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Phylogeny of tribe Rhinantheae (Orobanchaceae) with a focus on biogeography, cytology and re‐examination of generic concepts
Author(s) -
Scheunert Agnes,
Fleischmann Andreas,
Olano-Marín Catalina,
Bräuchler Christian,
Heubl Günther
Publication year - 2012
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.1002/tax.616008
Subject(s) - biology , polyphyly , genus , evolutionary biology , biogeography , taxon , orobanchaceae , indumentum , clade , tribe , phylogenetic tree , zoology , botany , ecology , sociology , gene , anthropology , biochemistry
A molecular systematic approach using DNA sequences of two non‐coding chloroplast loci ( trnK, rps16 ) and the nuclear ITS region was applied to reconstruct phylogenetic relationships within the tribe Rhinantheae (Orobanchaceae). This tribe includes approximately 19 genera of hemiparasitic plants predominantly occurring in the Old World. An exception is the genus Bartsia which, according to previous taxonomic treatments, includes a remarkable radiation (ca. 45 species) in the Andes, two species distributed in Afromontane regions, and only one species ( Bartsia alpina ) ranging from the alpine mountains of northern and central Europe to northeastern North America. The present phylogenetic study includes the most comprehensive taxon sampling of Rhinantheae to date, with main focus on the relationships of the Mediterranean genera. Both nuclear and plastid datasets reveal a core group of Rhinantheae comprising four major lineages. Our analyses suggest that (1) the northern temperate Bartsia alpina is sister to the rest of the core group; (2) African Bartsia are more closely related to the monotypic African genus Hedbergia than to other congeneric taxa; (3) South American Bartsia are nested within a highly supported clade including Parentucellia and Bellardia ; (4) Nothobartsia and Odontitella are likely to be the results of at least one intergeneric hybridization event. Despite topological conflicts regarding some taxa, the polyphyly of Bartsia and a broadly circumscribed Odontites are unambiguously supported by our results. Our tree topologies indicate that the importance of certain morphological characters traditionally used for generic delimitation (such as shape and indumentum of corolla, anthers, and capsules) has been overestimated, and that some of these characters are presumably convergent. Available information on chromosome numbers corroborates the results presented here.