Distribution patterns of cultivated watermelon forms in Zimbabwe using DIVA-GIS

Abstract

Identification of potential areas and regions for collection of watermelon germplasm is pivotal for better utilization of the available diversity. DIVA-GIS were used on all watermelon collections in the National Genebank of Zimbabwe to explore the pattern of distribution of two forms of watermelons; sweet watermelon (Citrullus lanatus var. lanatus) and cow-melon (Citrullus lanatus var. citroides). DIVA-GIS analysis revealed that most watermelon accessions have been collected at altitudes ranging from 160 to 1550 m above sea level, and that sandy loam and sand soils apparently are preferred. Distribution of the two forms of watermelons across soil types, altitudinal ranges and provinces is similar. In order to maintain watermelon diversity, promotion of in-situ or on-farm conservation of watermelon genetic resources using best practices in traditional farming system is recommended. Furthermore, this should be complemented by ex-situ conservation through gap collection missions in order to identify and document additional diversity hotspots. Key words: DIVA-GIS, sweet watermelon, cow-melon, Citrullus lanatus, in-situ, on-farm conservation.