Temperature and Sporulation of Aquatic Hyphomycetes

Temperature appears to be an important factor affecting the occurrence and distribution of aquatic hyphomycetes, the dominant leaf litter-decomposing fungi in streams. We compared conidium production by eight species of aquatic hyphomycetes grown on yellow poplar leaves in stream-simulating microcosms at three temperatures (15, 20, and 25°C). The greatest conidium production occurred at 15°C for one species, 20°C for two species, and 25°C for two species. Two species produced similar numbers of conidia at 20 and 25°C, and one species produced similar numbers of conidia at all three temperatures. Linear growth rates were determined on malt extract agar. Six species had the same pattern of temperature responses for growth on malt extract agar as for sporulation on leaves, as shown by the positive correlations between the two parameters at the three temperatures. The species examined also exhibited differences in number of conidia produced from a similar amount of leaf material at a given temperature. These differences appeared to be due primarily to differences in individual conidium mass (determined by weighing conidia produced from cultures), as shown by the relationship of the type Y = k/X (r² = 0.96), where Y is the number of conidia produced, X is the individual conidium mass in milligrams, and k is a constant empirically determined to be 2.11. This finding supports the hypothesis that aquatic hyphomycetes allocate similar amounts of their resources to reproduction but vary with respect how these resources are partitioned into reproductive units (conidia).     

Erysiphe azerbaijanica and E. linderae: Two new powdery mildew species (Erysiphales) belonging to the Microsphaera lineage of Erysiphe

Two new species, Erysiphe azerbaijanica on Castanea sativa and E. linderae on Lindera praecox, both belonging to the Microsphaera lineage of the genus Erysiphe are described based on morphological and molecular data. Erysiphe azerbaijanica is distinguished from other Erysiphe species occurring on Castanea spp. by its cylindrical conidia with a length/width ratio of 2–3.6, longer conidiophore, and foot-cells. Molecular analyses indicated that this species forms a clade of its own, supporting the morphological observations. Molecular phylogenetic analyses showed that E. blasti s. lat. is divided into two genetically differentiated groups associated with different host species. Based on the sequence differences in the 28S rRNA gene and ITS region, connected with differences in the number and length of appendages, the fungus on L. praecox is described as a new species, E. linderae.     

Conidial germination and germ tube elongation of Phomopsis amaranthicola and Microsphaeropsis amaranthi on leaf surfaces of seven Amaranthus species: Implications for biological control

Microsphaeropsis amaranthi and Phomopsis amaranthicola are potential biological control agents for several Amaranthus species. In an effort to understand the initial infection processes with these pathogens, a study was conducted of the conidial germination and germ tube length (μm) on the weed leaf surfaces at 21 °C and 28 °C. Weeds included Amaranthus rudis, A. palmeri, A. powellii, A. retroflexus, A. spinosus, A. hybridus, and A. albus. For P. amaranthicola, conidial germination and germ tube length varied among the seven weed species at both temperatures, while for M. amaranthi the differences in germ tube lengths were significant among weed species only at 21 °C. While the conidia of M. amaranthi and P. amaranthicola germinated on the leaf surfaces of all seven weed species, temperature appeared to impact the number and length of germ tubes on the leaf surfaces. The percentage of germinated conidia and the length of germ tubes at both temperatures were often greater for M. amaranthi than for P. amaranthicola. In order for the fungal pathogen to successfully infect and kill a weedy host, conidia must germinate and form a germ tube, two processes that vary with host species and temperature for M. amaranthi and P. amaranthicola. The extent to which successive infection processes, e.g., penetration, invasion and colonization, contribute to host specificity warrants study.     

Myxotrichum albicans,a new slowly-growing species isolated from forest litters in China

Myxotrichum albicans sp. nov. is a slowly-growing fungal species that was isolated from forest litters in northeast of China. The new species is morphologically characterized by its white colonies on CMA, PCA, PDA, and YMA, thallic conidiogenous cells, simple, catenate and hyaline conidia. Phylogenetic analysis based on internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences also supported the placement of M. albicans as a new species in the genus Myxotrichum. To compare with related species, the optimal pH and temperature for growth were investigated. The differences among Myxotrichum (Oidiodendron) species producing hyaline conidia were discussed.     

