A molecular phylogeny and generic rearrangement of the stapelioid Ceropegieae (Apocynaceae-Asclepiadoideae)

 Representatives of nearly all genera of the taxon-rich stem-succulent stapeliads and most of the few related, leafy genera were analyzed. Sequence data from two non-coding molecular markers (ITS region of nrDNA and trnT-L and trnL-F spacers as well as the trnL intron of cpDNA) support the traditional tribal affiliation of the genera, which form a monophyletic group. This monophylum breaks into a basal Neoschumannia/Anisotoma/Riocreuxia/Sisyranthus nk;clade, from which the core Ceropegieae are derived. The four Ceropegia species included are not monophyletic, and their relationship to Brachystelma changes depending on the marker studied. The stem succulent taxa fall in a number of well supported, but unresolved clades, the most prominent being the predominantly southern African clade comprising Orbea, Stapelia and some other genera. The most derived taxa of NE Africa, Duvaliandra and White-sloanea, are basal to this southern African clade. The other clades comprise the more basal genera of stem-succulent stapeliads, including the members of the Caralluma complex. Of the 17 genera accepted by Plowes for the Caralluma complex, seven are recognized: Caralluma, Apteranthes, Australluma, Boucerosia, Caudanthera, Desmidorchis and Monolluma. New combinations are proposed in 15 cases; Caralluma adscendens var. geniculata is raised to specific rank. Anomalluma is reinstated, and Pseudolithos mccoyi is transfered to it. A broadened concept for Orbea (incl. Angolluma and Orbeopsis) is recognized, but Orbeanthus is kept separate. The monotypic Ballyanthus, recently separated from Orbea, is nested within Duvalia. Piaranthus (incl. Huerniopsis) is monophyletic. The bitypic Notechidnopsis is reduced to the type species, N. tessellata, while N. columnaris is transferred to a new genus, Richtersveldia. Received February 25, 2002; accepted June 17, 2002 Published online: November 7, 2002 Address of the authors: Dr. Ulrich Meve (e-mail: ulrich.meve@uni-bayreuth.de) and Prof. Dr. Sigrid Liede (e-mail: sigrid.liede@uni-bayreuth.de), Universit?t Bayreuth, Lehrstuhl für Pflanzensystematik, Universit?tsstrasse 30, D-95440 Bayreuth, Germany.     

Chloroplast evidence for geographic stasis of the Australian bird‐dispersed shrub Tasmannia lanceolata (Winteraceae)

Few chloroplast‐based genetic studies have been undertaken for plants of mesic temperate forests in the southern hemisphere and fossil‐based models have provided evidence of vegetation history only at the broadest scales in this region. This study investigates the chloroplast DNA phylogeography of Tasmannia lanceolata (Winteraceae), a fleshy‐fruited, bird‐dispersed shrub that is widespread in the mountains of southeastern Australia and Tasmania. Thirty haplotypes were identified after sequencing 3206 bp of chloroplast DNA in each of 244 individuals collected across the species’ range. These haplotypes showed unexpectedly strong phylogeographic structuring, including a phylogeographic break within a continuous part of the species’ range, with the distribution of four major clades mostly not overlapping, and geographic structuring of haplotypes within these clades. This strong geographic patterning of chloroplast DNA provided evidence for the survival of T. lanceolata in multiple putative wet forest refugia as well as evidence for additional wet forest species refugia in southeastern Australia. In western Tasmania lower haplotype diversity below the LGM tree line compared to above the LGM tree line suggests that glacial refugia at high altitudes may have been important for T. lanceolata. The level of geographic structuring in T. lanceolata is similar to gravity dispersed southern hemisphere plants such as Nothofagus and Eucalyptus. Behavioural traits of the birds transporting seed may have had a strong bearing on the limited transport of T. lanceolata seed, although factors limiting establishment, possibly including selection, may also have been important.     

