Diversity and genetic structure in natural populations of Geonoma schottiana Mart (Arecaceae): implications for conservation

Abstract

Geonoma schottiana is an underbrush palm which is found in high densities in tropical forests. This species is known for having an asynchronous fruit producing pattern, over all seasons of the year, thus being an important food source for frugivores. This work aims to determine the diversity and spatial genetic structure of two natural populations, referred to as MC I and MC II, of which 60 individuals were sampled, in Poço Bonito Biological Reserve, Lavras, Minas Gerais state. Results of 10 polymorphic isozyme loci indicated a high genetic diversity for the species (Ĥe = 0.428 and Ĥo = 0.570), with an mean number of alleles per locus of 2.0. Estimates of Cockerham’s coancestry coefficients indicated an absence of intrapopulation (f = -0.343) and interpopulation inbreeding (F = -0.161), suggesting that on average populations are not endogamous. A high genetic divergence was found between populations (p θ ˆ = 13.5%), in comparison to most tropical species (<5%). Consequently, the estimated historical gene fl ow was low (Nˆ m = 0.40). The analysis of spatial distribution of G. schottiana genotypes in MCI revealed a random distribution of genotypes. The high genetic diversity indices found suggest that the populations in question favor in situ genetic conservation, consequently favoring the conservation of riparian environments. Key words: Allozymes, spatial genetic structure, genetic conservation.><5%). Consequently, the estimated historical gene fl ow was low (Nm = 0.40). The analysis of spatial distribution of G. schottiana genotypes in MCI revealed a random distribution of genotypes. The high genetic diversity indices found suggest that the populations in question favor in situ genetic conservation, consequently favoring the conservation of riparian environments.