A revision of Cyanonectria and Geejayessia gen. nov., and related species with Fusarium-like anamorphs

A revision of Fusarium-like species associated with the plant genus Buxus led to a reconsideration of generic concepts in the Fusarium clade of the Nectriaceae. Phylogenetic analyses of the partial second largest subunit of the RNA polymerase II (rpb2) and the larger subunit of the ATP citrate lyase (acl1) gene exons confirm the existence of a clade, here called the terminal Fusarium clade, that includes genera such as Fusariumsensu stricto (including its Gibberella teleomorphs), Albonectria, Cyanonectria, “Haematonectria”, the newly described genus Geejayessia, and “Nectria” albida. Geejayessia accommodates five species. Four were previously classified in Nectria sensu lato, namely the black perithecial, KOH–species G. atrofusca and the orange or reddish, KOH+ G. cicatricum, G. desmazieri and G. zealandica.Geejayessia celtidicola is newly described. Following our phylogenetic analyses showing its close relationship with Cyanonectria cyanostoma, the former Gibbera buxi is recombined as the second species of Cyanonectria. A three gene phylogenetic analysis of multiple strains of each morphological species using translation elongation factor 1 α (tef-1), rpb2 and acl1 gene exons and introns confirms their status as distinct phylogenetic species. Internal transcribed spacer of the ribosomal RNA gene cluster and nuclear large ribosomal subunit sequences were generated as additional DNA barcodes for selected strains. The connection of Fusarium buxicola, often erroneously reported as the anamorph of G. desmazieri, with the bluish black and KOH+ perithecial species C. buxi is reinstated. Most Cyanonectria and Geejayessia species exhibit restricted host ranges on branches or twigs of Buxus species, Celtisoccidentalis, or Staphyleatrifolia. Their perithecia form caespitose clusters on well-developed, mostly erumpent stromata on the bark or outer cortex of the host and are relatively thin-walled, mostly smooth, and therefore reminiscent of the more or less astromatous, singly occurring perithecia of Cosmospora, Dialonectria, and Microcera. The cell walls in outer- and inner layers of the perithecial walls of Cyanonectria and Geejayessia have inconspicuous pore-like structures, as do representative species of Albonectria, Fusarium sensu stricto, “Haematonectria”, and “Nectria” albida. The taxonomic significance of these structures, which we call Samuels' pores, is discussed.

Acremonium phylogenetic overview and revision of Gliomastix, Sarocladium, and Trichothecium

Over 200 new sequences are generated for members of the genus Acremonium and related taxa including ribosomal small subunit sequences (SSU) for phylogenetic analysis and large subunit (LSU) sequences for phylogeny and DNA-based identification. Phylogenetic analysis reveals that within the Hypocreales, there are two major clusters containing multiple Acremonium species. One clade contains Acremonium sclerotigenum, the genus Emericellopsis, and the genus Geosmithia as prominent elements. The second clade contains the genera Gliomastixsensu stricto and Bionectria. In addition, there are numerous smaller clades plus two multi-species clades, one containing Acremonium strictum and the type species of the genus Sarocladium, and, as seen in the combined SSU/LSU analysis, one associated subclade containing Acremonium breve and related species plus Acremonium curvulum and related species. This sequence information allows the revision of three genera. Gliomastix is revived for five species, G. murorum, G. polychroma, G. tumulicola, G. roseogrisea, and G. masseei. Sarocladium is extended to include all members of the phylogenetically distinct A. strictum clade including the medically important A. kiliense and the protective maize endophyte A. zeae. Also included in Sarocladium are members of the phylogenetically delimited Acremonium bacillisporum clade, closely linked to the A. strictum clade. The genus Trichothecium is revised following the principles of unitary nomenclature based on the oldest valid anamorph or teleomorph name, and new combinations are made in Trichothecium for the tightly interrelated Acremonium crotocinigenum, Spicellum roseum, and teleomorph Leucosphaerinaindica. Outside the Hypocreales, numerous Acremonium-like species fall into the Plectosphaerellaceae, and A. atrogriseum falls into the Cephalothecaceae.

