase and phosphatidylinositol-4-phosphate-5-kinase. The phylogeny of the 20 accessions was constructed using the generated SNPs data. Phylogenetic analysis data showed that the phenotypically tolerant line (El9)?makes a separate cluster and the same for the accessions HSD8653 and HSD5612 near to the cluster that includes most accessions with known post-flowering drought tolerance (HSD7410, HDS10033, HSD8552, GESHEISH and HSD8849). Post-flowering drought sensitive accessions (Tabat, Wadahmed, HSD6468 and HSD6478) formed a separate cluster while the sensitive accession HSD9959 and the tolerant accessions HSD8511 and HSD9566 were distributed between the two clusters. Thus, cluster analysis confirmed the variation among accessions in post-flowering drought tolerance. With further validation, these markers may be used for marker assisted selection for breeding new sorghum genotypes with stress adaptation.
Current efforts in sorghum breeding programs are exploiting genotyping-by-sequencing (GBS) data to provide full-genome scans for desired traits. The aim of this study was to utilize GBS approach for the identification of genomic regions associated with stress response in sorghum (Sorghum bicolor L. Monech) accessions. DNA samples of twenty sorghum accessions, having different response to drought, were used to prepare GBS libraries for sequencing. SNPs were called using the TASSELGBS pipeline and the tags that present at least 10 times in the dataset were considered and aligned to the reference genome of Sorghum bicolor. The identified SNPs were all compared with the published sorghum transcript related to stress response gene activity. Overall;94.40% tags were aligned and 69,736 putative SNPs positions were identified. Blast search revealed homology to annotated heat and drought–tolerance associated genes which code for ATPases, Peroxidase, Hydrophobic protein LTI6A, Aquaporin SIP2-1, Aconitate hydratase and phosphatidylinositol-4-phosphate-5-kinase. The phylogeny of the 20 accessions was constructed using the generated SNPs data. Phylogenetic analysis data showed that the phenotypically tolerant line (El9)?makes a separate cluster and the same for the accessions HSD8653 and HSD5612 near to the cluster that includes most accessions with known post-flowering drought tolerance (HSD7410, HDS10033, HSD8552, GESHEISH and HSD8849). Post-flowering drought sensitive accessions (Tabat, Wadahmed, HSD6468 and HSD6478) formed a separate cluster while the sensitive accession HSD9959 and the tolerant accessions HSD8511 and HSD9566 were distributed between the two clusters. Thus, cluster analysis confirmed the variation among accessions in post-flowering drought tolerance. With further validation, these markers may be used for marker assisted selection for breeding new sorghum genotypes with stress adaptation.
