| Arthrobotrys dactyloides | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Orbiliomycetes |
| Order: | Orbiliales |
| Family: | Orbiliaceae |
| Genus: | Arthrobotrys |
| Species: | A. dactyloides |
| Binomial name | |
| Arthrobotrys dactyloides Drechsler, 1937 [1] | |
| Synonyms [1] | |
| |
Arthrobotrys dactyloides is a species of fungus in the family Orbiliaceae. It is nematophagous, forming loops of hypha to trap nematodes, on which it then feeds.
The species has a whitish spreading mycelium of branched, hyaline hyphae (thread-like filaments) some 2 to 4 μm wide. The conidia (non-motile spores) are borne on specialized stalks called conidiophores which are hyaline, erect and 200 to 550 μm long. These taper upwards and expand into a knob-like tip which is a distinguishing feature of this species. The conidia are hyaline, tapering towards the base and 20 to 52 μm long. [2]
Arthrobotrys dactyloides has the ability to form rings of hypha that can constrict sharply and catch a nematode in the loop. [2] Each ring is a short branch of the hypha containing three cells, separated by three "T-shaped" areas of cell wall. When stimulated by the movement of a nematode inside the loop (or by heat, or by the tip of a researcher's needle), the three cells inflate suddenly, rather like balloons, and the nematode is trapped in a vice-like grip, its body constricted into two parts. Now branches of hypha invade the nematode on either side of the loop and digest and absorb the soft tissues. Within a few hours the nutrients from these are available to the mycelium of the fungus. [3] Unlike some other species of nematophagous fungi which create sticky nets, A. dactyloides is able to form constricting ring-traps immediately after emerging from the conidia. These are known as conidial traps and may constitute a survival mechanism under adverse conditions. Under normal conditions, a hypha is formed on germination of the conidia; this grows and branches to form a mycelium, and loop traps form on the hyphae in the mycelium. [4]
The fungus is being researched for use in biological control of root-knot nematodes. Compared to other nematophagous fungi it is rather slow growing. A. dactyloides has been mass-reared in liquid culture but because it is sensitive to desiccation, it has not been possible to use fast drying procedures. However, this problem has been overcome and it can now be formulated as granules which can be sprinkled on the soil close to plants. In greenhouse experiments it proved up to 96% effective at reducing root-knot nematodes. [5]
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of Ascomycota are asexual and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewers' and bakers' yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.
A hypha is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Hyphomycetes are a form classification of fungi, part of what has often been referred to as fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruit bodies, and are often referred to as moulds. Most hyphomycetes are now assigned to the Ascomycota, on the basis of genetic connections made by life-cycle studies or by phylogenetic analysis of DNA sequences; many remain unassigned phylogenetically.
Nematophagous fungi are carnivorous fungi specialized in trapping and digesting nematodes. Around 160 species are known. Species exist that live inside the nematodes from the beginning and others that catch them, mostly with glue traps or in rings, some of which constrict on contact. Some species possess both types of traps. Another technique is to stun the nematodes using toxins, a method employed by Coprinus comatus, Stropharia rugosoannulata, and the family Pleurotaceae. The habit of feeding on nematodes has arisen many times among fungi, as is demonstrated by the fact that nematophagous species are found in all major fungal groups. Nematophagous fungi can be useful in controlling those nematodes that eat crops. Purpureocillium, for example, can be used as a bio-nematicide.
The Orbiliaceae are a family of saprobic sac fungi. It is the only family in the monotypic class Orbiliomycetes and the monotypic order Orbiliales. The family was first described by John Axel Nannfeldt in 1932 and now contains 288 species in 12 genera. Members of this family have a widespread distribution, but are more prevalent in temperate regions. Some species in the Orbiliaceae are carnivorous fungi, and have evolved a number of specialized mechanisms to trap nematodes.
Dendrocollybia is a fungal genus in the family Tricholomataceae of the order Agaricales. It is a monotypic genus, containing the single species Dendrocollybia racemosa, commonly known as the branched collybia or the branched shanklet. The somewhat rare species is found in the Northern Hemisphere, including the Pacific Northwest region of western North America, and Europe, where it is included in several Regional Red Lists. It usually grows on the decaying fruit bodies of other agarics—such as Lactarius and Russula—although the host mushrooms may be decayed to the point of being difficult to recognize.
