Journal of Heredity Advance Access originally published online on October 30, 2008
Journal of Heredity 2009 100(2):206-216; doi:10.1093/jhered/esn092
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Phylogeographical Structure of the Neotropical Forest Tree Hymenaea courbaril (Leguminosae: Caesalpinioideae) and Its Relationship with the Vicariant Hymenaea stigonocarpa from Cerrado
From the Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, Belo Horizonte, MG, 31270-901, Brazil (Simões Ramos and Lovato); and the Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, Belo Horizonte, MG, 31270-901, Brazil (Pires de Lemos-Filho)
Address correspondence to Maria B. Lovato at the address above, or e-mail: lovatomb{at}icb.ufmg.br.
The phylogeography of Hymenaea courbaril var. stilbocarpa from Atlantic Forest and riverine forests of the Cerrado biome in central and southeastern Brazil was investigated. The data were compared with those of its congeneric Hymenaea stigonocarpa, a typical tree from savanna. In the Cerrado, H. courbaril var. stilbocarpa is found in sites contiguous with those of H. stigonocarpa, and they share common life-history attributes. The psbC/trnS3 region of the chloroplast DNA was sequenced in 149 individuals of H. courbaril var. stilbocarpa. High genetic variation was found in this species, with the identification of 18 haplotypes, similarly to what was found in H. stigonocarpa with 23 haplotypes in the same geographic region. Populations of H. courbaril var. stilbocarpa could be structured in 3 phylogeographic groups. Spatial analysis of molecular variation indicated that 46.4% of the genetic variation was due to differences among these groups. Three haplotypes were shared by H. courbaril var. stilbocarpa and H. stigonocarpa, and only 10.5% of the total genetic variation could be attributed to between-species difference. We surmise that during the glacial times, H. courbaril var. stilbocarpa populations must have gone extinct in most parts of the southern of its present-day occurrence area. After climate amelioration, these areas were probably recolonized from northern and eastern. The relatively similar phylogeographic structure of vicariant Hymenaea species suggests that they were subjected to the same impacts during the Quaternary climatic fluctuations. The sharing of haplotypes and the genetic similarity between the 2 Hymenaea species suggest the existence of ancestral polymorphism and/or hybridization.
Key Words: Hymenaea courbaril • Hymenaea stigonocarpa • phylogeography • cpDNA • Cerrado • Atlantic forest
Corresponding Editor: James Hamrick
Received June 19, 2008
Revised September 10, 2008
Accepted September 25, 2008