Morphological Characterization of Selected Pumpkin (Cucurbita Pepo L.) Accessions in Baringo County, Kenya

Abstract

Pumpkin is one of the most morphologically variable genera in the entire plant kingdom and most cultivated plant in all tropical and subtropical regions of the world. It is an annual herbaceous plant, highly branched with creeping or climbing branches. They are mainly cultivated as a marginal crop often on the edges of field crops or scantly scattered between other food crops. Kenya has a wide array of pumpkin landraces, making it a secondary centre of diversity that warrants detailed characterization. Despite its importance, pumpkin yields in Kenya are still very low due to lack of improved and high yielding varieties as well as insufficient variety information regarding genetic diversity. Numerous germplasms have already disappeared due to absence of concerted efforts to collect, characterize, evaluate, document and conserve pumpkin accessions. The objective of this study was to evaluate the diversity in morphological characters of pumpkin accessions in Baringo County. A high level of genetic diversity based on morphological traits was observed in our study. This diversity could be attributed to a wide range of environmental conditions which induces variability through accession by environment interaction. The dendrogram based on UPGMA cluster analysis did not separate the accessions based on their geographical distribution instead were mainly grouped according to their morphological differences. PCA showed that the first four principal components were important and indicated seed coat color, leaf shape, flower size, number of fruits per plant, fruit weight, seed yield per plant, fruit yield per hectare, fruit diameter and 100 seed weight were the most important characters and hence were most useful for distinguishing pumpkin accessions. Queensland blue, small sugar, flat white boer, Katch and Marigat showed better yield performance across the three environments. The use of these accessions in breeding programs would contribute to improving pumpkin varieties with a high fruit yield and hence improved food security. This research study, therefore, provides important insights into the diversity in morphological traits of pumpkin accessions in Baringo County and constitutes a set of useful genetic background information that can be used as a basis for future breeding strategies and pumpkin improvement programs.