The evolution of angiosperm lianescence without vessels--climbing mode and wood structure-function in Tasmannia cordata (Winteraceae)

? The lack of extant lianescent vessel-less seed plants supports a hypothesis that liana evolution requires large-diameter xylem conduits. Here, we demonstrate an unusual example of a lianoid vessel-less angiosperm, Tasmannia cordata (Winteraceae), from New Guinea. ? Wood mechanical, hydraulic and structural measurements were used to determine how T. cordata climbs and to test for ecophysiological shifts related to liana evolution vs 13 free-standing congeners. ? The tracheid-based wood of T. cordata furnished low hydraulic capacity compared with that of vessel-bearing lianas. In comparison with most nonclimbing relatives, T. cordata possessed lower photosynthetic rates and leaf and stem hydraulic capacities. However, T. cordata exhibited a two- to five-fold greater wood elastic modulus than its relatives. ? Tasmannia cordata provides an unusual example of angiosperm liana evolution uncoupled from xylem conduit gigantism, as well as high plasticity and cell type diversity in vascular development. Because T. cordata lacks vessels, our results suggest that a key limitation for a vessel-less liana is that strong and low hydraulically conductive wood is required to meet the mechanical demands of lianescence.     

Floral development of Urospatha: merosity and phylogeny in the Lasioideae (Araceae)

In this paper we study merosity in the genus Urospatha within the framework of a resolved phylogeny of the Araceae. We analyse how a transition from dimerous or tetramerous merosity to pentamerous or hexamerous merosity can occur developmentally in the Lasioideae. In Urospatha, initiation of floral primordia along the inflorescence is acropetal, while development of flowers is basipetal. This indicates the presence of two distinct phases in the development of the Urospatha inflorescence. The first phase corresponds to initiation of flowers and establishment of the phyllotactic pattern, and the second phase to differentiation of floral organs. Urospatha is characterized by the presence of trimerous, tetramerous, pentamerous and rarely hexamerous flowers. In all types of flowers, the stamens are closely associated and opposite to the tepals. Pentamerous flowers are formed by addition of a sector comprising a stamen and tepal. Likewise, in the case of hexamerous flowers, two sectors are added. In the Lasioideae, the increase in the number of tepals and stamens is linked with two developmental processes that have appeared independently in the subfamily: (1) addition of one or two stamen?Cpetal sectors (Anaphyllopsis and Urospatha), and (2) independent increase in the number of tepals and stamens on whorls, more or less organized and inserted in alternate position (Dracontium). Tetramerous whorls as they occur in basal Lasioideae would be homologous to two dimerous whorls from an evolutionary point of view.     

Floral morphology and phylogeny of the Disinae (Orchidaceae)

Previous classification of the Disinae has been based almost entirely on floral morphological data. These data are critically assessed by various methods to determine to what extent they support a classification resolved to sectional level. The variation in the characters relative to the sections and genera is mapped, homologies are established by careful morphological observation and ontogenetic studies, and finally hypotheses of homology are tested by congruence in several cladistic analyseS. It is found that although floral morphology allows the recognition of some groups, for others the results are ambiguouS. Floral morphological data are clearly inadequate to establish the taxonomy of the Disinae on a sound footing.     

Analysis of the Contents of Oil Cells in Tasmannia lanceolata(Poir.) A. C. Smith (Winteraceae)

The simple, robust oil cells found in leaves of Tasmannia lanceolata(Poir.)A. C. Smith (Winteraceae) are shown to contain a preponderanceof the bioactive compound polygodial using both direct samplingand GCMS analysis of cell contents and Fourier Transform infraredspectroscopy. The implications of this for comparison of plantmaterial on the basis of extracts and essential oils are discussed.Copyright 2000 Annals of Botany Company Tasmannia lanceolata, Winteraceae, polygodial, direct sampling, FTIR spectrometry, oil cell, idioblast, antifeedant     

Floral evolution and phylogeny in the tribeThelymitreae (Orchidaceae: Neottioideae)

The Australian orchid tribeThelymitreae, composed ofCalochilus, Epiblema, andThelymitra, is unique in theOrchidaceae because of the presence of a mitra or staminodal complex. Evidence from floral structure suggests thatEpiblema andThelymitra are sister genera and thatCalochilus is derived from aThelymitra ancestor. A Gene Pool Vortex model and a hypothetical phylogeny illustrate that introgressive hybridization, allopatry, and long distance dispersal have played a major role in the evolution of the tribe. Pollination and hybridization in the tribe are discussed with major emphasis on floral mimicry.     

