Phylogenetic significance of morphological characters in the taxonomy of Pestalotiopsis species

There has been considerable disagreement regarding the relationships among Pestalotiopsis species and their delimitations. A molecular phylogenetic analysis was conducted on 32 species of Pestalotiopsis in order to evaluate the utility of morphological characters currently used in their taxonomy. Phylogenetic relationships were inferred from nucleotide sequences in the ITS regions and 5.8S gene of the rDNA under four optimality criteria: maximum parsimony, weighted parsimony, maximum likelihood, and neighbor joining. Phylogenies estimated from all analyses yielded trees of essentially similar topology and revealed 3 major groups that correspond with morphology-based classification systems. Molecular data indicated that the genus contains two distinct lineages based on pigmentation of median cells and four distinct groupings based on morphology of apical appendages. The analyses did not support reliability of other phenotypic characters of this genus, such as spore dimensions. Characters with particular phylogenetic significance are discussed in relation to the taxonomy of Pestalotiopsis.     

山茶灰斑病病原菌斑污拟盘多毛孢的研究

山茶灰斑病病原菌的正名为斑污拟盘多毛孢Pestalotiopsis maculans(Cda.)Nag Raj,山茶盘多毛孢Pestalotia guepini Desm.和山茶拟盘多毛孢Pestalotiopsis guepini(Desm.)Stey.均为其异名。本文根据作者对自1978年以来采集的大量标本和分离菌株的研究,记述了斑污拟盘多毛孢的形态学、培养性状、致病性及寄主范围、电泳图谱等特征,并附有讨论。     

CLADISTICS OF THE BRYOPSIDALES: A PRELIMINARY ANALYSIS

The Bryopsidales contains some of the most species rich and ecologically dominant algae in tropical ecosystems. However, the evolutionary relationships among the 29 genera and several hundred species of this order remain poorly resolved. Because of a lack of known reproductive characters for many taxa, evolutionary hypotheses grouped genera by similarities in morphological characters. To apply standard cladistical analyses to further our understanding of this group, this study presents the first comprehensive compilation of reported morphological, reproductive, and subcellular characteristics for genera in the Bryopsidales. Computer-assisted cladistical analyses ultimately identified phylogenetically informative and uninformative characters. Although the topology of the trees generated in this study is expected to change as additional data are added to this matrix, many traditional groupings and recent groupings based on molecular data were supported.     

Analysis of the systematic relationships among ticks of the genera Rhipicephalus and Boophilus (Acari: Ixodidae) based on mitochondrial 12S ribosomal DNA gene sequences and morphological characters

A portion of mitochondrial 12S rDNA sequences (337-355 base pairs) and 63 morphological characters of 36 hard-tick species belonging to 7 genera were analyzed to determine the phylogenetic relationships among groups and species of Rhipicephalus and between the genera Rhipicephalus and Boophilus. Molecular and morphological data sets were first examined separately. The molecular data were analyzed by maximum parsimony (MP), maximum likelihood, and neighbor-joining distance methods; the morphological data were analyzed by MP After their level of congruence was evaluated by a partition homogeneity test, all characters were combined and analyzed by MP. The branches of the tree obtained by combining the data sets were better resolved than those of the trees inferred from the separate analyses. Boophilus is monophyletic and arose within Rhipicephalus. Boophilus species clustered with species of the Rhipicephalus evertsi group. Most of the clustering within Rhipicephalus was, however, consistent with previous classifications based on morphological data. Morphological characters were traced on the molecular reconstruction in order to identify characters diagnostic for monophyletic clades. Within the Rhipicephalus sanguineus complex, the sequences of specimens morphologically identified as Rhipicephalus turanicus were characterized by a high level of variability, indicating that R. turanicus-like morphology may cover a spectrum of distinct species.     

