Fine mapping of stay-green QTLs on sorghum chromosome SBI-10L ? An approach from genome to phenome uri icon

abstract

  • Sorghum is the fifth most important C4 cereal crop grownglobally in arid and semi-arid climatic conditions. Drought isthe major cause for loss of productivity worldwide. Delayedsenescence of plants leads to adaptation to drought stressconditions by staying-green and giving high yields. In orderto identify and dissect the stay-green genomic regions wehave developed a high resolution fine mapping populationfrom introgression line cross RSG04008-6 (stay-green) √óJ2614-11 (shoot fly resistant). Nearly 1894 F2 genotypes werescreened with 8 SSR in order to identify double recombinantsfor both the parents in the sorghum chromosome-10 long arm(SBI-10L). The selected F2:4 recombinants were GBSed to increasethe marker density between flanking markers Xgap001-Xtxp141 for stay-green QTLs on SBI-10L and a high resolutionlinkage map was developed using GBS SNPs. Out of 182 only152 recombinants were replicated thrice in field for staygreenscreening for two seasons (Summer 2013 and 2014).Fine mapping of the per cent Green Leaf Area (%GLA) traitsidentified 33 QTLs and 19QTLs were clustered into 7groupswhere 8 genes were identified. These were AP2/ERF transcriptionfactor family (Sb10g025053), Ankyrin-repeat protein(Sb10g025310), WD40 repeat protein (Sb10g025320), NBSLRRProtein (Sb10g025283), Calcium dependant protein kinase(Sb10g030150), LEA2 protein (Sb10g029570), a putativeuncharacterized protein (Sb10g024920) and senescence associatedprotein (Sb10g030520). With this study SBI-10L staygreengenomic regions were delimited from 15Mb to 8 genesco-localized with GWAS MTAs. Further cloning and expressionlevel studies of the identified candidate genes will improve thedevelopment of drought tolerant genotypes

publication date

  • 2017