New sections in<Emphasis Type="Italic">Taraxacum</Emphasis>

Sectional taxonomy ofTaraxacum in steppe or subsaline habitats in Central Asia is revised based on material collected during expeditions, cultivated or studied in herbarium. Two new sections are described from that area:T. sect.Stenoloba similar toT. sect.Leucantha (syn.:T. sect.Sinensia), andT. sect.Suavia allied toT. sect.Dissecta. The type species of the sectionSuavia is described asTaraxacum formosissimum Kirschner etŠtěpánek. Widespread mountain dandelions of the Caucasus, intermediate between the sect.Piesis andT. stevenii, are described asT. sect.Confusa. Taraxacum species dominating dry habitats in S Ukraine and Crimea are described asT. sect.Borysthenica. Species belonging to the new sections were found to be polyploid and agamospermous.     

Tlirolian and Ruscinian porcupines (genus<Emphasis Type="Italic">Hystrix</Emphasis>, Rodentia) from Europe,Asia and North Africa

Specimens of the larger Neogene porcupines, generally allocated toHystrix primigenia (Wagner, 1848), from 17 localities are studied, and their taxonomic status is recon-sidered. Material from one of these localities has recently been described asHystrix depereti Sen, 2001. The diagnoses of both species are revised. Tooth size and crown height are considered diagnostic characters at the species level. As a resuit, specimens from eight localities are allocated toH. primigenia, from eight other localities toH. depereti, and from one locality toHystrix sp. indet. The level of specialisation of the cranial morphology of these fossil species is compared withH. refossa Gervais, 1852 and with extant species. Diagnostic characters ofH. aryanensis SEN, 2001 and ofH. zhengi van Weers & Zhang, 1999, are discussed.     

The alternative<Emphasis Type="SmallCaps"> d</Emphasis>-galactose degrading pathway of<Emphasis Type="Italic"> Aspergillus nidulans</Emphasis> proceeds via<Emphasis Type="SmallCaps"> l</Emphasis>-sorbose

The catabolism of d-galactose in yeast depends on the enzymes of the Leloir pathway. In contrast, Aspergillus nidulans mutants in galactokinase (galE) can still grow on d-galactose in the presence of ammonium—but not nitrate—ions as nitrogen source. A. nidulans galE mutants transiently accumulate high (400 mM) intracellular concentrations of galactitol, indicating that the alternative d-galactose degrading pathway may proceed via this intermediate. The enzyme degrading galactitol was identified as l-arabitol dehydrogenase, because an A. nidulans loss-of-function mutant in this enzyme (araA1) did not show NAD⁺-dependent galactitol dehydrogenase activity, still accumulated galactitol but was unable to catabolize it thereafter, and a double galE/araA1 mutant was unable to grow on d-galactose or galactitol. The product of galactitol oxidation was identified as l-sorbose, which is a substrate for hexokinase, as evidenced by a loss of l-sorbose phosphorylating activity in an A. nidulans hexokinase (frA1) mutant. l-Sorbose catabolism involves a hexokinase step, indicated by the inability of the frA1 mutant to grow on galactitol or l-sorbose, and by the fact that a galE/frA1 double mutant of A. nidulans was unable to grow on d-galactose. The results therefore provide evidence for an alternative pathway of d-galactose catabolism in A. nidulans that involves reduction of the d-galactose to galactitol and NAD⁺-dependent oxidation of galactitol by l-arabitol dehydrogenase to l-sorbose.     

The impact of phosphorus on interactions of the hemiparasitic angiosperm <Emphasis Type="Italic">Rhinanthus minor</Emphasis> and its host <Emphasis Type="Italic">Lolium perenne</Emphasis>

