Molecular phylogeny and systematics of Genista (Leguminosae) and related genera based on nucleotide sequences of nrDNA (ITS region) and cpDNA (trnL-trnF intergenic spacer)

Phylogenetic relationships of Genista and related genera (Teline, Chamaespartium, Pterospartum, Echinospartum, Ulex, Stauracanthus and Retama) were assessed by the analysis of sequences of the nrDNA internal transcribed spacer (ITS region), and the cpDNA trnL-trnF intergenic spacer. The tree obtained by combining both sets of data indicates the existence of three lines of diversification within Genista, that correspond to three subgenera: Genista, Phyllobotrys and Spartocarpus, however, each of these lineages encompass also species of the related genera Echinospartum, Teline, Retama, Chamaespartium, Pterospartum, Ulex, Stauracanthus. The molecular data do not support division of these subgenera into taxonomical units at the sectional level; only sections Genista and Spartocarpus are monophyletic groups. The sequences of both regions are also informative at the specific level, grouping morphologically related species (e.g. the G. cinerea aggregate). The molecular data have also helped to clarify the position of taxa whose relationships were not well established (e.g. G. valdes-bermejoi). The relationships of related genera that belong to the Genista lines of diversification have also been investigated. Echinospartum splits into two separate clades matching the separation of two ecological and caryological differentiated groups. Teline also forms two groups, both placed near to Genista subgenus Genista, but that separated from the main core of the group. Retama, morphologically well differentiated from Genista, is close to Genista subgenus Spartocarpus. Chamaespartium and Pterospartum do not form a monophyletic group. Chamaespartium is closer to Genista subgenus Genista, whereas Pterospartum stands close to: 1) Genista subgenus Spartocarpus (particularly, sect. Cephalospartum); and 2) the Ulex-Stauracanthus clade (a terminal derivative of Genista subgenus Spartocarpus). Cases of incongruence (e.g. Echinospartum, Chamaespartium, Teline) between the trees obtained from the two molecular markers, may be indicating hybridisation and/or introgression between different lines of Genisteae.     

Comparison of molecular and morphological data on St Helena: Elaphoglossum

The endemic elaphoglossoid ferns, Elaphoglossum dimorphum, E. nervosum and Microstaphyla furcata of St Helena, form a closely related group within section Lepidoglossa when analysed phylogenetically using sequences from the chloroplast trnL intron (partial) and trnL-F intergenic spacer. Microstaphyla furcata, traditionally placed in its own genus, is clearly shown to belong to Elaphoglossum confirming the previous transfer of this species to Elaphoglossum as E. bifurcatum. There is hardly any trnL-F sequence divergence between the species, in fact sequences of E. nervosum and E. dimorphum are identical. These results are consistent with the possible origin of E. dimorphum as a hybrid between E. bifurcatum and E. nervosum or with the view that the three species are the result of a recent radiation. The potential conflict between phylogenetic and morphological distinctness in determining species conservation priorities is discussed.     

Carex, subgenus Carex (Cyperaceae) – A phylogenetic approach using ITS sequences

To evaluate the sectional classification in Carex, subgenus Carex, the ITS region of 117 species belonging to 32 sections was analyzed with Neighbor Joining (NJ) and Markov chain Monte Carlo (MCMC) methods. In our analyses (1) species of subgenus Indocarex appear as a statistically well supported group within subgenus Carex. (2) The representatives of sections Vesicariae, Hirtae, Pseudocypereae, Ceratocystis, Spirostachyae, Bicolores, Paniceae, Trachychlaenae, Scirpinae, Atratae and Albae group in statistically supported clades with higher support in MCMC than in NJ. (3) C. rariflora clusters with representatives of section Limosae, however only weakly supported. (4) Taxa of section Phacocystis are divided in two statistically supported subclusters that are closely related to a core group of section Hymenochlaenae. (5) Species of sections Montanae, Pachystylae, Digitatae, Phacocystis, Rhomboidales, Careyanae and Frigidae are segregated into two or more clusters each. (6) Five species of section Frigidae cluster together, whereas the seven others are in scattered positions. Based on these results, delimitation of sections is discussed.     

