Genetic variability in a crop population is important for
successful plant breeding. Sixteen cucumber (
Cucumis sativus
L.) genotypes were evaluated in the early and late
planting seasons to estimate the magnitude of their genetic
variability and heritability. Genotypes were also classified
into groups based on the performance and determination of
the highest discriminating trait that accounted for greater
variability using cluster analysis and principal component
analysis (PCA), respectively. The measured agronomic
traits were vine length, number of branches, number of
leaves, and leaf area 8 wk after planting, days to flower
initiation, days to 50% flowering, number of staminate
flowers per plant, number of pistillate flowers per plant, fruit
length, fruit girth, fruit weight per plant, number of fruits
per plant, mean fruit weight, and total fruit yield ha
-1. A high
coefficient of variation was recorded for most traits in both
seasons and high variability was found among genotypes.
High broad-sense heritability was associated with all the
traits in both seasons, except for mean fruit weight in the
early planting season and fruit girth, mean fruit weight, and
total fruit yield in late planting season. Cluster analysis
and its comparison of means showed that ‘Beit Alpha’,
‘Ashely’, ‘Straight 8’, and ‘Sumter’ from cluster F in the
early planting season and ‘Beit Alpha’ and ‘Ashely’ from
cluster E in the late planting season expressed the best
agronomic traits and yield potentials. Hence, selection for
any trait would favor genotypes in these clusters. Principal
component analysis involved vine length as the most
discriminating trait that accounted for greater variability in
cucumber in both the early and late planting seasons, and it
should be considered in cucumber improvement programs.
