Assessment of combining ability, gene action and heterosis for yield and grain characters in rice (Oryza sativa L.)

Abstract

Twenty four hybrids were tested along with eight lines and three testers for various yield and grain characters to understand the nature of gene action in the inheritance of various traits. gca/sca variance analysis exhibited the dominance of non-additive gene action for the traits viz., plant height, flag leaf length, flag leaf width, spikelet fertility, 1000 grain weight, single plant yield, grain length, grain breadth and L/B ratio. The lines ADT (R) 45, ADT 53, CO 54, ANNA (R) 4 and the testers 3-11-11-1 and 3-11-11-2 were determined to be good general combiners since they have contributed alleles with a positive effect on improving essential characters. The hybrids ADT (R) 45 x 3-11-11-2, ADT 37 x 3-11-11-1, ADT 37 x 3-11-11-2, ADT 53 x 3-11-11-1, CB 12132 x 3-11-11-1, CO 52 x 3-11-11-1, CO 52 x 3-1111-2, CO 52 x 3-11-11-1 and CO 54 x 3-11-11-1 were found to be good specific combiners. The crosses ADT 37x 3-11-11-2, CB 12132 x 3-11-11-1, ADT 53 x 3-11-11-2, ADT 53 x TR 13069 and CO 54 x 3-11-11-2 demonstrated significant results with respect to mean, sca and standard heterosis. These five crosses can be successfully used in further breeding programmes.