Assessment of genetic variation of wild rohu Labeo rohita (Hamilton 1822) populations using microsatellite markers

Abstract

For genetic improvement and management of stocks of the Indian major carp, Labeo rohita, assessment of 
genetic variation of wild stocks is essential. Six dinucleotide microsatellite loci Lr3, Lr12, Lr14b, Lr21, Lr24 
and Lr26 were analyzed to test the genetic variability of three populations of L. rohita collected from three 
different rivers, the Halda, the Jamuna and the Padma, and the analyzed loci were found to be polymorphic 
(P95) in all the populations. The average number of allele was highest (4.16) in the Jamuna population fol
lowed by the Halda (3.66) and the Padma populations (3.16). The average observed heterozygosity (0.633) 
was highest in the Padma population while the highest average expected heterozygosity (0.607) was ob
tained in the Jamuna population. Relatively low level of FST (0.034) and high level of Nm (7.043) was detected 
between the Jamuna and the Padma populations, while high level of FST (0.068) and low level of Nm (3.417) 
was detected between the Halda and the Padma populations. The Nei's (1972) genetic distance (D) between 
the Halda and the Padma populations was the highest (0.167) while that was the lowest (0.073) between the 
Jamuna and the Padma populations. The results indicated a relatively low level of genetic variation among 
the wild stocks of L. rohita and suggested that necessary measures need to be taken for its stock im
provement and conservation.