scispace - formally typeset
SciSpace - Your AI assistant to discover and understand research papers | Product Hunt

Journal ArticleDOI

Direct observation of trapping activities of nematode‐destroying fungi in the soil using fluorescence microscopy

01 Jun 1991-Fems Microbiology Letters (The Oxford University Press)-Vol. 85, Iss: 3, pp 207-210

TL;DR: The nematophagous fungi (Arthrobotrys oligospora and Monacrosporium cionopagum) were observed under semi-natural conditions by fluorescence microscopy after fluochroming, using fluorescein-diacetate to demonstrate the formation of 3-dimensional sticky networks and the capture of nematodes inside the soil.

AbstractThe nematophagous fungi (Arthrobotrys oligospora and Monacrosporium cionopagum) were observed under semi-natural conditions by fluorescence microscopy after fluochroming, using fluorescein-diacetate. The formation of 3-dimensional sticky networks and the capture of nematodes inside the soil could be demonstrated.

...read more

Content maybe subject to copyright    Report

Citations
More filters

Journal ArticleDOI
16 Mar 2011-Mycology
TL;DR: It is argued for an increased role for A. oligospora in complementing other model systems in biological control research, and as a system to identify and characterize the ecology and biology of nematode-trapping fungi.
Abstract: Arthrobotrys oligospora, a predacious fungus of nematodes, has been very useful in understanding the relationship between nematophagous fungi and their nematode hosts. Arthrobotrys oligospora is by far the most common nematode-trapping fungus with the characteristic ability of forming adhesive trapping nets once in contact with nematodes. This review highlights the versatility and development of A. oligospora as a system to identify and characterize the ecology and biology of nematode-trapping fungi. Using A. oligospora, advances in our knowledge of nematophagous fungi have been made through the discovery of special traits and virulence determinants involved in the pathogenic process, or by creating new ways of presenting these factors to the target nematodes. We argue for an increased role for A. oligospora in complementing other model systems in biological control research.

72 citations


Cites background or result from "Direct observation of trapping acti..."

  • ...the lumps of adhesive substances present on hyphaw of zygomycetes (Jensen and Lysek 1991)....

    [...]

  • ...The thickness of this extracellular material (about 0.1 µm) was comparable to similar layers found on other nematophagous fungi and less than the lumps of adhesive substances present on hyphaw of zygomycetes (Jensen and Lysek 1991)....

    [...]

  • ...Jensen and Lysek (1991) indicated that the attachment of hyphae of A. oligospora CBS 289.82 to second-stage juveniles of M. hapla was mediated by a layer of extracellular material produced by the fungus....

    [...]


Journal ArticleDOI
TL;DR: Growth and capture activities of nematophagous fungi in soil were observed using the low temperature scanning electron microscopy technique, which does not involve chemical fixation and dehydration of the sample and gives a more accurate view of organ isms in soil.
Abstract: Growth and capture activities of nematophagous fungi in soil were observed using the low temperature scanning electron microscopy technique. The advantages of this sample preparation technique, compared with conventional scanning electron microscopy, are that it does not involve chemical fixation and dehydration of the sample and, therefore, gives a more accurate view of organ isms in soil. Growth, sporulation, trap formation, capture and digestion of nematodes were observed in soil using the nematode-trapping fungi Arthrobotrys superba, A. dactyloides and A. oligospora CT, and the endoparasite Drechmeria coniospora.

28 citations


Journal ArticleDOI
TL;DR: Overall, the two trapping fungi appear to have greater potential than does H. rhossiliensis for biological control of certain plant-parasitic nema?
Abstract: A soil microcosm experiment was conduct? ed to measure the effect of nematode population den? sity on suppression of nematodes by Hirsutella rhos- siliensis, Monacrosporium cionopagum, and M. ellipsos- porum. These fungi use adhesive conidia, branches, and knobs, respectively, to parasitize nematodes, and were added to soil in the form of pelletized hyphae. Nematode population density was controlled by add? ing small to large numbers of the insect-parasitic nem? atode Steinernema glaseri. Suppression was determined by adding a fixed number of the root-knot nematode Meloidogyne javanica and measuring the number (rel? ative to a control without fungi) that penetrated the roots of a cabbage seedling planted in each microcosm. Suppression by M. ellipsosporum and H. rhossiliensis was positively related to S. glaseri density, suggesting that M. ellipsosporum, like H. rhossiliensis, depends on par? asitism rather than on saprophytism. The response of M. cionopagum to nematode density was inconsistent. In a second experiment, the change in suppression of M. javanica over time was measured in soil containing few nematodes. Suppression by M. cionopagum in? creased rapidly to nearly 100% within 10 days follow? ing addition of fungal inoculum to soil and then de? clined sharply. Suppression by M. ellipsosporum in? creased gradually throughout the study and was nearly 100% at day 120. Suppression by H. rhossiliensis in? creased to only about 50% by day 20 and then declined gradually. Overall, the two trapping fungi appear to have greater potential than does H. rhossiliensis for biological control of certain plant-parasitic nema? todes.

