The study was carried out to determine the combining ability estimates and heterosis for yield and yield components in rice (Oryza sativa L.) in Nigeria. A seven plant diallel was planted across three locations using a randomized complete block design with three replications. Parameters assessed include days to 50% heading, plant heights, panicle lengths, panicle weights, number of seeds per panicle, number of productive tillers, number of panicle branches, yields per hectare, 100 grain weight. Assessment of GCA and SCA were carried out. Percentage heterosis were also determined for all traits studied. Significantly higher yield was recorded by P5, P4, P3, P6, P7, P2, and P1 with means of 5.86t/ha, 5.26 t/ha, 5.09 t/ha, 4.94 t/ha, 4.91 t/ha, 4.74 t/ha and 4.49 t/ha respectively across three locations studied. Hybrids P1xP5, P3xP6, P4xP7, P3xP5 produced significantly higher yields of 6.14 t/ha, 6.13 t/ha, 6.22 t/ha), 6.95 t/ha compared to their parental means. Similarly, significant difference were recorded in all other traits studied among parents and hybrids. GCA means squares were significantly higher than that of SCA for most of the traits studied. Additive variance was shown to predominate for plant heights and productive tillers while dominance was higher in yield per plants. Narrow sense heritability was higher on days to flowering, plant heights, panicle length and productive tillers. Yield in general was found to be significantly higher for combining ability in P5, P3 and P4. The overall GCA status for the ten agronomical traits studied showed that P5, P3, P1 and P2 are higher general combiners. Hybrids P3xP5, P5xP6, P2xP3, P5xP7 and P2xP7 produced higher total overall SCA, however, some produced more dominance on a particular trait than others. Both positive and negative heterosis for mid-parent, standard and better parent were also observed.
Citation: Ayuba S; Vange T; Ojo G.O.S.; OchigboA.E (2022) Combining Ability Estimates and Heterosis for Yield and Yield Components in Rice (Oryza sativa L.) in Nigeria, Global Journal of Agricultural Research, Vol.10, No.5, pp.10-27
Keywords: Rice, Yield, combining ability, heterois