Phylogeny and ecology of the ubiquitous saprobe Cladosporium sphaerospermum, with descriptions of seven new species from hypersaline environments

Saprobic Cladosporium isolates morphologically similar to C. sphaerospermum are phylogenetically analysed on the basis of DNA sequences of the ribosomal RNA gene cluster, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S rDNA (ITS) and the small subunit (SSU) rDNA as well as β-tubulin and actin gene introns and exons. Most of the C. sphaerospermum-like species show halotolerance as a recurrent feature. Cladosporium sphaerospermum, which is characterised by almost globose conidia, is redefined on the basis of its ex-neotype culture. Cladosporium dominicanum, C. psychrotolerans, C. velox, C. spinulosum and C. halotolerans, all with globoid conidia, are newly described on the basis of phylogenetic analyses and cryptic morphological and physiological characters. Cladosporium halotolerans was isolated from hypersaline water and bathrooms and detected once on dolphin skin. Cladosporium dominicanum and C. velox were isolated from plant material and hypersaline water. Cladosporium psychrotolerans, which grows well at 4 °C but not at 30 °C, and C. spinulosum, having conspicuously ornamented conidia with long digitate projections, are currently only known from hypersaline water. We also newly describe C. salinae from hypersaline water and C. fusiforme from hypersaline water and animal feed. Both species have ovoid to ellipsoid conidia and are therefore reminiscent of C. herbarum. Cladosporium langeronii (= Hormodendrum langeronii) previously described as a pathogen on human skin, is halotolerant but has not yet been recorded from hypersaline environments.

Species and ecological diversity within the Cladosporium cladosporioides complex (Davidiellaceae, Capnodiales)

The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been resolved, resulting in the elucidation of numerous new taxa. In the present study, more than 200 isolates belonging to the C. cladosporioides complex were examined and phylogenetically analysed on the basis of DNA sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA, as well as partial actin and translation elongation factor 1-α gene sequences. For the saprobic, widely distributed species Cladosporium cladosporioides, both a neotype and epitype are designated in order to specify a well established circumscription and concept of this species. Cladosporium tenuissimum and C. oxysporum, two saprobes abundant in the tropics, are epitypified and shown to be allied to, but distinct from C. cladosporioides. Twenty-two species are newly described on the basis of phylogenetic characters and cryptic morphological differences. The most important phenotypic characters for distinguishing species within the C. cladosporioides complex, which represents a monophyletic subclade within the genus, are shape, width, length, septation and surface ornamentation of conidia and conidiophores; length and branching patterns of conidial chains and hyphal shape, width and arrangement. Many of the treated species, e.g., C. acalyphae, C. angustisporum, C. australiense, C. basiinflatum, C. chalastosporoides, C. colocasiae, C. cucumerinum, C. exasperatum, C. exile, C. flabelliforme, C. gamsianum, and C. globisporum are currently known only from specific hosts, or have a restricted geographical distribution. A key to all species recognised within the C. cladosporioides complex is provided.

