Grass core mushroom
| Grass core mushroom | ||||||||||||
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Grass core mushroom on Poa pratensis |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Epichloe typhina | ||||||||||||
| ( Pers ) Tul. & C. Tul. |
The grass core fungus ( Epichloe typhina ) is an endophytic fungus from the group of ascomycetes .
features
A whitish stroma , up to 5 cm long , forms on the infected grass around the stalk , on which light yellow pear-shaped perithecia with a short neck form: These are densely packed (103 ± 5 per mm²). This gives the surface a grainy, rough appearance. The asci are 163 × 6.9 µm in size and contain eight filamentous ascospores. These are 176 µm × 1.6 µm in size with 6–9 septa . When ripe, they are expelled as a whole.
Species delimitation
Several species look similar, but mainly differ in the host. While Epichloe typhina occurs mainly on common ballgrass , Epichloe clarkii occurs on woolly honeygrass , and Epichloe baconii on red ostrich grass . Another important distinguishing feature is that in both species, in contrast to Epichloe typhina, the ascospores disintegrate into partial spores at maturity. With Epichloe baconii these are only simply septate, with Epichloe clarkii they are multiple.
ecology
More than 50 different grasses from the sweet grass family ( Poaceae ) serve as hosts for the core fungus . However, the species is now split into several species (see species delimitation ). The fungus can influence the development of the flowers and leads to increased culm formation and lengthening.
Flower flies of the genus Botanophila feed on the hyphae . The conidia pass through their digestive tract and are thus spread. The infection is systemic, the fungus can be detected in all parts of the host plant with the exception of the roots .
The grass core fungus grows mainly intercellularly in all tissues and persists in the host plants and usually does not cause any visible symptoms for several years . When the infestation becomes visible, a white stroma initially forms in the area of the leaf sheath over a leaf knot . Conidia then form within this stroma . Yellow-orange perithecia are then formed with advancing age . The extent of the infestation can be very different for different grasses. The common ball grass , timothy grass and wood bluegrass are particularly susceptible. The infested plants usually do not bloom.
distribution
The distribution of the grass core fungus is restricted to the northern hemisphere. You can find it in Asia , Europe and North America .
meaning
In some years the fungus can cause considerable damage to grasses in certain locations, especially grasses that are cultivated for the production of seeds , which can lead to large losses in production. Since the fungus also occurs in seeds, contamination of seeds can become a problem. However, the core fungus also produces alkaloids , which are toxic to grazing cattle and herbivorous insects. So the plant can benefit from the fungus. There is therefore a mutualism .
swell
- IM Smith, J. Dunez, RA Lelliott, DH Phillips, SA Archer: European Handbook of Plant Diseases, Blackwell Scientific Publications 1988, ISBN 0-632-01222-6
- S. Ryman & I. Holmåsen: Mushrooms. Bernhard Thalacker Verlag, Braunschweig 1992, ISBN 3-8781-5043-1
- Josef Breitenbach, Fred Kränzlin (Ed.): Mushrooms of Switzerland. Contribution to knowledge of the fungal flora in Switzerland. Volume 1: Ascomycetes (Ascomycetes). 2nd, corrected edition. Mykologia, Luzern 1984, ISBN 3-85604-011-0 , p. 252.
Web links
Individual evidence
- ↑ a b c James F. White (1993) Endophyte-Host Associations in Grasses. XIX. A Systematic Study of Some Sympatric Species of Epichloë in England. Mycologia 85: 444-455. Stable url
- ↑ TL Bultman, JF White Jr., TI Bowdish, AM Welch, J. Johnston, 1995. Mutualistic transfer of Epichloë spermatia by Phorbia flies. Mycologia 87: 182-189.
- ^ Gary Stacey, Noel T. Keen: Plant-microbe interactions, Volume 1. Chapman & Hall, 1996, pp. 112ff