Heterosis and inbreeding depression in Aus Rice (Oryza sativa L.) for yield contributing traits
DOI: 10.37992/2024.1504.110
Abstract
The extent of relative heterosis (RH) and heterobeltosis (HB) of 17 F1s and inbreeding depression (ID) in 15 F2 generations of Aus rice were estimated for 13 yield traits. The F1s revealed significant negative heterosis for days to panicle exertion, days to maturity, plant height, empty grains/panicle, grain breadth in P1 × P4, P2 × P1, P2 × P5, P3 × P4, P6 × P4, P6 × P11 and P7 × P11 which indicated the possibility of superior segregants for desirable types. Significant and positive heterosis was found in the crosses P1 × P4, P2 × P1, P2 × P6, P3 × P4, P4 × P6 for effective tillers/plant, filled grains/panicle, 1000-seed weight and grain yield/plant. Heterosis for filled grains/panicle was significant positive in (P3 × P4) over mid parent and better parent. The highest significant positive RH and BH was exhibited by crosses P8 × P3 (34.08 and 18.65), P2 × P6 (23.58 and 8.53), P6 × P3 (16.97 and 15.27), P3 × P4 (11.66 and 11.10) for panicle length. Significant positive RH was observed in F1s P3 × P4 (160.22) and P4 × P6 (63.68), and P3 × P4 (88.85) showed desirable HB for grain yield/plant. High degree of ID was manifested by tillers/plant, empty grains/panicle, panicle length, grain breadth and 1000-seed weight in F1s P6 x P7, P1 x P4, P7 x P6, P1 x P4 and P6 x P7, respectively. Tillers/plant manifested positive and high ID in F2 of P6 x P7 (42.56). The F2 of P7 x P6 (-15.1) had the highest negative ID for panicle length. All crosses showed significant ID for filled grains/panicle except P3 x P4 and P6 x P7. The F2 populations of P6 x P7 (14.55) showed the highest positive ID for 1000-grain weight. The highest negative ID was observed in F2 generation of the cross P1 × P4 (-158.74) for seed yield per plant and the highest positive value in the F2 generation of P3 × P4 (44.84). It can be concluded that hybrid breeding would be more effective for effective tillers/plant, filled grains/panicle, 1000-seed weight and grain yield/plant in rice as they exhibited relative heterosis and heterobeltiosis in desired (positive) direction. On the other hand, plant height and days to maturity revealed negative association grain yield per plant as they exhibited negative estimates of relative heterosis and heterobeltiosis.
Keywords: Aus rice, recombination, heterosis, segregation, grain yield.
Heterosis and inbreeding depression in Aus Rice Oryza sativa L. for yield contributing traits
. 2025. Electronic Journal of Plant Breeding, 15 4, 877-884. Retrieved from https://ejplantbreeding.org/index.php/EJPB/article/view/5215It is certified that:
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