DEVELOPMENT OF SPORES AND CHARACTERS OF MYCORRHIZAE

OF THE GENUS ARCHAEOSPORA

Archaeospora trappei (R.N. Ames & Linderman) J.B. Morton & D. Redecker emend. Spain, the only member of the genus Archaeospora J.B. Morton & D. Redecker, is a dimorphic fungus, forming both acaulosporioid and glomoid spores (Morton and Redecker 2001; Sieverding and Oehl 2006; Spain 2003; Spain et al. 2006). Acaulosporioid spores develop laterally, directly on the neck of a sporiferous saccule, and, thus, they are sessile, similarly as most spores of the genus Acaulospora Gerd. & Trappe emend. S.M. Berch. Two-layered glomoid spores origin blastically at the tip of or intercalary in fertile hyphae, as spores of Glomus spp.

The subcellular structure of acaulosporioid spores Ar. trappei comprises a spore wall and one inner germination wall, each consisting of two to three layers.

Germination of Ar. trappei spores is by a germ tube emerging from an irregular germination structure (Spain 2003).

In PVLG
Mycorrhizae of Ar. trappei (1) do not contain intraradical vesicles or they form rarely, (2) have intraradical hyphae with many coils located within and between cortical cells, (3) stain lightly or not at all in trypan blue and other stains, and (4) are patchily distributed along roots (Morton 2002).

The method revealing the membership of arbuscular fungi to the genus Archaeospora is sequencing of 18S rDNA using specific primers (Morton and Redecker 2001; Schüßler et al. 2001).

 

REFERENCES

Morton J. B. 2002. International Culture Collection of Arbuscular and Vesicular-Arbuscular Mycorrhizal Fungi. West Virginia University.

Morton J. B., Redecker D. 2001. Two families of Glomales, Archaeosporaceae and Paraglomaceae, with two new genera Archaeospora and Paraglomus, based on concordant molecular and morphological characters. Mycologia 93, 181-195.

Schüßler A., Schwarzott D., Walker C. 2001. A new fungal phylum, the Glomeromycota: phylogeny and evolution. Myc. Res. 105, 1413-1421.

Sieverding E., Oehl F. 2006. Revision of Entrophospora and description of Kuklospora and Intraspora, two new genera in the arbuscular mycorrhizal Glomeromycetes. J. Appl. Bot. Food Qual. 80, 69-81.

Spain J. L. 2003. Emendation of Archeospora and its type species, Archaeospora trappei. Mycotaxon 87, 109-112.

Spain J. L., Sieverding E., Oehl F. 2006. Appendicispora: a new genus in the arbuscular mycorrhiza-forming Glomeromycetes, with a discussion of the genus Archaeospora. Mycotaxon 97, 163-182.