First Report of Chickpea Wilt Caused by Clonostachys rhizophaga in Syria

In 2007 and 2008, disease symptoms were observed on four cultivars of chickpea (Cicer arietinum L.), including two of the most popular cultivars grown in Syria (Ghab 3 and Ghab 4), in a replicated on-farm trial conducted in the fertile Al Ghab Plains. Affected plants exhibited chlorosis of the foliage, vascular discoloration, and death. In both years, plant mortality reached 100% in plots of cvs. ICC 12004, Ghab 3, and Ghab 4, but only 60% in plots of cv. ILC 97-706. Five monosporic isolates obtained from surface-disinfested stems and roots were identified morphologically. All micromorphological characteristics indicated that the isolated fungi fit the description of Clonostachys rhizophaga Schroers (1). Wilting of chickpea was widespread in the area, and fungal isolations from a random sample of diseased plants in neighboring farmers' fields revealed the presence of C. rhizophaga. In culture, isolates formed dimorphic, Verticillium-like (primary) or penicillate (secondary) conidiophores and ovoidal to elongate, slightly curved or asymmetrical, 5 to 9 μm long and 2.5 to 3.5 μm wide conidia showing a slightly laterally displaced hilum. The identification of the five isolates as C. rhizophaga was supported by sequencing approximately 600 bp of the β-tubulin gene (tub2). Two representative sequences have been deposited under GenBank, Accession No. FJ593882 for strain CBS 124507 and No. FJ593883 for CBS 124511. Both were 100% similar to the sequence of C. rhizophaga strain CBS 361.77 (GenBank Accession No. AF358158) but differed by a deletion of 2 nucleotides relative to the ex-type strain of C. rhizophaga, CBS 202.37 (GenBank Accession No. AF358156). Two methods were used to inoculate plants and complete Koch's postulates. Method 1 used a 10-mm-diameter mycelial plug to inoculate healthy 3-day-old seedlings grown on 40 ml of Hoagland nutrient agar medium in a glass tube (one seedling per tube). The plug was placed mycelial-side down on the surface of the medium, and the fungus subsequently colonized the medium and penetrated the plant roots. Method 2 involved mixing autoclaved seed that had been colonized by each isolate with sterilized soil (1:12 vol/vol) prior to transplanting healthy seedlings into the soil mix. Thirty plants of each cultivar were tested per isolate per method, and controls received sterile agar plugs or autoclaved chickpea seed only. Irrespective of inoculation method, all five isolates caused wilt and plant death of all cultivars within 15 days (method 1) or 2 months (method 2) postinoculation. Symptoms were similar to those originally observed in the field and controls remained healthy. C. rhizophaga was recovered from all affected plants. To our knowledge, this is the first report of C. rhizophaga as a pathogen of chickpea. In an earlier report, C. rhizophaga (as Verticillium rhizophagum Tehon & Jacobs, nom. invalid.) was identified as the causal agent of a disastrous disease of Ulmus americana in Ohio (2). C. rhizophaga has been reported from Chile, Ecuador, the United States, and Switzerland (1). References: (1) H.-J. Schroers. Stud. Mycol. 46:85, 2001. (2) L.-R. Tehon and H. L. Jacobs. Bull. Davey Tree Expert Company, Kent, OH. 6:3, 1936.

First Report of Phytophthora citricola Occurring on Fagus sylvatica in Slovenia

During 2005 and 2006, eight declining, mature Fagus sylvatica trees with severe crown dieback were encountered at two stands near Ljubljana and Kamnik in central Slovenia. Bleeding cankers were seen mostly in the lower parts of the stem. Fresh cankers showed orange brown necroses of the inner bark and cambium. Older cankers were dark brown and surrounded by cracks and shedding bark. Small pieces of marginal tissue were excised from fresh necrotic lesions and incubated in the dark at 20°C on P₅ARP and cornmeal (CMA) agar plates. Soil samples collected from around the base of these declining trees were submerged in sterile distilled water. Leaves of Rhododendron catawbiense were used as bait to test for the presence of Phytophthora spp. Several similar isolates were obtained from trees and soil from both stands. Colonies were narrowly petaloid, slow growing on P₅ARP, and fast growing on CMA. The colonies produced abundant sporangia when submerged in pond water. Semipapillate, noncaducous sporangia were ovoid to obpyriform, but were occasionally distorted, and 30 to 69 (49) μm long and 23 to 44 (34) μm wide. Neither hyphal swellings nor chlamydospores developed. Isolates were homothallic showing paragynous antheridia, spherical oogonia of 22 to 31 (25) μm diameter, and plerotic oospores of 20 to 27 (23) μm diameter. The morphological characters resembled those described for Phytophthora citricola (1). ITS rDNA, spanning ITS 1 and 2, plus the 5.8S rDNA were generated using primers ITS4 and ITS5. Isolates from symptomatic trees and the soil yielded identical sequences and were the same as various sequences deposited for P. citricola at GenBank. The ITS rDNA of one representative strain was deposited at GenBank (Accession No. EF423556). Mycelial plugs from one of the P. citricola strains grown on CMA were used to inoculate stem wounds of seven potted seedlings and wounds made on four freshly cut, healthy branches of F. sylvatica. Sterile agar plugs were used as controls. The test was carried out over 4 weeks at 20°C. Extensive necrotic lesions developed around inoculation points on seedlings and branches, whereas the controls showed no symptoms. P. citricola could also be reisolated from margins of these lesions. During the past decade, declining F. sylvatica trees were observed in an increasing number of stands in Germany (2). Several Phytophthora species appeared to be involved in this decline, but P. citricola was the most frequently recovered species (2,3). To our knowledge, this it the first report of P. citricola found associated with a decline of European beech in Slovenia. References: (1) D. C. Erwin and O. K. Ribeiro. Pages 282-287 in: Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) T. Jung. Forst Holz. 60:131, 2005. (3) T. Jung et al. Mycologist 19:159, 2005.

