Molecular diversity of Oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae) in Karnataka

Elucidation of genetic variation in geographical populations is an important aspect to study the pest populations and their management. Within an ecosystem, the extent of genetic variation between geographical populations depends on several factors, including gene flow between populations, host range, climatic factors etc. The genomic DNA was extracted from male flies of Bactrocera dorsalis (Hendel) collected from different agro ecological regions of Karnataka using modified 2% Cetyltrimethylammonium bromide (CTAB) method. 170 decamer primers, randomly selected from OPA-OPZ, OPAA-OPAX, OPBA-OPBD and OPYO series were screened and 51 primers which produced reproducible bands and were tested across the DNA samples. The RAPD-PCR of 31 DNA samples of B. dorsalis populations yielded 169 scorable bands. The per cent polymorphism varied from 33.33% to 100% and an average of 71.66%. The Jaccard s similarity coefficients ranged from zero to 0.91. UPGMA dendrogram generated by RAPD data indicated the segregation of populations into three clusters. Genetic diversity plays an important role in the survival and adaptability of a species therefore B. dorsalis populations of different agro ecological regions have undergone changes probably to survive or the changes are consequent to interplay between genes and the environment in which they have adapted.