Abstract

                                The present study was conducted to estimate the extent of heterosis and combining ability for various morphological traits using line x tester analysis during Kharif 2009 and Kharif 2010 in Randomized Block Design with three replications under rainfed condition. Five lines and three testers were used in crossing programme to obtain the fifteen crosses. Analysis of variance for all quantitative characters showed significant differences for all twelve characters under study except harvest index. Out of fifteen crosses, seven crosses were identified for high grain yield per plant. The maximum heterobeltiosis for grain yield per plant recorded for IR74371-54-1-1/ IR67017-124-2-4. The maximum standard heterosis and sca effect for grain yield was exhibited by IR 81413-B-B-75-4/ IR 81429-B-31. Among the lines, IR81413-B-B- 75-3 was identified as good general combiner for grain yield per plant with five other characters. Among the testers, IR74371-54-1-1 was identified as good general combiner for grain yield per plant with seven other characters. Thus hybrid IR81413-B-B-75-3/ IR81429-B-31 was identified as best specific combiner for grain yield per plant with some other morphological traits.

Key words : Rice, heterosis, gca, sca, gene interaction, per se, lines, testers, crosses.