Maximum Parsimony Analyses Research Articles

Chromosomal phylogeny and comparative chromosome painting among Neacomys species (Rodentia, Sigmodontinae) from eastern Amazonia

BackgroundThe Neacomys genus is predominantly found in the Amazon region, and belongs to the most diverse tribe of the Sigmodontinae subfamily (Rodentia, Cricetidae, Oryzomyini). The systematics of this genus and questions about its diversity and range have been investigated by morphological, molecular (Cytb and COI sequences) and karyotype analysis (classic cytogenetics and chromosome painting), which have revealed candidate species and new distribution areas. Here we analyzed four species of Neacomys by chromosome painting with Hylaeamys megacephalus (HME) whole-chromosome probes, and compared the results with two previously studied Neacomys species and with other taxa from Oryzomyini and Akodontini tribes that have been hybridized with HME probes. Maximum Parsimony (MP) analyses were performed with the PAUP and T.N.T. software packages, using a non-additive (unordered) multi-state character matrix, based on chromosomal morphology, number and syntenic blocks. We also compared the chromosomal phylogeny obtained in this study with molecular topologies (Cytb and COI) that included eastern Amazonian species of Neacomys, to define the phylogenetic relationships of these taxa.ResultsThe comparative chromosome painting analysis of the seven karyotypes of the six species of Neacomys shows that their diversity is due to 17 fusion/fission events and one translocation, pericentric inversions in four syntenic blocks, and constitutive heterochromatin (CH) amplification/deletion of six syntenic autosomal blocks plus the X chromosome. The chromosomal phylogeny is consistent with the molecular relationships of species of Neacomys. We describe new karyotypes and expand the distribution area for species from eastern Amazonia and detect complex rearrangements by chromosome painting among the karyotypes.ConclusionsOur phylogeny reflects the molecular relationships of the Akodontini and Oryzomyini taxa and supports the monophyly of Neacomys. This work presents new insights about the chromosomal evolution of this group, and we conclude that the karyotypic divergence is in accord with phylogenetic relationships.

Extended studies of interspecific relationships in Daucus (Apiaceae) using DNA sequences from ten nuclear orthologues

AbstractDaucus has traditionally been estimated to comprise 21–25 species, but a recent study expanded the genus to c. 40 species. The present study uses ten nuclear orthologues to examine 125 accessions, including 40 collections of 11 species (D. annuus, D. arcanus, D. decipiens, D. durieua, D. edulis, D. gracilis, D. minusculus, D. montanus, D. pumilus, D. setifolius and D. tenuissimus) newly examined with nuclear orthologues. As in previous nuclear orthologue studies, Daucus resolves into two well-defined clades, and groups different accessions of species together. Maximum likelihood and maximum parsimony analyses provide concordant results, but SVD quartets reveals many areas of disagreement of species within these two major clades. With maximum likelihood and maximum parsimony analyses Daucus montanus (hexaploid) is resolved as an allopolyploid between D. pusillus (diploid) and D. glochidiatus (tetraploid), whereas with SVD quartets it is resolved as an allopolyploid between D. glochidiatus and an unknown Daucus sp. We propose the new combination Daucus junceus (Durieua juncea) for a neglected species endemic to the south-western Iberian Peninsula often referred to as D. setifolius, and we place D. arcanus in synonymy with D. pusillus. Three lectotypes are also designated.

Maximum parsimony analysis of the effect of the environment on the evolution of galaxies

