as Mykorrhiza (of the old-Greek μυκησ (mykos) = mushroom and ριζα (rhiza) = root) one designates a form of the symbiosis of mushrooms and plants, in which a mushroom with the fine root system of a plant is in contact.
The Mykorrhizapilze suppliesand received for their part Assimilate produced a part by the photosynthesis (became green ) of the plants for the plant of feeding salts and water. The Mykorrhizapilze has a fortune substantially larger in the comparison to the plant to loosen nutrients and water from the soil.Frequently the water, nitrogen - and phosphate - is improved supply of the infected plants, moreover the Mykorrhizierung offers a certain protection from Wurzelpathogenen and generally increases the drying resistance of the plants, which particularly at extreme locations of advantage can be.
Tooptimal growth are dependent many plant types on specific Mykorrhizapilze. From evolution-biological view it is however to a large extent unclear why the Mykorrhizapartner should always appear as Mutualist. Symbioses are generally susceptibly to exploiters and Täu (English. “more cheater”), because it is ever more economical forthe deceptive partner to use the advantages of the partnership (e.g. free carbon of the plant) and no return (e.g. To supply nutrients). Newer concepts in the Mykorrhiza plant symbiosis proceed therefore with gradients of the relations, that from Mutualismus up tois enough to strict parasitism. Also plants try to profit from Mykorrhizapilzen to without furnishing returns. One finds Mykorrhiza parasites under plants under Orchideen and chlorophyll-free parasite plants. The mechanisms of the mutual manipulation and deception between symbiosis partners is one of the most exciting Forschungsgebiete of modern ecology.
Mykorrhizapilze belong to a substantial component of the ecological system of the tropical rain forest.
It is assumed that the Mykorrhiza made possible at all only the land settling of the first terrestrial plants. World-wide it gives approx. 200 kinds of VA-Mykorrhizapilzen (see below), with approx.90% of all land plant types in symbiosis stand. Such a nonspecific symbiosis can probably only with difficulty later have developed.
Begon, Harper and Townsend write in their “text book of the ecology” (1986) even: “Most higher plants do not have roots, it have Mykorrhizen.”(in the English. Original: “Most more higher plants DO emergency have roots, they have mycorrhizae. ”) The quotation comes from the American plant pathologist Stephen William and reads in the original: “… in agricultural field conditions, plants DO emergency, strictly speaking, have roots, they have mycorrhizas. ”
due to specific characteristics the Mykorrhizen traditionally in three different classes is divided:
- Ektomykorrhiza: The Mykorrhizapilz coats the suction roots of the plants and penetrates into inter+cellular ranges of the root crust. This form of the Mykorrhiza is typical for treesfrom the families of the Birken -, beeches -, Kiefern -, pastures - and rose plants. Mushroom partners are usually stand mushrooms from the orders Boletales and Agaricales, in rare cases of hose mushrooms like the Trüffel and special Becherlinge like the Zedern Sandborstling. Duringmost plant partners at suitable locations also without mushroom to prosper can, give it under the latters some, which are obligatorily on plants dependent as partners. It is accepted that a great many large mushrooms are capable of the Ektomykorrhiza - with us in Central Europeover 1.000 kinds from the kinds Schleierlinge, Täublinge & Milchlinge, Ritterlinge, Schnecklinge, Wulstlinge & tuber sheet mushrooms, Pfifferlinge.
- Endomykorrhiza: A part of the Hyphen of the mushroom penetrates into the cells of the root crust of the plant partner. The latters are predominantly herbs, Stauden and grasses, only in rare cases of trees. Plants of the following families nearly always stand with a mushroom partner in symbiosis:Heath herb, winter green plants and Orchideen. The symbiotischen mushrooms are mostly stand mushrooms from the order Tulasnellales, as well as of them anamorphe forms Rhizoctonia and Orcheomyces. At least with Orchideen this form of the Endomykorrhiza is mandatory for their development.
- VA-Mykorrhiza (vesikulär arbusculäre M.), a special form of the Endomykorrhiza: for the most frequent kind of Mykorrhiza the formation of vesicles is typical - D.h. in the root fabric of the partner plant thick-walled mushroom cells form - and Arbuskeln - which are branched out, tender Hyphen in Bäumchenform within the root cells. This kind of the Mykorrhiza becomes only of few kinds of the family Endogonaceae from the class of the Zygomycetesformed. The number of the plants, those of the VA-M. to profit can, is however very large. Among them many useful plants are, of them by VA-M. increased phosphate supply increasing their yield to affect can. In recent time one speaks rather of Arbuskulärer Mykorrhizaand arrange the mushrooms involved the Arbuskulären Mykorrhizapilzen and the again created department of the Glomeromycota to .
Another organization differentiates between five mutualistischen (Ekto, Ekt Endo, more arbutoider, more ericoider and V/A) and two antagonistic (Orchideen and more monotropoider) Mykorrhizen (after Smith& READ 1997, changes).
It is common to all three forms that pilzliche Hyphen pulls the soil through and transports nutrients to the plants.
Web on the left of
- a more modern classification of the Mykorrhiza on http://www.ipb-halle.de/myk/start/index.html one introduces.
- Working group of A. To Schüssler, DO Darmstadt: http://www.tu-darmstadt.de/fb/bio/bot/schuessler/homepage/welcome.html
- overview of suitable and unsuitable plant types: http://www.mykorrhiza-shop.de/liste.php