Comprehensive assessment of combining ability and heterosis for the development of superior three-line hybrids in rice (Oryza sativa L.).

The present study involved assessment of 70 three-line hybrids obtained by crossing five CMS lines and 14 testers using line x tester mating design for combining ability and heterosis for 13 yield and grain quality traits. The Analysis of Variance identified significant difference among crosses and the ratio of GCA and SCA variances were less than unity indicating non-additive gene action for all the traits. The line COMS 24A and testers RNR 15048, WGL 32100, CBSN 504, CBSN 509, CBSN 511 and IR64 DRT were identified as best general combiners through gca effects. Among the hybrids, COMS 24A X WGL 32100, COMS 24A X CBSN 504, COMS 25A X CBSN 511, COMS 25A X CBSN 517, COMS 23A X IR64 DRT and COMS 23A X CBSN 509 demonstrated outstanding sca effects, mean and standard heterosis over CORH 3 and CORH 4. Two hybrids viz., COMS 25A X CBSN 511 and COMS 25A X RNR 15048 had medium slender grain type and hold promise for commercial exploitation in south India especially Tamil Nadu. [ABSTRACT FROM AUTHOR]