The generic delimitation of Rhodella (Porphyridiales,Rhodophyta) with emphasis on ultrastructure and molecular phylogeny

We investigated the cellular features and molecular phylogeny of Rhodella species and related unicellular red algae including undescribed species that we isolated. Results provide a new taxonomic interpretation at both generic and specific levels. The genus Rhodella is defined by its pyrenoid that is free from any internal structures. Based on phylogenetic analysis using 18SrDNA, there are two possibilities for the generic delimitation of Rhodella: Rhodella sensu stricto and Rhodella sensu lato. The generic autonomy of Dixoniella and the taxonomic position of R. cyanea were also discussed.     

A molecular phylogeny of the Chalcidoidea (Hymenoptera)

Chalcidoidea (Hymenoptera) are extremely diverse with more than 23,000 species described and over 500,000 species estimated to exist. This is the first comprehensive phylogenetic analysis of the superfamily based on a molecular analysis of 18S and 28S ribosomal gene regions for 19 families, 72 subfamilies, 343 genera and 649 species. The 56 outgroups are comprised of Ceraphronoidea and most proctotrupomorph families, including Mymarommatidae. Data alignment and the impact of ambiguous regions are explored using a secondary structure analysis and automated (MAFFT) alignments of the core and pairing regions and regions of ambiguous alignment. Both likelihood and parsimony approaches are used to analyze the data. Overall there is no impact of alignment method, and few but substantial differences between likelihood and parsimony approaches. Monophyly of Chalcidoidea and a sister group relationship between Mymaridae and the remaining Chalcidoidea is strongly supported in all analyses. Either Mymarommatoidea or Diaprioidea are the sister group of Chalcidoidea depending on the analysis. Likelihood analyses place Rotoitidae as the sister group of the remaining Chalcidoidea after Mymaridae, whereas parsimony nests them within Chalcidoidea. Some traditional family groups are supported as monophyletic (Agaonidae, Eucharitidae, Encyrtidae, Eulophidae, Leucospidae, Mymaridae, Ormyridae, Signiphoridae, Tanaostigmatidae and Trichogrammatidae). Several other families are paraphyletic (Perilampidae) or polyphyletic (Aphelinidae, Chalcididae, Eupelmidae, Eurytomidae, Pteromalidae, Tetracampidae and Torymidae). Evolutionary scenarios discussed for Chalcidoidea include the evolution of phytophagy, egg parasitism, sternorrhynchan parasitism, hypermetamorphic development and heteronomy.     

Justification for the generic status of Courtoisina (Cyperaceae)

In the past, the two species of Courtoisina were placed either in Cyperus L., Mariscus Vahl, or in Courtoisia Nees (now Courtoisina Sojak). While these species show undoubted external similarities to both Cypm and Muriscus , they differ by their widely winged glumes and the arrangement of the veins of the glumes. They also differ profoundly from Mariscus and most species of Cypm in anatomical characteristics, and it is concluded that these differences warrant separate generic status.     

A multilocus molecular phylogeny of the parrots (Psittaciformes): support for a Gondwanan origin during the cretaceous

