As an arbuscular mycorrhizal species, it produces arbuscules penetrating a host’s cell wall. These obligate symbionts cannot be cultured without the plant host, as it is necessary for a complete reproductive cycle. AM fungi are known for helping plants receive nutrients in the soil through the penetration of a plant’s roots. (Colliton & Cooch, 2010)
A mycorrhizal fungi in soils found in Quebec and Norway as well as in India. (Gupta, 2016) Can be found in Sphagnum moss in Little Metis, Province of Quebec. (Uppsala University, 2016)
Glomus resides in soils around the world. Part of the reason this species is less studied is samples of soils have a diverse array of Glomus species present. (University of Sydney, 2004) Because of this huge distribution along with other genuses being present in samples, the Glomus genome has not been completely deciphered. (Colliton & Cooch, 2010).
However, there are known features that distinguish Glomus from other fungi. Glomus species are only known to reproduce asexually, and have large round spores produced on hyphae at the terminal end. Surprisingly, these spores can germinate whether or not a host is present. However, a host is needed to complete a life cycle. They are not considered pathogenic and are obligate heterotrophs, as are all AM fungi. (Colliton & Cooch, 2010)
Glomus boreale was previously described as Endogone borealis or Glomus borealis (Naturalis Biodiversity Center, 2016)
It is a fungus in the genus Glomus, which is a group of arbuscular mycorrhizal fungi. Although it was originally a part of the Zygomycota phylum, it was classified in the phylum Glomeromycota and then the subphylum Glomeromycota, phylum Mucoromycota (Spatafora, 2016). Very little research has been done on this species outside of classification.
Although it is sparsely documented, it is included in a comprehensive AMF phylogeny. Glomus arbuscules tend to have narrow trunks and are finely branched, staining dark in roots.
What differentiates Glomus boreale from other Glomus species is a chocolate brown spore mass, which is irregular and spongy. They are about seven to eight mm. They produce gleba, a mass of enclosed spore bearing fruiting bodies. Their gleba are loosely woven hyphae, about 10-25 microns in diameter. (Kent & Taylor, 1921)
It has a narrow isthmus with a small septum, but overall the endospore is not continuous under bright light. (Kent & Taylor, 1921)
The spores are thick-walled and reddish brown in the gleba. They are symmetrically elliptical and broad, in the range of 125x100 to 145 x 110 microns (Kent & Taylor, 1921). Spores in Glomus boreale are darker than other Glomus species. As well, the spore size differentiates it from Glomus flavisporus, which has slightly larger spores. (Gerdemann & Trappe, 1974) Auxiliary cells are absent but vesicles are present in this genus in most species. As well, the hyphae are intraradical, growing parallel to the root axis and each other. The hyphae are about 1.5-4 microns wide. They have H connections as well and stain darkly in trypan blue. (Souza, 2015)
Taxonomy
Kingdom: Fungi
Phylum: Glomeromycota
Class: Glomeromycetes
Order: Glomerales
Family: Glomeraceae
Genus: Glomus
Species: Glomus boreale
First defined as Endogone borealis in 1922 by Roland Thaxter and further studied and described by Metis and Edward Jeffrey. It was found in Little Metis, Province of Quebec (Kent & Taylor, 1921). It does not have a common name. Its name was updated in 1974 by James M. Trappe and James W. Gerdemann. It was further classified in the Glomeromycota by Walker and Schüßler and then Glomeromycotina (Mucoromycota) by Spatafora et al. 2016.
Original hypotheses for possible relatives, though not very clear, are Endogone candensis. It is now classified more closer to Glomus flavisporus. (Gerdemann & Trappe, 1974) Outside of the Glomus sp., it is most closely related to the Funneliformis sp. (Schüßler Lab, 2013)
The name boreale derives from its distribution in northern temperate and arctic regions, typically in Eurasia and North America. (Mifflin, 2002)
