Endogone pisiformis may look similar to other Endogone species or to gelatinous fungi. It is necessary to examine a number of characteristics to differentiate at the species level. One visible feature that helps to distinguish the species is the bright yellow to orangish-yellow sporocarp (Thaxter 1922; Gerdemann & Trappe 1979). A second key characteristic is substrate: growing on moss and dead wood. Using a microscope, the presence of zygospores, which are diploid and have thick cell walls is another good characteristic. Similar looking earth tongues and jelly fungi have basidia or asci, but neither feature is present in this zygomycete species. The presence of gametangia can also distinguish this species from basidiomycetes. Endogone pisiformis can be separated from other Endogone species by the presence of ellipsoid and granular yellow zygospores, hyphae that look swollen “vesicular,” and the presence of white hairs (tomentum) on the sporocarp (Thaxter 1922; Gerdemann & Trappe 1979).
Below is a more technical description of E. pisiformis compiled from the following sources: Thaxter 1922; Gerdemann & Trappe 1979; Grand & Randall 1981; Gibson et al. 1986; Jabari-Hare & Charest 1987):
Sporocarp: The sporocarp is yellow to orangish-yellow. The sporocarp overall is smoothe with a waxy appearance. Its shape is subspherical to reniform (kidney-like). Small clear colored hairs (tomentose) are present. The sporocarp can be either solid or hollow in the center and base. There are often multiple sporocarps in close proximity to each other.
Zygospores: Zygospores in this species are one celled spores and are ornamented evenly across the entire zygospore. The spores are distinctly yellow. The spores are 35-60 x 30-45 microns. Zygospores have two cell walls- the inner wall is distinctly thicker than the outer wall.
Hyphae: Hyphae are 4-6 µm wide, and are often branched. Hyphae is found in numerous shapes and branching in cultured samples. The cellular structure and macromolecule structure was examined by Jabari-Hare & Charest 1987. The structures found in E. pisiformis are typical of other Endogonales such as the presence of N-acetylglucosamine (helps bind chitin) in cell walls and fucose (importance for sugar manufacturing) (Jabaji-Hare & Charest 1987).
This species is seldom collected. Its conservation status is unknown and is in need of further research.
The changes in the amount of fatty acids, nitrogen and phosphatases were measured in cultures of E. pisiformis (Jabaji-Hare et al. 1988). The amount of each component fluctuated with age of the culture. Protein and nitrogen were initially high, then decreased (day 14), then increased by day 25. Phosphatase levels increased from day 4 to day 7 then decreased sharply (Jabaji-Hare et al. 1988). Fatty acids decreased from Day 4 to 7 then increased very slowly (Jabaji-Hare et al. 1988). It is unknown how these rates differ to E. pisiformis in nature.
With the rise of molecular techniques, it is increasingly easier to study cryptic species of ectomycorrhizae that cannot be cultured in lab. Endogone pisiformis is often used as an outgroup to construct phylogenies of distantly related ectomycorrhizal taxa. A few of the many examples are: Russell & Bulman 2004, Simon 1996, and Blazkowski et al. 2011.
Researchers have amplified specific genes of E. pisiformis for phylogenetic research. As of October, 2014, there are 15 sequences listed on Genbank (search under “nucleotide” option). Multiple sequences include data for the following genes: 18S ribosomal RNA, ITS1, 5.8S, ITS2, 26S ribosomal RNA (http://www.ncbi.nlm.nih.gov/nuccore/?term=endogone+pisiformis).
Endogone pisiformis was sequenced as part of the Assembling the Fungal Tree of Life (AFTOL) project funded by the National Science Foundation. Genes sequenced for this endeavor were RPB1, RPB2, ef1α, actin, and 18S ribosomal gene (http://www.ncbi.nlm.nih.gov/nuccore/?term=endogone+pisiformis).
The mycoportal records indicate that E. pisiformis is found in a variety of habitats such as: Douglas fir, loblolly pines, and bogs. It may be that E. pisiformis needs an acidic environment to grow in. The species is found in temperate climates and/or higher elevation (mycoportal.org) .
Endogone pisiformis was a species found in larger quantities in thinned rather than unthinned Douglas fir forests of the Pacific Northwest (Colgan et al. 1999).
This species is thought to be primarily saprotrophic, meaning it eats dead plant material on the floor of the forest (Berch & Fortin 1983).
Shows the primers used for Endogone pisiformis while assembling the Fungal Tree of Life.
Endogone pisiformis is generally found in northern North America and Europe in temperate conifer forests. As of October 2014, there are North American records from the following states: California, Minnesota, New York, North Carolina, Oregon, Pennsylvania, and Washington (http://mycoportal.org). The species is also known from Tennessee (Thaxter 1922). Endogone pisiformis is reported from the following provinces in Canada: British Columbia, and Quebec; and from Mexico: (state of Puebla) (http://mycoportal.org). In Europe, Endogone pisiformis has been found in Germany and Hungary (http://mycoportal.org).
The mycoportal.org data indicates that E. pisiformis can grow on: Sphagnum species (a moss), decaying wood of Pseudotsuga menziesii and Quercus garryana (Oregon), and “duff” (decaying plant material). It is not parasitic on Sphagnum and may be an example of commensalism.
Many species of Endogone are mycorrhizal, but E. pisiformis was able to be cultured without associating with the roots of Pinus and Sphagnum (Berch & Fortin 1983).
While many species of Endogone are mycorrhizal, E. pisiformis is saprotrophic and primarily breaks down dead material (a decomposer) (Berch & Fortin 1983). As a result of decomposition, nutrients that were inaccessible in the dead plant material become usable for other organisms to live. These nutrients are necessary for most forms of life. The nutrients would primarily be used by other microscopic organisms (Chapin et al. 2011).
