Phenotypic diversity of pumpkins from western Kenya using fruit morphological characters

Abstract

Pumpkin (Cucurbita spp.) is an important indigenous crop in Africa with high nutritional, medicinal and economic value. In Kenya, pumpkins still remain underutilised and neglected; as a result may face extinction. In this study, morphological diversity of eighty pumpkin samples from eight counties in western Kenya were evaluated based on qualitative and quantitative fruit characters, using International Plant Genetic Resources Institute (IPGRI) minimum descriptor for Cucurbitacea as a scoring guide. Principal component analysis (PCA) and cluster analysis of the morphological data, was conducted using XLSTAT 2017 software. Results showed that the first four principal components (PCs) were the most significant, accounting for a total variation of 73.85%. A scatterplot of the first two PCs accounted for 50.19% of the total variation. Majority of the samples were densely scattered. Cluster analysis and the similarity dendrogram grouped the samples into five clusters. The most effective characters for discriminating pumpkin fruits were fruit diameter, fruit width, fruit length, and length to diameter ratio. These may be described as fruit yield characters with desirable traits for productivity, therefore, presenting a good opportunity for breeders to improve pumpkins and for screening and selecting germplasms.

Key words: Cucurbita spp., IPGRI, morphological diversity