Species relationships and genetic variation in the New Zealand endemic Leucogenes (Asteraceae: Gnaphalieae)

Breitwieser

2011

Phylogenetic analyses have suggested that the everlasting daisy tribe Gnaphalieae colonized the globe repeatedly and rapidly from southern Africa. However, both the circumscription of monophyletic groups of "out of Africa" Gnaphalieae genera and the identification of their sister groups in southern Africa has proved difficult. We have analysed sequences of nrDNA spacers (ITS, ETS), cpDNA (ndhF, trnL intron, trnL-trnF intergenic spacer, trnK intron), and low-copy nuclear markers to examine selected relationships within the crown radiation of the tribe. We focused on relationships among two putative clades suggested by previous studies and a representative sampling of genera endemic to Australasia. Incongruities between nrDNA and cpDNA trees are frequent and some involve robustly supported clades. However, trees generated for two lowcopy nuclear markers are largely congruent with each other but imply that allopolyploidy preceded the radiations of at least four separate extant lineages within the tribe, one largely or entirely restricted to Australasia, one almost global, and two still poorly sampled. Collectively, these four putative allopolyploid lineages may account for more than half of the described species diversity of the tribe.

Section: Discussionmentioning

confidence: 99%

Ancient allopolyploidy in the everlasting daisies (Asteraceae: Gnaphalieae): Complex relationships among extant clades

Smissen

Breitwieser

2011

“…Incongruities between cpDNA and nrDNA, and allopolyploidy as a potential force for dispersal and diversification in the HAP clade. -Incongruence between cpDNA and nrDNA markers has been previously reported for several genera of tribe Gnaphalieae (Smissen & al., 2004Smissen & Breitwieser, 2008; and has largely been interpreted in those studies as evidence of past or present hybridisation events rather than sorting or retention of ancestral polymorphisms. For some particular clades, and with the additional evidence from low-copy markers and chromosome data, an allopolyploid origin has been hypothesised .…”

Section: Discussionmentioning

confidence: 99%

Phylogenetic relationships in Helichrysum (Compositae: Gnaphalieae) and related genera: Incongruence between nuclear and plastid phylogenies, biogeographic and morphological patterns, and implications for generic delimitation

Unwin

Garcia‐Jacas

et al. 2014

The Helichrysum-Anaphalis-Pseudognaphalium (HAP) clade is a major component of the tribe Gnaphalieae (Compositae) and includes the genera Helichrysum, Anaphalis, Achyrocline and Pseudognaphalium. Allopolyploid origins for at least two clades within the HAP clade have previously been suggested, one involving the genus Anaphalis and the MediterraneanAsian Helichrysum species, and a second one involving part of Pseudognaphalium. In the present paper, with the use of two nuclear ribosomal and two plastid DNA markers and an extensive sampling of the HAP clade, further evidence relevant to the origin, composition and closest relatives of these clades is provided, and additional cases of incongruence are discussed. The superposition of distribution areas on the phylogeny suggests that the HAP clade originated in the Cape region of southern Africa and subsequently dispersed to and diversified in the Afromontane regions of east southern Africa, mainly the Drakensberg, before spreading northward and giving rise to several lineages in afromontane and afroalpine areas of central tropical Africa and in Madagascar. Allopolyploidy may have preceded the dispersal and diversification of the HAP lineage out of Africa to the Mediterranean area, and to the Americas and Asia. Finally, discussion on the distribution of several morphological characters in the phylogeny and their taxonomic relevance is also provided, with views on the need for a new generic delimitation.

“…These results partially reflect the intraspecific variation found in the ITS, ETS and rpl32-trnL intergenic spacer sequences in both species, as commented in the Results section. Smissen & Breitwieser (2008) have already documented notable intraspecific variation for New Zealand Leucogenes Beauverd (Gnaphalieae), both in nuclear (ITS) and chloroplast (psbA-trnH intergenic spacer) DNA sequences, which showed the species of this genus to be non-monophyletic in molecular phylogenies. In our case, this sequence polymorphism again suggests hybridization, incomplete lineage sorting, or at least a complex scenario of the relationships among these morphologically well-delimited species.…”

Section: Species Distributionmentioning

confidence: 99%

How many of Cassini anagrams should there be? Molecular systematics and phylogenetic relationships in the Filago group (Asteraceae, Gnaphalieae), with special focus on the genus Filago

Andrés‐Sánchez

Garcia‐Jacas

et al. 2010

The Filago group (Asteraceae, Gnaphalieae) comprises eleven genera, mainly distributed in Eurasia, northern Africa and northern America: Ancistrocarphus, Bombycilaena, Chamaepus, Cymbolaena, Evacidium, Evax, Filago, Logfia, Micropus, Psilocarphus and Stylocline. The main morphological character that defines the group is that the receptacular paleae subtend, and more or less enclose, the female florets. The aims of this work are, with the use of three chloroplast DNA regions (rpl32‐trnL intergenic spacer, trnL intron, and trnL‐trnF intergenic spacer) and two nuclear DNA regions (ITS, ETS), to test whether the Filago group is monophyletic; to place its members within Gnaphalieae using a broad sampling of the tribe; and to investigate in detail the phylogenetic relationships among the Old World members of the Filago group and provide some new insight into the generic circumscription and infrageneric classification based on natural entities. Our results do not show statistical support for a monophyletic Filago group. The traditional generic circumscription of most of the genera, as well as the traditional infrageneric classification of the genus Filago, do not correlate with the inferred phylogenetic relationships. A monophyletic circumscription of Filago and a new subgeneric treatment for this genus are proposed, this involving description of a new subgenus (Filago subg. Crocidion Andrés‐Sánchez & Galbany, subg. nov.) and four new combinations (Filago subg. Pseudevax (DC.) Andrés‐Sánchez & Galbany, comb. et stat. nov.; Filago discolor (DC.) Andrés‐Sánchez & Galbany, comb. nov.; Filago gaditana (Pau) Andrés‐Sánchez & Galbany, comb. et stat. nov. and Filago griffithii (A. Gray) Andrés‐Sánchez & Galbany, comb. nov.). The genera Cymbolaena, Evacidium and Evax are synonymised under Filago. Several incongruences found between chloroplast and nuclear DNA sequence analyses, as well as a notable degree of intraspecific sequence variation in all regions sequenced are documented and discussed.