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1.
The waveform and some characteristics of the electric organ discharges have been studied in 11 individuals of Cyphomyrus petherici, the only representative of the genus in the Nilotic fauna. The discharge is characterized by three to five phases with a prevalence of the second phase in terms of the relative amplitude and a wide variability of the total duration of discharge (from 212 to 558 μs). The comparison of the discharges of the species under study with those in the congeneric species and representatives of the genus Pollimyrus (which previously encompassed C. petherici) demonstrates a general similarity of the C. petherici discharges with those of Cyphomyrus, but not Pollimyrus. This is in agreement with the correspondence of the discharge characteristics observed in other mormyrids to the phylogenetic position and taxonomic status of the species.  相似文献   

2.
The paper reports spontaneous generation of weak electric discharges with an amplitude of 0.4–1.0 mV and a frequency of 3–9 min–1 by solitary Synodontis caudovittatus fish. When fish individuals were tested in pairs, their aggressive–defense interactions were associated with an increase in the amplitude of the discharges (up to 30–45 mV) compared to the discharges of individual fish, while the duration of the pulses increased up to 20–25 ms due to the prolongation of the second phase. In S. eupterus, electric activity was recorded only in the course of aggression–defense interactions, while spontaneous generation of discharges was not observed at all. The paper discusses the different aspects of electrocummunication between the catfish including the role of the reversion of polarity of the merged summated discharges with increased duration.  相似文献   

3.
A post-release study was performed to assess the impact of Torymus sinensis (Hymenoptera: Torymidae), the biological control agent of Dryocosmus kuriphilus (Hymenoptera: Cynipidae), on native cynipid gall inducers in Italy. In total, 14,512 non-target galls were collected, corresponding to seven genera: Andricus, Aphelonyx, Biorhiza, Cynips, Diplolepis, Neuroterus, and Synophrus, and 8708 chalcid parasitoids were recorded. The Torymidae family accounted for about 30%, and Bootanomyia (=Megastigmus) dorsalis, Torymus affinis and T. flavipes were the most represented species. A total of 116 T. sinensis emerged from 15 different oak galls, mainly Andricus curvator and A. inflator. In controlled conditions, oviposition was recorded on A. cydoniae, A. grossulariae and A. lucidus, while no mating with native congeneric species occurred. This paper confirms the realised host-range expansion by T. sinensis. Even if it were extremely difficult to evaluate its magnitude, the impact appears minimal, and an occasional feeding with no changes in the distribution or abundance of non-target hosts is expected.  相似文献   

4.
In spite of the self-cleaning property of its leaves called the lotus effect, leaves of lotus (Nelumbo nucifera) provide a habitat for an unknown fungal diversity. The aim of this study was to detect and identify fungi from leaves of N. nucifera, including ectophytic, parasitic and endophytic fungi, in Taiwan using different collection strategies, as well as morphological and diverse molecular markers established in the different systematic groups of fungi. Among ectophytic and parasitic fungi, a new species of Dissoconium and of Pseudocercospora are described, respectively. Phyllosticta nelumbonis Sawada is transferred to Diaporthe. Among plant parasitic fungi, Erysiphe takamatsui and Ps. nymphaeacea are recorded in Taiwan for the first time. Euryale is recorded as a new host genus for Ps. nymphaeacea. The basidiomycetous yeast Fereydounia khargensis is recorded for the first time from living plants and in East Asia. Endophytic fungi from lotus were studied for the first time. From 1002 plant segments, 476 endophytic isolates were produced in culture, comprising 33 typical terrestrial species mainly belonging to the genera Colletotrichum (mainly C. siamense), Diaporthe (D. tulliensis and D. ueckerae) and Fusarium (F. solani species 6, hitherto known from clinical samples), as well as to Xylariaceae, but no Ingoldian fungi. Most isolates were from leaf laminas (71%) compared to those from petioles (29%). From this observation, we conclude that the fungi of the aquatic lotus plant appear to have terrestrial origin and, after dispersal by wind and in spite of the lotus effect, may enter the plant from the lamina. Only three species isolated as endophytes were also found as ectophytic or parasitic fungi.  相似文献   

