Allelic Diversity, Genetic Structure and Gene Flow of Natural Populations of Terminalia paniculata Roth. (Combretaceae) from Southern Parts of Western Ghats Revealed by Allozyme Based Assay

We examined allozyme variation in the dominant Western Ghats tree, Terminalia paniculata Roth. (Combretaceae) to determine the genetic variation within and among populations, the biogeographic relationships of populations, and the potential out breeding in the species. We surveyed four populations consisting of 50 individuals per population along a 136-km north– south transect across the Western Ghats. All six allozyme loci examined were polymorphic, with up to five alleles per locus. A survey of allozyme variability using electrophoresis revealed high species levels of polymorphism (P=86.66), allelic diversity (A= 2.66) and expected heterozygosity (He = 0.2104) and high interpopulational gene flow (Nm = 11.88). Nei's genetic distances estimated from allozymes indicated low differentiation among population. In spite of this, low frequencies of certain rare alleles and the presence of private alleles indicate that efforts should be made to conserve Sasthakovil and Courtallam populations.