Detecting a genetic bottleneck in Gilbert's Potoroo (Potorous gilbertii) (Marsupialia: Potoroidae), inferred from microsatellite and mitochondrial DNA sequence data

Gilbert's Potoroo isAustralia's most critically endangeredmarsupial, known from a single population inthe Two Peoples Bay National Park in WesternAustralia. We present results from a study ofgenetic variation in microsatellite andmitochondrial DNA. Mean heterozygosity at fivemicrosatellite loci was 49.3%, and the amountof mtDNA variation was extremely low ( =0.0004). There was evidence for a bottleneckin both sets of markers, and this wasconsistent with a demographic decline. Effective population size was estimated usingtwo different models of mutation formicrosatellites (N _e = 243 and 362). The results from this study highlight theconcern for the long-term survival of thisspecies.     

Seven new calochroid and fulvoid species of Cortinarius

We describe seven new European species of Cortinarius. All species are based on analyses of morphological and DNA sequence data. They all belong to a well-supported clade comprising most species traditionally treated in Cortinarius subgenus Phlegmacium sections Fulvi and Calochroi (i.e. the/Calochroi clade). All taxa are either fulvoid (containing anthraquinoid pigments) or calochroid (without these pigments). Morphological and ecological data are presented for all species and compared with similar species. A dichotomous key is presented for C. calochrous and similar species, including all six newly described calochroid species. The calochroid species C. albertii, C. chailluzii, C. cisticola, C. sancti-felicis, C. selandicus and C. vesterholtii spp. nov., and the fulvoid species C. langeorum sp. nov. are described.     

The use and limits of AFLP data in the taxonomy of polyploid wild potato species in Solanum series Conicibaccata

Solanum sect. Petota (tuber-bearing wild and cultivated potatoes) are a group of approximately 190 wild species distributed throughout the Americas from the southwestern United States south to Argentina, Chile, and Uruguay. Solanum series Conicibaccata are a group of approximately 40 species within sect. Petota, distributed from central Mexico to central Bolivia, composed of diploids (2n = 2x = 24), tetraploids (2n = 4x = 48) and hexaploids (2n = 6x = 64); the polyploids are thought to be polysomic polyploids. This study initially was designed to address species boundaries of the four Mexican and Central American species of series Conicibaccata with AFLP data with the addition of first germplasm collections of one of these four species, Solanum woodsonii, as a follow-up to prior morphological, chloroplast DNA, and RAPD studies; and additional species of series Conicibaccata from South America. AFLP data from 12 primer combinations (1722 polymorphic bands) are unable to distinguish polyploid species long thought to be distinct. The data suggest a complex reticulate history of the tetraploids or the need for a broad downward reevaluation of the number of species in series Conicibaccata, a trend seen in other series of sect. Petota. Separately, through flow cytometry, we report the first ploidy level of S. woodsonii, as tetraploid (2n = 48). The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.     

Phylogenetic relationships and taxonomy of subfamily Zygophylloideae (Zygophyllaceae) based on molecular and morphological data

Phylogenetic analysis of noncoding trnL plastid DNA sequences and morphological data for 43 species of Zygophylloideae, representing most of the morphological and geographical variation in the subfamily, indicates that the currently recognised genera Augea (monotypic, southern Africa), Tetraena (monotypic, China), and Fagonia (c. 30 species, widespread), are embedded in Zygophyllum (c. 150 species, widespread). A generic classification based on six monophyletic and morphologically distinctive entities is proposed: Roepera with c. 60 species in Australia and southern Africa, Zygophyllum with c. 50 species in Asia, Tetraena with c. 40 species in Africa and Asia, Augea with a single species in southern Africa, Melocarpum with two species in the Horn of Africa region, and Fagonia with c. 30 species in both the Old and the New World. Scanning electron microscopy studies of testa structure provided important characters for the delimitation of some genera. New combinations (61) are made in Roepera, a resurrected genus originally described from Australia, one new name is proposed in Zygophyllum, 35 new combinations are made in Tetraena, and two new combinations are made in Melocarpum (previously Zygophyllum sect. Melocarpum).     