Zoophthora phytonomi andConidiobolus osmodes [Zygomycetes:Entomophthoraceae], two pathogens ofHypera species [Col.: Curculionidae] coincidental in time and place

Two entomophthoraceous species, found at different localities in Israel, caused epizootics onHypera variabilis Herbst. larvae during spring of 1976 and 1977.Zoophthora phytonomi (Arthur) Batko, emend.Ben-Ze’ev & Kenneth (syn.Entomophthora phytonomi Arthur) produced in the field only conidia, whereasConidiobolus osmodes Drechsler formed only dark, rough-walled resting spores that had been erroneously thought in the past to belong toZ. phytonomi. In culture,Z. phytonomi, isolated from conidia, produced subhyaline, smooth resting spores, whereasC. osmodes from resting spores produced rotund conidia, which proved pathogenic toH. variabilis larvae and adult houseflies. All species connected by different authors withZ. phytonomi are discussed, includingE. elateridiphaga, transferred here toZoophthora.     

Aspergillus terreus Accessory Conidia Are Unique in Surface Architecture,Cell Wall Composition and Germination Kinetics

Infection with Aspergillus terreus is more likely to result in invasive, disseminated disease when compared to other Aspergillus species; importantly this species appears to be less susceptible to the antifungal drug amphotericin B. Unique to this species is the ability to produce specialized structures denoted as accessory conidia (AC) directly on hyphae both in vitro and in vivo. With the hypothesis that production of AC by A. terreus may enhance virulence of this organism, we analyzed the phenotype, structure and metabolic potential of these conidia. Comparison of A. terreus phialidic conidia (conidia that arise from conidiophores, PC) and AC architecture by electron microscopy revealed distinct morphological differences between the two conidial forms; AC have a smoother, thicker outer cell surface with no apparent pigment-like layer. Further, AC germinated rapidly, had enhanced adherence to microspheres, and were metabolically more active compared to PC. Additionally, AC contained less cell membrane ergosterol, which correlated with decreased susceptibility to AMB as determined using a flow cytometry based analysis. Furthermore, AC exhibited surface patches of β1-3 glucan, suggestive of attachment scarring. Collectively, the findings of this study suggest a possible role for AC in A. terreus pathogenesis.     

A review of the genus Paraphyllanthoxylon

Thirteen species of petrified wood have been assigned previously to the genus Paraphyllanthoxylon which was established by Bailey (1924) as representative of the section Phyllanthoideae of the family Euphorbiaceae. Mädel (1962) considered the genus Paraphyllanthoxylon representative of only the Glochidion wood group of the section Phyllanthoideae. This necessitates the establishment of a new genus, Phyllanthoideoxylon, for fossil woods which have characteristics in common with several of the other wood groups in the section Phyllanthoideae. The thirteen previously identified species of Paraphyllanthoxylon are reviewed and compared with the characteristics of the genus. Eleven of these species are retained in Paraphyllanthoxylon Bailey (emend. Mädel), one (P. bangalamodense) is assigned to Phyllanthoideoxylon nov. gen. and one (P. keriense) is transferred to Bridelioxylon Ramanujam.     

Comparative study of the antennal sensilla of five species of root maggots: Delia radicum L., D. floralis F., D. antiqua Mg., D. platura MG. (Diptera : Anthomyiidae) and Psila rosae F. (Diptera : Psilidae)

A comparative study of the antennal sensilla of Delia radicum L., D. floralis F., D. antiqua Mg., D. platura Mg. (Diptera : Anthomyiidae) and Psila rosae F. Diptera Psilidae) is undertaken. For both sexes of each species, the type, distribution, and density of sensilla are determined. All 5 species have trichoid (olfactory) and grooved (olfactory) sensilla. Basiconica I (blunt) sensilla (olfactory) are found on each of the species examined, except D. platura. Basiconica II (tapered) (olfactory) and clavate (olfactory) sensilla are found only on Delia species. Also, only Delia species have single-chambered, dorsal pits, and these contain basiconic II pit sensilla (olfactory). Common to all 5 species is a multi-chambered ventral pit (olfactory). In the ventral pit, all 5 species have grooved pit sensilla (olfactory). In addition to this type of sensillum the Delia species have smooth-walled conical pit sensilla (hygro-/thermosensitive) and P. rosae has granular pit sensilla (hygro-/thermosensitive). Smooth-walled tapered pit sensilla (hygro-/thermosensitive) are found in D. radicum. Similarities and differences in the density of surface sensilla between dorsal and ventral funicular surfaces, male and female flies, and oligophagous (D. antiqua, D. radicum, D. floralis and P. rosae) and polyphagous (D. platura) species are compared. Several differences in sensillum density between the dorsal and ventral funicular surfaces are observed, but these do not fit into a consistent trend. Except for D. radicum, there are differences in sensillum density between male and female flies. For the oligophagous species, females have a greater sensillum density, whilst for the polyphagous D. platura males have a greater sensillum density. Comparisons between species show the greatest differences between the Delia species and P. rosae, and within the 4 Delia species, differences in sensillum density do not correlate with host range or body size.     

