title: Molecular systematics of the Amazonian genus Aldina, a phylogenetically enigmatic ectomycorrhizal lineage of papilionoid legumes.
abstract: Aldina (Leguminosae) is among the very few ecologically successful ectomycorrhizal lineages in a family largely marked by the evolution of nodulating symbiosis. The genus comprises 20 species predominantly distributed in Amazonia and has been traditionally classified in the tribe Swartzieae because of its radial flowers with an entire calyx and numerous free stamens. The taxonomy of Aldina is complicated due to its poor representation in herbaria and the lack of a robust phylogenetic hypothesis of relationship. Recent phylogenetic analyses of matK and trnL sequences confirmed the placement of Aldina in the 50-kb inversion clade, although the genus remained phylogenetically isolated or unresolved in the context of the evolutionary history of the main early-branching papilionoid lineages. We performed maximum likelihood and Bayesian analyses of combined chloroplast datasets (matK, rbcL, and trnL) and explored the effect of incomplete taxa or missing data in order to shed light on the enigmatic phylogenetic position of Aldina. Unexpectedly, a sister relationship of Aldina with the Andira clade (Andira and Hymenolobium) is revealed. We suggest that a new tribal phylogenetic classification of the papilionoid legumes should place Aldina along with Andira and Hymenolobium. These results highlight yet another example of the independent evolution of radial floral symmetry within the early-branching Papilionoideae, a large collection of florally heterogeneous lineages dominated by papilionate or bilaterally symmetric flower morphology.
authors.affiliation: Departamento de Botânica, Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s.n., Ondina, 40170-115 Salvador, Bahia, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Ramos
authors.affiliation: Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, 22460-030 Rio de Janeiro, Brazil.
authors.forename: Haroldo Cavalcante
authors.initials: HC
authors.lastname: de Lima
authors.affiliation: Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Prenner
authors.affiliation: Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s.n., Novo Horizonte, 44036-900 Feira de Santana, Bahia, Brazil.
authors.forename: Luciano Paganucci
authors.initials: LP
authors.lastname: de Queiroz
authors.affiliation: Instituto Nacional de Pesquisas da Amazônia (INPA), Department of Biodiversity, Av. André Araújo, 2936, Petrópolis, 69060-001 Manaus, Amazonas, Brazil.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Zartman
authors.affiliation: Departamento de Botânica, Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s.n., Ondina, 40170-115 Salvador, Bahia, Brazil; Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Av. Transnordestina, s.n., Novo Horizonte, 44036-900 Feira de Santana, Bahia, Brazil. Electronic address: cardosobot@gmail.com.
authors.forename: Domingos
authors.initials: D
authors.lastname: Cardoso
mesh_terms: D001499:Bayes Theorem; D005075:Biological Evolution; D002736:Chloroplasts / Q000235:genetics; D007887:Fabaceae / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics / Q000382:microbiology*; D035264:Flowers / Q000033:anatomy & histology; D016013:Likelihood Functions; D038821:Mycorrhizae; D010802:Phylogeny; D053204:Root Nodules, Plant / Q000382:microbiology; D013559:Symbiosis
keywords: Floral symmetry; Leguminosae; Papilionoideae; Phylogeny; Swartzieae