Examination of the hybrid origin of the wild potato Solanum ruiz-lealii Brücher

The common potato, tetraploid Solanum tuberosum spp. tuberosum L. (tbr), has a narrow genetic base but a large number of related tuber-bearing species that harbor genetic diversity for agronomic characters. The taxonomic status of Solanum ruiz-lealii Brücher (rzl), a diploid species endemic to Mendoza province, Argentina, is controversial. It has been described as a new species of non-hybrid origin and as a natural hybrid between S. kurtzianum Bitt. & Wittm. (ktz) and S. chacoense Bitt. (chc). The hypothesis of the hybrid origin of rzl is examined systematically for the first time by phenetic analyses of morphological and molecular (SSR markers) data, and cytological analyses of interspecific hybrids. The morphological, cytological and molecular data are congruent, and suggest that rzl is not a recent natural hybrid between the ktz and the chc populations studied but has probably originated by divergence of chc, or by hybridization between chc and another taxon.     

Molecular Phylogeny of the Chipmunks Inferred from Mitochondrial Cytochrome b and Cytochrome Oxidase II Gene Sequences

There are currently 25 recognized species of the chipmunk genus Tamias. In this study we sequenced the complete mitochondrial cytochrome b (cyt b) gene of 23 Tamias species. We analyzed the cyt b sequence and then analyzed a combined data set of cyt b along with a previous data set of cytochrome oxidase subunit II (COII) sequence. Maximum-likelihood was used to further test the fit of models of evolution to the cyt b data. Other sciurid cyt b sequence was added to examine the evolution of Tamias in the context of other sciurids. Relationships among Tamias species are discussed, particularly the possibility of a current sorting event among taxa of the southwestern United States and the extreme divergences among the three subgenera (Neotamias, Eutamias, and Tamias).     

The phylogenetic position of the Galápagos Cormorant

The endangered Galápagos Cormorant, Phalacrocorax harrisi, is unique among the species of the Phalacrocoracidae in being flightless and sequentially polyandrous. It has had a vexed taxonomic history, variously being lumped with all the species in Phalacrocorax, being accorded its own genus, Nannopterum, or being included in Leucocarbo or Compsohalieus. Different authorities have similarly suggested a number of different species as being its closest relative. Here we use novel mitochondrial DNA sequence data to show that the Galápagos Cormorant is related to the sister pair of the mainland Americas, the Double-crested Cormorant, P. auritus, and the Neotropic Cormorant, P. brasilianus. This trio of species has high statistical support (Bayesian posterior probability of 1.00; NJ bootstrap 98%; MP bootstrap 91%). The Galápagos Cormorant is thus a relatively recent offshoot of the mainland form, which has subsequently evolved flightlessness. Until the phylogeny of the cormorants is more clearly resolved, we recommend the continued use of Phalacrocorax for all species.     

Evolutionary relationships among aquatic anamorphs and teleomorphs: Lemonniera, Margaritispora, and Goniopila

The hypothesis that similar conidial morphologies in aquatic hyphomycetes are a result of convergent evolution was tested using molecular sequence data. Cladistic analyses were performed on partial sequences of 28S rDNA of seven species of Lemonniera, one species of Margaritispora and one species of Goniopila. Lemonniera has tetraradiate conidia with long arms, whereas Margaritispora and Goniopila have typically globose (isodiametric) conidia, with short conical protuberances in a stellate or quadrangular arrangement. Lemonniera and Margaritispora have phialidic conidiogenesis and both produce dark, minute sclerotia in culture whereas Goniopila has holoblastic conidiogenesis and does not produce sclerotia in culture. Goniopila produces a microconidial phialidic synanamorph in culture. All three genera have schizolytic conidial secession. Molecular analyses demonstrate that Lemonniera species are placed in two distinct clades: one within Leotiomycetes; the other within Pleosporales, Dothideomycetes. Margaritispora is placed with Lemonniera species within Leotiomycetes. Goniopila and Lemonniera pseudofloscula are placed within Dothideomycetes. No morphological character was entirely congruent with the molecular derived phylogeny. This suggests that for the group of species studied, conidial shape is not a reliable indicator of phylogeny but more likely the result of convergent evolution in response to the aquatic environment.     

