IBODA   05360
INSTITUTO DE BOTANICA DARWINION
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A molecular phylogeny and classification of Verbenaceae.
Autor/es:
MARX, H., N. OLEARY, Y. YUAN, P. LU-IRVING, D. TANK, M.E. MÚLGURA & R. OLMSTEAD.
Lugar:
La Plata, Buenos Aires, Argentina
Reunión:
Otro; IX Reunión Argentina de Cladística y Biogeografía,; 2010
Institución organizadora:
Fac. Ciencias Naturales y Museo, La Plata
Resumen:
Verbenaceae
consist of trees, shrubs, lianas, and herbs distributed primarily in Latin America where they occur in a wide array of
ecosystems. Seven chloroplast DNA
regions were analysed for 121 samples representing 109 species of Verbenaceae
and 18 outgroup species from other families in Lamiales. The 109 ingroup taxa represent 33 genera,
including all but one (Verbenoxylum) genera. Sampling within genera attempted to reflect
generic and tribal diversity in the family, resulting in relatively less sampling
of species-rich genera such as Lippia, Lantana, Glandularia, Citharexylum,
and Stachytarpheta. Overall this study presents the most extensive
phylogenetic study in terms of both taxa and geographic distribution of the
Verbenaceae. Three datasets were compiled and analyzed to accommodate the two
sampling strategies: 1) all 139 accessions for two regions (ndhF, trnLF),
2) 33 accessions for all seven regions, and 3) all 139 accessions for all seven
regions (with missing data scored for the taxa unsampled for the other five
regions). Sequence lengths ranged from
903 nucleotides (nt) in Pitraea cuneato-ovata to 941 nt in Priva
lappulacea, and yielded an aligned length of 1232 bp, of which 287
positions were parsimony informative.
This study provides the first phylogeny of Verbenaceae with
comprehensive, genus-level sampling. By
including sufficient outgroup sampling, this study confirms the monophyly of
Verbenaceae (ML bs = 98%; MP bs = 92%; pp = 1.0; also a unique 6 nt deletion in
trnLF). These analyses identify eigth well-supported clades, recognized as
tribes (Casselieae, Citharexyleae, Duranteae, Lantaneae, Neospartoneae trib.
nov., Petreeae, Priveae, Verbeneae), some of which correspond to tribal level
groups in recent classifications, but with many differences relative to those
treatments. The main stem of the tree also is moderately to well-supported and
resolution is weak or missing only among terminal clades of closely related
species (e.g., within tribe Lantaneae and Citharexylum). The
small group Petreeae, consisting of Neotropical lianas, is sister to the rest
of the family, with Duranteae forming the second branch. Casselieae and Citharexyleae together form a
well-supported clade, which is sister to a large clade comprising Priveae,
Neospartoneae trib. nov., Verbeneae, Lantaneae, and the two small genera, Dipyrena
and Rhaphithamnus, which remain unplaced in these larger clades.
Priveae, Rhaphithamnus, and then Neospartoneae diverge in sequence,
leaving a clade comprised of the two most species rich clades, Verbeneae and
Lantaneae. One new tribe, Neospartoneae trib. nov., is recognized to
accommodate three small genera of Argentine species (Diostea, Neosparton,
Lampaya). A secondary distribution
in Verbenaceae occurs mostly in Africa, with a few species in Europe and Asia. Phylogenetic
inference suggests a South American origin for Verbenaceae, with approximately
six colonization events giving rise to the Old World
species.