Context. Galaxy evolution and the effect of the environment are most often studied using scaling relations or regression analyses around a given property. However, these approaches do not take into account the complexity of the physics of the galaxies and their diversity. Aims. We here investigate the effect of the cluster environment on the evolution of galaxies through multivariate, unsupervised classification and phylogenetic analyses applied to two relatively large samples from the Wide-field Nearby Galaxy-cluster Survey (WINGS), one of cluster members and one of field galaxies (2624 and 1476 objects, respectively). Methods. These samples are the largest ones ever analysed with a phylogenetic approach in astrophysics. To be able to use the maximum parsimony (cladistics) method, we first performed a pre-clustering in 300 clusters with a hierarchical clustering technique, before applying it to these pre-clusters. All these computations used seven parameters: B − V, log(Re), nV, ⟨μ⟩e, Hβ, D4000, and log(M*). Results. We have obtained a tree for the combined samples and do not find different evolutionary paths for cluster and field galaxies. However, the cluster galaxies seem to have accelerated evolution in the sense that they are statistically more diversified from a primitive common ancestor. The separate analyses show a hint of a slightly more regular evolution of the variables for the cluster galaxies, which may indicate they are more homogeneous compared to field galaxies in the sense that the groups of the latter appear to have more specific properties. On the tree for the cluster galaxies, there is a separate branch that gathers rejuvenated or stripped-off groups of galaxies. This branch is clearly visible on the colour-magnitude diagram, going back from the red sequence towards the blue one. On this diagram, the distribution and the evolutionary paths of galaxies are strikingly different for the two samples. Globally, we do not find any dominant variable able to explain either the groups or the tree structures. Rather, co-evolution appears everywhere, and could depend itself on environment or mass. Conclusions. This study is another demonstration that unsupervised machine learning is able to go beyond simple scaling relations by taking into account several properties together. The phylogenetic approach is invaluable in tracing the evolutionary scenarios and projecting them onto any bivariate diagram without any a priori modelling. Our WINGS galaxies are all at low redshift, and we now need to go to higher redshfits to find more primitive galaxies and complete the map of the evolutionary paths of present day galaxies.

Phylogenetic relationships within the flatworm genus Matuxia (Platyhelminthes, Tricladida, Continenticola) inferred from molecular data with the description of a southern lineage of the genus

The genus Matuxia Carbayo et al., 2013 currently comprises two species with distribution restricted to southeastern Brazil. In the present study, based on an integrative approach, we examine the genetic diversity within the genus and describe a new species, Matuxia tymbyra Rossi and Leal-Zanchet, sp. nov., representing a southern lineage of the genus. We employed one mitochondrial (cytochrome c oxidase subunit I, COI) and other nuclear (elongation factor 1a, EF-1a) markers to investigate the phylogenetic relationships within the genus. Maximum-parsimony analysis in a segment of the COI gene of 676 nucleotides showed 79 (11.68%) nucleotide positions exhibiting autapomorphic characters that support the occurrence of three independent evolutionary molecular operational taxonomic units in the genus. Similar evaluation for the dataset of the EF-1a gene showed a much smaller number of autapomorphies. Bayesian inference, maximum-likelihood and delimitation approaches, based on evolutionary models, showed that M. tymbyra is the sister species of the type-species of the genus, Matuxia tuxaua. They should be considered sibling species, only distinguishable based on details regarding eye arrangement and prostatic vesicle. The existence of 15 and 23 molecular autapomorphies, as revealed by maximum-parsimony analysis in a segment of the COI gene for M. tymbyra and M. tuxaua, respectively, allowed us to propose a molecular diagnosis for the new species, which is essential in cases of sibling species. The new species seems to be endemic from areas of Araucaria Forest in southern Brazil; the record augments the known distribution of the genus to the south.

The appendicular morphology of Sinoburius lunaris and the evolution of the artiopodan clade Xandarellida (Euarthropoda, early Cambrian) from South China

