Combining ability analysis indicated the importance of both additive and non-additive gene action for the inheritance of all the characters; however the ratio of 2 gca/2 sca revealed the preponderance of additive gene action for plant height, days to 50% flowering and kernel length while Grains per panicle, Grain yield / plant, Kernel breadth, Amylose content (%), Protein conte nt (%), K+ / Na+ ratio in Shoot and K+ / Na+ ratio in root showed predominance of non -additive gene action. An observation of the general combining ability effects suggested that female parent Gurjari was found to be good general combiner for majority of the traits, while male parents viz., IET -19347, GNR-2, GAR-1 and IR- 71907 were best general combiner for grain yield per plant and also for number of yield components and biochemical characters. GNR -3 and IR- 55179 were identified as the most promising parents for im parting dwarfness and earliness, respectively.
Estimates of sca effects did not reveal any specific trend. However, the comparison of sca effects with per se performance of crosses indicated that at least one good general combiner was necessary for better per se performance along with sca effects. The hybrids which recorded maximum significant positive sca effects for grain yield were IET -21734 x Jaya, Gurjari x GAR-1 and GNR-3 x IET-22608. Higher K+/Na+ ratio in shoot and root were found in salt tolerance genotypes these biochemical traits can be utilized as marker characters in salt tolerance breeding programme in rice.