Phylogenetics of Amaranthaceae based on matK/trnK sequence data - evidence from parsimony, likelihood, and Bayesian analyses

Müller KF, Borsch T

Forschungsartikel (Zeitschrift)

Zusammenfassung

Amaranthaceae and Chenopodiaceae together represent the most species-rich monophyletic group in the angiosperm order Caryophyllales. So far, phylogenetic relationships between Amaranthaceae and Chenopodiaceae have remained unclear. Previous morphological and molecular studies have indicated that most of the currently accepted infrafamilial taxa in Amaranthaceae do not reflect natural groups. With the aim to provide a robust phylogenetic framework for analyzing the evolution Of pollen and other phenotypic characters within the family, we conducted maximum parsimony, maximum likelihood, and Bayesian analyses using chloroplast matK/trnK DNA sequence data. The {Amaranthaceae-Chenopodiaceae} lineage was resolved as monophyletic, with Achatocarpaceae and Caryophyllaceae being Successive sisters. Within the monophyletic Amaranthaceae, a basal grade of Bosea L. {(Macaronesian} islands, Cyprus, Himalaya), followed by Charpentiera Gaudich. (endemic to Hawaii and the Australian Ridge) receives high support. Celosieae appear as sister to Amaranthus L. + Chamissoa Kunth. While Celosieae were Supported as natural. most other currently recognized infrafamiliar taxa were revealed to be para- or polyphyletic. Among former Aervinae, an Achyranthoid and an Aervoid clade were newly recovered. Psendoplantago Suess.., sharing some morphological features with Amaranthoideae, was found within Gomphrenoideae rather than being in a position linking both subfamilies. The evolution of morphological characters previously used for classification and of some pollen characters was analyzed based on the {matK/trnK} tree. The recently described metareticulate pollen architecture is reconstructed to have evolved once in the ancestor of a highly supported core Gomphrenoid clade that comprises the traditional Gomphrenoideae but excludes Iresine P. Browne. in contrast, the complex stellate pore ornamentation was reconstructed as having evolved at least twice in parallel. Unlike other morphological characters discussed in this paper, pollen characters in general represent morphological synapomorphies circumscribing many clades recovered with molecular data. In addition. the present paper provides a brief survey of the taxonomic history and the current state of research on systematics and evolution in Amaranthaceae.

Details zur Publikation

Seiten: 37
Veröffentlichungsjahr: 2005
Sprache, in der die Publikation verfasst ist: Englisch
Link zum Volltext: http://www.jstor.org/stable/3298649