The question of when modern birds (Neornithes) first diversified has generated much debate among avian systematists. Fossil evidence generally supports a Tertiary diversification, whereas estimates based on molecular dating favor an earlier diversification in the Cretaceous period. In this study, we used an alternate approach, the inference of historical biogeographic patterns, to test the hypothesis that the initial radiation of the Order Psittaciformes (the parrots and cockatoos) originated on the Gondwana supercontinent during the Cretaceous. We utilized broad taxonomic sampling (representatives of 69 of the 82 extant genera and 8 outgroup taxa) and multilocus molecular character sampling (3,941 bp from mitochondrial DNA (mtDNA) genes cytochrome oxidase I and NADH dehydrogenase 2 and nuclear introns of rhodopsin intron 1, tropomyosin alpha-subunit intron 5, and transforming growth factor ss-2) to generate phylogenetic hypotheses for the Psittaciformes. Analyses of the combined character partitions using maximum parsimony, maximum likelihood, and Bayesian criteria produced well-resolved and topologically similar trees in which the New Zealand taxa Strigops and Nestor (Psittacidae) were sister to all other psittaciforms and the cockatoo clade (Cacatuidae) was sister to a clade containing all remaining parrots (Psittacidae). Within this large clade of Psittacidae, some traditionally recognized tribes and subfamilies were monophyletic (e.g., Arini, Psittacini, and Loriinae), whereas several others were polyphyletic (e.g., Cyclopsittacini, Platycercini, Psittaculini, and Psittacinae). Ancestral area reconstructions using our Bayesian phylogenetic hypothesis and current distributions of genera supported the hypothesis of an Australasian origin for the Psittaciformes. Separate analyses of the timing of parrot diversification constructed with both Bayesian relaxed-clock and penalized likelihood approaches showed better agreement between geologic and diversification events in the chronograms based on a Cretaceous dating of the basal split within parrots than the chronograms based on a Tertiary dating of this split, although these data are more equivocal. Taken together, our results support a Cretaceous origin of Psittaciformes in Gondwana after the separation of Africa and the India/Madagascar block with subsequent diversification through both vicariance and dispersal. These well-resolved molecular phylogenies will be of value for comparative studies of behavior, ecology, and life history in parrots.     

Comparative morphology and molecular phylogeny of aplanochytrids (Labyrinthulomycota)

Aplanochytrids comprise one of three major subgroups within the Labyrinthulomycota. We have surveyed the diversity of aplanochytrids and have discovered that most isolates are difficult to identify to species because of character plasticity and ambiguity. Ten isolates were studied using molecular phylogenies based on small subunit ribosomal gene sequences (SSU rDNA) and morphological characters derived from light microscopy, SEM and TEM (e.g., colony size, colony shape, colony pattern, agar penetration, cell shape, cell surface patterns, cell inclusion characteristics and ectoplasmic net morphology). Of these isolates, we could positively identify two of them to species, namely Aplanochytrium yorkensis (Perkins, 1973) Leander and Porter, 2000 and A. minuta (Watson and Raper, 1957) Leander and Porter, 2000. We used standardized conditions for growing aplanochytrid isolates in order to minimize environmentally induced phenotypic plasticity in our comparative studies of morphology. By mapping the morphological characters listed above onto a conservative phylogenetic topology derived from SSU rDNA sequences, we were able to identify several synapomorphies (e.g., gross colony characteristics and cell surface patterns) that serve as valuable taxonomic characters for the identification of species and specific clades of aplanochytrids.     

Floral development and floral phyllotaxis in Anaxagorea (Annonaceae)

Background and Aims Anaxagorea is the phylogenetically basalmost genus in the large tropical Annonaceae (custard apple family) of Magnoliales, but its floral structure is unknown in many respects. The aim of this study is to analyse evolutionarily interesting floral features in comparison with other genera of the Annonaceae and the sister family Eupomatiaceae. Methods Live flowers of Anaxagorea crassipetala were examined in the field with vital staining, liquid-fixed material was studied with scanning electron microscopy, and microtome section series were studied with light microscopy. In addition, herbarium material of two other Anaxagorea species was cursorily studied with the dissecting microscope. Key Results Floral phyllotaxis in Anaxagorea is regularly whorled (with complex whorls) as in all other Annonaceae with a low or medium number of floral organs studied so far (in those with numerous stamens and carpels, phyllotaxis becoming irregular in the androecium and gynoecium). The carpels are completely plicate as in almost all other Annonaceae. In these features Anaxagorea differs sharply from the sister family Eupomatiaceae, which has spiral floral phyllotaxis and ascidiate carpels. Flat stamens and the presence of inner staminodes differ from most other Annonaceae and may be plesiomorphic in Anaxagorea. However, the inner staminodes appear to be non-secretory in most Anaxagorea species, which differs from inner staminodes in other families of Magnoliales (Eupomatiaceae, Degeneriacae, Himantandraceae), which are secretory. Conclusions Floral phyllotaxis in Anaxagorea shows that there is no signature of a basal spiral pattern in Annonaceae and that complex whorls are an apomorphy not just for a part of the family but for the family in its entirety, and irregular phyllotaxis is derived. This and the presence of completely plicate carpels in Anaxagorea makes the family homogeneous and distinguishes it from the closest relatives in Magnoliales.     

