Germ pore
The germ pore is a typical feature of the spores of fungi . The term describes a clearly defined area of the spore wall of conidia , ascospores or basidiospores , in which the wall is strongly thinned. The germ tube (the germ hypha) can penetrate to the outside during spore germination through this porus, which is usually arranged at one end of elongated spores (polar, apical) . The area can also be elongated like a slit and is then called a germ line .
Polar germ pores are found in many representatives of the Basidiomycetes in the order Agaricales and in a few Ascomycetes . On the other hand, crevices occur in spores of the Ascomycetes (especially in the order Xylariales ). In the case of spores without a germ pore, the germ tube emerges from the spore at any point. Shortly after it emerges, it forms the first hypha and, under suitable conditions, finally a mycelium .
Especially with conidia, two or more germ tubes can be formed, which emerge at the ends of the conidia or at any point (bipolar, for example Drechslera iridis ( Pleosporales ); multipolar, for example Alternaria sp. And Massospora cicadina ( Entomophthorales )).
Fungus identification
In the case of dark spores and colored specimens, in particular, germ pores and crevices can be easily seen under the light microscope. Their existence or nonexistence as well as their location on the spore surface are important indications for the microscopic determination of fungi. In the case of basidiospores, the germ pore is always on the opposite side of the apiculus and must be distinguished from it. The apiculus is usually recognizable as a small protuberance.
Examples
- apical, basidiomycete: hay manure , curtain
- apical, Ascomycete: Sordaria fimicola , Podospora sp. ( Sordariales )
- Germ gap , Ascomycete: Hypoxylon serpens , Rosselinia necatrix (Xylariales)
- Germ gap , conidia: Wardomyces humicola ( Microascales )
Hay manure; Spores with germ pore and apiculus
Hung crinkle; Spores with germ pore
Sordaria macrospora ; Ascospores with apical germ pore
Xylaria anisopleura ; Ascospores with a germ line
Mucor circinelloides ; multipolar germinating conidia
literature
- Heinrich Dörfelt (Hrsg.): BI-Lexikon Mykologie - Pilzkunde . 1st edition. Bibliographisches Institut, Leipzig 1988, ISBN 3-323-00187-7 , p. 218 .
- Miguel Ulloa, Richard T. Hanlin: Illustrated Dictionary of Mycology . 2nd Edition. APS Press, St. Paul, Minnesota 2012, ISBN 978-0-89054-400-6 (English).
