Vol. 9, Special Issue 10, Part C (2025)

The investigation on “Heterosis Studies for Yield and Yield Contributing Traits in Aerobic Rice (Oryza sativa L.)” was conducted during Rabi 2024-25 at the Regional Agricultural Research Station, Karjat, Dist. Raigad. Line × Tester mating design involving 3 lines (female) and 5 testers (male) were used to generate 15 hybrids. The experimental material, including parents, hybrids, and two checks, was evaluated in a randomized block design with three replications for 16 yield and quality-related traits. Analysis of variance revealed significant differences among genotypes for all traits, except straw yield per plant and protein content, indicating the presence of substantial genetic variability. The cross Ratnagiri 2 × Sahbhagi Dhan recorded the highest grain yield per plant (66.9 g), followed by (Ratnagiri 2 × Siri 1253) and (Karjat 3 × CR Dhan 202). These hybrids also exhibited high harvest index values, indicating efficient resource partitioning. The cross Karjat 5 × CR Dhan 202 exhibited the highest protein content (7.19%), while Ratnagiri 2 × Sahbhagi Dhan recorded the highest amylose content (25.13%). Combining ability analysis revealed that Ratnagiri 2 was the best general combiner among lines for grain yield and its components, while Siri 1253 and Sahbhagi Dhan were superior among testers. The hybrid Ratnagiri 2 × Sahbhagi Dhan showed the highest specific combining ability effects for grain yield and root biomass. Traits like plant height, productive tillers per plant, and grain yield per plant were governed predominantly by non-additive gene action (SCA > GCA), suggesting the suitability of heterosis breeding for these traits. High heritability in narrow sense was recorded for days to 50% flowering (89.87%), followed by test weight and harvest index, indicating scope for selection-based improvement. The study identified Karjat 3 × CR Dhan 202, Ratnagiri 2 × Sahbhagi Dhan, and Karjat 3 × Sahbhagi Dhan as promising hybrids with significant standard and economic heterosis for yield and associated traits. These results highlight their potential in the development of early maturing, high-yielding aerobic rice hybrids suitable for water-limited conditions.