Two minnows, indigenous olive barb, Puntius sarana and exotic silver barb, Barbodes gonionotus are important fish species in Bangladesh. Therefore, it is essential to identify diversed population of these fish species for selective breeding programme. Sixty olive barb fish were collected from three different natural stocks (Mymensingh, Madaripur and Sylhet) and 20 silver barbs from hatchery stock of Jashore in Bangladesh. Out of 40 decamer primers tested, 5 primers were selected for the Polymerase Chain Reaction (PCR) based RAPD (Randomly Amplified Polymorphic DNA) analysis. Upon agarose gel electrophoresis, RAPD bands were scored as separately on the basis of their presence or absence for each sample and primer. A total of 43 polymorphic bands and highest proportion of polymorphic bands (62.79%) were found in the Madaripur populations. The gene diversity (0.2132±0.2067) and Shannon's Information index (0.3161±0.2950) within populations were highest in Jashore stock. Among olive barb stocks, these values were higher in Sylhet stock. Besides, four populations segregated in two main clusters based on the Neis genetic distance. Indicating the segregation of two different species of minnows, the silver barb stock made one separate cluster while other three stocks of olive barb remained in another cluster. The present study exposed a distinct pattern of genetic variation and phylogenetic relatedness that would be helpful in selecting broodfish for genetic improvement as well as in conservation of these fish species.
Key words: Genetic diversity, Polymorphic loci, RAPD analysis, Olive barb, Silver barb
|
