Abstract

Umma Salma Tonny, Abdullah Al Faroque, Rafiqul Islam Sarder and Fazlul Awal Mollah

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 followed 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 obtained 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 improvement and conservation.