The effects of phosphorus supply on the outcome of interactions between the hemiparasitic angiosperm Rhinanthus minor L. with its host species Lolium perenne L. were investigated in a glasshouse experiment. Host plants were grown in 3-l pots in the presence and absence of R. minor at limiting (0.13 mm P) and optimal (0.65 mm P) concentrations of phosphorus for the growth of the host species. Phosphorus was supplied at 2-day intervals in the form of half-strength Long Ashton nitrate-based solution with phosphorus concentrations adjusted accordingly. Parasitism by R. minor significantly suppressed host growth, with final biomass losses ranging between 32% and 44%. Phosphorus supply had a marked impact on the outcome of the host-parasite interaction. By the end of the growing period, parasite biomass at 0.65 mm P was 90% lower than that achieved at 0.13 mm P. In contrast, host biomass at 0.65 mm P was 74% higher than achieved at 0.13 mm P, indicting that the negative impact of parasitism on the host species was reduced when phosphorus supply was increased. The effects of phosphorus on the host-parasite association appeared to be mediated by changes in both the morphological characteristics of the host roots and the relative sink strengths of the host and parasite. Received: 29 May 1999 / Accepted: 20 December 1999     

Revision of<Emphasis Type="Italic">Cheliderpeton vranyi</Emphasis><Emphasis Type="SmallCaps">Fritsch</Emphasis>, 1877 (Amphibia,Temnospondyli) from the Lower Permian of Bohemia (Czech Republic)

The temnospondylCheliderpeton vranyi Fritsch, 1877 from the Lower Permian Ruprechtice horizon (Rotliegend) of the Intrasudetic Basin (Bohemia, Czech Republic) is redescribed. Many features of the skeleton permit a new understanding of the type species and consequently of the genus. Diagnostic characters are the narrow and round-tipped snout, straight to convex outline of the skull roof, narrow and long otic notch, posteriorly expanded quadratojugal, and the relatively wide and short rhombic interclavicle. The ilium with a short, expanded dorsal branch and the missing contact of nasal/maxilla are features shared with the related Upper PermianIntasuchus from Russia and the Eryopidae.Actinodon germanicus is a junior synonym ofCheliderpeton vranyi.      

Phylogenetic affiliation of <Emphasis Type="Italic">Choiromyces magnusii</Emphasis> and <Emphasis Type="Italic">C. venosus Tuberaceae Ascomycota</Emphasis>) from Spain

The only two species of Choiromyces collected up to now in Spain, C. venosus and C. magnusii, were studied with both morphological and molecular methods. Phylogenetic inference of nrDNA ITS and LSU sequences showed that they should be considered independent species in the genus Choiromyces. Choiromyces venosus is a hypogeous fungus, infrequent but naturally present in the Iberian Peninsula, that is imported into Spain from central Europe without any indication of its origin or proper taxonomic identification. It is usually sold as highly-prized edible species of the genus Tuber such as T. magnatum. Choiromyces magnusii is a more frequent hypogeous fungus in Spain that is commercialized in spring on a local scale together with different species in the genus Terfezia. Additionally, the Australian species Reddellomyces westraliensis, which was introduced with Eucalyptus camaldulensis plantations, is cited here for the first time in Spain and Europe.     

Trichome micromorphology of the Chinese-Himalayan genus <Emphasis Type="Italic">Colquhounia</Emphasis> (Lamiaceae), with emphasis on taxonomic implications

Trichome micromorphology of leaves and young stems of nine taxa (including four varieties) of Colquhounia were examined using light and scanning microscopy. Two basic types of trichomes were recognized: eglandular and glandular. Eglandular trichomes are subdivided into simple and branched trichomes. Based on the number of cells and trichome configuration, simple eglandular trichomes are further divided into four forms: unicellular, two-celled, three-celled and more than three-celled trichomes. Based on branching configuration, the branched eglandular trichomes can be separated into three forms: biramous, stellate and dendroid. Glandular trichomes can be divided into two subtypes: capitate and peltate glandular trichomes. Results from this study of morphological diversity of trichomes within Colquhounia lend insight into infrageneric classification and species relationships. Based on the presence of branched trichomes in C. elegans, this species should be transferred from Colquhounia sect. Simplicipili to sect. Colquhounia. We provide a taxonomic key to species of Chinese Colquhounia based on trichome morphology and other important morphological traits.     