Virgaria boninensis,a new hyphomycete (Xylariaceae) from soils in the Bonin Islands,Japan

Virgaria boninensis, a new hyphomycete classified in the Xylariaceae (Ascomycota), was isolated from soils in the Bonin Islands, Japan. It is characterized by olive gray colonies and solitary, reniform, light brown sympodial conidia. Morphologically, the species is similar to V. nigra, but it is different from V. nigra in phylogeny and also differs with length of fertile part.     

Articulospora – Phylogeny vs morphology

The taxonomy of the aquatic hyphomycete genus Articulospora (Ascomycota, Pezizomycotima, Leotiales, Helotiaceae) is based on the morphology of the generative phase of its lifecycle. The type species is Articulospora tetracladia, which is distributed worldwide. Its most frequent populations in nature have dimorphic conidia, differing by the extent of conidial branching (i.e., one or two levels of branching). Some strains, stable in culture, produce exclusively conidia of one type. With the molecular analyses employed here and the relatively low number of available isolates (20), separation based on branching of conidia has not been fully supported. Therefore we propose to retain the broad concept of A. tetracladia with dimorphic conidia. Among the three gene sequences tested as potential barcodes, the internal transcribed spacer (ITS) gene was the most promising region. All strains yielded amplifiable DNA which provided adequate resolution, according to accepted ranges in inter/intraspecific differences, to differentiate among the three Articulospora and two Fontanospora species that were tested (Articulospora atra, Articulospora proliferata, A. tetracladia, Fontanospora eccentrica, Fontanospora fusiramosa). D1/D2 primers also permitted amplification in all strains, however without much resolution. Amplification of the COX1 gene sequence was least consistent.     

Susceptibility of Phyllophaga polyphylla and Anomala cincta larvae to Beauveria bassiana and Metarhizium anisopliae isolates, and the interaction with soil properties

The white grub species Phyllophaga polyphylla and Anomala cincta (Coleoptera: Melolonthidae) are economically important species that affect many crops in Mexico. A series of experiments to study the pathogenic interaction between isolates of Beauveria bassiana and Metarhizium anisopliae and these two insect species were undertaken. First, the susceptibility of third instar P. polyphylla larvae to each of seven isolates representing both species of fungus was evaluated by dipping the insects in 1?×?10⁸ conidia?ml^?1 suspensions. A second study examined the differences in the susceptibility of P. polyphylla and A. cincta larvae to two selected isolates for each of the fungal species. Finally, the susceptibility of A. cincta larvae to one M. anisopliae isolate when incubated in soil collected from four different sites was assessed. No significant differences in proportion of infection of P. polyphylla larvae were observed amongst the fungal isolates tested and mortality due to fungal infection was never greater than 20% after 36?days incubation. Anomala cincta larvae were more susceptible than P. polyphylla larvae, with greater than 90% infection when inoculated with isolates of M. anisopliae whereas mortalities of only 20% where achieved against P. polyphylla larvae. The soil type in which A. cincta were incubated following inoculation with M. anisopliae affected their susceptibility to infection. The results demonstrated that there is a complex interaction amongst entomopathogenic fungi, white grub larvae and soil properties, and points to the need of further investigation of this system in order to optimize the efficacy of entomopathogenic fungi against these insect species.     