Faunal changes and geographic crypticism indicate the occurrence of a biogeographic transition zone along the southern East Pacific Rise

Aim Deep‐sea hydrothermal vents have now been reported along all active mid‐ocean ridges and back‐arc basins, but the boundaries of biogeographic entities remain questionable owing to methodological issues. Here we examine biogeographic patterns of the vent fauna along the East Pacific Rise (EPR) and determine the relative roles of regional and local factors on the distribution of biodiversity associated with mussel beds along a poorly explored zone, the southern EPR (SEPR). Location East Pacific Rise. Methods A species list of macrobenthic invertebrates along the EPR was compiled from the literature and supplemented with data recovered during the French research cruise BIOSPEEDO carried out in 2004 along the SEPR. Biogeographic patterns were assessed by combining the identification of morphological species with a molecular barcoding approach. A multivariate regression tree (MRT) analysis was performed to identify any geographic breaks, and an empirical distribution of species richness was compared with predictions provided by a mid‐domain effect model. Macrofaunal community structure associated with mussel beds along the SEPR was analysed in relation to environmental factors using cluster and canonical redundancy analyses. Results Sequencing of the cytochrome c oxidase subunit I gene revealed the occurrence of several cryptic species complexes along the EPR, with the equator separating the southern and northern clades. Furthermore, during the BIOSPEEDO cruise at least 10 still unnamed species were collected between 7°25′ S and 21°33′ S. The shift in community structure identified by MRT analysis was located south of 17°34′ S or south of 13°59′ S, depending on the data used, suggesting that the southern part of the SEPR (17°25′–21°33′ S) constitutes a biogeographic transition zone in the vent fauna along the EPR. At a regional scale, latitude combined with the type of venting was significantly correlated with the community structure associated with mussel beds. Main conclusions Together, the molecular data, in situ observations, and the distribution of species suggest that the high diversity of vent fauna species presently observed between 17°25′ S and 21°33′ S is probably a result of the overlap of several distinct biogeographic provinces. We argue that this area thus constitutes a biogeographic vent fauna transition zone along the EPR.     

A new species of Nicon Kinberg, 1866 (Polychaeta,Nereididae) from Ecuador,Eastern Pacific,with a?key?to?all known?species?of the genus

A new species of Nicon Kinberg, 1866 from the east Pacific coast of Ecuador is described. The new species is characterized by a long, thin dorsal ligule on median and posterior parapodia and infracicular sesquigomph falcigers in the neuropodia. A key to all species of Nicon is provided.     

A protocol for temporal calibration of general area cladograms

Aim To describe a protocol for incorporating a temporal dimension into historical biogeographical analysis, while maintaining the essential independence of all datasets, involving the generation of general area cladograms. Location Global. Methods General area cladograms (GACs) are a reconstruction of the evolutionary history of a set of areas and unrelated clades within those areas. Nodes on a GAC correspond to speciation events in a group of taxa; general nodes are those at which multiple unrelated clades speciate. We undertake temporal calibration of GACs using molecular clock estimates of splitting events between extant taxa as well as first appearance data from the fossil record. We present two examples based on re‐analysis of previously published data: first, a temporally calibrated GAC generated from secondary Brooks parsimony analysis (BPA) of six extant bird clades from the south‐west of North America using molecular clock estimates of divergence times; and second, an analysis of African Neogene mammals based on a phylogenetic analysis for comparing trees (PACT) analysis. Results A hypothetical example demonstrates how temporal calibration reveals potentially critical information about the timing of both unique and general events, while also illustrating instances of incongruence between dates generated from molecular clock estimates and fossils. For the African Neogene mammal dataset, our analysis reveals that most mammal clades underwent geodispersal associated with the Neogene climatic optimum (c. 16 Ma) and vicariant speciation in central Africa correlated with increased aridity and cooler temperatures around 2.5 Ma. Main conclusions Temporally calibrated GACs are valuable tools for assessing whether coordinated patterns of speciation are associated with large‐scale climatic or tectonic phenomena.     

Comparative morphology of the foliage leaf epidermis, with emphasis on papillae characters, in key taxa of woody bamboos of the Asian tropics (Poaceae: Bambusoideae)

The foliage leaf epidermis of 35 species representing 12 key genera of woody bamboos of the Asian tropics was investigated using light and scanning electron microscopy. The results indicated that papillae forms and distributional patterns around the stomatal apparatus of the abaxial foliage leaf epidermis were usually constant and were of great taxonomic significance at the specific and generic levels. However, papillae characters were not suitable for dividing subtribes within woody bamboos of the Asian tropics. On the basis of papillae characters, Schizostachyum s.s. and Cephalostachyum were confirmed, but their delimitations should be modified. The transfer of Leptocanna chinensis and Schizostachyum sanguineum into Cephalostachyum was supported, and Cephalostachyum virgatum and C .  pergracile were confirmed to be members of Schizostachyum s.s. The subtribe Racemobambosinae did not obtain support and Racemobambos appeared to be better placed in subtribe Bambusinae. Neomicrocalamus was supported as a close relative and better treated as a synonym of Racemobambos . Gigantochloa was closely related to Dendrocalamus .  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 411–423.     