Xenocylindrocladium guianense andX. subverticillatum, two new species of hyphomycetes from plant debris in the tropics

Two new species of hyphomycetes,Xenocylindrocladium guianense andX. subverticillatum, are described from plant debris collected in French Guiana and Singapore, respectively. The genusXenocylindrocladium has thus far been known from one species,X. serpens, which was described from plant debris collected in Ecuador. The two new taxa are compared with and distinguished fromX. serpens based on morphology, cultural characteristics and phylogenetic analysis of DNA sequence data of the 5.8S rDNA with flanking ITS1 and ITS2 regions and the 5′ end of the β-tubulin gene. These species are also compared with other closely related hypocrealean taxa. Present collection data suggest that species ofXenocylindrocladium could be restricted to the tropics.     

A comparative study of the food niches of lake-dwelling triclads and leeches

The food niches of four species of triclads and three species of non-parasitic leeches living in the littoral zone of British lakes of different trophic status were investigated, over one year, using a serological technique. Antisera against ten potential prey groups were employed. The basic data were adjusted to compensate for differences in predator size and seasonal changes in field temperatures. Data on two of the leech species have been presented elsewhere, but comparisons of the diet of all seven predator species are made in this paper. Much overlap in diet between the various predator species occurs, but, with one exception, each of the genera has a major food resource. The Polycelis spp. feed extensively on oligochaetes, Dugesia polychroa on molluscs, Dendrocoelum lacteum on Asellus, Erpobdella octoculata on chironomids and Glossiphonia complanata on molluscs. Helobdella stagnalis is a generalist feeder. Problems of coexistence of the leech species, and of the leech and triclad species are discussed.     

Phylogenetics of the slipper orchids (Cypripedioideae, Orchidaceae): Nuclear rDNA ITS sequences

Cypripedioideae (Orchidaceae) have been the subject of numerous taxonomic treatments with conflicting interpretations of relationships among the five genera and the 150–170 species. We have produced nuclear ribosomal ITS nucleotide sequences for nearly 100 slipper orchid species and used parsimony analysis to investigate their relationships. Our results demonstrate that each genus, as currently circumscribed, is monophyletic (Mexipedium andSelenipedium being represented by a single taxon). LikerbcL data, ITS sequences placeMexipedium sister toPhragmipedium. Relationships at the sectional level inPaphiopedilum are largely as described byCribb. However, the division ofPaphiopedilum into subgg.Brachypetalum andPaphiopedilum is not supported; subg.Brachypetalum is paraphyletic to subg.Paphiopedilum. Phragmipedium species are divided into the same three major clades as in the taxonomic scheme ofMcCook. The plicate-leaved genera,Cypripedium andSelenipedium, are successive sister groups to the rest of the subfamily, confirming generally held opinions that they display plesiomorphic characters compared to the conduplicate-leaved genera. A survey of karyotypes in the context of the ITS tree reveals a general trend toward increased chromosome number, probably brought about by centric fission. These data also accord with a previously suggested biogeographic hypothesis of a widespread Northern Hemisphere distribution, followed by range fragmentation due to Miocene cooling.     

A molecular phylogeny of the genus Gagea (Liliaceae) in Germany inferred from non-coding chloroplast and nuclear DNA sequences

The systematics of the mainly yellow flowered Gagea species complex (Liliaceae) has long been considered difficult because only a few phenotypic features within this genus and as a result of hypothesized interspecific hybridisation. A molecular phylogenetic study of seven Gagea species (G. bohemica, G. lutea, G. minima, G. pomeranica, G. pratenis, G. spathacea and G. villosa) from Germany has been undertaken, based on plastid DNA sequences (trnL(UAA)-trnF(GAA), psbA-trnH) and on the nuclear ribosomal internal transcribed spacer (ITS). Sequence divergence within the Gagea species ranges up to 15.5% for psbA-trnH, 22.0% for trnL-trnF and 23.7% for ITS (ITS1 + 5.8S rRNA + ITS2). Two subspecies of Gagea bohemica: G. bohemica subsp. saxatilis and G. bohemica subsp. bohemica are characterized by trnL-trnF data and morphological features. Analysis of the ITS region shows that G. pomeranica represents a hybrid of G. pratensis and G. lutea. Lloydia serotina was initially used as an outgroup species, but it was placed within the investigated Gagea species in the psbA-trnH and the trnL-trnF phylogenetic tree.     

