Studies on gene action and combining ability for yield and its component traits in rice (Oryza sativa L.)

Abstract

The knowledge of combining ability is useful to assess the nicking ability of parents and at the same time elucidate the nature and magnitude of gene action involved for trait of interest. The main aim of this investigation was to study the gene action governing the inheritance of grain yield and yield cornponents and to identify good general and specific combiners among blast resistant low temperature tolerant lines/varieties suitable for hill ecology Half diallel set of F1 crosses generated from crossing eight diverse varieties/elite lines of hill rice possessing blast resistance and tolerance to low temperature viz., IR 9202, VL Dhan 16, Pant Dhan 6, VHC 1253, VL Dhan 221, VRS 1000-1, NR 10073, HPU 856. Thirty-days old seedlings of eight parents and 28 F1 crosses were transplanted in a well-puddled field using randomized block design with three replications. Standard agronomic practices were used to raise good crop. Observations were recorded on days to flowering, plant height (em), panicle bearing tillers/plant (PST/plant), panicle length (em), grain weight/ panicle (g), fertile, sterile and total spikelets/panicle, 1000-grain weight, primary and secondary branches/panicle, length and width of flag leaf and grain yield/ plant using Standard Evaluation System of rice proposed by International Rice Research Institute, Manila, Philippines [1]. The estimates of combining ability and variances were estimated following method 2, model 1 of Griffing [2].