Reliability of the RAPD technique for germplasm analysis of sesame from Venezuela

The random amplified polymorphic DNA (RAPD) technique was used to evaluate two commercial cultivars (Fonucla and UCLA-1) and 7 lines (UCLA-249; UCLA-295; UCLA-37-1; UCLA-65; UCLA-83; UCLA-90; UCV-2) of sesame (Sesamum indicum L) obtained by the breeding program of the Universidad Centroccidental Lisandro Alvarado, Venezuela. Ninety four polymorphic bands using 12 random 10-mer primers indicated a high level of variability. Three primers were able to discriminate 8 out of the 9 materials and, in combination, they were able to resolve all of them. Probability of identical match by chance was 5.22×10-29. Polymorphic information content (PIC), resolving power (RP) and marker index (MI) of each primer failed to correlate significantly with number of genotypes resolved. Unique bands were observed in 6 genotypes with 9 primers. Jaccard’s similarity coefficients ranged from 0.04 to 0.53. UPGMA clustering resulted in two major groups and the genotype classification agreed closely with the grouping observed when using principal coordinates analysis (PCA). The results of the present study showed that RAPD-based fingerprinting was a useful tool to identify unequivocally the sesame genotypes and to assess the genetic variability of the breeding stocks.