Chromosome numbers and karyotypes within the Ranunculus alpestris-group (Ranunculaceae)

The Ranunculus alpestris-group comprises six white-flowered species growing in mostly alpine zones of central and southern European mountains. They all are diploid with 2n=16 chromosomes. The common karyotype of the group was established based on 75 metaphases (6–26 metaphases per species). The haploid karyotype consists of four metacentric (chromosomes 1, 3, 6, 7) and four more or less subtelocentric chromosomes (2, 4, 5, 8). This karyotype is similar to that of other white-flowered European Ranunculus species as well as the yellow-flowered R. thora-group. Analysis of karyotypes partly confirms relationships inferred from molecular phylogenies. Species with this karyotype are placed on rather basal branches in existing phylogenies, which may indicate that this karyotype is primitive within the genus Ranunculus.     

Isoasparagine as a marker amino acid in the taxonomy of Characeae

Fourteen species of Characeae were analyzed for their free amino acids. This study, in combination with previous results (Sakanoet al., 1984) showed that all the species that belong to the generaChara (6 species),Lamprothamnium (1 species),Nitellopsis (1 species),Lychnothammus (1 species) and 5Nitella species of the members of the subsectionAnarthrodactylae contained a large amount of isoasparagine. In contrast, no isoasparagine was found in the species belonging toTolypella (3 species) and otherNitella (7 species). Presence of isoasparagine in some species of Characeae (N. flexillis andNitellopsis obtusa) was found to be independent of their localities (Japan, Canada and England). Species lacking isoasparagine (N. oligogyra and N. axilliformis) did not produce isoasparagine even under the condition that induced a great increase of this amino acid in the species that contained it (C. corallina andN. flexilis). These results indicate that isoasparagine is a distinct taxonomic marker and suggest that theNitella species of the subsectionAnarthrodactylae are the most primitive group inNitelleae in that they share synthesis and accumulation of isoasparagine withChareae and, hence, support the view (Kasaki, 1964) that the subsection may be treated as an independent genus.     

Fruit infesting tephritids [Dipt.: Tephritidae] and associated parasitoids in Chiapas,Mexico

A total of 1,302 parasitoids representing 8 species and 4 families were recovered from 9,818 fruit fly host fruits sampled. The most common parasitoid species wasDiachasmimorpha longicaudata (Ashmead). Average percent parasitism ranged between 0.44 and 29.23%. Parasitoid emergence data indicate thatAnastrepha ludens (Loew),A. obliqua (Sein),A. serpentina (Wiedeman),A. striata (Schiner) andToxotrypana curvicauda (Gerstaecker) were subject to parasitism. We provide information on the population fluctuation ofAnastrepha ludens, A. obliqua, A. serpentina, A. distincta (Greene),A. striata, A. fraterculus (Wiedeman),A. chiclayae (Greene),A. montei (Costa Lima),A. leptozona (Hendel) andA. tripunctata (Wulp).Anastrepha ludens andA. obliqua were the most common species, representing 95.3% of all fruit fly species caught in McPhail traps.      

The microdistribution of mayflies (Ephemeroptera) in myriophyllum beds in Pennington Creek,Johnston County,Oklahoma

I studied the population densities and the microdistributions of the four most abundant mayfly (Ephemeroptera) nymphs in Myriophyllum heterophyllum beds in Pennington Creek, Johnston County, Oklahoma, from May to December, 1977. The section of the stream studied has relatively constant flow rates and temperatures throughout the year due to continuous inflow from groundwater. This uniform physical environment allows the plant beds to grow throughout the year and provide a permanent habitat. The four mayflies are Tricorythodes fictus (Tricorythidae), Caenis delicata (Caenidae), Baetis favistriga and B. quilleri (Baetidae). All four species are of similar size and feed by scraping periphyton from the surface of the Myriophyllum. T. fictus and the two species of Baetis have overlapping microdistributions in the leafy, upper one-half of the plant bed. T. fictus and C. delicata have overlapping microdistributions in the lower portion of the plant bed and roots. Each species has similar population densities where their distributions overlap. There is no significant selection for position with respect to current flow in the Myriophyllum for any of the species. Food and space are always abundant, especially in the top one-half of the Myriophyllum. There are no major changes in these trends over the year.     

