GENETIC VARIABILITY IN WILD POPULATIONS OF (Clarias gariepinus) USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) MARKER FOR SELECTIVE BREEDING

Abstract

Utilisation of molecular markers-assisted genetic variability study is critical and imperative for a more robust selection and breeding programmes in aquaculture. Polymorphism and genetic variation in wild populations of Clarias gariepinus using Random Amplified Polymorphic DNA (RAPD) marker were investigated in this study. Twenty (20) C. gariepinus species were randomly selected five (5) individuals each from four locations-Argungu (ARG), Yauri (YUR), in Kebbi State, Eleyele (ELY)
and Oba (OBA), in Oyo State, Nigeria. Genomic DNA extraction and purification from caudal fin tissue sample was performed, primed using OPA09, OPA11 and OPA13 RAPD primers and amplified using polymerase chain reaction (PCR). The amplified fragments were ran on gel electrophoresis and visualized under ethidium bromide dye. Band scoring from gel and band size calculation was done to establish polymorphism. The population genetic analysis was done. The computer package was used
to construct an Un-weighted Pair Group Method of Algorithms (UPGMA) dendrogram among populations. Polymorphism revealed by each fish population ranged from 46.67 – 80.00%. The gene diversity of C. gariepinus species from ELY was highest (0.342) followed by ARG (0.335) while, those of YUR (0.287) had the least. Present result showed that C. gariepinus strain from ELY and ARG exhibited a genetic identity of 0.779 while, they were distant apart from each by 0.250. UPGMA dendrogram generated two major clusters. From the findings, it was concluded that there is wide genetic variation in the populations studied, which could encourage selection of C. gariepinus from ARG and ELY populations for the purpose of breeding and improvement.