25 citations


Journal ArticleDOI
TL;DR: Fluorochroming of soil samples makes it possible to study soil fungi in their natural habitat and this is demonstrated with some nematophagous (predacious) fungi.
Abstract: Fluorochroming of soil samples makes it possible to study soil fungi in their natural habitat This is demonstrated with some nematophagous (predacious) fungi

19 citations


Journal ArticleDOI
TL;DR: The number of observed occurrences of nematophagous fungi in soils correlated with number of isolations from the soils and network-forming fungi had the highest percentage occurrence in both observation by fluorescence and isolation.
Abstract: Thirty natural soil samples were collected from various sites in Berlin. These were nematode-enriched stained with fluorescein-diacetate (FDA) and observed by fluorescence microscopy for the occurrence of nematophagous fungi. The same soil samples were used for the isolation of nematophagous fungi. With the fluorescence microscope 50 observations of these fungi were made including different trapping organs, trapped nematodes nematodes with assimilative hyphae and endoparasites. A total of 65 isolates were obtained in culture representing 38 predators and 27 endoparasites. Network-forming fungi had the highest percentage occurrence in both observation by fluorescence and isolation. Trappers with non-constricting rings were absent. Comparisons of the occurrence of nematophagous fungi observed in natural soils by fluorescence and those isolated showed no consistent relationship. But quantitatively, the number of observed occurrences of nematophagous fungi in soils correlated with number of isolations from the soils.

13 citations


References
More filters

Journal ArticleDOI
TL;DR: In experiments with pure cultures, good correlation was obtained between relative staining efficiency, growth rate, and respiration, and FDA appears to be a true vital stain, in that it stains only metabolically active mycelia.
Abstract: A method for vital staining of fungal mycelium with fluorescein diacetate (FDA) is described. In experiments with pure cultures, good correlation was obtained between relative staining efficiency, growth rate, and respiration. FDA thus appears to be a true vital stain, in that it stains only metabolically active mycelia. In fresh soil suspensions stained with FDA, brightly fluorescent hyphae and portions of hyphae were observed. The applicability of the method for measurement of active mycelium in the soil is discussed.

329 citations


Journal ArticleDOI
TL;DR: This review of the status of natural enemies for control of nematode pests attempts to analyze recent studies, compile re­ ports of new organisms and stimulate and guide future research in this important field.
Abstract: +3741 Various aspects of biological control of plant-parasitic nematodes have been reviewed a number of times (5, 9, 16, 39, 56, 75), but the numerous recent developments in this area and the impending loss of several of the most widely used nematicides for reasons of hazards to human health have prompted this examination of the status of natural enemies for control of nematode pests. It is not my intent to list or consider all organisms in this category because little information has been acquired on many of them since previous reviews. This review deals only with the most important and promising natural enemies on which there is sufficient information to make at least preliminary interpretations of their value and potential role in biological control. It also attempts to analyze recent studies, compile re­ ports of new organisms and, I hope, stimulate and guide future research in this important field.

137 citations


Journal ArticleDOI
TL;DR: Living nematodes induced trap formation in Arthrobotrys oligospora more rapidly than did additions of morphogenetic peptides, and ammonia was shown by gas chromatography to be excreted in nematode suspensions in amounts that could affect trap formation.
Abstract: Living nematodes induced trap formation in Arthrobotrys oligospora more rapidly than did additions of morphogenetic peptides. In nematode-induced morphogenesis, excreted substances as peptides and amino acids were only partly responsible for the effect. Additional effects were due to volatile substances from nematodes or to direct contact between living nematodes and the hyphae. Ammonia was shown by gas chromatography to be excreted in nematode suspensions in amounts that could affect trap formation. It is proposed that living nematodes act primarily through another mechanism than peptide-induced morphogenesis.

91 citations


Journal ArticleDOI
TL;DR: It appears that the development of predaceous efficiency has been accompanied by a tendency to lose those characters associated with an efficient saprophytic existence in the soil; namely rapid growth rate and good competitive sa Prophytic ability.
Abstract: SUMMARY A study of thirteen species of nematode-trapping Hyphomycetes demonstrated wide differences in their growth rate, competitive saprophytic ability, effect on free-living nematode populations and ability to produce traps spontaneously. The species producing adhesive reticulate traps tended to have the most rapid growth rates and the highest saprophytic ability ratings. In the soil they appeared to be pre-daceously inefficient and did not form traps in pure culture. In contrast the ring-formers had slow growth rates and lower saprophytic ability ratings. They tended to be predaceously efficient and two of the four species studied formed traps spontaneously. The adhesive branch or knob-forming fungi resembled the ring-formers in their growth rates, predaceous efficiency and spontaneous trap formation. Thus it appears that the development of predaceous efficiency has been accompanied by a tendency to lose those characters associated with an efficient saprophytic existence in the soil; namely rapid growth rate and good competitive saprophytic ability.

89 citations


Journal ArticleDOI
TL;DR: Evidence suggests that fungi forming the constricting ring type of trap are more efficient in reducing soil nematode populations than fungi forming adhesive reticulate traps.
Abstract: SUMMARY Predaceous activity of different species of nematode-trapping fungi introduced into non-sterile soil varies in both intensity and duration. In some cases free-living nematode populations increase after the addition of mycelium of these fungi to the soil and in other cases decrease. Evidence suggests that fungi forming the constricting ring type of trap are more efficient in reducing soil nematode populations than fungi forming adhesive reticulate traps,

35 citations