TY - JOUR
T1 - Phylogeny and evolution of achenial trichomes in the lucilia-group (Asteraceae
T2 - Gnaphalieae) and their systematic significance
AU - Luebert, Federico
AU - Moreira-Muñoz, Andrés
AU - Wilke, Katharina
AU - Dillon, Michael O.
N1 - Funding Information:
We are grateful to the Dahlem Centre of Plant Sciences (DCPS, grant to FL) and FondecytChile (grant 1150425 to AMM) for financial support. We thank the curators and staff of the herbaria B, BAB, BONN, CONC, F, FB, GH, HAO, HSP, HUSA, LP, MO, NY, SGO, TEX, US, and USM for permitting access to their material and Maximilian Weigend for resources and space in his working group at the University of Bonn. Miguel Álvarez, Silvia ArroyoLeuenberger, Hartmut Hilger, Marcelo Monge, and Luis Palazzesi provided material. The Botanical Garden Berlin Dahlem (BGBM) granted permission to use material from the garden. The help of Anne Schindhelm and Nicole Schmandt in the lab is gratefully acknowledged. This research was also supported by the SYNTHESYS project (http:// www.synthesys.info/), which is financed by European Community Research Infrastructure Action under the FP7 “Capacities” (grants ACTAF2001, FRTAF1977) programme. MOD thanks the National Geographic Society and National Science Foundation (DEBBSI0071506) for grants that supported exploration and field collecting activities. He also thanks J. Ward and I. Breitwieser for discussions of New Zealand and South American Gnaphalieae and two anonymous reviewers for constructive criticism. We thank T. Joßberger and H.J. Ensikat for their help and the Bonn Botanical Gardens for permitting access to their collections.
Publisher Copyright:
© International Association for Plant Taxonomy (IAPT) 2017.
PY - 2017/10
Y1 - 2017/10
N2 - The Gnaphalieae (Asteraceae) are a cosmopolitan tribe with around 185 genera and 2000 species. The New World is one of the centers of diversity of the tribe with 24 genera and over 100 species, most of which form a clade called the Lucilia-group with 21 genera. However, the generic classification of the Lucilia-group has been controversial with no agreement on delimitation or circumscription of genera. Especially controversial has been the taxonomic value of achenial trichomes and molecular studies have shown equivocal results so far. The major aims of this paper are to provide a nearly complete phylogeny of the Lucilia-group at generic level and to discuss the evolutionary trends and taxonomic significance of achenial trichome morphology. We conducted a phylogenetic analysis of the New World Gnaphalieae with nrDNA (ETS, ITS) sequence data from a sampling of 18 genera of the Lucilia-group and utilized these results to examine morphological evolution of achenial trichome types and presence of apical myxogenic cells. Seven well-supported subclades can be recognized within the Lucilia-group (L1–L7). These results support Brazilian and Andean Berroa, Facelis, Lucilia, and Micropsis forming a clade (L1), the inclusion of Chilean Lucilia under Belloa (L2), the monophyly of Stuckertiella +Gamochaeta +Gamochaetopsis (L3), Chevreulia +Cuatrecasasiella (L4) and Antennaria (L5) excluding Antennaria linearifolia, which is resolved in a monophyletic group together with Jalcophila, Loricaria and Mniodes (L6), and the recognition of Gnaphaliothamnus (L7) removed from Brazilian taxa of Chionolaena (L2). Ancestral character state reconstruction of achenial trichome morphology suggests that clades are homogeneous in terms of trichome type, but with exceptions that make it highly homoplastic. Conversely, our results suggest that the presence of myxogenic apical cells is less homoplastic and that closely related species tend to resemble each other more than expected under random variation.
AB - The Gnaphalieae (Asteraceae) are a cosmopolitan tribe with around 185 genera and 2000 species. The New World is one of the centers of diversity of the tribe with 24 genera and over 100 species, most of which form a clade called the Lucilia-group with 21 genera. However, the generic classification of the Lucilia-group has been controversial with no agreement on delimitation or circumscription of genera. Especially controversial has been the taxonomic value of achenial trichomes and molecular studies have shown equivocal results so far. The major aims of this paper are to provide a nearly complete phylogeny of the Lucilia-group at generic level and to discuss the evolutionary trends and taxonomic significance of achenial trichome morphology. We conducted a phylogenetic analysis of the New World Gnaphalieae with nrDNA (ETS, ITS) sequence data from a sampling of 18 genera of the Lucilia-group and utilized these results to examine morphological evolution of achenial trichome types and presence of apical myxogenic cells. Seven well-supported subclades can be recognized within the Lucilia-group (L1–L7). These results support Brazilian and Andean Berroa, Facelis, Lucilia, and Micropsis forming a clade (L1), the inclusion of Chilean Lucilia under Belloa (L2), the monophyly of Stuckertiella +Gamochaeta +Gamochaetopsis (L3), Chevreulia +Cuatrecasasiella (L4) and Antennaria (L5) excluding Antennaria linearifolia, which is resolved in a monophyletic group together with Jalcophila, Loricaria and Mniodes (L6), and the recognition of Gnaphaliothamnus (L7) removed from Brazilian taxa of Chionolaena (L2). Ancestral character state reconstruction of achenial trichome morphology suggests that clades are homogeneous in terms of trichome type, but with exceptions that make it highly homoplastic. Conversely, our results suggest that the presence of myxogenic apical cells is less homoplastic and that closely related species tend to resemble each other more than expected under random variation.
KW - Achenial trichome
KW - Lucilia-group
KW - Morphology
KW - Phylogeny
KW - South America
KW - nrDNA
UR - http://www.scopus.com/inward/record.url?scp=85032348169&partnerID=8YFLogxK
U2 - 10.12705/665.11
DO - 10.12705/665.11
M3 - Article
AN - SCOPUS:85032348169
VL - 66
SP - 1184
EP - 1199
JO - Taxon
JF - Taxon
SN - 0040-0262
IS - 5
ER -