Morphogenetic diversity of the ectomycorrhizal genus <Emphasis Type="Italic">Cortinarius</Emphasis> section <Emphasis Type="Italic">Calochroi</Emphasis> in the Iberian Peninsula

The taxonomic and genetic diversity of Cortinarius section Calochroi in one of the most biodiversity-rich regions in Europe, the Iberian Peninsula, was investigated through morphological and phylogenetic methods. This combined methodological approach allowed the identification of 15 known species and one new species, Cortinarius ortegae, which is described here. A dichotomous key is provided for field recognition of Calochroi species inhabiting different Iberian and Balearic Island woodlands. Polymorphism analyses within some studied species showed that the distribution of intraspecific lineages is dependent on geography and, in some cases, tree host. Furthermore, the dating analysis suggested that diversification within Calochroi started in the Pliocene and most of the current genetic diversity originated in the Pleistocene. This temporal scenario supports hypotheses in which climatic oscillations in the Quaternary may have been driving the evolution of this group of ectomycorrhizal fungi.     

Geographic genetic structure of Iberian columbines (gen. <Emphasis Type="Italic">Aquilegia</Emphasis>)

Southern European columbines (genus Aquilegia) are involved in active processes of diversification, and the Iberian Peninsula offers a privileged observatory to witness the process. Studies on Iberian columbines have provided significant advances on species diversification, but we still lack a complete perspective of the genetic diversification in the Iberian scenario. This work explores how genetic diversity of the genus Aquilegia is geographically structured across the Iberian Peninsula. We used Bayesian clustering methods, principal coordinates analyses, and NJ phenograms to assess the genetic relationships among 285 individuals from 62 locations and detect the main lineages. Genetic diversity of Iberian columbines consists of five geographically structured lineages, corresponding to different Iberian taxa. Differentiation among lineages shows particularly complex admixture patterns at Northeast and highly homogeneous toward Northwest and Southeast. This geographic genetic structure suggests the existence of incomplete lineage sorting and interspecific hybridization as could be expected in recent processes of diversification under the influence of quaternary postglacial migrations. This scenario is consistent with what is proposed by the most recent studies on European and Iberian columbines, which point to geographic isolation and divergent selection by habitat specialization as the main diversification drivers of the Iberian Aquilegia complex.     

Taxonomic notes on<Emphasis Type="Italic">Linaria</Emphasis> mill. (<Emphasis Type="Italic">Scrophulariaceae</Emphasis>) for Flora Iberica

Taxonomic considerations and nomenclatural adjustments as a part of a revision ofLinaria Mill. undertaken within the “Flora iberica” project are presented. Data on morphology, seed coat surface, chorology, ecology, synonymy and variability of 11 accepted taxa are reported. The following new combinations are proposed:Linaria aeruginea subsp. cardonica (Font Quer)L. Sáez etM. Sainz,Linaria depauperata subsp.ilergabona (M.B. Crespo etV.J. Arán)L. Sáez, andLinaria saturejoides subsp.angustealata (Willmott)L. Sáez etM.B. Crespo.     

<Emphasis Type="Italic">Nramp1</Emphasis> deletion does not confer susceptibility to<Emphasis Type="Italic"> Rhodococcus equi</Emphasis> infection in mice

Rhodococcus equi is an intracellular bacterium that causes pneumonia in immunocompromised people and foals. The Nramp1 gene influences susceptibility to a variety of intracellular bacteria (including mycobacterial species), but not to Mycobacterium tuberculosis. In this study, we demonstrate that mice functionally deleted of the Nramp1 gene were not more susceptible to infection with virulent R. equi (ATCC 33701) than wild-type mice. Susceptibility of mice to infection with the intracellular bacterium R. equi is more similar to that of M. tuberculosis than to other intracellular bacteria, including other mycobacteria.     

Deciduous and semi-deciduous oak forests (<Emphasis Type="Italic">Quercus robur,Q. petraea</Emphasis> and <Emphasis Type="Italic">Q. pyrenaica</Emphasis>) floristic composition in the Northwest Iberian Peninsula

Oak forests in the Northwest Iberian Peninsula represent climax communities with a high floristic diversity of vascular plants. This study presents data from 189 botanical samples randomly collected in stands of deciduous and semi-deciduous oak as Quercus robur (98), Q. petraea (50) and Q. pyrenaica (41). Within these stands, 187 species or subspecies were identified, in addition to 20 genera and 68 families, all of them present in forests of Quercus robur. A total of 126 species occur in more than five relevés. The largest number of species corresponds to Poaceae (22), Fabaceae (19) and Rosaceae (14). The biological spectrum is dominated by hemicryptophytes, with mainly Atlantic and Sub-Atlantic floristic elements. The distribution of the stands has been studied by using Two-Way Indicator Species Analysis, obtaining like pseudo-species, with shrubby and arborea form, the following ones: Fagus sylvatica, Castanea sativa, Sorbus aucuparia, Corylus avellana, Crataegus monogyna, Pyrus cordata, Erica arborea, Frangula alnus and Cytisus scoparius.     