A phylogenetic study of krill (Crustacea: Euphausiacea) reveals new taxa and co-evolution of morphological characters

The first comprehensive phylogenetic study of Euphausiacea (all 86 valid species) is presented. It is based on four molecular markers and 168 morphological characters (including 58 characters of the petasma). Phylogenetic analyses support the monophyly and robustness of the families Bentheuphausidae and Euphausiidae and reveal three major clades for which we erect three new subfamilies: Thysanopodinae, Euphausiinae and Nematoscelinae. All genus-level clades are statistically supported (except Thysanopoda in molecular analyses), deeply nested within the subfamily-level clades, and encompass 14 new species groups. Copulatory structures have a major impact on tree topology in the morphological analysis, the removal of which resulted in only half the number of supported clades and genera. We revealed three groups of morphological characters, which are probably coupled with the same biological role and thus interlinked evolutionarily: (i) antennular peduncle and petasma (copulation); (ii) eyes and anterior thoracopods (feeding); and (iii) shape of carapace and pleon (defence). We analysed the evolutionary pathways of the clades into main oceanic biotopes and compared them with morphological adaptations most likely to be coupled with this process.     

Phylogeny of haplo–diploid,fungus‐growing ambrosia beetles (Curculionidae: Scolytinae: Xyleborini) inferred from molecular and morphological data

Cognato, A. I., Hulcr, J., Dole, S. A. & Jordal, B. H. (2010). Phylogeny of haplo‐diploid, fungus‐growing ambrosia beetles (Curculionidae: Scolytinae: Xyleborini) inferred from molecular and morphological data. —Zoologica Scripta, 40, 174–186. The ambrosia beetle tribe Xyleborini currently contains 30 genera and approximately 1200 species which are distributed throughout worldwide forests with most diversity located in the tropics. They also represent the most invasive scolytines in North America. Despite economic concerns and biological curiosity with this group, a comprehensive understanding of generic boundaries and the evolutionary relationship among species is lacking. In this study, we include 155 xyleborine species representing 23 genera in parsimony and Bayesian analyses using 3925 nucleotides from mitochondrial (COI) and nuclear genomes (28S, ArgK, CAD, EF‐1α) and 39 morphological characters. The phylogenies resulting from the parsimony analyses, which treated gap positions either as missing or fifth character states, and the Bayesian analysis were generally similar. Clades with high support or posterior probabilities were found in all trees, while those with low support were not recovered by all analyses. Fourteen of the 23 genera were monophyletic although not all relationships among the genera were resolved. We show monophyly of several species groups associated with particular morphological and biological characters and suggest recognition of these groups as genera. Most interesting was the monophyly of South and Central American species representing several genera. This finding suggests recent and fast radiation of xyleborines in the New World accompanied by morphological and biological diversification.     

A phylogeny of extant penguins (Aves: Sphenisciformes) combining morphology and mitochondrial sequences

The phylogenetic relationships among the penguins have received little attention, despite their well‐known anatomy and the conspicuous nature of the group. Previous attempts have included datasets limited to few, mostly osteological characters, and one study was based on integumentary and breeding characters. We developed a morphological matrix comprising 159 morphological characters of osteology (70 characters), myology (15), digestive tract (1), integument (66), and breeding (7 characters), scored in 18 extant forms (all currently recognized species plus one distinct subspecies). A gaviiform was placed at the root, and 11 species of representative procellariiform groups completed the outgroup. A heuristic parsimony analysis under equal weights was performed. We also compiled DNA sequences available in GenBank for the mitochondrial genes 12S rDNA and cytochrome b. We included the two data partitions in a combined analysis under direct optimization. Both analyses recovered the monophyly of Sphenisciformes and all the traditional polytypic genera. Morphological characters performed optimally at the ordinal and generic nodes, also providing resolution and varying degrees of support at supra‐ and intrageneric nodes. The comparison of molecular and morphological results indicated that the most significant problem in the phylogeny of extant penguins is rooting the ingroup. The mutual interaction of molecular and morphological data decreases the ambiguity regarding the placement of the root, and provides a resolved, relatively well‐supported phylogeny of extant penguins. Biogeographical patterns based on breeding ranges and derived from the combined analysis show that the major intercontinental vicariance events detected are consistent with cold marine current patterns of the Southern Hemisphere. © The Willi Hennig Society 2005.     

