Species of Endogone form underground structures called sporocarps—fruiting structures measuring between a few millimeters to 2–3 cm (0.8–1.2 in) in diameter, containing densely interwoven hyphae and zygospores. Sporocarps are typically found in humus-rich soil or leaf mold, or in mosses.[2] Although most species will only produce spores in nature, the type speciesE. pisiformis can be made to sporulate in test tube culture when grown with conifer seedlings.[3]
Taxonomy
Endogone was first circumscribed by Johann Heinrich Friedrich Link in an 1809 publication.[4] In 1922, Roland Thaxter revised the taxonomy of the family Endogonaceae, recognizing four genera: Endogone, Sphaerocreas, Sclerocystis, and Glaziella.[5] In 1935, Herbert Zycha transferred the sole species of Sphaerocreas recognized by Thaxter to Endogone. In their 1974 monograph of the Endogonaceae, James Gerdemann and James Trappe deviated from Thaxter’s concept of Endogone, which contained taxa with chlamydospores and zygospores, including only those species that formed zygospores in sporocarps. In the mid-1990s, Yi-Jian Yao and colleagues further restricted Endogone to those species that produced suspensors that were in contact with one another along the entire length. Those taxa in which the suspensors did not touch one another were transferred to a new genus, Youngiomyces.[6][7]
The generic name is derived from the Greek words endo (inside) and gone (reproductive organs).[8]
Description
Endogone species are sporocarpic—they form a fruit body termed a sporocarp, on which spore-bearing structures are borne. The zygospores—a diploid reproductive stage in the life cycle—are formed above the point of union of two gametangia, or from a budding from the larger of the two.[8] Species in the genus can be saprobic, ectomycorrhizal, or both.
Ecology
Depending on the species, sporocarps have been noted to have the odor of onions, burnt sugar, or fish.[9]Endogone grows in soil, on rotting wood, sphagnum or other plant material either as saprobes or ectomycorrhizal associates.[10]Endogone is especially important in the ecology of nutrient-poor soils. For example, Endogone fungi are known to grow in sand dunes, a nutrient-deficient substrate. Dune plants are dependent upon the fungus for growth and ecological success: the mycelium of the fungus helps aggregate and stabilize the sand in a network of hyphae, giving it cohesion and helping early succession plants establish roots. It also traps and binds fragments of organic material such as decaying roots and rhizomes.[11]
^Warcup JH. (1990). "Taxonomy, culture, and mycorrhizal associations of some zygosporic Endogonaceae". Mycological Research. 94 (2): 173–178. doi:10.1016/S0953-7562(09)80609-6.
^Koske RE, Sutton JC, Sheppard BR (1975). "Ecology of Endogone in Lake Huron sand dunes". Canadian Journal of Botany. 53 (2): 87–93. doi:10.1139/b75-014.
^Carraway LN, Verts BJ, Whitaker JO, Kennedy ML (2000). "Diet of the southeastern shrew (Sorex longirostris) in Tennessee". Journal of the Tennessee Academy of Science. 75 (1–2): 42–43. ISSN0040-313X.
^Orrock JL, Farley D, Pagels JF (2003). "Does fungus consumption by the woodland jumping mouse vary with habitat type or the abundance of other small mammals?". Canadian Journal of Zoology. 81 (4): 753–756. doi:10.1139/Z03-035.
^McIntyre PW. (1984). "Fungus consumption by the Siskiyou chipmunk within a variously treated forest". Ecology. 65 (1): 137–146. doi:10.2307/1939466. JSTOR1939466.
^Baszkowski J, Tadych M, Madej T (1998). "Endogone maritima, a new species in the Endogonales from Poland". Mycological Research. 102 (9): 1096–1100. doi:10.1017/S0953756298006170.
^Beeli M. (1923). "Notes mycologiques. Champignons nouveaux pour la flore Belge, récoltés de 1915 à 1923". Bulletin de la Société Royale de Botanique de Belgique (in French). 56: 57–68.