Allozyme diversity in South Western Ghats populations of Terminalia paniculata Roth. (Combretaceae)

Abstract

Terminalia paniculata Roth. (Combretaceae) is a tropical tree with a large natural distribution in Western Ghats. The tree is extensively utilized in pharmaceutical, timber tannin, leather and silk industries. However, the species has been overexploited and information on its existing gene pool is currently lacking. The present work was therefore carried out using allozyme markers to assess the genetic diversity within and between populations in order to suggest conservation and management strategies. Six enzyme systems generated 15 loci from four populations which were used to estimate allele frequency, percentage of polymorphic loci, observed heterozygosity (Ho) and expected heterozygosity (He) and Shannon information index. In the Sasthakovil populations 12 rare alleles, two private alleles (AAT-1C and PGM -2C), and a high level of polymorphism (86.66%) were observed. The levels of heterozygosity observed in all populations were lower than expected from Hardy-Weinberg equilibrium values, except Sasthakovil populations. As a priority, the population at Sasthakovil may be targeted for conservation. This would ensure the conservation of a relatively rich proportion of genetic diversity and presence of private allele representative of that existing in other populations. Key words: Allozyme, genetic variation, allele frequency, heterozygosity, homozygosity.