5.
Agarum clathratum, brown algae, play important ecological roles in marine ecosystem, but can cause secondary environment pollution when they pile up on the beach. In order to resolve the environment problem by A. clathratum, we focus to isolate and identify Penicillium because many species are well known to produce extracellular enzymes. A total of 32 Penicillium strains were isolated from A. clathratum samples that collected from 13 sites along the mid-east coast of Korea in summer. They were identified based on morphological characters and phylogenetic analysis using β-tubulin DNA sequences as well as a combined dataset of β-tubulin and calmodulin. A total of 32 strains were isolated and they were identified to 13 Penicillium species. The commonly isolated species were Penicillium citrinum, P. roseomaculatum, and Penicillium sp. Among 13 Penicillium species, four species – P. bilaiae, P. cremeogriseum, P. madriti, and P. roseomaculatum – have not been previously recorded in Korea. For these four new species records to Korea, we provide morphological characteristics of each strain.  相似文献   

6.
Ramularia is a species-rich genus in the order Capnodiales (Dothideomycetes, Ascomycota) that includes numerous phytopathogenic taxa, several of which are economically important plant pathogens. In this study, six isolates of Ramularia were recovered from leaf spot symptoms on six herbaceous and woody plants from Guilan, East and West Azarbaijan provinces in the north and northwest of Iran. The isolates were studied by a polyphasic approach involving morphological and cultural data, and multi-gene phylogeny (ITS, TEF1-α, ACT, HIS, RPB2 and GAPDH). The isolates were grouped in three species clades of the R. eucalypti species complex. Of these, R. mali is recorded for the first time in Asia and R. glennii represents a new record for the mycobiota of Iran. Ramularia taleshina on Alnus subcordata is described as a new species. Ramularia taleshina is phylogenetically related to R. mali, but they can be differentiated by morphological and cultural characters as well as molecular data. Acalypha australis, Ficus carica and Platanus sp. are reported as new hosts of R. glennii, and Prunus cerasus and Vitis vinifera as new hosts of R. mali.  相似文献   

7.
The subgenera Roelofsideporaus and Deporaus s. str. of the genus Deporaus with four species (D. affectatus, D. unicolor, D. nidificus, and D. betulae) recorded from the Russian fauna are revised. Keys to the species of the subgenus Roelofsideporaus and to the females of the subgenera Roelofsideporaus and Deporaus s. str. are given. The distribution of D. nidificus in Russia is not confirmed.  相似文献   

8.
Results are presented from the study of the electrical and optical characteristics of a transverse RF discharge in Xe/Cl2 mixtures at pressures of p≤400 Pa. The working mixture was excited by a modulated RF discharge (f=1.76 MHz) with a transverse electrode configuration (L≤17 cm). The emission spectrum in the spectral range of 210–600 nm and the waveforms of the discharge current, discharge voltage, and plasma emission intensity were investigated. The UV emission power from the discharge was studied as a function of the pressure and composition of a Xe/Cl2 mixture. It is shown that a discharge in a xenon-chlorine mixture acts as planar excimer-halogen lamp operating in the spectral range of 220–450 nm, which contains a system of overlapping XeCl(D, B-X; B, C-A) and Cl2(D′-A′) bands. Transverse RF discharges in Xe/Cl2 mixtures can be used to create a wideband lamp with two 50-cm2 planar apertures and the low circulation rate of the working mixture.  相似文献   