BackgroundArtiopodan euarthropods represent common and abundant faunal components in sites with exceptional preservation during the Cambrian. The Chengjiang biota in South China contains numerous taxa that are exclusively known from this deposit, and thus offer a unique perspective on euarthropod diversity during the early Cambrian. One such endemic taxon is the non-trilobite artiopodan Sinoburius lunaris, which has been known for approximately three decades, but few details of its anatomy are well understood due to its rarity within the Chengjiang, as well as technical limitations for the study of these fossils. Furthermore, the available material does not provide clear information on the ventral organization of this animal, obscuring our understanding of phylogenetically significant details such as the appendages.ResultsWe employed X-ray computed tomography to study the non-biomineralized morphology of Sinoburius lunaris. Due to the replacement of the delicate anatomy with pyrite typical of Chengjiang fossils, computed tomography reveals substantial details of the ventral anatomy of Sinoburius lunaris, and allow us to observe in detail the three-dimensionally preserved appendicular organization of this taxon for the first time. The dorsal exoskeleton consists of a crescent-shaped head shield with well-developed genal spines, a thorax with seven freely articulating tergites, and a fused pygidium with lateral and median spines. The head bears a pair of ventral stalked eyes that are accommodated by dorsal exoskeletal bulges, and an oval elongate ventral hypostome. The appendicular organization of the head is unique among Artiopoda. The deutocerebral antennae are reduced, consisting of only five podomeres, and bear an antennal scale on the second podomere that most likely represents an exite rather than a true ramus. The head includes four post-antennal biramous limb pairs. The first two biramous appendages are differentiated from the rest. The first appendage pair consists of a greatly reduced endopod coupled with a greatly elongated exopod with a potentially sensorial function. The second appendage pair carries a more conventionally sized endopod, but also has an enlarged exopod. The remaining biramous appendages are homonomous in their construction, but decrease in size towards the posterior end of the body. They consist of a basipodite with ridge-like crescentic endites, an endopod with seven podomeres and a terminal claw, and a lamellae-bearing exopod with a slender shaft. Contrary to previous reports, we confirm the presence of segmental mismatch in Sinoburius lunaris, expressed as diplotergites in the thorax. Maximum parsimony and Bayesian phylogenetic analyses support the monophyly of Xandarellida within Artiopoda, and illuminate the internal relationships within this enigmatic clade. Our results allow us to propose a transformation series explaining the origin of archetypical xandarellid characters, such as the evolution of eye slits in Xandarella spectaculum and Phytophilaspis pergamena as derivates from the anterolateral notches in the head shield observed in Cindarella eucalla and Luohuilinella species. In this context, Sinoburius lunaris is found to feature several derived characters within the group, such as the secondary loss of eye slits and a high degree of appendicular tagmosis. Contrary to previous findings, our analyses strongly support close affinities between Sinoburius lunaris, Xandarella spectaculum and Phytophilaspis pergamena, although the precise relationships between these taxa are sensitive to different methodologies.ConclusionsThe revised morphology of Sinoburius lunaris, made possible through the use of computed tomography to resolve details of its three-dimensionally preserved appendicular anatomy, contributes towards an improved understanding of the morphology of this taxon and the evolution of Xandarellida more broadly. Our results indicate that Sinoburius lunaris possesses an unprecedented degree of appendicular tagmosis otherwise unknown within Artiopoda, with the implication that this iconic group of Palaeozoic euarthropods likely had a more complex ecology and functional morphology than previously considered. The application of computer tomographic techniques to the study of Chengjiang euarthropods holds exceptional promise for understanding the morphological diversity of these organisms, and also better reconstructing their phylogenetic relationships and evolutionary history.

The Family Placement of Cyrtandromoea

Abstract—Cyrtandromoea is a genus consisting of about 12 species of perennial caulescent herbs with a distribution in China, India, Myanmar, Thailand, and western Malesia. The genus has previously been associated with either Gesneriaceae or the tribe Mimuleae in Phrymaceae (in former Scrophulariaceae) with morphology in favor of the latter and molecular plastid ndhF data the former. We addressed the placement of this genus by assembling a four gene dataset (matK, ndhF, rps16, and trnL-F) comprising 270 ingroup samples representing 270 species and 51 families of the core asterids, including all families of Lamiales currently recognized. These included 111 species representing 66 genera of Gesneriaceae. We used maximum parsimony, maximum likelihood, and Bayesian inference analyses to reconstruct phylogenies that showed Cyrtandromoea to be placed in Phrymaceae. A fine-scale analysis focusing on Phrymaceae using ITS and trnL-F and 79 samples revealed that Cyrtandromoea is most closely related to a clade of genera in Phrymaceae that included Mimulus s. s. A combination of morphological synapomorphies such as cymose inflorescences, 5-angled toothed calyx, flowers with bilocular ovary with axile placentation with numerous small seeds with endosperm, and loculicidal dehiscing capsule support this placement. Our results strongly support the placement of Cyrtandromoea in Phrymaceae.

Two new species of Eutypella and a new combination in the genus Peroneutypa (Diatrypaceae)

We describe two new species of Eutypella, E. persica from dead branch of Alnus sp. in Guilan province and E. quercina from dead branch of Quercus sp. in East Azerbaijan province of Iran, using morphological and molecular data. Eutypella persica has large stromata with 20–70 perithecia in a valsoid arrangement, sulcate to smooth ostioles, and produces an asexual structure on both natural substrate and culture media. Eutypella quercina, lacking the asexual structure, is characterized by mostly circular stromata with 10–50 perithecia in a valsoid arrangement and smooth ostioles. Phylogenetic relationships of Eutypella with other genera of the Diatrypaceae are here inferred using maximum parsimony and neighbor-joining analyses of the ITS rDNA and partial β-tubulin gene. The new combination, Peroneutypa iranica, is proposed based on morphological features.

