Genetic Characterization of Cashew (Anacardium occidentale L) Cultivars from Benin

Abstract

Cashew (Anacardium Occidentale L.) is a fruit plant introduced in Benin in 1950 and is widely cultivated in private plantations in three regions (Central, North East and North West) of the country. These plantations contain different varieties of cashew with reduced productivity and quality of nuts. In this study we characterized the genetic diversity of Benin’s cashew accessions by SSR (simple sequence repeat) markers. Sixty cashew morphotypes from three regions of Benin, West Africa, were analyzed using eight SSR markers. A total of 146 polymorphic bands were produced. The polymorphic bands showed low genetic diversity (Shannon index = 0.04) that are relatively important for an imported species. Low diversity was found in North western regions compared to the other two regions (Center and North East). Genetic distance-based UPGMA dendrogram and Principal Coordinate Analysis (PCoA) showed a genetic differentiation between morphotypes. This genetic differentiation allowed us to cluster the samples into three clusters based on their genetic variations. This work further provides genetic information for the improvement of cashew production, conservation and better management of A. occidentale genetic resources in Benin.