Mitochondrial DNA cytochrome-b assisted DNA barcoding for the exploration of spatio-genetic variation among the population of Labeo rohita from different parts of India

Abstract

Labeo rohita, of the Cyprinidae family, is one of the most important fish species in any aquaculture system, with immense potential in terms of both commercial production and biodiversity maintenance. Accordingly, in order to find out the spatio-genetic variation and uncover any divergence in the population structure among the Labeo rohita population, partial sequencing of the 425 bp cytochrome b (mt Cytb ) gene was carried out. The study revealed the presence of eleven haplotypes with nine polymorphic sites, of which 2 are singleton sites and six parsimony informative sites. It was observed that the haplotypes obtained from the same water system clustered separately, which suggests the variability due to the spatial distribution of the population in different environmental conditions. These detected high phenotypic differences between the rivers lead us to think and investigate that the divergent populations may have evolved over time and have been undergoing mutation. They may undergo micro-evolutionary processes and differentiate into genetically distinct sub-populations or stocks over time if reproductively and geographically isolated. Thus, the study signifies the presence of the huge biodiversity of Labeo rohita in the Indian River systems, which helps the species to adapt to the environmental changes and will also prove helpful for the breeding of new and better adaptable strains suitable for the climate change scenario.