genetic dissection of some important agronomic traits in rice using line × tester method

a study was conducted on genetics of some important agronomic traits (number of productive tillers per hill, plant height (cm), panicle length (cm), number of spikelets per panicle and 100-grain weight) in rice during 2012-13. two lines were crossed with five testers in line × tester fashion to produce 10 f1 hybrids. analysis of variance revealed significant differences among genotypes and crosses. variances of sca were higher than the gca variances for number of productive tillers per hill, panicle length (cm) and 100-grain weight (gr) which indicated predominance of non-additive gene action in the inheritance of these traits. p35 tester produced the lowest height among testers, highest number of productive tillers and number of spikelets per panicle among parents and its hybrids produced highest number of productive tillers,  highest panicle length (cm), highest number of spikelets per panicle (tarom-jelodar × p35) and lowest height (danesh × p35)  among hybrids. also this variety was found to be good general combiner for height (cm) and panicle length (cm). crosses namely tarom-jelodar × sange-tarom, danesh × jahesh and danesh × p35 had useful and significant heterosis for all traits. these crosses were identified as promising genotypes for increasing of rice yield in future improvement programs. thus hybrid varieties have positive potential for rice breeding.