Genetic Analysis for Development of Rice Hybrids for South Asia

Combining ability analysis revealed importance of non-additive gene action in the expression of various yield contributing characters.The results indicated that the UPR 3406-7-2-2 (L5 ) and UPR 3413-15-2-1 (L28 ) were the best general combiners among lines as evident from significant GCA effects for ten characters. The best heterotic hybrids, UPR 3434-6-2-1× UPRI 95167 (L32 × T1), UPRI 2008-5 × IR 58025A (L33× T2) and UPR 3528-8-1-2× UPRI 95167 (L36× T1) in normal conditions expressing higher SCA effects and per se performance, were also involved good/ good combining parents into them. The crosses, L32 × T1, L33× T2 and L36× T1 involving good/good combining parents were suggested to exploitation for isolating high yielding pure lines and/or for straight use in hybrid breeding. On the basis of spikelet fertility percent, indica lines were grouped as maintainer, restorer and partial restorer / maintainer lines. Among 50 indica lines only 3 lines (L31, L37 and L42) behave like a maintainer with both of CMS lines (IR 58025A and Pusa 6A),19 lines behave like a restorer with both of CMS (IR58025A and Pusa 6A) lines and rest behave like partial restorer / maintainer lines.