Assessment of Genetic Diversity among Elite Cultivars of Ricinus communis L. Using RAPD Markers for Plant Breeding

The present investigation screened the diversity among 19 elite cultivars of castor bean (Ricinus communis L.) genotypes based on RAPD markers together with morphological traits in an approach to mine genes governing commercially important traits for future crop improvement programmes. A total of six primers were selected from an initial screening of 64 RAPD primers. The frequency of polymorphic amplicons observed among cultivars varied greatly from 0.05 to 0.95 in all 19 cultivars. A dendrogram showing genetic similarities among the cultivars was constructed based on the polymorphic bands using UPGMA cluster analysis. The UPGMA clustering method revealed two major groups. The first one was made up of two cultivars, ‘DCH 190’ and ‘RG 90’ while the remaining cultivars were clustered into the second group. Cultivars belonging to the second group were grouped into five sub-clusters. Genetic differences ranging from 0 to 0.86 among the cultivars indicate a diverse gene pool in the castor bean genotypes studied. Morphological and RAPD tools to determine genetic diversity among R. communis cultivars were established.