Abstract

Root traits were targeted for improvement of drought tolerance in rabi sorghum through marker assisted backcrossing. Two stable QTLs, qRV3 and qRV10 for root volume from sorghum landrace, Basavanapada were chosen to pyramid into three recurrent backgrounds that were previously introgressed with three stay-green QTLs and one water use efficiency QTL viz., SPV86 qSTG + CID, SPV570 qSTG + CID and M35-1 qSTG + CID and two genotypes that were introgressed with three charcoal rot QTLs viz; M35-1qCR and SPV86qCR. The parental lines were surveyed for polymorphism assessment with 109 SSR markers. However, 12 markers that accounted for 11%, were polymorphic among the parents. The parental lines were crossed with Basavanapada as male parent and resulting F1s were subjected to hybridity confirmation by using SSR markers that were polymorphic among parents. At first level, the target markers conditioning the QTLs were screened among the backcross progenies to achieve the foreground selection, and at second level, selecting backcross progeny with the tightly-linked flanking markers to target QTLs (non-QTL region) was done, in order to minimize linkage drag-‘recombinant selection’.