First molecular phylogeny of Paralucilia Brauer & Bergenstamm, 1891 (Insecta, Diptera, Calliphoridae): A preliminary approach

Paralucilia Brauer & Bergenstamm, 1891 (Diptera, Oestroidea, Calliphoridae) is a small genus of blowflies restricted to the Neotropical region, which is commonly reported on decaying corpses and vertebrate carcasses. The number of species currently assigned to this genus and their denominations are contentious, with either three or five species recognized by different authors. This taxonomic instability results in a lack of consensus in species determination, making it impossible to compare results from different studies as well as to elaborate confident taxonomic keys. In order to solve some of the most commonly reported taxonomic conflicts within this genus, to the best of our knowledge, this study presents the first phylogenetic hypothesis for the relationships among Paralucilia species, based on molecular analysis of the COI, ITS2, 28S, and 16S genes. Maximum parsimony, maximum likelihood, and Bayesian inference analyses were used for phylogenetic reconstruction and divergence time estimation analyses. Intra- and interspecific genetic distances were calculated among species using the COI dataset. The results showed that at least three of the five currently accepted species are well defined: P. fulvinota, P. pseudolyrcea, and P. paraensis, however, a significant level of intraspecific variation was observed in P. fulvinota. These findings will assist future revisions of the description, classification, and distribution of species of Paralucilia, as well as in the elaboration of taxonomic keys. Additionally, we show that it is possible to clarify the evolutionary history of this Neotropical genus using supplementary evidence such as morphology and molecular data.

Endophytic fungi from the branches of Camellia taliensis (W. W. Smith) Melchior, a widely distributed wild tea plant

Camellia taliensis (W. W. Smith) Melchior is a wild tea plant endemic from the west and southwest of Yunnan province of China to the north of Myanmar and is used commonly to produce tea by the local people of its growing areas. Its chemical constituents are closely related to those of C. sinensis var. assamica, a widely cultivated tea plant. In this study, the α diversity and phylogeny of endophytic fungi in the branches of C. taliensis were explored for the first time. A total of 160 fungal strains were obtained and grouped into 42 species from 29 genera, which were identified based on rDNA internal transcribed spacer sequence analysis. Diversity analysis showed that the endophytic fungal community of the branches of C. taliensis had high species richness S (42), Margalef index D' (8.0785), Shannon-Wiener index H' (2.8494), Simpson diversity index DS (0.8891), PIE index (0.8947) and evenness Pielou index J (0.7623) but a low dominant index λ (0.1109). By contrast, that in the branches of C. taliensis had abundant species and high species evenness. Diaporthe tectonigena, Acrocalymma sp. and Colletotrichum magnisporum were the dominant endophytic fungi. The phylogenetic tree was established by maximum parsimony analysis, and the 11 orders observed for endophytic fungi belonging to Ascomycota and Basidiomycota were grouped into 4 classes.

Multigene phylogenetic analyses to establish new Valsaria species and taxonomic significance of spore ornamentation.

During our studies on fungal diversity from plant substrates, a new species of Valsaria was isolated from dead branches of Ostrya carpinifolia. The taxon is morphologically similar to other taxa in Valsariaceae and is characterized by pseudostromata, apically free pseudoparaphyses, bitunicate asci, and dark brown, 2-celled ascospores. However, it differs from extant species in number of guttules and ornamentation of spore. It is introduced herein as Valsaria ostryae sp. nov. within the family Valsariaceae. Multigene phylogenies based on combined LSU, ITS and RPB2 DNA sequence data generated from maximum likelihood, maximum parsimony and MrBayes analyses indicate that V. ostryae is basal to V. lopadostomoides and V. rudis and its establishment as a new species is strongly supported. No discordance was found between our morphological and phylogenetic species boundaries as postulated by other researchers and our molecular data strongly supports ornamentation of spore as useful for species delineation. Valsaria species do not appear to be host specific. Full morphological details are provided herein and phylogenetic relationships of Valsaria species are also discussed in light with host association.

Multi-gene phylogeny and morphotaxonomy of Phaeosphaeria ampeli sp. nov. from Ficus ampelas and a new record of P. musae from Roystonea regia

Phaeosphaeria ampeli is a new species collected from dead leaves of Ficus ampelas in Fanlu Township area, Dahu forest, Chiayi, Taiwan. Phaeosphaeria musae is a new record from dead leaves of Roystonea regia. Both species are described, illustrated and compared with similar species. Phaeosphaeria ampeli is distinguished from other Phaeosphaeria species based on distinct size differences of the ascomata, asci, ascospores and analyses of DNA sequence data. Maximum parsimony, maximum likelihood and Bayesian inference analyses of combined ITS, LSU, SSU and tef1-α sequence data are used to clarify the phylogenetic affinities of the species.