A molecular systematic revision of two historically problematic songbird clades: Aimophila and Pipilo

The emberizid genera Aimophila and Pipilo represent longstanding taxonomic conundrums. Each is comprised of sub-clades whose members appear to share diagnostic morphological and behavioral characters; however, relationships among sub-clades within each of these genera remain unclear, and numerous authors have suggested that either one or both of these genera may be polyphyletic. We addressed this taxonomic problem by sequencing and analyzing complete mitochondrial cytochrome- b and NADH dehydrogenase subunit 2 genes for all members of Aimophila and Pipilo along with 33 species representing 17 additional emberizid genera. Our maximum likelihood and Bayesian analyses indicate that both Aimophila and Pipilo are polyphyletic. Aimophila is divided into a minimum of three distinct groups. The forms notosticta, ruficeps , and rufescens are part of a well-supported clade that includes all members of Melozone and some members of Pipilo . Aimophila quinquestriata is placed within Amphispiza , and the remaining members of Aimophila are placed within a clade that includes all members of Arremonops and some members of Ammodramus . Within Pipilo , the "rufous-sided" and "brown" towhee groups do not form sister groups. Rather, the former are most closely related to the tropical genus Atlapetes whereas the latter are placed nearest Melozone and some Aimophila . Our analyses reject traditional taxonomic arrangements for both genera, and we present suggestions for a revised taxonomy for all members of Aimophila and Pipilo . These results provide further evidence of discordance among phylogenetic hypotheses based on morphological and molecular characters for groups of birds with generally conserved morphology.     

Relationships within Podocarpaceae based on DNA sequence,anatomical, morphological,and biogeographical data

Despite considerable recent progress in understanding intergeneric relationships, a comprehensive analysis of Podocarpaceae at the species level using molecular data, biogeography, anatomy, and morphology has not been previously attempted. Here we present sequence analyses of rbcL, nrITS1 and NEEDLY intron 2 for two‐thirds (183 accessions of 145 taxa) of all Podocarpaceae species representing all genera except Parasitaxus. These analyses include many more species and accessions than previous studies and result in a more resolved phylogeny. The comprehensive anatomical and morphological study ensures that the identification of taxa is correct and also provides clade support. Bayesian and parsimony analyses were used to resolve 20 well‐supported monophyletic groups including 11 groups of the formerly poorly resolved subgenera Podocarpus and Foliolatus. The well‐resolved topology is supported by anatomical and morphological features and is highly congruent with geographical distribution. © The Willi Hennig Society 2011.     

Phylogenetic analyses of marine sponges within the order Verongida: a comparison of morphological and molecular data

Abstract. Because the taxonomy of marine sponges is based primarily on morphological characters that can display a high degree of phenotypic plasticity, current classifications may not always reflect evolutionary relationships. To assess phylogenetic relationships among sponges in the order Verongida, we examined 11 verongid species, representing six genera and four families. We compared the utility of morphological and molecular data in verongid sponge systematics by comparing a phylogeny constructed from a morphological character matrix with a phylogeny based on nuclear ribosomal DNA sequences. The morphological phylogeny was not well resolved below the ordinal level, likely hindered by the paucity of characters available for analysis, and the potential plasticity of these characters. The molecular phylogeny was well resolved and robust from the ordinal to the species level. We also examined the morphology of spongin fibers to assess their reliability in verongid sponge taxonomy. Fiber diameter and pith content were highly variable within and among species. Despite this variability, spongin fiber comparisons were useful at lower taxonomic levels (i.e., among congeneric species); however, these characters are potentially homoplasic at higher taxonomic levels (i.e., between families). Our molecular data provide good support for the current classification of verongid sponges, but suggest a re-examination and potential reclassification of the genera Aiolochroia and Pseudoceratina . The placements of these genera highlight two current issues in morphology-based sponge taxonomy: intermediate character states and undetermined character polarity.     