Purpureocillium lilacinum is a species of filamentous fungus in the family Ophiocordycipitaceae. It has been isolated from a wide range of habitats, including cultivated and uncultivated soils, forests, grassland, deserts, estuarine sediments and sewage sludge, and insects. It has also been found in nematode eggs, and occasionally from females of root-knot and cyst nematodes. In addition, it has frequently been detected in the rhizosphere of many crops. The species can grow at a wide range of temperatures – from 8 to 38 °C for a few isolates, with optimal growth in the range 26 to 30 °C. It also has a wide pH tolerance and can grow on a variety of substrates. P. lilacinum has shown promising results for use as a biocontrol agent to control the growth of destructive root-knot nematodes.
Keissleriella rara is a rare species of fungus in the family Lophiostomataceae. The species fruits exclusively on dead or dying standing culms of the saltmarsh plant Juncus roemerianus. It is known only from the Atlantic Coast of North Carolina.
Leohumicola atra is a species of fungus. It is named after the dark-brown colour of its terminal conidia cells. It was found in Crater Lake National Park, Oregon, from heated soil. This species' conidia terminal cell becomes a darker brown compared to its cogenerate species, being nearly black.
Leohumicola levissima is a species of fungus. It is named after the smooth walled appearance of its terminal conidial cells. It was first found in Crater Lake National Park, Oregon. The terminal cell of this species’ conidia remains smooth even after 3 months’ time, as opposed to the encrusted terminal cells of L. verrucosa and L. incrustata. Conidia of L. atra have similarly smooth terminal cells, but which are darker.
Harposporium anguillulae is a member of the genus Harposporium. It is an endoparasitic nematophagous fungus that attacks nematodes and eelworms and is isolated commonly from field and agricultural soils as well as used as an experimental organism in the laboratory.
Arthrobotrys oligospora was discovered in Europe in 1850 by Georg Fresenius. A. oligospora is the model organism for interactions between fungi and nematodes. It is the most common nematode-capturing fungus, and most widespread nematode-trapping fungus in nature. It was the first species of fungi documented to actively capture nematodes.
Dactylellina haptotyla is a common soil-living fungus that develops structures to capture nematodes as nutrient source. In the presence of nematodes, spores can germinate into sticky knobs or non-constricting loops. The fungus traps nematodes with sticky knobs and non-constricting loops, then breakdown the cuticle, and penetrates the body of nematodes to obtain nutrients. For its predatory nature, Dactylellina haptotyla is also considered as nematode-trapping fungus or carnivorous fungus.
Mariannaea elegans an anamorphic fungus. It is mainly found on rotting wood and soil. M. elegans is not pathogenic to humans, animals, or plants.
Myriodontium keratinophilum is a fungus widespread in nature, most abundantly found in keratin-rich environments such as feathers, nails and hair. Despite its ability to colonize keratinous surfaces of human body, the species has been known to be non-pathogenic in man and is phylogentically distant to other human pathogenic species, such as anthropophilic dermatophytes. However, its occasional isolation from clinical specimens along with its keratinolytic properties suggest the possibility it may contribute to disease.
Stylopage is a polytypic genus of predacious fungus in the order Zoopagales, within the subphylum Zoopagomycotina. All known species of Stylopage subsist on various species of amoebae or nematodes by trapping their prey, typically using an adhesive substance that coats their vegetative hyphae, and absorbing nutrients through the projection of a haustorium. 17 extant Stylopage species have been described thus far.
Birgit Ann-Marie Margareta Nordbring-Hertz, was a Swedish scientist at Lund University known for her work on the interactions between fungi and nematodes.
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found in glossary of biology and glossary of botany, among others. List of Latin and Greek words commonly used in systematic names and Botanical Latin may also be relevant, although some prefixes and suffixes very common in mycology are repeated here for clarity.
Meristacrum is a fungal genus in the monotypic family Meristacraceae, of the order Entomophthorales. They are parasites of soil invertebrates, they typically infect nematodes, and tardigrades.
Arthrobotrys musiformis is a species of nematode catching fungi, genus Arthrobotrys. This, like other Arthrobotrys species, captures and feeds on nematodes. It is widespread, with its initial discovery being in Norfolk, Virginia. This species demonstrates promising anti-helminth potential, and is hypothesized to reduce the number of parasitic nematodes in plants and livestock as either a biocontrol or through isolating metabolites.