Assessment of Heterosis and inbreeding Depression for Yield, and its Associated Components Traits in Rice (Oryza sativa L.)

Abstract

The present investigation entitled was carried out at Main Rice Research Centre, Navsari Agricultural University, Navsari during kharif-2023 with an objectives to obtain information on manifestation of heterosis and extent of inbreeding depression involved in the inheritance of various yield attributing characters in rice (Oryza sativa L.). This study comprised three crosses using four diverse lines. The experimental material comprised of five generations each cross of pair parents i.e. P1, P2, F1, F2 and F3 of three different crosses were conducted in Compact Family Block Design with three replications during kharif 2023. For grain yield per plant all the three crosses (IRBB 55 × Mahisagar, IRBB 55 × GR-11 and IRBB 55 × TN-1) exhibited significant and positive relative heterosis as well as heterobeltiosis. Among them the highest mid parent heterosis of 39.67% and heterobeltiosis of 7.56% were exhibited by cross IRBB 55 × GR-11. This hybrid showed positive and significant relative heterosis for all the four important characters viz., productive tillers per plant, panicle length, grains per panicle and 100 grain weight. While, the inbreeding depression was found significant and positive for all the three crosses which is not desirable for grain yield per plant. Here, all the three crosses exhibited positive heterosis followed by positive inbreeding depression indicated that trait is under influence of non-additive type of gene action and heterosis breeding would be found rewarding for improvement for grain yield per plant.