A molecular phylogeny reveals frequent changes of growth form in Carlina (Asteraceae)

Abstract

The genus Carlina, with its 28 currently accepted species, ranks among the most thoroughly studied plant genera in Europe. Previous evolutionary hypotheses rested on a priori assumptions of character change, but for this study, DNA sequence data from nuclear ETS and three chloroplast regions obtained from all but one species of Carlina were used to produce a phylogenetic hypothesis. The results reveal that early branching lineages were morphologically divergent and that growth form shifts occurred more often and in different directions than previously thought, rendering a reconstruction of character states for the common ancestor of Carlina difficult to achieve. Nonetheless, results indicate that treelets were not plesiomorphic and that they most likely evolved in parallel in two island lineages growing in Macaronesia and in the Aegean. In addition, an independent evolution of two annual species in Carlina was revealed and most of the 50 morphological, biochemical, and karyological characters plotted on the tree proved to be homoplasic. Twenty-three anatomical characters from the stem-base/hypocotyl region provided no clear evidence for secondary woodiness and only the length of libriform fibers was clearly associated with plant height, but not without exceptions.

Overland flow generation mechanisms affected by topsoil treatment: Application to soil conservation

“…5). The thick root system is likely to be highly absorbent and responsible for the lower soil water content at 10 cm depth (Wahrmund et al, 2010).…”

Genome composition and origin of the polyploid Aegean grass Avenula agropyroides (Poaceae)

“…, 2009) by corroborating a kind of ‘conservatory’ character for the Aegean flora as reflected, for example, by its high degree of endemism at the species and even genus levels. The area is a hotspot of outstanding plant biodiversity because of the weak Late Pliocene and particularly Pleistocene climatic fluctuations in this region and the long‐lasting geographical isolation, especially of the Aegean Archipelago (Médail & Quézel, 1997; Thompson, 2005; Wahrmund et al. , 2010).…”

“…Although there are no genomic data on other polyploids from this region that could be used for comparison, the results for A. agropyroides support conclusions drawn from previous studies based on species-level systematics, floristics and biogeography of the east Mediterranean in other groups of vascular plants (Greuter, 1971;Cellinese et al, 2009) by corroborating a kind of 'conservatory' character for the Aegean flora as reflected, for example, by its high degree of endemism at the species and even genus levels. The area is a hotspot of outstanding plant biodiversity because of the weak Late Pliocene and particularly Pleistocene climatic fluctuations in this region and the long-lasting geographical isolation, especially of the Aegean Archipelago (Médail & Quézel, 1997;Thompson, 2005;Wahrmund et al, 2010). These conditions could be interpreted as having acted against 'northern invaders' and competitors of the autochthonous flora during the repeated latitudinal shifts of the vegetation zones in western Eurasia during the Pleistocene (Horvat et al, 1998).…”

Peer Review #1 of "Geography shapes the phylogeny of frailejones (Espeletiinae Cuatrec., Asteraceae): a remarkable example of recent rapid radiation in sky islands (v0.1)"

“…However, the external transcribed spacer region (ETS) of the nuclear 18S-26S ribosomal repeat showed fairly good phylogenetic resolution power. Numerous studies in related groups have used ETS for reconstructing phylogenies (Baldwin & Markos 1998;Clevinger & Panero 2000;Ekenäs et al 2007;Garcia et al 2011;Masuda et al 2009;Mavrodiev et al 2008;Moore et al 2012;Morgan et al 2009;Schilling & Panero 2011;Soltis et al 2008;Timme et al 2007b;and others;Wahrmund et al 2010). Timme et al (2007b) reported a large region of one to five subrepeats (each of ~250 bp) in the ETS for Helianthus L., with intraspecific variation, evidenced by multiple bands during gel PeerJ reviewing PDF | (2016:11:14650:1:1:NEW 2 Jan 2017)…”