Ramos Ana Carolina Simões, De Lemos-Filho José Pires, Lovato Maria Bernadete
Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, Belo Horizonte, MG, 31270-901, Brazil.
J Hered. 2009 Mar-Apr;100(2):206-16. doi: 10.1093/jhered/esn092. Epub 2008 Oct 30.
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.
对来自巴西中南部塞拉多生物群落的大西洋森林和河岸森林中的巴西孪叶豆（Hymenaea courbaril var. stilbocarpa）的系统地理学进行了研究。将这些数据与其同属的典型稀树草原树种具刺孪叶豆（Hymenaea stigonocarpa）的数据进行了比较。在塞拉多，巴西孪叶豆生长在与具刺孪叶豆相邻的地点，它们具有共同的生活史特征。对149株巴西孪叶豆个体的叶绿体DNA的psbC/trnS3区域进行了测序。在该物种中发现了高遗传变异，鉴定出18个单倍型，这与在同一地理区域发现的具刺孪叶豆的23个单倍型情况类似。巴西孪叶豆种群可分为3个系统地理组。分子变异的空间分析表明，46.4%的遗传变异是由于这些组之间的差异所致。巴西孪叶豆和具刺孪叶豆共有3个单倍型，总遗传变异中只有10.5%可归因于种间差异。我们推测，在冰川时期，巴西孪叶豆种群在其现今分布区域的南部大部分地区一定已经灭绝。气候改善后，这些地区可能是从北部和东部重新定殖的。异域分布的孪叶豆物种相对相似的系统地理结构表明，它们在第四纪气候波动期间受到了相同的影响。这两个孪叶豆物种单倍型的共享和遗传相似性表明存在祖先多态性和/或杂交现象。