Endogone pisiformis Link is a distinctive, widespread Zygomycete species found in temperate North America and Europe (Thaxter 1922, Trappe & Gerdemann 1979). The species has a thick, waxy, yellowish sporocarp (visible fruiting body) and unbranched to branched hyphae.Endogone pisiformis is saprotrophic while most of the other species in the genus are ectomycorrhizal (Berch & Fortin 1983). It is commonly found in conifer forests on Sphagnum moss and on bare ground (Thaxter 1922, Berch & Fortin 1983). This species is important because it one of the few Endogone species that can be cultured in the laboratory because it is not ectomycorrhizal. As a result of its ability to be cultured in lab, it is more thoroughly studied than other Endogone species. It is also widely used as a comparison (outgroup) for phylogenetic work. Endogone pisiformis is the type species for the genus Endogone (Mucormycotina, Endogonales) (Benny et al. 2014). It was described by Link in 1809.
One unique feature of Endogone pisiformis is that it can be cultured in a laboratory setting (Berch & Castellano 1986). The species is not ectomycorrhizal, and thus not dependent on plant species for survival.
Depending on the culturing method, E. pisiformis can be fertile or sterile. If it is grown from an isolate (a fragment of a specimen), it can form sporocarps (Berch & Castellano 1986). These cultures had very similar characteristics (spore size, and shape) to E. pisiformis found in nature. In another experiment, cultures from zygospores were used and the specimens only formed mycelium. When zygospores were cultured, the spores germinated but failed to produce zygospores (Dalpe 1990 as cited in Benny et al. 2014).
To grow E. pisiformis that has sporocarps, the petri dish should contain the following components: glucose, peat, vermulite and Melin-Norkrans agar (MMN) (Berch & Castellano 1986). A sterile specimen will still grow as long as either peat or glucose is used along with MMN and vermulite. Absence of two of the four ingredients will result in no fungal growth. (Berch & Castellanon 1986).
The mechanisms of E. pisiformis dispersal to new localities has not been studied. They may be dispersed by the wind, externally on animals, or in the gut of animals. Each possibility needs further study. Endogone pisiformis produce zygospores which a thick cell wall which enables it to survive long term until favorable conditions for germination (Webster & Weber 2007).
Species distribution and substrate can be looked up using this link. Also the herbaria that contain this species can be found.
In regards to ecology, E. pisiformis is a decomposer (Berch & Fortin 1983). Its total biomass in an ecosystem is unknown, but collectively it may be important for microhabitat nutrition for organisms that live near it such as Sphagnum species. In addition, ancestors of Endogone may have been one of the first types of fungi to form mycorrhizal associations with plants (Bidartondo et al 2011). Mycorrhizal associations increase the amount of nutrients a plant can obtain (Raven et al. 2005).
Endogone is currently in the (Mucormycotina, Endogonales). Other genera in the Endogonales include Densospora, Peridiospora, Sclerogone and Youngiomyces (Gerdemann & Trappe 1974; Benny et al 2014). Endogone pisiformis is the type species for the genus Endogone (Thaxter 1922; Trappe & Gerdemann 1979). The location of the holotype that Link designated in 1809 is not known. A collection from the Farlow Herbarium (FH), Bucholtz B1767 was designated the neotype (Trappe & Gerdemann 1979). The specimen is from Ludwig, Germany. The following are a list of synonyms of Endogone pisiformis as listed from Thaxter 1922:
Endogone ludwigii (Bucholtz)
Endogone sphagnophila Atkinson
Endogone xylogena Schroeter
Shows a current classification of all Zygomycetes
Endogone pisiformis je grzib[1], co go ôpisoł Link 1809. Endogone pisiformis nŏleży do zorty Endogone i familije Endogonaceae.[2][3][4]
Endogone pisiformis je grzib, co go ôpisoł Link 1809. Endogone pisiformis nŏleży do zorty Endogone i familije Endogonaceae.
Endogone pisiformis Link, 1809 : Fr., 1821
Endógone pisifórmis — вид зигомицетовых грибов, относящийся к роду Endogone. Типовой вид рода.
Плодовые тела мясистые, шаровидные, клубневидные или неправильной формы, до 4,5 мм в диаметре, сначала распростёртые по субстрату, затем несколько приподнятые над ним, при созревании с центральным отверстием. Окраска от бледно-жёлтой до золотисто-жёлтой, при высыхании — от беловатой до бежевой.
Перидий шерстистый, тонкий (до 60 мкм толщиной), из ценоцитных ветвистых гиф 4,8—7,5 мкм толщиной, на концах заострённых.
Глеба представлена спороносной стенкой 0,3—0,7 мм толщиной, ограничивающей срединную полость, состоит из зигоспор и густых ценоцитных гиф до 17 мкм толщиной.
Зигоспоры случайным образом разбросаны по глебе, сферические, эллиптические или неправильной формы, 31—57×35—73 мкм, во влажном состоянии жёлтые, в сухом — гиалиновые.
Встречается на гаметофитах растений рода Sphagnum — Sphagnum capillifolium (Ehrh.) Hedw., Sphagnum squarrosum Crome, а также на разлагающейся древесине и древесной коре, на старых плодовых телах трутовых грибов.
Родовое название образовано от др.-греч. ἔνδον — «внутренний» и γόνος — «рождённый», что относится к образованию грибом репродуктивных структур внутри плодовых тел. Видовой эпитет образован от лат. pisum — «горох» и forma — «форма».
Endógone pisifórmis — вид зигомицетовых грибов, относящийся к роду Endogone. Типовой вид рода.
