Genetic differentiation among varieties of a Neotropical savanna tree

The Neotropical savanna fruiting tree species, Hancornia speciosa (Apocynaceae) has high social and economic importance in Brazil. Originally classified as six botanical varieties, more recently only two have been recognised.

In a study of the genetic diversity and structure of over 750 individuals from 28 populations Collevatti et al. found five distinct genetic groups, supporting the older classification. Although there was evidence of high historical gene flow between populations in the central geographical range, genetic differentiation was associated with geographical distance between populations. Although genetic variation was not apparently linked to climatic or soil conditions, areas of higher historical climatic suitability in Central Brazil have higher genetic diversity. The authors suggest that this population forms a climatic refuge has facilitating the long-term persistence and genetic connectivity of populations in the region.