Osteoderm histology of the Pampatheriidae (Cingulata,Xenarthra, Mammalia): Implications for systematics,osteoderm growth,and biomechanical adaptation

Pampatheres are extinct, large‐bodied cingulates, which share morphological characters with both armadillos and glyptodonts but are considered to be more closely related to the latter. The osteoderm histology of six pampathere taxa was examined and compared to the histology of other cingulate osteoderms. This study investigates the development and functional adaptation of pampathere osteoderms as well as the phylogenetic relationships of the Pampatheriidae within the Cingulata. We found that pampathere osteoderms share a uniform histological organization based on a basic diploe‐like structure. After initial stages of intramembranous growth, metaplastic ossification, that is, the direct incorporation and mineralization of pre‐existing protein fibers, plays an important role in osteoderm development and provides information on various kinds of soft tissue otherwise not preserved. The latest stages of osteoderm growth are dominated by periosteal bone formation especially in the superficial cortex. Movable band osteoderms show regular arrangements of incorporated fibers that may increase the resistance of particularly weak areas against strain. The histological composition of pampathere osteoderms is plesiomorphic in its basic structure but shows a number of derived features. A unique array of Sharpey's fibers that are incorporated into the bone matrix at sutured osteoderm margins is interpreted as a synapomorphy of pampatheres. The arrangement of dermal fibers in the deep and superficial cortexes supports the close relationship between pampatheres and glyptodonts. J. Morphol., 2012. © 2011 Wiley Periodicals, Inc.     

Molecular approach to the phylogeny and systematics of Cytisus (Leguminosae) and related genera based on nucleotide sequences of nrDNA (ITS region) and cpDNA (trnL-trnF intergenic spacer)

 Phylogenetic relationships of Cytisus and allied genera (Argyrocytisus, Calicotome, Chamaecytisus, Cytisophyllum, and Spartocytisus) were assessed by analysis of sequences of the nrDNA internal transcribed spacer (ITS) and the cpDNA trnL-trnF intergenic spacer. Genera of the Genista-group (Chamaespartium, Echinospartum, Genista, Pterospartum, Spartium, Teline and Ulex) were included to check the position of Cytisus species transferred to Teline. The tree obtained by combining both sets of data indicates that the Genista and Cytisus groups form two separate clades. Cytisus heterochrous and C. tribracteolatus are more closely related to the Cytisus-group, thus their transfer to Teline is not supported by molecular data. Cytisus fontanesii (syn. Chronanthos biflorus) groups with Cytisophyllum sessilifolium and Cytisus heterochrous within the Cytisus-group. Similarly, Argyrocytisus battandieri falls within the Cytisus-group as a well differentiated taxon. All these taxa seem to have early diverged from the Cytisus-group. Their taxonomic rank should be reconsidered to better reflect their phylogenetic separation from Cytisus. On the contrary, Chamaecytisus proliferus and Spartocytisus supranubius enter in the main core of Cytisus, and they should better be included in sections of Cytisus (sect. Tubocytisus and Oreosparton, respectively). Sect. Spartopsis is not monophyletic and the position of several species, currently included in this section, deserves reevaluation: C. arboreus aggregate is closely related to C. villosus (sect. Cytisus) and to Calicotome; C. striatus is closely related to Cytisus sect. Alburnoides; and the position of C. commutatus (incl. C. ingramii) remains unclear. The relationships and positioning of several minor taxa (C. transiens, C. megalanthus, and C. maurus) are also discussed. Received November 22, 2001; accepted March 16, 2002 Published online: October 14, 2002 Addresses of the authors: Paloma Cubas (e-mail: cubas@farm.ucm.es) and Cristina Pardo (e-mail: cpardo@farm.ucm.es), Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, E-28040 Madrid, Spain. Hikmat Tahiri Faculté des Sciences, Université Mohammed V, BP 1014 Rabat, Morocco (e-mail: tahiri@ fsr.ac.ma).