Phylogenetic relationships of Microdontinae (Diptera: Syrphidae) based on molecular and morphological characters

The intrasubfamilial classification of Microdontinae Rondani (Diptera: Syrphidae) has been a challenge: until recently more than 300 out of more than 400 valid species names were classified in Microdon Meigen. We present phylogenetic analyses of molecular and morphological characters (both separate and combined) of Microdontinae. The morphological dataset contains 174 characters, scored for 189 taxa (9 outgroup), representing all 43 presently recognized genera and several subgenera and species groups. The molecular dataset, representing 90 ingroup species of 28 genera, comprises sequences of five partitions in total from the mitochondrial gene COI and the nuclear ribosomal genes 18S and 28S. We test the sister‐group relationship of Spheginobaccha with the other Microdontinae, attempt to elucidate phylogenetic relationships within the Microdontinae and discuss uncertainties in the classification of Microdontinae. Trees based on molecular characters alone are poorly resolved, but combined data are better resolved. Support for many deeper nodes is low, and placement of such nodes differs between parsimony and Bayesian analyses. However, Spheginobaccha is recovered as highly supported sister group in both. Both analyses agree on the early branching of Mixogaster, Schizoceratomyia, Afromicrodon and Paramicrodon. The taxonomical rank in relation to the other Syrphidae is discussed briefly. An additional analysis based on morphological characters only, including all 189 taxa, used implied weighting. A range of weighting strengths (k‐values) is applied, chosen such that values of character fit of the resulting trees are divided into regular intervals. Results of this analysis are used for discussing the phylogenetic relationships of genera unrepresented in the molecular dataset.     

New insights into Trimezieae (Iridaceae) phylogeny: what do molecular data tell us?

Background and Aims

The Neotropical tribe Trimezieae are taxonomically difficult. They are generally characterized by the absence of the features used to delimit their sister group Tigridieae. Delimiting the four genera that make up Trimezieae is also problematic. Previous family-level phylogenetic analyses have not examined the monophyly of the tribe or relationships within it. Reconstructing the phylogeny of Trimezieae will allow us to evaluate the status of the tribe and genera and to examine the suitability of characters traditionally used in their taxonomy.

Methods

Maximum parsimony and Bayesian phylogenetic analyses are presented for 37 species representing all four genera of Trimezieae. Analyses were based on nrITS sequences and a combined plastid dataset. Ancestral character state reconstructions were used to investigate the evolution of ten morphological characters previously considered taxonomically useful.

Key Results

Analyses of nrITS and plastid datasets strongly support the monophyly of Trimezieae and recover four principal clades with varying levels of support; these clades do not correspond to the currently recognized genera. Relationships within the four clades are not consistently resolved, although the conflicting resolutions are not strongly supported in individual analyses. Ancestral character state reconstructions suggest considerable homoplasy, especially in the floral characters used to delimit Pseudotrimezia.

Conclusions

The results strongly support recognition of Trimezieae as a tribe but suggest that both generic- and species-level taxonomy need revision. Further molecular analyses, with increased sampling of taxa and markers, are needed to support any revision. Such analyses will help determine the causes of discordance between the plastid and nuclear data and provide a framework for identifying potential morphological synapomorphies for infra-tribal groups. The results also suggest Trimezieae provide a promising model for evolutionary research.     

Phylogenetic relationships of Central European wolf spiders (Araneae: lycosidae) inferred from 12S ribosomal DNA sequences

We have analyzed a sequence dataset of a portion of mitochondrial 12S rRNA gene of the ribosomal small subunit for 27 species of the family Lycosidae (wolf spiders) from Central Europe, belonging to six genera (Alopecosa, Arctosa, Pardosa, Pirata, Trochosa, and Xerolycosa) and four subfamilies (Evippinae, Lycosinae, Pardosinae and Venoniinae). Phylogenetic analyses were performed in two steps and corroborate the monophyly of all the genera analyzed with strong bootstrap support. In the first step focusing on the most ancestral splits the genus Pirata consistently emerged as the most ancestral branch, followed by the two genera Arctosa and Xerolycosa, with conflicting branching order, however. The second step of analysis placed Xerolycosa more ancestral than Arctosa. Arctosa appeared as sister group to the genera Alopecosa, Trochosa, and Pardosa. The palearctic genus Xerolycosa was not yet included in previous studies derived from morphological characters, but its placement based on mtDNA sequences is in good agreement to that according to current diagnostic morphological features. Further, the single representative of the genus Arctosa examined in our study was placed at a more ancestral position than in a previous investigation based on phenotypic characters. The superimposition of the currently used diagnostic phenotypic characters on the DNA-based phylogeny shows that both character sets are widely congruent; only 3 out of 16 phenotypic characters were resolved as homoplasious, suggesting their parallel evolution and/or reversal. Among the three different styles of predation found in the Lycosids, tube builders appear to be the most ancestral from which burrow dwellers descended and from which two groups of vagrant hunters evolved in parallel.     