A molecular phylogeny of the cotingas (Aves: Cotingidae)

The phylogenetic relationships of members of Cotingidae were investigated using >2100 bp of sequence data from two nuclear introns (myoglobin intron 2 and G3PDH intron 11) and one protein-coding mitochondrial gene (cytochrome b). Strong support was found for a monophyletic clade including 23 traditional cotingid genera, corresponding to the Cotingidae sensu [Remsen, J.V. Jr., Jaramillo, A., Nores, M., Pacheco, J.F., Robbins, M.B., Schulenberg, T.S., Stiles, F.G., da Silva, J.M.C., Stotz, D.F., Zimmer, K.J., 2005. Version 2005-11-15. A classification of the bird species of South America. American Ornithologists' Union. ]. Neither Oxyruncus nor any of the genera in Tityrinae sensu [Prum, R.O, Lanyon, W.E., 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91, 444-461.] are members of Cotingidae. Within Cotingidae a polytomy of four well-supported clades was recovered: (1) the fruiteaters Pipreola and Ampelioides; (2) the Ampelion group, including Phytotoma; (3) Rupicola and Phoenicircus; and (4) the 'core cotingas' consisting of the remainder of the Cotingas (e.g. fruitcrows, Cotinga, Procnias, Lipaugus, and Carpodectes), with Snowornis in a basal position. The separation of Snowornis from Lipaugus [Prum, R.O, Lanyon, W.E., 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91, 444-461.] was strongly supported, as were the close relationships between Gymnoderus and Conioptilon, and between Tijuca and Lipaugus. However, basal relationships among 'core cotinga' clades were not resolved.     

Morphological and molecular evidence of the phylogeny of Nereidiform polychaetes (Annelida)

The phylogeny of Nereidiformia is assessed in a parsimony analysis of combined morphological and DNA data, with special focus on previously questioned relationships between Chrysopetalidae and Hesionidae, between Pilargidae and Hesionidae, and the affinities of Hesionides and Microphthalmus. A 660 bp segment of the mtDNA cytochrome c oxidase subunit I gene was sequenced for two chrysopetalids, one nereidid, one pilargid, one pisionid, two hesionids, plus the two questionable hesionids Hesionides arenaria and Microphthalmus sp. Phylogenetic resolution was poor for the cytochrome c oxidase subunit I gene data alone, but the combined analysis yielded partially robust topologies, suggesting that nereids are the sister group to chrysopetalids, and that pilargids, Hesionides and Microphthalmus do not belong within the hesionids     

A molecular phylogeny of scaly tree ferns (Cyatheaceae)

Tree ferns recently were identified as the closest sister group to the hyperdiverse clade of ferns, the polypods. Although most of the 600 species of tree ferns are arborescent, the group encompasses a wide range of morphological variability, from diminutive members to the giant scaly tree ferns, Cyatheaceae. This well-known family comprises most of the tree fern diversity (～500 species) and is widespread in tropical, subtropical, and south temperate regions of the world. Here we investigate the phylogenetic relationships of scaly tree ferns based on DNA sequence data from five plastid regions (rbcL, rbcL-accD IGS, rbcL-atpB IGS, trnG-trnR, and trnL-trnF). A basal dichotomy resolves Sphaeropteris as sister to all other taxa and scale features support these two clades: Sphaeropteris has conform scales, whereas all other taxa have marginate scales. The marginate-scaled clade consists of a basal trichotomy, with the three groups here termed (1) Cyathea (including Cnemidaria, Hymenophyllopsis, Trichipteris), (2) Alsophila sensu stricto, and (3) Gymnosphaera (previously recognized as a section within Alsophila) + A. capensis. Scaly tree ferns display a wide range of indusial structures, and although indusium shape is homoplastic it does contain useful phylogenetic information that supports some of the larger clades recognised.