Genetic Variability, Coefficient of Variance, Heritability and Genetic Advance of Pro-Vitamin A Maize Hybrids

2017

English

Vitamin A deficiency (VAD) is a worldwide nutritional problem affecting especially children and pregnant women. A long term solution to VAD and probably much safer is cultivation of biofortified crops through home gardening and commercial production with crops that are high in pro-vitamin A. Breeding for Pro-vitamin A (PVA) maize varieties requires a thorough understanding of the genetic mechanisms governing yield and the PVA trait. Genetic variability for example may influence breeding programmes while heritability studies give important information about traits that are normally transferred from parents to their offspring and their successive generations. The objective of this study therefore was to determine the genetic variability, genotypic coefficient of variance (GCV), phenotypic coefficient of variance (PCV), heritability and genetic advance (GA) of pro-vitamin A maize hybrids with the aim of obtaining information for selecting and breeding for PVA maize varieties. The parents for the crosses included Akposoe (Quality Protein Maize (QPM) variety 80-85 days maturity), Aburohemaa (QPM variety 90 days maturity), Honampa (normal orange PVA variety 110 days maturity) and ZM305 (normal orange PVA inbred line 85 days maturity). Field evaluations were conducted in 2014 major and minor seasons in 8 environments. The number of entries was 20 made up of the parents and their crosses. The design was an RCBD with 3 replications. Results from the studies indicated that narrow sense heritability of PVA was high (87%) in the top cross hybrid but very low (6-14%) in the varietal cross hybrids. High narrow-sense heritability coupled with high values of PCV, GCV and GA as a percentage of the mean for PVA content in the top cross hybrid obtained from this study implied that this trait was mostly controlled by additive genes and was highly heritable. Thus, progress in selection for this trait could be achieved more quickly and hybridization as well as synthetic breeding could be recommended.

Ewool, M. B.; Akromah, R.