The existence of hybrid vigour with high heritability in vegetative traits of Gongronema latifolia will increase its productivity. This study was therefore undertaken to estimate heterosis and heritability in the vegetative traits of G. latifolia. Stem cuttings of five heterozygous parents of different geographical origin, and seeds of 10 hybrids resulting from their crosses were laid out in a randomized complete block design with three replications in a field. Data on the vegetative traits were obtained at the maximum growth period in each year of study and was used to estimate heterosis and heritability over the years. Better parent heterosis (BPH) ranged from -72% to 78% over three years. All the vegetative traits—with the exception of cordate base size—showed positive heterosis in a minimum of four cross combinations in two years. The cross AKS-33-EKPENE EDIENE X ANS-53-AWKA gave a higher BPH ranging from 5% to 6% in leaf area in the three years. The crosses ENS-48-MBU X IMS-50-NJIABA and ENS-48-MBU X ANS-53-AWKA gave higher BPH for leaf length and breadth for the first two years. All crosses showed positive and negative BPH for number of vines/plant and cordate base size, respectively. The hybrids ENS-48-MBU X IMS-50-NJIABA and EBS-49-ISHIAGU X IMS-50-NJIABA, with highly heritable BPH > 60 cm2 leaf area, will be selected in favour of other hybrids and parents. The selection of these hybrids will improve and maintain productivity in the species as the leaves are the harvestable part and the species is vegetatively propagated.
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