Endoparasites of soil nematodes and rotifers II The genus Haptocillium (original) (raw)
Two new species of Haptoglossa, H. erumpens and H. dickii, infecting nematodes in cow manure
Mycological Research, 2000
Two species of Haptoglossa isolated from nematodes from cow manure from N.E. England are described. H. erumpens sp. nov., infecting Bunonema nematodes, is aplanosporic, the cysts being released after rupture of the nematode cuticle in the absence of an evacuation tube. H. dickii sp. nov. is zoosporic, infecting several species of rhabditid nematodes. Aplanospores and zoospore cysts germinated to produce secondary spores (gun cells) with which to infect further nematode hosts. Some key ultrastructural features in both species have been included. Haptoglossa (Drechsler, 1940) comprises obligately endoparasitic fungi which infect nematodes and rotifers. There are presently six species, four of which are zoosporic and two of which are aplanosporic (
Nematophagous Fungi as Root Endophytes
Nematophagous fungi constitute a group of fungal antagonists to nematodes. The latter arc small roundworms living in soil and water. Most nematodes are saprotrophic, but many species are parasites of plants and animals (Poinar 1983). The nematophagous fungi have been suggested as promising candidatesfor bioiogical control of parasitic nematodes (Stirling 1991), but so far no successful commercial products have been .presented.
Soil Biology and Biochemistry, 1988
A "dilution plate assay" was developed to quantify parasitism of C. xenoplux by H. rhossiliensis. Aliquots of C. xenoplax in suspension (treated with 0.5% NaOCl after extraction from soil by wet sieving and centrifugation) were spread onto 1.5% water agar plates supplemented with 200 parts 10e6 streptomycin sulfate. After 5 days at 22 k Z'C, the numbers of C. xenoplax with or without sporulating H. rhossiliensis were determined using a dissecting microscope. The assay was used to measure the rate of decay (disappearance) of parasitized C. xenoplax in field samples incubated in the laboratory. Time required for 50% reduction in number of parasitized nematodes (averaged across all life stages) incubated at-33 kPa soil water potential and at IO, I5 or 2o'C was 61 , 26 or I6 days, respectively. Rate of decay was much faster for parasitized second-and third-stage juveniles than for parasitized fourth-stage juveniles and adults. Rate of infection can be estimated if the number of parasitized nematodes and rate of decay of such nematodes are known INTRODUCl'ION Criconemellu xenoplux Nordbrina-Hertz B. (1987) Ouantification of nredatorv and endoparasitic nematophagous fungi in soil. ,Wicrobial Ecology 13. 89-93. Day P. R. (1965) Particle fractionation and particle-size analysis. In Merhod.s of Soil Analysis. I. (C. A. Black. Ed.). pp. 545-567. American Society of Agronomy. Madison. Gray N. F. (1984) Ecology of nematophagous fungi: com
Frontiers in Fungal Biology
In this review, we supply a framework for the importance of nematophagous fungi (nematophagous fungi [NF]) and their role in agricultural ecosystems. We characterize the taxonomy, diversity, ecology, and type of NF, depending on their interaction with plant-parasitic nematodes (PPNs). We described potential mechanisms of NF in the control of PPNs, the efficiency and methods of utilization, and the use of nematicides in sustainable agriculture. We explain the utilization of NF in nanotechnology as a new approach. NF are significant in the soil for having the effective potential for use in sustainable agriculture. These types of fungi belong to wide taxa groups, such as Ascomycota, Basidiomycota, and other groups. Diverse NF are available in different kinds of soil, especially in soils that contain high densities of nematodes. There is a relationship between the environment of nematodes and NF. NF can be divided into two types according to the mechanisms that affect nematodes. These t...
Fungal and Bacterial Endophytes as Microbial Control Agents for Plant-Parasitic Nematodes
International Journal of Environmental Research and Public Health
Endophytes are symbiotic microorganisms that colonize plant tissues and benefit plants in multiple ways including induced systemic resistance to biotic and abiotic stresses. Endophytes can be sustainable alternatives to chemical nematicides and enhance plant health in a variety of cropping and natural environments. Several in vitro and in vivo studies demonstrated the potential of multiple species of Fusarium and Bacillus against plant-parasitic nematodes in horticultural, agricultural, and fodder crops and in forestry. While there were efforts to commercialize some of the endophytes as bionematicides, a lack of good formulations with consistent field efficacy has been a major hurdle in commercializing endophytes for nematode control. Identification of efficacious and environmentally resilient strains, a thorough understanding of their modes of action, interactions with various biotic and abiotic factors, and developing strategies that improve their effectiveness are critical areas ...