MSP-PCR and RAPD molecular biomarkers to characterize<Emphasis Type="Italic">Amanita ponderosa</Emphasis> mushrooms

Amanita ponderosa is a specie of wild edible mushrooms growing spontaneously in some Mediterranean microclimates, namely in Alentejo and Andaluzia, in the Iberian Peninsula. The nutritional values of these fungi make them highly exportable. Due to the wide diversity of mushrooms in nature, it is essential to differentiate and to identify the various edible species. RAPD markers have been used as a valuable tool to distinguish the different genotypes, although this method has not yet been used toAmanita ponderosa. Two methods were used to establish different genetic fingerprinting patterns of edible mushrooms. Samples ofAmanita ponderosa were collected in six different regions of the southwest of the Iberian Peninsula and compared by RAPD-PCR and MSP-PCR. Additionally, to compare molecular profiles with others genera of edible mushrooms, three species of Basidiomycetes (Pleurotus ostreatus, Lactarius deliciosus andCoriolus versicolor) and an Ascomycete were used. Results showed that some molecular markers discriminate among an Ascomycete from Basidiomycetes (Amanita ponderosa, Pleurotus ostreatus, Lactarius deliciosus andCoriolus versicolor) and discriminate among the different genera within basidiomycetes, as it is expected. Moreover, OPF-6, OPG-2, OPG3 and M13 primes allowed to unravel a level of genetic polymorphism withinAmanita ponderosa mushrooms collected from different geographic origin.     

<Emphasis Type="Italic">Rhodocollybia</Emphasis> in neotropical montane forests

Traditional concepts of Collybia (Agaricales) have included a variety of morphologically disparate taxa. Reapplication of some characters used in circumscribing Collybia s.l. suggests realignment of well-known North American and European species into three genera, viz. Collybia s.s, Rhodocollybia, and Gymnopus. Rhodocollybia is recognized here at generic rank based on morphological characteristics and phylogenetic signaling. Seven new species epithets under Rhodocollybia, and a new combination under Gymnopus, are proposed. A key to species of Rhodocollybia found in neotropical montane forests is provided.     

Identification and genomic distribution of<Emphasis Type="Italic"> gypsy</Emphasis> like retrotransposons in<Emphasis Type="Italic"> Citrus</Emphasis> and<Emphasis Type="Italic"> Poncirus</Emphasis>

Transposable elements might be importantly involved in citrus genetic instability and genome evolution. The presence of gypsy like retrotransposons, their heterogeneity and genomic distribution in Citrus and Poncirus, have been investigated. Eight clones containing part of the POL coding region of gypsy like retrotransposons have been isolated from a commercial variety of Citrus clementina, one of the few sexual species in Citrus. Four of the eight clones might correspond to active elements given that they present all the conserved motifs described in the literature as essential for activity, no in-frame stop codon and no frame-shift mutation. High homology has been found between some of these citrus elements and retroelements within a resistance-gene cluster from potato, another from Poncirus trifoliata and two putative resistance polyproteins from rice. Nested copies of gypsy like elements are scattered along the Citrus and Poncirus genomes. The results on genomic distribution show that these elements were introduced before the divergence of both genera and evolved separately thereafter. IRAPs based on gypsy and copia types of retrotransposons seem to distribute differently, therefore gypsy based IRAPs prove a new, complementary set of molecular markers in Citrus to study and map genetic variability, especially for disease resistance. Similarly to copia-derived IRAPs, the number of copies and heterozygosity values found for gypsy derived IRAPs are lower in Poncirus than in Citrus aurantium, which is less apomictic and the most usual rootstock for clementines until 1970.Communicated by C. Möllers     

