Anil KumarTabassum2018-04-192018-04-192016-06http://krishikosh.egranth.ac.in/handle/1/5810044162The present investigation was carried out to study variance, genetic advance, heritability, correlations, combining ability, gene action, and heterosis using line × tester mating design at Norman E. Borlaug Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar during rabi, 2013-14 and 2014-15. The experimental materials for the present investigation consisted of twelve lines viz., HD 3091, WH 1139, PBW 681, DBW 88, WH 1126, UP 2848, PBW 644, HD 3123, UP 2845, UP 2696, UP 2425, UP 2554, three testers viz., WH 1105, UP 2672 and HD 3059 and two checks viz., HD 2967 and UP 2526. The experiment was carried out in randomized block design and observations were recorded on fourteen characters namely days to 75% heading, days to maturity, number of effective tillers per plant, plant height, flag leaf area, peduncle length, spike length, number of spikelets per spike, number of grains per spike, grain weight per spike, 1000-grain weight, biological yield per plant, grain yield per plant and harvest index. Results revealed that grain yield per plant showed highly significant and positive genotypic correlations with number of tillers per plant, spike length, number of spikelets per spike, grain weight per spike and biological yield. DBW 88 was identified as best general combiner for maximum number of traits followed by WH 1126 and UP 2425. UP 2848 × UP 2672 showed good specific combining ability for days to 75% heading, number of grains per spike, grain weight per spike, 1000-grain weight and biological byield per plant. WH 1139 × HD 3059 emerged as good specific combiner for number of tillers per plant, 1000-grain weight, biological yield per plant and grain yield per plant. The best heterotic cross for grain yield per plant was DBW 88 × WH 1105 followed by DBW 88 × UP 2672, WH 1139 × HD 3059, DBW 88 × HD 3059 and PBW 644 × WH 1105.ennullThesis