Ultrastructural and Molecular Identification of the sarcocysts of Sarcocystis tenella and Sarcocystis arieticanis Infecting Domestic Sheep (Ovis aries) from Egypt.

In spite of the global economic significance of sheep production, little is known about the prevalence of various Sarcocystis spp. infecting the domestic sheep (Ovis aries) in Egypt. Muscle samples were collected from 175 sheep (>2years) slaughtered at El-Mahalla El-Kubra abattoir, Gharbia governorate, Egypt. Samples were initially examined by naked eye for the existence of macrosarcocysts. The microscopic sarcocysts were detected and identified using the light microscopy and the Transmission electron microscopy (TEM). Different microscopic species of ovine Sarcocystis were molecularly confirmed by PCR, sequence analyses and phylogeny. Preliminary light microscopic inspection of the muscle specimens revealed the existence of only the microscopic sarcocysts of Sarcocystis tenella and Sarcocystis arieticanis in 152 (86.8%) out of the175 examined animals. Sarcoysts of S.tenella had striated thick cyst wall that amounted from 3.5-5.5 μm in thickness whereas, S.arieticanis sarcocysts had a thin cyst wall that ranged from 1-3 μm in thickness. S.tenella sarcocysts were detected in 115 sheep (65.7%), and were more prevalent than those of S.arieticanis, observed only in 68 sheep (38.8%). No macroscopic sarcocysts were observed in any of the examined carcasses. Transmission electron microscopy (TEM) of the cyst wall of S.tenella revealed the existence of the short stubby villar protrusions (VP) with the characteristic disk-like structures at the tips of the (VP). While, TEM of S.arieticanis showed that the cyst wall had elongated tubular protrusions that measured approximately 5-7 μm in length. Each (VP) consisted of a dome-shaped base (0.3-0.9 μm in diameter), a relatively thick middle portion (0.1-0.3 μm) in width, and a thin hair-like distal portion that measured about (0.03 x 1-4.5 μm). Comparative analyses of the sequences of the four genetic markers (18S rRNA, 28S rRNA, mitochondrial cox1 and ITS-1) for S.tenella and S.arieticanis isolates detected herein, revealed genetic variations of 95% and 95- 96% among the different isolates on the level of the 18S rRNA and 28S rRNA, respectively. Whereas, the cox1 and ITS-1 shared sequence identities of 76-78% and 70-73%, respectively. S.tenella was strongly related to S.capracanis infecting goats (Capra hircus). Sequence identity of 98% on the level of 18S rRNA, 28S rRNA genes was observed between the currently identified isolates of S.tenella and the formerly GenBank deposited isolates of S.capracanis. While, cox1 sequences shared identities of 92-93%. Furthermore, S.arieticanis isolates identified here were closely related to the formerly published sequences of S.hircicanis. The 18S rRNA and 28S rRNA sequences of S.arieticanis shared 98% and 94-95% identities with those of S.hircicanis, respectively. However, 87-88% homologies were observed between the cox1 sequences of S.arieticanis and S.hircicanis. Consequently, cox1 and ITS-1 gene sequences act as better genetic markers than 18S rRNA and 28S rRNA sequences for the characterization of ovine Sarcocystis spp. Maximum parsimony analyses based on the sequences of three genetic markers, (18S rRNA, 28S rRNA and mitochondrial cox1), yielded the same placement of the currently identified isolates of the two taxa (S.tenella and S.arieticanis) within a clade of Sarcocystis species with carnivorous animals as known, or assumed, final hosts.

Deniquelata quercina sp. nov.; a new endophyte species from Persian oak in Iran

In this study, a new endophyte species within the genus Deniquelata (Didymosphaeriaceae) was isolated from the branches of Persian oak trees (Quercus brantii) in Zagros forests, Iran. The maximum parsimony and Bayesian analyses of 18S, 28S and ITS, rDNA sequence data revealed that the isolates were distinct from other species of the Deniquelata. Based on molecular phylogenetic and morphological characteristics, this fungus was demonstrated to be a new species, Deniquelata quercina. Detailed descriptions and illustrations were provided for D. quercina and it was compared with other known species in the genus.

