Study of heterosis in rice (Oryza sativa) in relation to yield and its contributing characters under coastal salt affected soil

Analysis of variance indicated significant differences among the parents and hybrids for all the characters stud ied, which revealed existence of variability in the genotypes. Based on mean performance, Gurjari, GNR-3 and IET-15429 among females and GNR-2, IR-55179 and GAR-1 among males were found superior for grain yield and most of the yield attributing traits. Among hybrids, Gurjari x GAR -1, Gurjari x IET- 19347 and IET-21734 x Jaya exhibited highest mean performance for grain yield and the major yield components. In general, the parents showing superior performance gave superior hybrids and higher magnitude of heterosis in hybrid combination. Among 40 hybrids, the maximum value of heterobeltiosis for grain yield per plant was observed in cross IET-21734 x Jaya, Gurjari x GAR-1 and IET-21734 x IET-19347. On the other hand 14 hybrids exhibited significant positive standard heterosis over Dandi, while only 6 hybrids depicted significant positive standard heterosis over CST - 7-1. The highly heterotic response in these hybrids for grain yield per plant resulted due to significant positive heterosis for yield contributin g characters like panicle lengt h and number of grains per panicle.