Abstract
Genetic diversity in four geographically distinct rohu (Labeo rohita) populations such as rohu Khulna, rohu India, rohu Faridpur and rohu Barisal was determined by RAPD. The banding pattern showed that rohu India was genetically different from the rest three. A total of 87 bands were found in four rohu populations where 35 bands were polymorphic, indicating 48.38% polymorphisms with an average of 12 bands per primer. The molecular size of amplified DNA fragments ranged from 400 to 1250 bp. Eight unique bands were observed in the four populations of which six were found in rohu Indian population. The genetic distance was highest (0.7221) and genetic identity was lowest (0.4857) between rohu India and rohu Barisal populations. Among three local varieties, the lowest genetic distance and highest genetic identity were found between rohu Khulna and rohu Faridpur populations. The UPGMA dendrogram segregated four populations of rohu into three major clusters - C1, C2 and C3. Rohu India was positioned at a fully different cluster - C3, rohu Khulna was placed in C2 and the rest two populations in C1.