Molecular phylogeny of the genus Hylodesmum (Fabaceae)

The phylogenetic relationships of 12 Hylodesmum species and closely related genera were reconstructed using maximum parsimony, maximum likelihood, and Bayesian analyses based on two chloroplast DNA regions (rps16-trnQ and trnL-F) and one nuclear marker (internal transcribed spacer, ITS). All analyses yielded reliable relationships among the major lineages within Hylodesmum, suggesting that Hylodesmum is monophyletic. Neither the traditionally defined Desmodium sect. Podocarpium nor D. sect. Repanda within the genus was supported as being monophyletic based on the ITS analyses and the combined ITS and chloroplast dataset analyses. The phylogenetic topologies indicated that the three species included in D. sect. Repanda were separated into different clades, which suggested that D. sect. Repanda is paraphyletic. Generally, the clades retrieved by phylogenetic analyses within D. sect. Podocarpium were consistent with traditionally defined groups except for the American group. The molecular analysis provides information regarding the revision of the traditional taxonomic system of Hylodesmum and for the evaluation of the systematic positions of each species within the genus Hylodesmum.

Description and phylogenetic placement of a new marine species of phytosaur (Archosauriformes: Phytosauria) from the Late Triassic of Austria

AbstractPhytosaurs are a group of carnivorous, semi-aquatic archosaurian reptiles that attained an almost global distribution during the Late Triassic. We here describe a new species of the phytosaur genus Mystriosuchus from the Norian Dachstein Limestone of Austria, from a marine lagoonal depositional environment. The new Austrian material comprises remains of at least four individuals of similar size (c. 4 m in total length) found in association but disarticulated, and includes one complete and two partial skulls and postcrania. All of these specimens apparently represent a single taxon, which is distinguished by numerous anatomical features from the two previously named Mystriosuchus species. Maximum parsimony analysis of a comprehensive morphological dataset provides strong statistical support for the phylogenetic position of the new Austrian taxon in Mystriosuchus, as the sister taxon to a clade comprising M. planirostris and M. westphali. Histological analysis suggests that the Austrian phytosaur specimens represent individuals that were at least eight years old at time of death, but which had not yet reached skeletal maturity. Taphonomic and palaeoenvironmental data suggest that these phytosaurs were living in the marine lagoon in which they were preserved, providing the strongest evidence to date of marine adaptations in phytosaurs.

Cranial anatomy of the predatory actinopterygian Brazilichthys macrognathus from the Permian (Cisuralian) Pedra de Fogo Formation, Parnaíba Basin, Brazil

ABSTRACTBrazilichthys macrognathus is the only named actinopterygian from the Permian (Cisuralian) Pedra de Fogo Formation of northeastern Brazil, in which it is represented by a single three-dimensionally preserved, but incompletely described, skull of unclear systematic placement. We used X-ray micro-computed tomography (µCT) to redescribe its anatomy, in particular parts of the internal skeleton, and assess its phylogenetic affinities. We correct errors in the original description, including the number of infraorbital bones and the misidentification of the dermosphenotic as sclerotic ossifications. These reinterpretations of external anatomy are accompanied by new data on internal structure, including the palate, the parasphenoid, and the branchial and hyoid arches. A maximum parsimony analysis of anatomical data resolves Brazilichthys as a stem actinopterygian, crownward of all Devonian species. This placement is supported by the absence of a dermosphenotic posterior ramus and the presence of opercular process of the hyomandibula. A similar placement is suggested by a Bayesian analysis of the same data set, although relationships throughout the tree are less resolved. Our results reject previous interpretations of Brazilichthys as a relative of Birgeriidae, a Triassic group traditionally placed within the actinopterygian crown. Although Acrolepis is too poorly known to be included in our analysis, we also reject relationship between that taxon and Brazilichthys, because their only shared similarities appear to be broadly distributed among early actinopterygians.

Phylogenetic interrelationships of the eel families Derichthyidae and Colocongridae (Elopomorpha: Anguilliformes) based on the pectoral skeleton.