Phylogenetic relationships among microgastrine braconid wasp genera based on data from the 16S, COI and 28S genes and morphology

Abstract Phylogenetic relationships among the genera of the large braconid wasp subfamily Microgastrinae were explored using DNA sequence data from the mitochondrial large ribosomal subunit (16S), nuclear large ribosomal subunit (28S) and mitochondrial cytochrome oxidase (COI) genes, along with morphological characters, both new and from previous studies. The taxonomic history of this group of wasps is reviewed, along with a critique of previous phylogenetic studies on the group. Molecular data were sampled from forty-six species representing twenty-six genera of microgastrines, plus three species representing the close outgroup taxa Cardiochilinae and Miracinae. Some 2300 base pairs of aligned sequence were obtained per taxon from the three genes. In addition, fifty-three morphological characters were coded for all known genera, including two undescribed genera, except Semionis Nixon (known from only a single male type specimen). Relationships among several groups of genera are clarified and challenge some major assumptions made in earlier classifications. In particular, it is clear that dependence on one or a few major morphological character systems oversimplifies relationships, and can lead to misleading results. Despite the large amount of data analysed, basal divergences within the subfamily remain poorly resolved and essentially unsupported in any rigorous statistical sense.     

A PHYLOGENETIC STUDY OF THE CORALLINALES (RHODOPHYTA) BASED ON NUCLEAR SMALL-SUBUNIT rRNA GENE SEQUENCES

Conflicting classifications for the Corallinales were tested by analyzing partial sequences for the nuclear small-subunit ribosomal RNA (SSU) gene of 35 species of coralline algae. Parsimony and likelihood analyses of these data yielded congruent hypotheses that are inconsistent with classifications for the group that include as many as eight subfamilies. Four major clades are resolved within the order, including the early-diverging Sporolithaceae as well as the Melobesioideae and Corallinoideae. The fourth clade, which is supported robustly, includes both nongeniculate and geniculate species classified in the subfamilies Mastophoroideae, Metagoniolithoideae, Lithophylloideae, and Amphiroideae. Molecular and morphological data support the proposal that the latter two subfamilies are sister taxa. Although relationships among some genera are not resolved clearly, the order of branching of taxa among and within the four principal lineages is concordant with paleontological evidence for the group. Relationships inferred among genera within each of the clades is discussed. Seven morphological characters delimiting higher taxonomic groups within the order were combined with the sequence data, analyzed, and optimized onto the resulting tree(s). Except for the presence or absence of genicula, all other characters were found to be phylogenetically informative. Genicula are nonhomologous structures that evolved independently in the Amphiroideae, Corallinoideae, and Metagoniolithoideae. The phenetic practice of separating coralline algae into two categories solely on the basis of the presence or absence of genicula does not accurately reflect the evolutionary history of the group.     

Systematic Position of the African Dormouse Graphiurus (Rodentia, Gliridae) Assessed from Cytochrome b and 12S rRNA Mitochondrial Genes