The morphology of the imperfect states of powdery mildews (Erysiphaceae)

In contrast to popular belief, a rich variety of morphological characteristics exists in the imperfect states of powdery mildews. Because it has been generally assumed that species cannot be distinguished by their appressoria, haustoria, conidiophores, conidia, fibrosin bodies, and conidial germ tubes, their morphology has received little attention and several older publications have even been forgotten. As with the perfect states, few species can be recognized by one characteristic of the imperfect state alone but many species can be identified when a combination of several characteristics is used. Important characteristics are the location of the mycelium, the production of conidia singly or in chains, the presence or absence of conspicuous fibrosin bodies, the appressoria, the size and shape of the conidia, and the position and type of their germ tubes. Many species are associated with particular families or genera of plants and therefore these are included in a key to identify 131 species of powdery mildew. This key shows how much and especially how little is known about many species. It is hoped that this review will stimulate study of the morphology of the imperfect states of numerous species. Consideration of both the perfect and the imperfect state should result in a more natural classification of several genera, for exampleUncinula andErysiphe which at present include both species which produce conidia in long chains and those which produce conidia singly. It appears that there are two lines of development of the imperfect states. One is characterized by lobed appressoria and conidiophores which produce conidia singly. The other is characterized by more or less rounded, unlobed appressoria and conidiophores which produce conidia in chains. A better knowledge of all the different imperfect states may provide more information regarding the evolution of powdery mildews.     

Morphological variation of perch Perca fluviatilis in humic lakes: the effect of predator density,competition and prey abundance

Between and within‐lake variations in morphology of perch Perca fluviatilis were studied in four humic lakes in eastern Finland. Perca fluviatilis were more streamlined and smaller headed in a lake with the highest abundance of cyprinids, but lowest abundance of predators (Lake Tuopanjärvi), indicating adaptation to planktivorous feeding and low predator density. Highest bodied fish were found from a lake with the lowest cyprinid but highest predator abundance (Lake Koppelojärvi), which conversely indicates adaptation to more effective predator avoidance. Furthermore, the length of the paired fins was longest in Lake Kinnasjärvi and Lake Tuopanjärvi, where the abundance of benthic macroinvertebrates was lowest, suggesting selection for more effective benthivory. Clear morphological differences of P. fluviatilis between habitats were found only in Lake Kinnasjärvi, whereas in Lake Koppelojärvi and Lake Tuopanjärvi only the length of the paired fins differed and in Lake Harkkojärvi no differences were found. Taken together, these results suggest that inter and intrapopulation morphological differences are probably highly dependent on different biotic factors (i.e. predation risk, resource availability and competition). Spatial and temporal variations in these factors may have a great effect on body morphology of P. fluviatilis.     

Interaction between Paracoccidioides brasiliensis conidia and the coagulation system: involvement of fibrinogen

The infectious process starts with an initial contact between pathogen and host. We have previously demonstrated that Paracoccidioides brasiliensis conidia interact with plasma proteins including fibrinogen, which is considered the major component of the coagulation system. In this study, we evaluated the in vitro capacity of P. brasiliensis conidia to aggregate with plasma proteins and compounds involved in the coagulation system. We assessed the aggregation of P. brasiliensis conidia after incubation with human serum or plasma in the presence or absence of anticoagulants, extracellular matrix (ECM) proteins, metabolic and protein inhibitors, monosaccharides and other compounds. Additionally, prothrombin and partial thromboplastin times were determined after the interaction of P. brasiliensis conidia with human plasma. ECM proteins, monosaccharides and human plasma significantly induced P. brasiliensis conidial aggregation; however, anticoagulants and metabolic and protein inhibitors diminished the aggregation process. The extrinsic coagulation pathway was not affected by the interaction between P. brasiliensis conidia and plasma proteins, while the intrinsic pathway was markedly altered. These results indicate that P. brasiliensis conidia interact with proteins involved in the coagulation system. This interaction may play an important role in the initial inflammatory response, as well as fungal disease progression caused by P. brasiliensis dissemination.     

Parablastocatena tetracerae gen. et sp. nov. and Corynesporella licualae sp. nov. from Hainan, China

Parablastocatena tetracerae gen. et sp. nov. and Corynesporella licualae sp. nov., collected on dead branches of Tetracera asiatica and Licuala fordiana, respectively, in tropical forests of China, are described and illustrated. Parablastocatena tetracerae is the type species for a new monotypic genus in possessing macronematous conidiophores forming distinct synnemata with holoblastic conidiogenesis and euseptate, short-chained conidia ending in a paler brown rostrum, whereas C. licualae is distinguished from described species by the smaller conidia with long appendages. A key to currently accepted species of Corynesporella is provided.     

