Genotypic variation of Kenyan tomato (
Lycopersicon esculentum
L.)
germplasm
Systematic genotypic analysis of Kenyan tomato germplasm was carried out in
order to delineate potential variability based on various morphological,
agronomic and biochemical traits. Both landraces and market cultivars were
examined with a view to facilitating tomato improvement. In an experiment
conducted in 1993 in a glasshouse at the Federal Agriculture Research Centre
(FAL), Germany, 26 tomato landraces and nine market cultivars were investigated
using block design. Analysis of variance clearly illustrated a large variation
for all the quantitative traits. Landraces on average produced more fruit per
plant (90) but of a smaller size than the market cultivars (19). However, market
cultivars had a superior average fresh fruit weight of 56.5g while the landraces
registered on average 40.6 g. Multiple correlation analysis confirmed the
superiority of landraces for trait of fruit quality and a strong negative
association between fruit weight. Limited structure groupings were detected on
the basis of a principal components analysis. Using this method, processing and
fresh tomato cultivars within the germplasm could be clearly separated on the
basis of fruit characters. Furthermore, this analysis distinguished a few
landraces from the market cultivars, although closer phylogeny through
introgression was highly suspected. Within the landraces, the yellow-cherry
types were distinct from all the others, On the basis of this study, the use of
more prolific landraces, in terms of number of fruit as well as actual fruit
yield, would be desirable for intensive and continuous production of tomatoes.
