Geographical genetic structuring and phenotypic variation in the Vellozia hirsuta (Velloziaceae) ochlospecies complex

• Published in: American journal of botany Vol. 99; no. 9; pp. 1477 - 1488
• Main Authors: Barbosa, Ariane R, Fiorini, Cecília F, Silva-Pereira, Viviane, Mello-Silva, Renato, Borba, Eduardo L
• Format: Journal Article
• Language: English
• Published: United States Botanical Society of America 01.09.2012; Botanical Society of America, Inc
• Subjects: Anatomy; Bayes Theorem; Biological taxonomies; campos rupestres; center of diversity; chloroplast DNA; Climate change; Cluster Analysis; DNA, Chloroplast - genetics; DNA, Intergenic - genetics; Evolution; Evolution and Phylogeny; Evolutionary genetics; forests; Genetic Variation; Genetics, Population; Genotype & phenotype; Geographic regions; Geography; Haplotypes; Haplotypes - genetics; intergenic DNA; lowlands; Magnoliopsida - anatomy & histology; Magnoliopsida - genetics; Morphology; Nonnative species; ochlospecies; Paleobotany; Phenotype; phenotypic variation; Phylogeny; phylogeography; Plants; Pleistocene; Population genetics; Population geography; Vegetation; Vellozia; Brazil
• ISSN: 0002-9122; 1537-2197
• DOI: 10.3732/ajb.1200070

• Premise of the study: Vellozia hirsuta forms a complex presenting wide morphological and anatomical variation, resulting in five specific names and 14 morpho-anatomical patterns occurring in disjunct populations. We carried out a phylogeographical study to investigate the existence of correlation among the genetic and morphological patterns within this complex, and to determine whether it is composed of various species or should be treated as an ochlospecies, a species having widely polymorphic and weakly polytypic complex variation, with morphological characteristics varying independently.• Methods: We carried out phylogeographical analyses using cpDNA rpl32F-trnL intergenic region.• Key results: We found 20 haplotypes in 23 populations sampled. The populations are genetically structured (ΦST = 0.818) into four phylogeographical groups demonstrating geographical structuring but with no correlation with morpho-anatomical patterns. Our analyses do not support recognizing any of the species now synonymized under Vellozia hirsuta. The northern populations were the most genetically differentiated and could be considered a distinct taxon, as they are also morphologically different.• Conclusions: It is recommended that Vellozia hirsuta be considered a single enormously variable species. The patterns of variation within V. hirsuta probably are related to climatic changes that occurred during the Pleistocene Epoch in tropical Brazil when reductions in forest cover favored the expansion of V. hirsuta populations into extensive lowland areas. The expansion of forest cover at the end of the glaciations would have again restricted the occurrence of campos rupestres vegetation to high elevations, which constitute the current centers of diversity of this species.