Molecular Variability of Ocimum gratissimum L. Accessions Using RAPD Marker

Aim: This study investigated the molecular variability among accessions of Ocimum gratissimum from selected states in Nigeria and Mali using RAPD marker.

Study Design: The experimental design was complete randomized design (CRD) with three replicates.

Materials and Methods: Twenty accessions of Ocimum gratissimum were collected from nineteen selected Local Governments in four South-western States of Nigeria (Ogun, Oyo, Osun and Lagos) and Mali, to assess their genetic diversity and phylogenetic relationship. Molecular statistics of binary data generated from Random Amplified Polymorphic DNA (RAPD) marker was conducted using numerical taxonomic and multivariate analysis (NTSYS-PC) package, while dendrogram was constructed by Jaccard’s similarity coefficient using unweighted paired group method of arithmetic mean (UPGMA).

Results: Accession Y3 from Ona-Ara yielded the highest total volume of DNA concentration (736.9 µ/l), while the highest genomic DNA concentration of 2.44 ng/ was recorded in accession L-04 from Agege.

Out of total number of 52 bands from three primers of RAPD, 48 produced polymorphic amplified products. OPO-08 primer was highly polymorphic with 94.73%, and had the highest allele numbers, gene diversity and polymorphic information contents of 16.0, 0.914 and 0.909 respectively, while OPO-06 produced the highest number of 20 polymorphic bands. Cluster II was the highest group in the dendogram, and comprised of two states (Oyo and Lagos) and Mali which constituted seven accessions; Y-03 (Ona-Ara), Y-04 (Egbeda), Y-05 (Ido), L-01 (Surulere), L-03 (Ifako-Ijaye), L-04 (Agege) and M (Mali).

Accession S-03 from Ife-North was the most distant with highest similarity index of 1.188.

Conclusion: The RAPD is highly polymorphic, and could be useful in characterizing and revealing wide range of genomic variation and phylogenetic relationship among different accessions of O. gratissimum with broad genetic base.