STUDIES ON ECONOMIC HETEROSIS FOR GRAIN YIELD UNDER IRRIGATED AND TIMELY TRANSPLANTED CONDITION IN RICE (ORYZA SATIVA L)

The experiment was conducted at N E Borlaug Crop Research Centre, G B Pant University of Agriculture and Technology, Pantnagar under irrigated and timely transplanted condition during Kharif 2015. Thirteen high yielding rice genotypes comprising 10 genotypes used as lines (including improved aromatic and non-aromatic genotypes) and 3 popular varieties were used as testers to generate 30 hybrids. All 30 F1’s along with their parents were evaluated in the next year during Kharif 2016 to estimate the economic heterosis (standard heterosis over the check variety Pant Dhan 24) and better parent heterosis (heterobeltiosis) for six yield and its contributing traits including plant height, number of tillers per plant, number of panicles per plant, panicle length, number of filled grains per panicle and grain yield per plant. Among the parental lines, four lines namely, UPR 3037-2-2-2-1-3, UPR 2760-10-1-2, UPRI 2015-5 and Pant Dhan 26 emerged as best heterotic lines for grain yield and its main contributing traits when they were crossed with all three testers viz., HKR 47, NDR 359 and Pant Dhan 24. The estimated data on heterosis of 30 hybrids were revealed that, six crosses viz., UPR 3037-2-2-2-1-3 x HKR 47, UPR 2760-10-1-2 x HKR 47, Pant Sugandh Dhan 17 x Pant Dhan 24, UPRI 2015-5 x Pant Dhan 24, UPRI 2015-5 x NDR 359 and Pant Dhan 26 x NDR 359 exhibited highly significant and maximum economic as well as better parent heterosis for grain yield per plant and its contributing traits, indicating presence of over dominance type of gene action for these traits. Therefore, these six cross combination may be considered for selecting high yielding genotypes from segregating generations as well as development of hybrids for irrigated and timely transplanted condition