Study of Population Dynamic of Nematophagous Fungi
Summary A total of 308 soil samples were collected from different sites of southern ( Basrah , Thi- Qar and Missan ) provinces of Iraq, during the period of August 1995 and September 1996. Twenty seven species of Nematophagous fungi ( 16 species of nematode-trapping fungi and 11 species of Endonematophagous fungi ) were isolated during this study . All recovery species were newly recorded in Iraq except four species . 183 isolates were isolated . The results showed that the frequency of fungal species was varied according to the collecting sites . The highest occurrence of fungal species was found in Basrah (43 %) followed by Missan (31.6 %) and the lowest occurrence was in Thi-Qar (25.4 %) . Meantime's, the number of isolates was also varied among the fungal species and collecting sites . The species Monacrosporium eudermatum revealed highest frequency percentages reached 22.3 % followed by Arthrobotrys oligospora (13 %) . A.dactyloides, A. oligospora , M. eudermatum , Harposporium anguillulae were isolated from all the collecting sites , the rest species revealed large differentiation in their occurrences . The results showed that the seasonal variation in the number and the type of isolated species . The highest occurrence of species were found in the January , and the lowest occurrence showed in August . The reasons for this variation may be due to the effect of environmental factors such as temperature and moisture of soil . The dominance of fungal species was varied among the collecting sites . Apparently that M.eudermatum was the most dominant species in the studied location reached 100 % , followed by Arthrobotrys oligospora . Keywords: Nematophagous fungi , Nematode trapping fungi ,Endonematophagous fungi , Arthrobotrys oligospora , Monacrosporium eudermatum .
Bio web of conferences/BIO web of conferences, 2024
In Kazakhstan, parasitic nematodes affect up to 35-40% of the harvest of sugar beets, potatoes and tomatoes. Until recently, сhemical nematicides were used to control nematode numbers but posed risks of toxicity to humans and animals, and their effectiveness decreased due to resistant nematodes. There is an urgent need to create alternative non-toxic plant protection products. Arthrobotrys oligospora is one of the most studied hyphomycete fungi that is used to create biological products against nematodes. In a laboratory experiment in a pot culture, the activity of Arthrobotrys predatory fungi against parasitic nematodes of the genus Meloidogyne was assessed when growing tomatoes of the «F1 Russian size» variety in a vermiculite/soil mixture. Physiological indicators of plant growth (stem length, number of leaves, stem and root weight) were used for analysis. To ensure the reliability of the obtained results of the activity of predatory fungi, the number of nematodes and the presence of colonies of native predatory fungi in the soil samples of the used variants postexperiment were taken into account. The length of stems, the number of leaves and the weight of roots and stems during the growing season changed within the experimental error. The most significant result was estimated by the number of live nematodes post-experiment. It was shown that when preparations of predatory fungi were added to the soil, the number of nematodes significantly decreased in all variants. Thus, the nematophagous activity of local predatory fungi of the genus Arthrobotrys in tomato cultivation has been proven.
Acta entomology and zoology, 2024
Nematophagous fungi are natural predators of soil-dwelling nematodes and can detect and respond to their prey's ascarosides pheromones. They can be endoparasitic, nematode-trapping, egg-parasitic, or toxin-producing depending on how they attack worms. They are found throughout the world in a wide range of habitats and climates, but few are from extreme environments. They are mostly concentrated in the upper part of the soil, in pastures, leaf litter, mangroves, and certain shallow aquatic habitats. They use methods including non-constricting loops, adhesive hyphal strands, adhesive knobs, adhesive nets made of hyphal threads, and hyphae loops that tighten around caught worms. There are numerous advantages for the ecology and economy that come from nematophagous fungi in the soil. They help promote the cycling of nutrients and stabilize soil ecosystems. They are also used to protect plants and animals from nematode disease and avoid drug resistance. However, there is no comprehensive review assessing the above roles and, therefore, this review intended to assess the general overview of nematophagous fungi, their agroecology, isolation and identification, and their role in biological control of helminthic parasites.
Infection of nematodes by conidia of Drechmeria coniospora was studied by optical-and electron microscopy. After penetration, trophiC hyphae invaded solely via the pseudocoel; penetration of internal organs was never observed. The invading hyphae had a characteristic wave-like appearance, this pattern possibly having the advantage of preventing rupture of hyphae due to host movements. After death of the host 30-48 h after infection, trophic hyphae contained numerous lipid droplets often associated with microbodies (peroxisomes) which were characterized by the presence of catalase and the l3-oxidation enzyme thiolase. Conidiophores developed from tips of trophiC hyphae; the process of outgrowth being similar to that for initial penetration in that it occurred via enzymic action and mechanical force. Intimate association between fungal cell wall and nematode cuticle suggested that leakage of nematode contents was prevented after outgrowth. Conidiophores possessed an electron dark layer at the outside of their wall which was not continuous with developing conidia. Numerous spores were successively formed from each individual peg present on the conidiophore. Pegs were ordered at regular distances, located in close proximity to septa and on the apical end of the conidiophore. Invariably immature spores are formed; development of the adhesive knob occurred after release from the peg. Approximately 5000-10000 spores were formed at the expense of a single nematode.