Studies on combining ability to develop medium slender and aromatic short grain rice hybrids

Combining ability study was carried out on rice using line x tester analysis for grain yield per plant and its attributing characters involving three CMS (Cytoplasmic Male Sterile) lines, 20 medium slender and short aromatic grain type testers and resulting 60 rice hybrids (cross combinations). The analysis revealed the predominance of non-additive gene action for all the characters suggests the possibility of exploiting heterosis in the present material. CMS line IR58025A was rated as good general combiner for grain yield per plant, fertile spikelet panicle and other component traits. Tester viz. HR-NPT6-3, IR72164-352-2-5-5, IR72910-177-1-1-3, R1659-3629-1-462-1, Chinikapoor (aromatic short grain), Sawrna selection-2 and Mahsuri (medium slender grain) were identified good general combiner for grain yield per plant, and other contributing traits. Cross combinations viz. IR58025A X Mancha, IR58025A X IR72164-352-2-5-5, CRMS 32A X IR72910-177-1-1-3, CRMS 31A X R1557-1317-1-580-1 and CRMS 31A X HR-NPT-6-3 possessed significant and positive SCA effect for grain yield per plant and other component traits.