Glomus geosporum

(Nicol. & Gerd.) C. Walker

SPORES formed singly in the soil; yellow (3A8) to orange (5B8); globose to subglobose; (130-)175(-260) µm diam; sometimes ovoid; 130-150 x 220-260 µm; with a single subtending hypha.

 

SUBCELLULAR STRUCTURE OF SPORES of one wall with three layers (swl1-3).

In PVLG+Melzer's reagent
In PVLG

Layer 1 evanescent, hyaline, (0.5-)1.1(-1.4) µm thick, staining reddish white (8A2) to pale red (8A3) in Melzer's reagent, usually absent in field-collected specimens.

Layer 2 laminate, yellow (3A8) to orange (5B8), (5.0-)9.5(-13.5) µm thick, not reacting in Melzer's reagent.

Layer 3 semi-rigid, pale yellow (4A4-8) to orange (5B8), (0.6-)1.0(-1.2) µm thick, forming a recurved septum in the subtending hypha, not reacting in Melzer's reagent.
In PVLG
In PVLG+Melzer's
SUBTENDING HYPHA yellow (3A8) to orange (5B8); straight or recurved; funnel-shaped to almost cylindrical; (15-)23.2(-28.5) µm wide at the spore base.

Wall of subtending hypha yellow (3A8) to orange (5B8); (3.5-)4.5(-5.0) µm thick at the spore base; composed of two layers (shwl 1 and 2) continuous with spore wall layers 1 and 2; layer 2 continuing distally for up to 25 µm along the subtending hypha.

Pore closed by a curved septum, continuous with the innermost spore wall layer 3.

GERMINATION. Not observed.

MYCORRHIZAE. In roots of Plantago lanceolata L., the mycorrhizae of Gl. geosporum consisted of arbuscules, vesicles, as well as intra- and extraradical hyphae. The arbuscules and vesicles were patchily distributed along the roots examined. The intraradical hyphae were evenly distributed and frequently formed coils. All the structures stained moderately (arbuscules) to intensively in 0.1% trypan blue.

In roots of P. lanceolata

DISTRIBUTION. In Poland, Gl. geosporum has been revealed in many both cultivated and uncultivated sites (Blaszkowski 1993).

Literature data indicate that Glomus geosporum has a worldwide distribution. This fungus has originally been described from spores isolated from among root of Hordeum vulgare L. cultivated in Scotland (Nicolson and Gerdemann 1968). Glomus geosporum has also been reported from cultivated and natural sites of, e. g., Canada (Hamel et al. 1994; Molina et al. 1978), U. S. A. (Hetrick and Bloom 1986;Ho 1987; Koske and Tews 1987; Miller at al. 1985; Molina et al. 1978; Schenck and Smith 1981; Walker et al. 1982), Brazil (Moreira-Souza et al. 2003), Italy (Puppi and Riess 1982), The Netherlands and Germany (Hildebrandt et al. 2001; Oehl et al. 2003), France and Switzerland (Oehl et al. 2003), Israel (Blaszkowski et al. 2001; Haas and Menge (1990), China (Wu et al. 2002), and New Zealand (Hall 1977; Hayman 1978; Johnson 1977).

NOTES. When seen under a dissecting microscope, spores of Gl. geosporum most resemble in size and colour those of Gl. verruculosum Blaszk. (Blaszkowski and Tadych 1997). The two fungi also have a 3-layered spore wall structure. However, the outermost evanescent spore wall layer of Gl. geosporum stains reddish white to pale red in Melzer's reagent, whereas that of Gl. verruculosum i nonreactive in this reagent. Additionally, the inner surface of the innermost spore wall layer of Gl. geosporum is smooth, and that of the innermost wall layer of Gl. verruculosum spores is ornamented with warts.

REFERENCES

Blaszkowski J. 1993. Comparative studies of the occurrence of arbuscular fungi and mycorrhizae (Glomales) in cultivated and uncultivated soils of Poland. Acta Mycol. 28, 93-140.

Blaszkowski J., Tadych M. 1997. Glomus multiforum and G. verruculosum, two new species from Poland. Mycologia 89, 804-811.