Gliridae is a small family of rodents including three subfamilies: the Eurasian Glirinae (with three genera) and Leithiinae (with four genera) and the African Graphiurinae (with a single genus). Phylogenetic relationships among these eight genera are not fully resolved based on morphological characters. Moreover, the genus Graphiurus is characterized by numerous peculiar features (morphological characters and geographical distribution), raising the question of its relationships to the family Gliridae. The phylogenetic position of Graphiurus and the intra-Gliridae relationships are here addressed by a molecular analysis of 12S RNA and cytochrome b mitochondrial gene sequences for six glirid genera. Phylogenetic analyses are performed with three construction methods (neighbor-joining, maximum parsimony and maximum likelihood) and tests of alternative topologies with respect to the most likely. Our analyses reveal that Graphiurus is clearly a member of the Gliridae, refuting the hypothesis that the family could be paraphyletic. Among Gliridae, phylogenetic relationships are poorly resolved: the Leithiinae could be monophyletic, there is no support for the subfamily Glirinae, and the closest relative of Graphiurus is not identified. The inclusion of Graphiurus among Gliridae allows us to postulate that its hystricomorphous condition has been achieved convergently with other hystricomorphous rodents.     

Multivariate analysis of the phenotypic relationships of the species of Paragalaxias and Galaxias (Pisces: Galaxiidae) in Tasmania

The 10 species of Galaxias in Tasmania, G. olidus from mainland Australia and the four species of Paragalaxias were studied using principal co-ordinates analysis (PCOA) and cluster analysis of a standardized Euclidean distance matrix based upon variate means, and by canonical variate analysis (CVA) conducted as a stepwise multiple discriminant analysis. Thirty-five variables comprising 30 morphometric and five meristic characters were analysed. The meristic characters were not included in the CVA. Excellent separation of the two genera was achieved in all analyses. The multivariate analyses were repeated on each genus separately to see if relationships suggested by the overall analysis remain stable. When the resultant groupings of species are compared for the different analyses, no consistent, distinct groupings of species within each genus are apparent. Despite the absence of distinct groupings, some trends in the affinities of some species are evident. In particular, species affinities as indicated by the CVA are more consistent with established opinions of species relationships. From the results of the study it is suggested that caution be exercised in the application of multivariate statistical analyses of morphological data to ichthyological systematics and phylogeny.     

绣球属(Hydrangea L.)植物分子系统学及系统发育分析

该研究基于对绣球属(Hydrangea L.)的大尺度取样,选取国内外61种绣球属和近缘属植物,分别基于核基因片段(ITS)和叶绿体基因片段(rbcL,trnL-F,atpB)重建了绣球属及其近缘种属的系统发育关系。结果表明:(1)核基因与叶绿体基因树之间在树形上没有明显的冲突,进而基于核基因和叶绿体基因联合数据重建了绣球属及其近缘种属的系统发育关系。(2)基于联合数据构建的系统树确认了2个大分支,并得到了果实顶端截平与否这一形态学证据的强力支持;每个大分枝又分为4个类群,共确定了8个类群。部分类群也得到了广义宏观形态性状的支持,如第1类群得到了叶形、花粉以及种子形态的支持。因此,该系统发育关系的重建对于全面理解绣球属及其近缘种属的演化关系具有重要的启发。     

Evolutionary trends in Tetrastigma (Vitaceae): Morphological diversity and taxonomic implications

Tetrastigma (Miq.) Planch. (Vitaceae) is a genus with ca. 100 species showing great morphological diversity. Previous molecular phylogenetic studies suggested that traditional classification systems are not consistent with the molecular phylogeny, and Tetrastigma is undergoing further systematic investigation. We traced the evolutionary trends of 20 morphological characters within a robust phylogenetic framework. Our results revealed that many morphological characters show either multiple transitions or few state changes, however, some characters show distinct variation. The two subgenera in Tetrastigma (subgen. Tetrastigma and subgen. Palmicirrata) based on unbranched/bifurcate versus digitately branched tendrils are not supported because subgen. Tetrastigma is paraphyletic. However, the unbranched versus bifurcate/digitately branched tendril is of taxonomic utility to characterize some of the major clades. Inflorescences in Tetrastigma appear axillary, but are leaf‐opposed on a compressed axillary shoot. We found most of the species in Tetrastigma retained the ancestral compound dichasial inflorescence, except those of clade IV that have derived pseudo‐umbellate inflorescences. Other characters including habit, leaf organization, and berry shape provide additional morphological support for the major clades. Our morphological analysis and recent molecular study suggest each of the five major clades within Tetrastigma be treated as distinct taxonomic sections (five sections in the genus).