Characterization of Nigerian Sesame (Sesamum Indicum L.) Using Random Polymorphic DNA (RAPD) Marker

The assessment of genetic diversity among 23 sesame genotypes (Sesamum indicum L.) obtained from different locations across 10 states in Nigeria was carried out using Random Amplified Polymorphic DNA (RAPD) technique. The field trial tests were carried out on the 23 sesame accessions for two seasons to have uniform genotypes from each accessions. A standard protocol of CTAB with slight modifications was employed for DNA extracted from the harvested seeds. The extracted DNA samples were observed under UV illumination using agarose gel electrophoresis after staining with ethidium bromide. A total of 7 primers were used for PCR amplification, 5 of which have been previously used to discriminate sesame genotypes from other countries. Only 3 of the 7 primers considered produced strong amplification with the selected 23 sesame samples. A total of 47 amplified products were produced by the 3 primers among the 23 accessions all of which are 100% polymorphic. The estimates of similarity index for the 23 accessions ranged from 0.29 to 0.92. Cluster analysis revealed 2 main clusters with some of the accessions from different geographical origin cluster together in the same group which might indicate the involvement of human factor in the spread of sesame varieties in Nigeria. The relevance of RAPD to this study was evident from the high level of polymorphism reported in this study. There is therefore existence of adequate genetic diversity among the 23 Nigerian sesame accessions for sesame breeders to develop improved varieties.