Blaszkowski J., Tadych M., Madej T., Adamska I., Iwaniuk A. 2001. Arbuscular mycorrhizal fungi (Glomales, Zygomycota) of Israeli soils. Mat. II Polsko-Izraelskiej Konf. Nauk. nt. „Gospodarowanie zasobami wodnymi i nawadnianie roslin uprawnych”. Przeglad naukowy Wydz. Inz. Ksztalt. Srod. 22, 8-27.

Haas J. H., Menge J. A. 1990. VA-mycorrhizal fungi and soil characteristics in avocado (Persea americana Mill.) orchard soils. Plant and Soil 127, 207-212.

Hall I. R. 1977. Species and mycorrhizal infections of New Zealand Endogonaceae. Trans. Br. Mycol. Soc. 68, 341-356.

Hamel C., Dalpé Y., Lapierre C., Simard R. R., Smith D. I. 1994. Composition of the vesicular-arbuscular mycorrhizal fungi population in an old meadow as affected by pH, phosphorus and soil disturbance. Agric. Ecosys. Environ. 49, 223-231.

Hayman D. S. 1978. Mycorrhizal populations of sown pastures and native vegetation in Otago, New Zealand. N. Z. J. Agric. Res. 21, 271-276.

Hetrick B. A. D., Bloom J. 1986. The influence of host plant on production and colonization ability of vesicular-arbuscular mycorrhizal spores. Mycologia 78, 32-36.

Hildebrandt U., Janetta K., Ouziad F., renne B., Nawrath K., Bothe H. 2001. Arbuscular mycorrhizal colonization of halophytes in Central European salt marshes. Mycorrhiza 10, 175-183.

Ho I. 1987. Vesicular-arbuscular mycorrhizae of halophytic grasses in the Alvord esert of Oregon. Nortwest Sci. 61, 148-151.

Johnson P. N. 1977. Mycorrhizal Endogonaceae in a New Zealand forest. New Phytol. 78, 161-170.

Koske R. E., Tews L. L. 1987. Vesicular-arbuscular mycorrhizal fungi of Wisconsin sandy soils. Mycologia 79, 901-905.

Miller D. D., Domoto P. A., Walker C. 1985. Mycorrhizal fungi at eighteen apple rootstock plantings in the United States. New Phytol. 100, 379-391.

Molina R. J., Trappe J. M., Strickler G. S. 1978. Mycorrhizal fungi associated with Festuca in the western U.S. and Canada. Can. J. Bot. 56, 1691-1695.

Moreira-Souza M., Truem S. F. B., Gomes-da-Costa S. M. Cardoso E. J. B. N. 2003. Arbuscular mycorrhizal fungi associated with Araucaria angustifolia (Bert.) O. Ktze. Mycorrhiza 13, 211-215.

Nicolson T. H., Gerdemann J. W. 1968. Mycorrhizal Endogone species. Mycologia 60, 313-325.

Oehl F., Sieverding E., Ineichen K., Mader P., Boller T., Wiemken A. 2003. Impact of land use intensity on the species diversity of arbuscular mycorrhizal fungi in agroecosystems of Central Europe. Appl. Environ. Microbiol.69, 2816-2824.

Puppi G., Riess S. 1982. Notes on the occurrence of endogonaceous spores and vesicular-arbuscular mycorrhizal associations in woodland sites in the middle valley of the Tiber (Italy). Acc. Lincei-Rend. Sc. fis. mat. e nat. 22, 279-286.

Schenck N. C., Smith G. S. 1981. Distribution and occurrence of vesicular-arbuscular mycorrhizal fungi on Florida agricultural crops. Soil Crop Sci. Soc. Florida, Proc. 40, 171-175.

Walker C., Mize C. W., McNabb H. S. 1982. Populations of endogonaceous fungi at two localities in central Iowa. Can. J. Bot. 60, 2518-2529.

Wu T., Hao W., Lin X., Shi Y. 2002. Screening of arbuscular mycorrhizal fungi for the revegetation of eroded red soils in subtropical China. Platn and Soil 239, 225-235.