9.
Introduction Fungal spores constitute an important fraction of bioaerosols in the atmosphere. Objectives To analyse the content of Alternaria and Cladosporium spores in the atmosphere of Beja and the effect of meteorological conditions on their concentrations. Methodology The daily and hourly data of Alternaria and Cladosporium fungal spores concentration in the atmosphere of Beja were monitored from April 12, 2012 to July 30, 2014, based on the Portuguese Aerobiology Network methodology. The influence of meteorological conditions on the studied types of fungal spore concentrations was assessed through Spearman’s correlation analysis. Results During the study period, 20,741 Alternaria spores and 320,862 Cladosporium spores were counted. In 2013, there were 5,822 Alternaria spores and 123,864 Cladosporium spores. The absolute maximum concentrations of Alternaria and Cladosporium spores were recorded on November 8, 2013, with 211 and 1301 spores/m3, respectively. Temperature, insolation and wind direction parameters showed a positive correlation with Alternaria and Cladosporium spore levels, while relative humidity and precipitation presented a negative correlation, which is statistically significant. Wind speed only showed a statistically significant positive correlation in terms of Alternaria spore levels. Conclusion Alternaria and Cladosporium spores are present in the atmospheric air of Beja throughout the year, with the highest concentration period occurring during spring and autumn. There was a clear effect of meteorological parameters on airborne concentrations of these fungal spores.  相似文献   

10.
Trueperella pyogenes is one of the most important microorganisms causing metritis in post-partum cattle. Co-infection with other bacterial species such as Escherichia coli or Fusobacterium necrofurom increases the severity of the disease and the persistence of bacteria in utero. The aim of this study was to investigate the frequency of T. pyogenes strains, and their virulence and antimicrobial resistant profiles in metritis cases. The study was carried out on 200 samples obtained from metritis discharges of postpartum cattle on 18 farms around Tehran, Iran. Sixty-five T. pyogenes isolates (32.5%) were identified, of which 16 isolates were detected as pure cultures and the other 49 isolates from cultures most commonly mixed with E. coli or F. necrofurom. In terms of diversity in biochemical characteristic of T. pyogenes strains, 8 different biotypes were identified among the isolates. Single or multi antimicrobial resistance was observed in 48 isolates (73.9%), which was mostly against trimethoprim sulfamethoxazole, azithromycin, erythromycin and streptomycin. The tetracycline resistance gene tetW and macrolide resistance genes ermB and ermX were detected in 30, 18 and 25 isolates, respectively. In the screening of genes encoding virulence factors, fimA and plo genes were identified in all tested isolates. Genes encoding nanP, nanH, fimC, fimG, fimE and cbpA were detected in 50, 54, 45, 40, 50 and 37 of isolates, respectively. Thirteen different genotypes were observed in these T. pyogenes isolates. A significant association between clonal types and virulence factor genes, biochemical profile, CAMP test result, severity of the disease and sampling time was detected.  相似文献   

11.
The factors that control lichen distribution in Antarctica are still not well understood, and in this investigation we focused on the distribution, local and continental, and gas exchange of a species pair, closely related lichens with differing reproductive strategies, Usnea aurantiaco-atra (fertile) and Usnea antarctica (sterile, sorediate). The local distributions of these species were recorded along an altitudinal gradient of nearly 300 m at South Bay, Livingston Island, and microclimate was also recorded over 1 year. The photosynthetic responses to temperature, light and thallus water content were determined under controlled conditions in the laboratory. The species were almost identical in their photosynthetic profiles. Locally, on Livingston Island, U. antarctica was confined to low altitude sites which were warmer and drier, whilst U. aurantiaco-atra was present at all altitudes. This contrasts with its distribution across Antarctica where U. antarctica grows 9° latitude further south than U. aurantiaco-atra. Temperature appears not to be the main controller of distribution in these species, but dryness of habitat, which will influence length of activity periods, may be important.  相似文献   

