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Adaptive radiation in mediterranean cistus (cistaceae).

Guzmán B, Lledó MD, Vargas P - PLoS ONE (2009)

Bottom Line: Molecular dating estimates a Mid Pleistocene (1.04+/-0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments).A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence).Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats.

View Article: PubMed Central - PubMed

Affiliation: Real Jardín Botánico - CSIC, Madrid, Spain. bguzman@rjb.csic.es

ABSTRACT

Background: Adaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis.

Methodology/principal findings: We conducted a "total evidence" analysis combining nuclear (ncpGS, ITS) and plastid (trnL-trnF, trnK-matK, trnS-trnG, rbcL) DNA sequences and using MP and BI to test the hypothesis of radiation as suggested by previous phylogenetic results. One of the five well-supported lineages of the Cistus-Halimium complex, the white-flowered Cistus lineage, comprises the higher number of species (12) and is monophyletic. Molecular dating estimates a Mid Pleistocene (1.04+/-0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments). A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence). Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats.

Conclusions/significance: The observation that radiation in the Cistus salviifolius lineage has been accompanied by the emergence of divergent leaf traits (such as shape, pubescence and labdanum secretion) in different environments suggets that radiation in the group has been adaptive. Here we argued that the diverse ecological conditions of Mediterranean habitats played a key role in directing the evolution of alternative leaf strategies in this plant group. Key innovation of morphological characteristics is supported by our dated phylogeny, in which a Mediterranean climate establishment (2.8 Ma) predated the adaptive radiation of the white-flowered Cistus.

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Phylogenetic chronogram of the                                          Cistus-Halimium complex based on the                                          Bayesian consensus tree.Fossil calibration points are indicated on the tree. Shaded                                          area delineates the establishment of the Mediterranean                                          climate 2.8 million years ago [50]. Geological timescales are                                          shown both at the top and the bottom. Photographs                                          illustrate diversity in leaf morphology of the                                          white-flowered Cistus species (only                                          subsp. ladanifer of C.                                          ladanifer, subsp. clusii of                                                C. clusii and subsp.                                                populifolius of C.                                                populifolius are illustrated). Species                                          insolation conditions [77] are plotted on the right                                          side of the tree (, helioxerophyllous and subhelioxerophyllous;, subsciophyllous and                                    submesophyllous).
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pone-0006362-g004: Phylogenetic chronogram of the Cistus-Halimium complex based on the Bayesian consensus tree.Fossil calibration points are indicated on the tree. Shaded area delineates the establishment of the Mediterranean climate 2.8 million years ago [50]. Geological timescales are shown both at the top and the bottom. Photographs illustrate diversity in leaf morphology of the white-flowered Cistus species (only subsp. ladanifer of C. ladanifer, subsp. clusii of C. clusii and subsp. populifolius of C. populifolius are illustrated). Species insolation conditions [77] are plotted on the right side of the tree (, helioxerophyllous and subhelioxerophyllous;, subsciophyllous and submesophyllous).

Mentions: Results of the dating analysis are shown in Table 6 and Fig. 4. In general, the data indicated a Pliocene-Pleistocene (2.11±0.87 Ma) divergence between the basal-most Halimium and Cistus-Halimium groups, followed by a Pleistocene differentiation of the major clades of the latter group. An ancestor shared by Halimium umbellatum and Cistus appeared to have diverged after the Pliocene-Pleistocene boundary (1.47±0.35 Ma). Short branch lengths may reflect a rapid divergence process in the white-flowered lineage. An early divergent lineage of C. clusii and C. mumbyi (C. clusii lineage) at 1.04±0.25 Ma was followed by differentiation of 10 species (C. salviifolius lineage) in the Mid Pleistocene (0.88±0.22 Ma). The average per-lineage species diversification rate for the C. salviifolius lineage was 1.46–2.44 species per million years.


Adaptive radiation in mediterranean cistus (cistaceae).

Guzmán B, Lledó MD, Vargas P - PLoS ONE (2009)

Phylogenetic chronogram of the                                          Cistus-Halimium complex based on the                                          Bayesian consensus tree.Fossil calibration points are indicated on the tree. Shaded                                          area delineates the establishment of the Mediterranean                                          climate 2.8 million years ago [50]. Geological timescales are                                          shown both at the top and the bottom. Photographs                                          illustrate diversity in leaf morphology of the                                          white-flowered Cistus species (only                                          subsp. ladanifer of C.                                          ladanifer, subsp. clusii of                                                C. clusii and subsp.                                                populifolius of C.                                                populifolius are illustrated). Species                                          insolation conditions [77] are plotted on the right                                          side of the tree (, helioxerophyllous and subhelioxerophyllous;, subsciophyllous and                                    submesophyllous).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2719431&req=5

pone-0006362-g004: Phylogenetic chronogram of the Cistus-Halimium complex based on the Bayesian consensus tree.Fossil calibration points are indicated on the tree. Shaded area delineates the establishment of the Mediterranean climate 2.8 million years ago [50]. Geological timescales are shown both at the top and the bottom. Photographs illustrate diversity in leaf morphology of the white-flowered Cistus species (only subsp. ladanifer of C. ladanifer, subsp. clusii of C. clusii and subsp. populifolius of C. populifolius are illustrated). Species insolation conditions [77] are plotted on the right side of the tree (, helioxerophyllous and subhelioxerophyllous;, subsciophyllous and submesophyllous).
Mentions: Results of the dating analysis are shown in Table 6 and Fig. 4. In general, the data indicated a Pliocene-Pleistocene (2.11±0.87 Ma) divergence between the basal-most Halimium and Cistus-Halimium groups, followed by a Pleistocene differentiation of the major clades of the latter group. An ancestor shared by Halimium umbellatum and Cistus appeared to have diverged after the Pliocene-Pleistocene boundary (1.47±0.35 Ma). Short branch lengths may reflect a rapid divergence process in the white-flowered lineage. An early divergent lineage of C. clusii and C. mumbyi (C. clusii lineage) at 1.04±0.25 Ma was followed by differentiation of 10 species (C. salviifolius lineage) in the Mid Pleistocene (0.88±0.22 Ma). The average per-lineage species diversification rate for the C. salviifolius lineage was 1.46–2.44 species per million years.

Bottom Line: Molecular dating estimates a Mid Pleistocene (1.04+/-0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments).A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence).Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats.

View Article: PubMed Central - PubMed

Affiliation: Real Jardín Botánico - CSIC, Madrid, Spain. bguzman@rjb.csic.es

ABSTRACT

Background: Adaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis.

Methodology/principal findings: We conducted a "total evidence" analysis combining nuclear (ncpGS, ITS) and plastid (trnL-trnF, trnK-matK, trnS-trnG, rbcL) DNA sequences and using MP and BI to test the hypothesis of radiation as suggested by previous phylogenetic results. One of the five well-supported lineages of the Cistus-Halimium complex, the white-flowered Cistus lineage, comprises the higher number of species (12) and is monophyletic. Molecular dating estimates a Mid Pleistocene (1.04+/-0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments). A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence). Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats.

Conclusions/significance: The observation that radiation in the Cistus salviifolius lineage has been accompanied by the emergence of divergent leaf traits (such as shape, pubescence and labdanum secretion) in different environments suggets that radiation in the group has been adaptive. Here we argued that the diverse ecological conditions of Mediterranean habitats played a key role in directing the evolution of alternative leaf strategies in this plant group. Key innovation of morphological characteristics is supported by our dated phylogeny, in which a Mediterranean climate establishment (2.8 Ma) predated the adaptive radiation of the white-flowered Cistus.

Show MeSH
Related in: MedlinePlus