Development of high yielding short duration Boro rice through Aus x Boro crossing

This research aimed to develop high-yielding, short-duration Boro rice by examining F₂ populations of inter-varietal crosses of Oryza sativa at the experimental farm of Sher-e-Bangla Agricultural University (SAU), Dhaka. Key objectives included evaluating mean performance, general and specific combining abilities (GCA and SCA), and residual heterosis. Combining ability analysis indicated significant GCA and SCA effects across most traits, suggesting the involvement of both additive and non-additive gene actions. The cross BR21 x BR24 showed the highest, desirable SCA effect for days to maturity, indicating its potential as the best specific combiner for earliness. For yield and yield-contributing traits, BR26 x BRRI Dhan29 displayed the most favorable SCA effects, emerging as a strong candidate for yield improvement, followed by BRRI Dhan28 x BRRI Dhan29, BR26 x BRRI Dhan36, and BR24 x BR26. These combinations also demonstrated heterosis, making them promising for further evaluation of earliness and yield performance. Mean performance results highlighted BR21 x BRRI Dhan36 and BR24 x BRRI Dhan36 as requiring the shortest time to flowering and maturity while maintaining reasonable yields, suggesting their potential for developing short-duration, high-yielding rice varieties.