A cladistic analysis of the eel families Derichthyidae and Colocongridae is herein proposed for the first time on the basis of morphological data. We discovered dozens of new phylogenetic characters derived from a detailed analysis of the pectoral skeleton, an anatomical system neglected by most previous studies. Our maximum parsimony analysis indicates that Colocongridae sensu lato is paraphyletic, with its two constituent genera Coloconger and Congriscus appearing as successive sister groups of derichthyids. Monophyly of the family Derichthyidae, which has been questioned by some studies, is herein strongly supported by 10 unambiguous synapomorphies. We also stress the importance of the appendicular skeleton as a useful source of phylogenetic information for the resolution of systematic problems within Anguilliformes.

A brainstorm on the systematics of Turnera (Turneraceae, Malpighiales) caused by insights from molecular phylogenetics and morphological evolution

With 145 species, Turnera is the largest genus of Turneraceae (Malpighiales). Despite several morphotaxonomic and cytogenetic studies, our knowledge about the phylogenetic relationships in Turnera remains mainly based on morphological data. Here, we reconstruct the most comprehensive phylogeny of Turnera with molecular data to understand the morphological evolution within this group and to assess its circumscription and infrageneric classification. We analyzed two nuclear and six plastid markers and 112 taxa, including species and infraspecific taxa, 97 from Turnera, covering the 11 series of the genus. Bayesian inference, maximum parsimony and maximum likelihood analyses show that Turnera, as traditionally circumscribed, is not monophyletic. The genus is divided into two well-supported independent clades; one of them is sister to the genus Piriqueta and is here segregated as the new genus Oxossia. According to our reconstructions, Turnera probably evolved from an ancestor without extrafloral nectaries and with solitary, homostylous flowers with yellow petals. The emergences of extrafloral nectaries and distyly, both common in extant taxa, played an important role in the diversification of the genus. An updated infrageneric classification reflecting the relationships within Turnera is now possible based on morphological synapomorphies and is here designed for further studies.

Phytophthora acaciae sp. nov., a new species causing gummosis of black wattle in Brazil

ABSTRACTA new Phytophthora species was found associated with gummosis in black wattle plantations in the subtropical, humid, south of Brazil. The new species Phytophthora acaciae is formally named herein based on phylogenetic and morphological analyses. This is the fourth Phytophthora species found from this pathogen complex in black wattle plantations causing gummosis in Brazil. The other three species are P. nicotianae, P. boehmeriae, and P. frigida. Phytophthora acaciae is heterothallic with amphigynous antheridia, noncaducous, papillate sporangia and is placed in the Phytophthora clade 2 based on nuc rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) sequences. Maximum parsimony and maximum likelihood phylogenetic analyses of P. acaciae isolates based on multigene sequences, including partial DNA sequences of three nuclear protein-coding genes (β-tubulin, translation elongation factor-1α, and ras-related protein), two mitochondrial protein-coding genes (cytochrome c oxidase subunits I and II), in addition to ITS sequence data, support the delimitation of this new species on Acacia mearnsii from the other previously described clade 2 Phytophthora species. Pathogenicity trial confirmed that the new species causes necrotic lesions on the plant stem, with either the presence or absence of gum.

A New Subclade of Leptosphaeria biglobosa Identified from Brassica rapa.

Blackleg (Phoma stem canker) of crucifers is a globally important disease caused by the ascomycete species complex comprising of Leptosphaeria maculans and Leptosphaeria biglobosa. Six blackleg isolates recovered from Brassica rapa cv. Mizspoona in the Willamette Valley of Oregon were characterized as L. biglobosa based on standard pathogenicity tests and molecular phylogenetic analysis. These isolates were compared to 88 characterized L. biglobosa isolates from western Canada, 22 isolates from Australia, and 6 L. maculans isolates from Idaho, USA using maximum parsimony and distance analysis of phylogenetic trees generated from the ITS rDNA (internal transcribed spacer rDNA) sequence, and the actin and β-tubulin gene sequences. The L. biglobosa isolates derived from B. rapa collected in Oregon formed a separate subclade based on concatenated gene sequences or a single gene sequence, regardless of the analyses. Pathogenicity tests showed that these isolates failed to infect either resistant or susceptible B. napus cultivars, but caused severe symptoms on three B. rapa cultivars (Accession number: UM1113, UM1112, and UM1161), a B. oleracea var. capitata (cabbage) cultivar (Copenhagen Market), and two B. juncea cultivars (CBM, a common brown Mustard, and Forge). These findings demonstrated that the L. biglobosa isolates derived from a B. rapa crop in Oregon were genetically distinct from existing species of L. biglobosa, and constitute a new subclade, herein proposed as L. biglobosa ‘americensis’.