Development of In Vitro Macrophage System to Evaluate Phagocytosis and Intracellular Fate of Penicillium marneffei Conidia

Penicillium marneffei is a pathogenic fungus that can cause a life-threatening systemic mycosis in the immunocompromised hosts. We established the model for the phagocytosis of P. marneffei conidia by RAW264.7 murine macrophages and designated the fate of P. marneffei in RAW264.7 cells with respect to persistence, phagosome–lysosome-fusion. And we impaired the immune status of mouse and compared the fate and phagosome–lysosome-fusion of P. marneffei in immunocompetent and immunosuppressed mouse peritoneal macrophages cells. We found that conidia could germinate and survive in macrophages. Within 30 min and up to 2 h of heat-killed conidia internalization, the majority of all phagosome types were labeled for the EEA1 (endosomal markers) and LAMP-1 (lysosomal markers), respectively. But both the percentages of LAMP-1 and EEA1 that associated with live conidia were significantly lower than that with heat-killed conidia. Administration of cyclophosphamide resulted in a significant suppression of macrophages function (phagocytic and fungicidal) against P. marneffei that were not apparently seen. Our data provide the evidence that (i) intracellular conversion of P. marneffei conidia into yeast cells still could be observed in macrophages. (ii) Phagosomes containing live Penicillium marneffei conidia might inhibit the phagosome–lysosome-fusion and result to no acidification surrounding the organisms. (iii) Immunity impaired by cyclophosphamide could not influence the function, including phagocytosis, fungicidal activity and phagosome–lysosome-fusion, of macrophages against P. marneffei.     

A new endophytic species of Arthrinium (Apiosporaceae) from Jatropha podagrica

During study of endophytic fungal diversity in tropical region, a new species of Arthrinium was isolated from healthy petiole of Jatropha podagrica. It is characterized by aseptate, dark brown, circular, lenticular conidia with hyaline margin, broad, hyaline conidiophores with numerous brown septa and ampulliform–lageniform conidiophore mother cells. The new species superficially resembles A. phaeospermum and A. saccharicola in having circular lenticular conidia, but differs in conidia and conidiophore size, and shape of conidiophore mother cells. Phylogenetic study using sequence analysis of ITS region (ITS1–5.8S–ITS2) separates the new species (A. jatrophae) from other related species of Arthrinium.     

Two undescribed hyphomycetes from Malaysia

Raffaelea variabilis is described as a new species in culture fromLannea grandis. It is distinguished by turbinate to cuneiform conidia measuring 4–16×2.5–7.5 μm, and compared and contrasted with established species.Trichocladium lobatum is described as a new species in culture with 1–2 euseptate spherical conidia, 19–22 μm diam., ornamented with flabelliform, spathulate or petaloid lobes 7 μm long. It is compared and contrasted with establishedTrichocladium species and representatives ofChlamydomyces, Histoplasma, Mycogone, Sepedonium andThermomyces.     

Separation of Fungal Propagules by Partition in Aqueous Polymer Two-Phase Systems

Conidia of Penicillium chrysogenum and Penicillium frequentans and sporangiospores of Rhizopus rhizopodiformis, Rhizomucor pusillus, and Mucor racemosus were subjected to partition in aqueous polymer two-phase systems. The partition behavior differed drastically between the conidia of the two Penicillium species and the sporangiospores of the three species of phycomycetes. This difference in partition behavior can be used for purification of fungi belonging to different taxonomical groups. P. frequentans was completely separated from M. racemosus by two extractions, whereas four extractions were needed to purify M. racemosus. This method was used on an air sample from a locality where wood fuel chips are handled. The conidia of the fungi Trichoderma viride and Rhizopus rhizopodiformis were removed completely by only two extractions.     

Molecular and morphological data reveal two new species of Scolecobasidium

Two species of Scolecobasidium were isolated from soil in Hainan and Hebei Provinces, China. The two taxa develop broadly ellipsoid conidia and ellipsoidal to oblong conidia, respectively. Their taxonomic placement in Scolecobasidium was confirmed by morphological similarity and phylogenetic analysis of the RNA polymerase II subunit b (RPB2) sequence data. The two fungi, which are morphologically distinct to previously described species, and occupy unique positions in the phylogenetic tree, are thus introduced as the new species Scolecobasidium terricola and S. ellipsoideum. They are described and illustrated and compared with similar species in the genus.