Diversity and genetic structure of the monotypic genus Colombobalanus (Fagaceae) in Southeast of Colombian Andeans

Colombobalanus is a genus with a single species Colombobalanus excelsa, currently categorized as vulnerable (VU) and known from only five localities in the Colombian Andes. We analyzed the diversity and genetic structure of four C. excelsa forest remnants in one locality in the coffee-producing area of the southeastern corner of Department of Huila, Colombia. Samples from ten trees were collected from each forest remnant for a total of 40 sample leaves, which were analyzed using 7 microsatellite markers. The resulting data matrix was used to perform genetic diversity (H_e), genetic structure (F_ST), and genetic distance analyses, as well as the Jaccard similarity index. Fourteen alleles were found for the entire population, with a heterozygosity (H_e) of 0.2797 and a genetic structure (F_ST) of 0.049. These indices suggest that the forest remnants are members of a panmictic population with historical patterns of genetic flow. The results also allow us to conclude that the low number of alleles found in these populations compared with other populations in the country show a signature of historical bottleneck in these forest remnants, where few individuals were seedlings of C. excelsa due to the disturbances caused by human activity.