SHESHSHAYEE, M SPRINCE, CHOYAL2016-11-032016-11-032013-07-27Th-10552http://krishikosh.egranth.ac.in/handle/1/83664Cultivated groundnut (Arachis hypogaea L.), an important dietary energy source, is grown as rainfed crop in the semi- arid regions of the world. Water availability is hence the most important constraint. Water mining associated with roots and efficiency of water use for biomass production are considered as the most important physiological traits that when pyramided can boost productivity under rainfed conditions. Pyramiding complex traits requires the adoption of focused molecular breeding strategy. Toward identifying markers flanking QTL governing these traits, a mapping population comprising of 268 recombinant inbred lines developed by crossing TAG 24 and GPBD 4 were phenotyped for root traits, WUE and associated physiological traits. A significant variability in all these traits was observed. Transposon based markers (5) were added to the existing 188 SSR marker map and a QTL analysis was done by both SMA and CIM strategies using QTL cartographer. Along with several makers linked, markers GM 1357 for root length and GM1717 and pPGSseq18A05b for root biomass were found to be associated by both SMA and CIM. Likewise Marker GM 2724b and GM 1573 were found to be associated for total leaf area by both strategies. Similarly, QTLTDM-12-1 and QTLTDM-9-1 were identified for total dry matter. In addition, five QTLs were identified for mineral ash content by CIM. These QTLs would be useful in breeding for improving drought tolerance in groundnut.en---Thesis