Food Preference of Wireworms Analyzed with Multinomial Logit Models

Many species of wireworms (larvae of click beetles, Elateridae) are poly- phagous root herbivores. In grasslands under restoration succession with various grass species, we aim to determine the role of wireworms in aboveground vegetation succession. Therefore, it is crucial to know whether wireworms prefer some food plants to others. We have investigated the root preference to different grass species for Agriotes obscurus and Athous haemorrhoidalis and whether these preferences can be explained by covariates. In Experiment 1, individual wireworms could choose between four different plants, one of each species (Anthoxanthum odoratum, Festuca rubra, Holcus lanatus, and Lolium perenne). In Experiment 2, groups of wireworms were released into the soil in the center of 16 plants (4 from each species). We used multinomial logit models (MLMs) to analze the data. In the appendix the use of multinomial response models is clarified with a fictitious example, using the SAS statistic software package. No preference was found in Experiment 1. In Experiment 2 we found differences in attractiveness of plant species depending on wireworm species: A. obscurus preferred grass species from nutrient-rich grasslands (L. perenne and H. lanatus). Both wireworm species disliked F. rubra. The distance from the release point influenced the probability of being found at a certain place at the end of the experiment: wireworms tended to stay in the proximity of the release point. A. haemorrhoidalis was more often found farther from the point of release than A. obscurus. Dispersal was farther from the release point in experiments with young plants (6 weeks) compared to older ones (9 weeks). Results are discussed in a broad ecological context.     

Pollination of sevenPlectranthus spp. (Lamiaceae) in southern Natal, South Africa

The genusPlectranthus (Lamiaceae) shows remarkable radiation on the sandstones of southern Natal and northern Transkei in South Africa, where six endemic species occur. Two of these endemic species,P. hilliardiae andP. oribiensis, are included in this study, as well asP. reflexus, for which only limited data are available. The other species that were studied areP. ambiguus, P. ciliatus, P. ecklonii, P. madagascariensis andP. zuluensis. Four of these taxa,P. ambiguus, P. hilliardiae, P. reflexus andP. saccatus var.longitubus, have uniquely long corolla-tubes (20–30mm) and this is related to pollination by nemestrinid flies of the genusStenobasipteron that have proboscides of similar length. Other nemestrinid species of the genusProsoeca have shorter proboscides and pollinate two species ofPlectranthus with shorter corolla-tube lengths (6–15mm). Acrocerid flies, tabanid flies and anthophorid bees are also important visitors to these species. This study on the pollination of seven species of varying corolla-tube lengths shows a correlation between floral tube length and proboscis length of insect visitors, many of which are recorded for the first time as pollinators ofPlectranthus.     

Re-evaluation of the systematics of the endemic corals of Brazil by molecular data

Recent genetic work on various coral genera has shown that morphological convergence between Atlantic and Pacific corals obscures evolutionary relationships and inferred levels of endemicity between the regions. Based on DNA sequences from nuclear and mitochondrial loci that provide higher resolution than those previously presented, this study shows that relationships within parts of the Atlantic coral fauna are also in need of substantial revision. The data presented here indicate that (1) the endemic Brazilian genus Mussismilia is a monophyletic clade, (2) Mussismilia is more closely related to the Caribbean Faviidae than Mussidae, the family in which it is currently placed, (3) the Brazilian endemic coral Favia leptophylla is much more closely related to Mussismilia than other species of Favia and has most likely been incorrectly placed in the genus Favia and (4) the other endemic Favia species found in Brazil, Favia gravida, is genetically distinct from Favia fragum, a Caribbean congener with which it is frequently synonymized. The nuclear data also suggest the possible presence of a cryptic species within Mussismilia, but additional sampling and morphological information is required to confirm this finding.     

Collapse of species boundaries in the wild potatoSolanum brevicaule complex (Solanaceae, S. sect.Petota): Molecular data

TheSolanum brevicaule complex is a group of morphologically very similar wild and cultivated potato taxa (Solanum sect.Petota). This study uses single to low-copy nuclear RFLPs and RAPDs to investigate their species boundaries and relationships. Cladistic analyses of both data sets are largely concordant with each other and with a recently published phenetic analyses of the same accessions using morphology. All three data sets separate members of the complex into populations from Peru and immediately adjacent northwestern Bolivia, including most cultivated species accessions, and populations from northwestern Bolivia to Argentina. The molecular results suggest that the complex is paraphyletic as currently circumscribed. Many species of theS. brevicaule complex should be relegated to synonymy.