Exploration of Possibilities to Identify Heterotic Cross Combinations in Aromatic Rice (Oryza sativa L.) for Grain Yield and Quality Parameters

Twenty eight crosses generated using eight aromatic rice varieties crossed in half diallel fashion were evaluated and analyzed along with parents to investigate combining ability and gene action for grain yield and various grain quality traits. The general combining ability and specific combining ability variances were significant for all the traits that indicated the role of both additive and non-additive genetic components. Ratio of σ2gca/σ2sca< 1 indicated preponderance of non-additive gene action in the expression of these traits. Pusa Basmati-1 was the good general combiner showing significantly high GCA effect for a maximum of seven-grain quality traits viz., milling recovery (0.81), kernel length (0.28), kernel breadth (-0.05), kernel length/breadth ratio (0.26), cooked kernel length (0.79), alkali digestion value (0.67) and amylose content (0.60) but not for yield. Cross PSD-15×Pant Basmati-1 (P7×P8) was the good specific combiner showing high SCA effects for a maximum of eight grain quality traits viz. hulling recovery (2.76), milling recovery (2.06), kernel length (0.89), kernel length/breadth ratio (0.69), cooked kernel length (3.06), kernel elongation ratio (0.12), alkali digestion value (1.11) and amylose content (1.01) but not yield. None of the top three crosses (Pusa Sugandh-6×PSD-15, Pusa Basmati-1×PSD-15 and Pusa Sugandh-4×Basmati-370) based on high SCA effect for grain yield plant-1exhibited as high SCA effect to fall within top three crosses on that basis for any of the grain quality traits.