12.
Paracoccidioidomycosis ceti is a cutaneous disease of cetaceans caused by uncultivated Paracoccidioides brasiliensis or Paracoccidioides spp. Serological cross-reactions between paracoccidioidomycosis ceti and paracoccidioidomycosis, paracoccidioidomycosis and histoplasmosis, and paracoccidioidomycosis and coccidioidomycosis have been reported before. The present study aimed to detect immunohistochemical cross-reaction between antibodies to Paracoccidioides sp. and Histoplasma capsulatum, and vice versa. Thirty murine sera, obtained from experimental infections of 6 isolates of H. capsulatum, were reacted with paraffin-embedded yeast-form cells of Paracoccidioides sp. derived from a case of paracoccidioidomycosis ceti in Japan. The murine sera were also reacted with human isolates of H. capsulatum yeast cells, with P. brasiliensis yeast cells, and with fungal cells of Coccidioides posadasii. Three dolphins’ sera from cases of paracoccidioidomycosis ceti, two human sera from patients with paracoccidioidomycosis, and a serum from a healthy person with a history of coccidioidomycosis were used in order to determine that the tested fungal cells reacted properly. Sera derived from mice infected with an isolate of H. capsulatum reacted positively against yeast cells of Paracoccidioides sp., yeast cells of P. brasiliensis, and fungal cells of C. posadasii, while those derived from other strains were negative. The present study recorded for the first time the cross-reaction between the yeast cells of H. capsulatum and antibodies against Paracoccidioides spp., the yeast cells of Paracoccidioides sp. and antibodies against H. capsulatum, the yeast cells of Paracoccidioides sp. and antibodies against Coccidioides sp., and fungal cells of C. posadasii and antibodies against Paracoccidioides spp.  相似文献   

13.
A total of 28 strains of 19 Penicillium species were isolated in a survey of extracellular enzyme-producing fungi from macroalgae along the coast of Jeju Island of Korea. Penicillium species were identified based on morphological and β-tubulin sequence analyses. In addition, the halo-tolerance and enzyme activity of all strains were evaluated. The diversity of Penicillium strains isolated from brown algae was higher than the diversity of strains isolated from green and red algae. The commonly isolated species were Penicillium antarcticum, P. bialowiezense, P. brevicompactum, P. crustosum, P. oxalicum, P. rubens, P. sumatrense, and P. terrigenum. While many strains showed endoglucanase, β-glucosidase, and protease activity, no alginase activity was detected. There was a positive correlation between halo-tolerance and endoglucanase activity within Penicillium species. Among 19 Penicillium species, three species–P. kongii, P. olsonii, and P. viticola–have not been previously recorded in Korea.  相似文献   

14.
In Slovakia, a diversity of entomopathogenic fungi (Ascomycota, Hypocreales) associated with outbreaks of Ips typographus was studied in 81 localities and as many as 113 in vitro cultures of five entomopathogenic species were isolated from infected individuals: Beauveria bassiana (87 isolates), B. pseudobassiana (14 isolates), B. caledonica (6 isolates), Lecanicillium lecanii (4 isolates) and Isaria farinosa (2 isolates). B. pseudobassiana is recorded in natural populations of I. typographus for the first time. Biological properties of selected Beauveria isolates, including colony growth, biomass production, conidia yield and pathogenicity to I. typographus adults, were studied in a series of laboratory bioassays and much intra- and interspecific variability was detected. B. bassiana isolates produced biomass or conidia at significantly higher rate than B. pseudobassiana and B. caledonica isolates. Two B. bassiana isolates were selected as the most virulent to bark beetle adults, demonstrating a mean LC50 ranging from 0.72 to 2.05?×?106 conidia ml?1, and were qualified as promising candidates for biocontrol of I. typographus. Their virulence was significantly higher than that of the mycoinsecticides Boverol®, which was used as a reference strain in the virulence bioassays.  相似文献   

