The study on genetics of Oryza sativa L. lowland rice for submergence tolerance was carried out, using two most farmer-preferred commercial rice varieties in Nigeria. The experimental design was completely randomized design, having crossing blocks with three replications. Parameters estimated include; broad sense heritability (h2b), genotypic variance, phenotypic variance, additive variance, and narrow-sense heritability (h2n). Moderate to high narrow sense heritability in conjunction with moderate to high expected gain were observed in most of the traits, especially the yield component traits. The results of the generation mean analysis showed significance of at least one out of the four scales (A, B, C & D) for all the traits studied in the two crosses. The six parameters analysis revealed that besides the additive and dominance gene actions, epistatic interaction mechanisms have also contributed to the expressions of the traits studied. However, the relative magnitudes of these effects varied from character to character and cross to cross. The result showed a high magnitude of dominance gene effect with duplicate epistasis were observed for plant height, days to 50% flowering, numbers of panicle, panicle length and grain yield. Hence, the additive genes effect can also be considerable and significant for these traits.
Epistatic, Additive, Variance, Dominance, Genetic
Uwuigbe, E.U., Ehirim, B.O., Jimoh, K.S., Njuguna, J.W. (2025): Effect of gene actions on two lowland rice (Oryza sativa L.) accessions as influenced by submergence. Scientia Agriculturae Bohemica, 56, 4, 15, DOI: 10.7160/sab.2025.560415