GENETIC-DIVERGENCE AMONG INDIAN AND OTHER CONTINENTAL POPULATIONS OF DROSOPHILA-MELANOGASTER

Fourteen Indian natural populations of D. melanogaster collected along 22 degrees latitudinal range were analysed electrophoretically so as to compare the geographical patterns of allozymic variation at thirteen loci. Acph, Mdh-2 and five esterase loci (Est-1 to Est-5) revealed monomorphisrn while the other loci were found to be highly polymorphic. The genetic structure of Indian D. melanogaster populations were characterised by significantly higher values of genetic indices as compared with other continental populations. Indian geographical populations of D. melanogaster revealed higher genic differentiation on the basis of moderate to higher F-ST values. Significant statistical correlation of allelic frequencies with latitude was observed. The patterns of genic differentiation in D. melanogaster populations were comparable to those of populations from other continents. The present data on clinal allozymic variation in Indian populations of D. melanogaster further support and validate the hypothesis that occurence of parallel or complementary latitudinal dines across different continental populations provide strong evidence of natural selection maintaining such clinal variation.