15.
The slow oxidation of alkanes (from methane to hexane) in their stoichiometric mixtures with oxygen or air under the action of nanosecond pulsed discharges was investigated. The discharges were excited in a tube of diameter 5 cm and length of 20 cm by 25-ns voltage pulses with an amplitude of 10 kV and a repetition rate of 40 Hz. The initial pressure in the mixture was varied in the range 0.76–10.1 torr. The current, the electric field strength, and the power deposited in a discharge were measured with a nanosecond time resolution. In time-resolved and time-integrated measurements, the intensities of the following bands were determined: CO 2 + (B2Σ → X2Π, δv=0), CH(A2Δ, v′=0 → X2Π, v″=0), OH(A2Σ, v′=0 → X2Π, v″=0), CO(B1Σ, v′=0 → A1Π, v″=2), NO(A2Σ → X2Π, δv=3), N2(C3Π, v′=1 → B3Π, v″=7), N2(B3Π, v′=6 → A3Σ, v″=3), and N 2 + (B2Σ, v′=0 → X2Σ, v″=2). The methane concentration was measured from the absorption of He-Ne laser radiation. Based on the results of optical measurements, the times of the complete oxidation of hydrocarbons were determined.  相似文献   

16.
Ectomycorrhizal (ECM) and ectendomycorrhizal fungal species associated with Pinus montezumae were recorded in 8 year-old trees established in microcosms and compared with those associated with 2 year-old trees, in order to determine their persistence over the long-term. Mycorrhizal root tips were morphologically and anatomically characterized and sequenced. The extension of extramatrical mycelium of ECM fungi with long exploration strategies was evaluated. In total, 11 mycorrhizal species were registered. Seven mycorrhizal species were detected on both 2 and 8 year-old pines: Atheliaceae sp., Rhizopogon aff. fallax, R. aff. occidentalis, Suillus pseudobrevipes, Tuber separans, Wilcoxina mikolae and Wilcoxina rehmii. One species, Thelephora terrestris, was exclusively associated with two year–old seedlings, while Cenococcum geophilum, Pezizaceae sp. and Pyrenomataceae sp. were exclusively found on 8 year-old trees. Atheliaceae sp. was the ECM fungal species that presented the most abundant mycelium. Finally, we report one new fungal species of Pezizaceae occurring as a symbiont of P. montezumae.  相似文献   

17.
18.
Molecular phylogenetic tools are often useful in distinguishing cryptic species with similar morphologies, but they can also be helpful in identifying morphotypes of a species, which displays completely different shapes. We performed molecular-phylogenetic analysis of supra-tidal green algae in the Kamchatka peninsula that belong to the order Prasiolales (Trebouxiophyceae, Chlorophyta). Based on rbcL sequences results, two new species were recorded for the first time in Kamchatka. Approximately 1.4% of the field-collected Rosenvingiella constricta had a unique uniseriate hood-like blade shape, although their rbcL sequences were 100% identical with typical multiseriate filamentous plants. Kamchatka’s population of R. constricta showed 99.4–99.6% identity in rbcL sequences with the populations from Canada and New Zealand. Another similar-looking Rosenvingiella species collected from the same locality had 93.5% identity of the rbcL gene sequence with R. constricta. Morphological and geographical analyses also suggested that this species might be a new species of the genus Rosenvingiella. Prasiola delicata was recorded for the first time in Kamchatka. The Kamchatka population of P. delicata showed 100% identity in rbcL gene sequence with the population from Vancouver, but differed from the Canadian population morphologically.  相似文献   

19.
Endelus (Kubaniellus) indicus sp. n. from India, E. (K.) lao sp. n. and E. (K.) khnzoriani sp. n. from Laos, E. (s. str.) sausai sp. n. from China, and E. (s. str.) dembickyi sp. n. from India are described, the two latter species are included in the Endelus bicarinatus Théry, 1932 species-group recently established by the author. E. collinus Obenberger, 1922 is included in this group; lectotype of this species is designated. Keys to species of the subgenus Kubaniellus and of the E. collinus group are provided. E. (K.) kareni Kalashian is for the first time recorded for Shaanxi Prov., E. pacholatkoi Kalashian, E. smaragdinus Desc. et Vill., and E collinus Obenb., for Laos (the latter species, also for Myanmar).  相似文献   

20.
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