Cloning and expression of <Emphasis Type="Italic">mel</Emphasis> gene from <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Previous work from our laboratory has shown that most of Bacillus thuringiensis strains possess the ability to produce melanin in the presence of l-tyrosine at elevated temperatures (42 °C). Furthermore, it was shown that the melanin produced by B. thuringiensis was synthesized by the action of tyrosinase, which catalyzed the conversion of l-tyrosine, via l-DOPA, to melanin. In this study, the tyrosinase-encoding gene (mel) from B. thuringiensis 4D11 was cloned using PCR techniques and expressed in Escherichia coli DH5 . A DNA fragment with 1179 bp which contained the intact mel gene in the recombinant plasmid pGEM1179 imparted the ability to synthesize melanin to the E. coli recipient strain. The nucleotide sequence of this DNA fragment revealed an open reading frame of 744 bp, encoding a protein of 248 amino acids. The novel mel gene from B.thuringiensis expressed in E. coli DH5 conferred UV protection on the recipient strain.     

<Emphasis Type="Italic">Oenothera speciosa</Emphasis> versus <Emphasis Type="Italic">Macroglossum stellatarum</Emphasis>: killing beauty

Hovering and dead individuals of the diurnal hawk-moth Macroglossum stellatarum (Linnaeus, 1758) (Lepidoptera: Sphingidae) were found with proboscides got stuck into flowers of the ornamental plant Oenothera speciosa Nutt (Onagraceae). The phenomenon was observed in several locations in Bulgaria where the plant has been introduced. Microscopic examination revealed that the reason for this unusual interaction is pubescence of thick-walled basiscopically oriented trichomes in the basal part of the hypanthium and style of the plant. When a foraging moth inserts its proboscis into this area, the tips of the trichomes are inserted into the transverse grooves of proboscis and hamper its back movement. As a result the moths are suspended for a long time, sometimes until death. Other trapped moth species were also observed but they always effected self-release. This plant–insect interaction is also a conservation issue as an estimation of its impact on wild insect populations is lacking.     

<Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> phage endolysin can enhance permeability of<Emphasis Type="Italic"> Pseudomonas aeruginosa</Emphasis> outer membrane and induce cell lysis

To determine the function of the C-terminal region of Bacillus amyloliquefaciens phage endolysin on Pseudomonas aeruginosa lysis, the permeabilization of the outer membrane of P. aeruginosa was analyzed. Glu-15 to His (E15H) and Thr-32 to Glu (T32E) substitutions were introduced into the Bacillus phage endolysin. Neither E15H nor T32E substitution induced enzymatic and antibacterial activities. These two, Glu-15 and Thr-32, were considered to be the active center of the enzyme. The addition of purified E15H and T32E proteins to P. aeruginosa cells induced the release of periplasmic -lactamase from the cells, indicating that both proteins enhance permeabilization of the outer membrane. However, the addition of E15H and T32E proteins to P. aeruginosa cells did not induce the release of cytoplasmic ATP from the cells. These results indicate that the antibacterial activity of the endolysin requires both the C-terminal enhancement of the permeabilization of the P. aeruginosa outer membrane and N-terminal enzymatic activity.     

Membrane-bound <Emphasis Type="SmallCaps">l</Emphasis>- and <Emphasis Type="SmallCaps">d</Emphasis>-lactate dehydrogenase activities of a newly isolated <Emphasis Type="Italic">Pseudomonas stutzeri</Emphasis> strain

Pseudomonas stutzeri SDM was newly isolated from soil, and two stereospecific NAD-independent lactate dehydrogenase (iLDH) activities were detected in membrane of the cells cultured in a medium containing dl-lactate as the sole carbon source. Neither enzyme activities was constitutive, but both of them might be induced by either enantiomer of lactate. P. stutzeri SDM preferred to utilize lactate to growth, when both l-lactate and glucose were available, and the consumption of glucose was observed only after lactate had been exhausted. The Michaelis–Menten constant for l-lactate was higher than that for d-lactate. The l-iLDH activity was more stable at 55°C, while the d-iLDH activity was lost. Both enzymes exhibited different solubilization with different detergents and different oxidation rates with different electron acceptors. Combining activity staining and previous proteomic analysis, the results suggest that there are two separate enzymes in P. stutzeri SDM, which play an important role in converting lactate to pyruvate. Ma and Gao contributed equally to this work.