Classification of the guava wilt fungus Myxosporium psidii, the palm pathogen Gliocladium vermoesenii and the persimmon wilt fungus Acremonium diospyri in Nalanthamala

Psidium guajava wilt is known from South Africa, Malaysia and Taiwan. The fungus causing this disease, Myxosporium psidii, forms dry chains of conidia on surfaces of pseudoparenchymatous sporodochia, which develop in blisters on bark. Similar sporodochia are characteristic of Nalanthamala madreeya, the type species of Nalanthamala. Nalanthamala, therefore, is the appropriate anamorph genus for Myxosporium psidii, while Myxosporium is a nomen nudum (based on M. croceum). For M. psidii the combination Nalanthamala psidii is proposed. Nalanthamala psidii, the palm pathogen Gliocladium (Penicillium) vermoesenii, another undescribed anamorphic species from palm, two species of Rubrinectria and the persimmon pathogen Acremonium diospyri are monophyletic and belong to the Nectriaceae (Hypocreales) based on partial nuclear large subunit ribosomal DNA (LSU rDNA) analyses. Rubrinectria, therefore, is the teleomorph of Nalanthamala, in which the anamorphs are classified as N. vermoesenii, N. diospyri or Nalanthamala sp. Nalanthamala squamicola, the only other Nalanthamala species, has affinities with the Bionectriaceae and is excluded from this group. Rubrinectria/Nalanthamala species form dimorphic conidiophores and conidia in culture. Fusiform, cylindrical, or allantoid conidia arise in colorless liquid heads on acremonium-like conidiophores; ovoidal conidia with somewhat truncated ends arise in long, persistent, dry chains on penicillate conidiophores. No penicillate but irregularly branched conidiophores were observed in N. diospyri. Conidia of N. psidii that are held in chains are shorter than those of N. madreeya, of which no living material is available. Nalanthamala psidii and N. diospyri are pathogenic specifically to their hosts. They form pale yellow to pale orange or brownish orange colonies, respectively, and more or less white conidial masses. Most strains of Rubrinectria sp., Nalanthamala sp. and N. vermoesenii originate from palm hosts, form mostly greenish or olive-brown colonies and white-to-salmon conidial masses. They form a monophyletic clade to which Nalanthamala psidii and N. diospyri are related based on analyses of the internal transcribed spacer regions and 5.8S rDNA (ITS rDNA), LSU rDNA, and partial beta-tubulin gene. Few polymorphic sites in the ITS rDNA and beta-tubulin gene indicate that Nalanthamala psidii comprises two lineages, one of which has been detected only in South Africa.

The hyphomycete Teberdinia hygrophila gen. nov., sp. nov. and related anamorphs of Pseudeurotium species

A hyphomycetous fungus isolated from montane fen soil in the Caucasus Mountains, Russia, had obscurely sympodial conidiogenous cells that suggested a link to the heterogeneous genus Leptodontidium. Sequence analysis of the nuclear ribosomal small subunit and internal transcribed spacer region, however, disclosed that the fungus was an anamorphic member of a clade containing the cleistothecial ascomycetous genus Pseudeurotium. Teberdinia, gen. nov., is proposed for the blastic, generally sympodially proliferating anamorphs in this group, and Teberdinia hygrophila, sp. nov., is proposed for the species from upland fens. Binomials are not proposed for the remaining Teberdinia anamorphs of Pseudeurotium species. Purely anamorphic isolates in this clade are difficult to recognize using current morphological keys and might be more widely distributed and ecologically significant than is currently evident.

