| dc.description.abstract | The objective of this study was to investigate the
presence of heritable variation in Kenyan landrace
populations of spiderflower (Gynandropsis gynandra (L)
Briq) and assess the utility of yield components in the
improvement of yield and duration of .harvesting through
the c'~ponent breeding approach. Genetic componenCS of
variat10n and expected gain from selection as a percentage
of the population mean were estimated from an S famdly
mating design. The experiment was conducted during the
short rains of 1988 and the long rains of 1989 at the
Field Station of the University of Nairobi, Kabete Campus
and the National Horticultural Research Station, Thika.
Twenty S families from each population were planted in a
three-replicate compact family block design at both sites.
The data was collected for days to flowering, plant
hei9ht, number of primary leaves, leaf length, leaf
breadth, fresh leaf weight and dry leaf weight. The
analysis was based on family means.
The results indicated that there was significant
variation among populations for leaf length and dry leaf
weight at Thika and number of primary leaves at Kabete.
This reflected a variation in the yield potential of the
populations. Significant variation was detected within
population E for days to flowering and population M for
both fresh leaf yield and dry leaf yield. Yield prediction
studies revealed that duration of harvesting could be
prolonged by selecting late flowering genotypes in
population E. Dry leaf yield and fresh yield could be
improved by direct selection in population M. There was no
inherent variation for any of the traits studied in
populations P, Q, D and I. Therefore.the improvement of
these population would necessitate the creation and
maintenance of genetic variability by incorporation of
genes from other populations and intermating within the
populations. | en |
