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The species of Niesslia including anamorphs formerly known as Monocillium form a distinct group in the Hypocreales and can be delimited by several unique morphological characters. Niesslia species inhabit decaying plant substrates, such as leaf litter or bark of diverse plants, especially coniferous hosts. Certain species occur on and may parasitize lichens, fruiting bodies of other fungi and even nematode eggs. Taxonomically, species of Niesslia are classified in the Niessliaceae. Niesslia species are recognised by their tiny superficial, mostly dark brown, shiny and typically spine covered ascomata. Monocillium-like phialides formed in situ and in culture are usually partly or entirely thick-walled. Phialides with wall thickening only in their basal parts sometimes expand in width to taper again into a conidiiferous neck, while others terminate in a non-sporulating vesicle. Based on the revised generic concept presented here, Niesslia accommodates 50 cultured species plus around 40 species known only from herbarium material. Some of the latter species may eventually have to be excluded from Niesslia but are maintained in the genus ad interim, until DNA sequences necessary for their accurate reclassification are available. The taxonomic concept based on morphological characters is corroborated by DNA sequences of phylogenetic marker loci such as the large subunit (28S) of the ribosomal RNA gene, internal transcribed spacer regions 1 and 2 including the 5.8S ribosomal RNA gene, and partial sequences of translation elongation factor 1-α, β-tubulin 2 and γ-actin genes. These DNA barcodes support most of the morphologically delimited species and the generic concept of Niesslia.

Unlike most phialide-producing fungi that liberate a multiplicity of conidia from each conidiogenous cell, only single conidia are formed on phialide-like conidiogenous cells in Aphanocladium, Verticimonosporium, and some species of Sibirina. A group of isolates obtained from soil of native Artemisia tridentata (sagebrush) grassland in Wyoming and from desert soil in Iraq is compared with these genera and classified as a fourth genus, Stanjemonium, honouring Stanley J. Hughes. Phylogenetic analyses of partial nuclear small- (18S) and large-subunit (28S) rDNA sequences indicate that Stanjemonium spp. form a monophyletic group with Emericellopsis. Sequences from the nuclear 18S and 28S rDNA were too conserved to resolve morphological species of Stanjemonium; however, phylogenetic analysis of b-tubulin and translation elongation factor 1a gene exons and introns resolved all species distinguished morphologically. Numerous conidiogenous cells or denticles are scattered along the cells of aerial hyphae in Aphanocladium and Stanjemonium spp., very rapidly collapsing into denticles in the former, somewhat more persistent and leaving broad scars in the latter. In Cladobotryum-Sibirina and Verticimonosporium spp., conidiogenous cells are discrete in terminal and intercalary whorls; phialides of the latter taxon are particularly swollen. The taxonomy of Aphanocladium is not yet resolved. Two species are recognized in Verticimonosporium. Three new species of Stanjemonium are described, and one new combination from Aphanocladium is proposed, along with one new species of Cladobotryum.Key words: Aphanocladium, Cladobotryum, conidiogenesis, hyphomycetes, molecular phylogeny, phialide, Stanjemonium, systematics, Verticimonosporium.

Photokinetic studies of an intermolecular [4 + 2] photocycloaddition starting from 3,4,5,6-tetrachloro-1,2-benzoquinone ( o -chloranil) and of CO elimination from 3,5-di- tert -butyl-1,2-benzoquinone (DBQ) are reported. Both reactions were initiated by exciting the lowest energetic 1 (π-π) * [and also the 1 (n-π) * state in the case of DBQ] with argon ion laser emission lines. The kinetic analyses were mostly carried out with the use of time-dependent IR intensity alterations in the range of C=O stretching modes. The reactions have a non-uniform character which reveals the existence of intermediates. The intermediate of the dimerization could be established by the wavelength-dependent quantum yield related to the initial compound. The laser-induced reaction can be described by a two-photon process in which the first photon excites the starting compound while the second photon interacts with the intermediate. In the case of the CO elimination, the bis-ketene intermediate could be identified by recording the asymmetric stretching vibration at 2173 cm −1 in the vicinity of the vibration of free carbon monoxide at 2134 cm −1 .

The photodecarbonylation of 3,5-di-tert-butyl-1,2-benzoquinone was initiated by excitation of the 1 (π−π*) and the 1 ( n −π*) state, respectively, with the use of emission lines of an argon ion laser. The UV—vis reaction spectra exhibit a strong sensitivity to the selected solvents. Both UV—vis spectra and MR spectra show the existence of a persistent bis-ketene intermediate. The kinetic analysis yields that the course of reaction can be described as a consecutive process. The primary step acts as a light-induced electrocyclic ring cleavage generating the intermediate. In the second step, the CO abstraction leads to the corresponding monoketone.

An intermolecular [4+2] photocycloaddition was initiated by excitation of the lowest energetic 1 (π—π*) state of o -chloranil (3,4,5,6-tetr

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.

The photochemical reaction of o—chloranil (3 ,4,5,6 —tetrachioro— 1 ,2 —benzoquinone) was initiated by the excitation of the lowest energetic l(fl_fl*) state using emission lines of an argon ion laser1 . The data of liquid chromatography establish that only one final compound is generated. The photoproduct has dimeric structure identified by mass spectroscopy. The isotopic distribution of the molecular peaks closely corresponds to the isotopic pattern of octachloro—substituted molecules. Moreover, the mass spectrum exhibits the stepwise loss of two carbon monoxide groups. This feature is characteristic for quinones. The dimeric photoproduct reveals that the reaction can be described by an intermolecular [4+21 photocycloaddltion. In contrast to the reaction of 3,5—di--tert.-butyl—1,2—benzoquinone (investigated under same conditions) in which an absorption band (at 2134 cm') of CO dissolved in the reaction mixture was visible, a parallel CO abstraction can be excluded.

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.