Fusarium foetens, a new species pathogenic to begonia elatior hybrids (Begonia x hiemalis) and the sister taxon of the Fusarium oxysporum species complex

A new disease recently was discovered in begonia elatior hybrid (Begonia × hiemalis) nurseries in The Netherlands. Diseased plants showed a combination of basal rot, vein yellowing and wilting and the base of collapsing plants was covered by unusually large masses of Fusarium macroconidia. A species of Fusarium was isolated consistently from the discolored veins of leaves and stems. It differed morphologically from F. begoniae, a known agent of begonia flower, leaf and stem blight. The Fusarium species resembled members of the F. oxysporum species complex in producing short monophialides on the aerial mycelium and abundant chlamydospores. Other phenotypic characters such as polyphialides formed occasionally in at least some strains, relatively long monophialides intermingled with the short monophialides formed on the aerial mycelium, distinct sporodochial conidiomata, and distinct pungent colony odor distinguished it from the F. oxysporum species complex. Phylogenetic analyses of partial sequences of the mitochondrial small subunit of the ribosomal DNA (mtSSU rDNA), nuclear translation elongation factor 1α (EF-1α) and β-tubulin gene exons and introns indicate that the Fusarium species represents a sister group of the F. oxysporum species complex. Begonia × hiemalis cultivars Bazan, Bellona and Netja Dark proved to be highly susceptible to the new species. Inoculated plants developed tracheomycosis within 4 wk, and most died within 8 wk. The new taxon was not pathogenic to Euphorbia pulcherrima, Impatiens walleriana and Saintpaulia ionantha that commonly are grown in nurseries along with B. × hiemalis. Inoculated plants of Cyclamen persicum did not develop the disease but had discolored vessels from which the inoculated fungus was isolated. Given that the newly discovered begonia pathogen is distinct in pathogenicity, morphology and phylogeny from other fusaria, it is described here as a new species, Fusarium foetens.

Analysis of phylogenetic relationship of Cylindrocarpon lichenicola and Acremonium falciforme to the Fusarium solani species complex and a review of similarities in the spectrum of opportunistic infections caused by these fungi

An emerging pattern of similarity in medical case reports led to a project to compare the phylogenetic affinities of two well-known tropical fungal opportunistic pathogens, Cylindrocarpon lichenicola and Acremonium falciforme, to members of the Fusarium solani species complex. C. lichenicola and A. falciforme, despite their deviating conidial morphologies, were shown via sequencing of the ribosomal large subunit to be well instituted within a clade mainly consisting of typical F. solani strains and other species until recently considered variants of F. solani. The original name Fusarium lichenicola C. B. Massalongo is reestablished, and the new combination F. falciforme is made. Recognition of these species as fusaria is necessary for correct interpretation of current and future molecular diagnostic tests. Reevaluation of species morphology in light of the molecular findings showed that certain features, especially elongate filiform conidiophores with integrated terminal phialides, facilitate correct microscopic classification of these atypical Fusarium species. There is a strong and underrecognized overlap in the spectra of cases caused by members of the F. solani clade, particularly ocular infections, mycetomas, and, in the neutropenic host, disseminated and other serious systemic infections. A novel synthesis of case reports shows that patients from areas with warm climates may develop a distinctive fusarial intertrigo caused by F. solani, Fusarium lichenicola, or Fusarium oxysporum.

Determination of physiological levels of volatile organic compounds in blood using static headspace capillary gas chromatography with serial triple detection

A static capillary gas chromatographic method using three different detectors [photoionization detector (PID), electron capture detector (ECD) and flame ionization detector (FID)] switched in series is presented for the determination of volatile organic compounds (VOCs) in sub microgram l-1 levels. The method was applied for the analysis of selected environmentally and occupationally relevant non-halogenated and chlorinated aromatic hydrocarbons (e.g., benzene, toluene, xylenes, dichlorobenzenes) as well as chlorinated aliphatic hydrocarbons (e.g., trichloroethene, tetrachloroethene) in blood samples. Detailed investigations, in respect to the figures of merit were carried out. For most of the selected VOCs detection limits (calculated as the three-fold standard deviation of low level calibration standards) in the range from 26 (benzene) to 67 ng l-1 (m/p-xylene) were achieved which are comparable with those reported for dynamic headspace techniques in combination with mass spectrometric detection. For the individual VOCs the within-series precision varied from 4 to 19% and the day-to-day precision from 11 to 28%. Regarding PID as well as FID the calibration graphs for all substances were linear up to at least 10 micrograms l-1 while the ECD response was linear up to concentrations of about 0.6 microgram l-1 for the halogenated compounds. Our method is applicable for the quantitative determination of VOCs in blood in the occupationally as well as in the physiologically relevant (normal) concentration range.