Heterobasidion annosum
This article was " Mycology " is entered in the biology section to improve on the basis of formal and / or substantive deficiencies in quality assurance. This is done to bring the quality of biology articles to an acceptable level. Please help to improve this article! Products are not significantly improved, may optionally be deleted.
Read also the more detailed information in the minimum requirements in biology articles.
Common root fungus ( Heterobasidion annosum )
The common root fungus ( Heterobasidion annosum ) is a species of fungus in the family Bergporlingsverwandten. As forest pest he caused in the infested pines a red rot. This heart rot is economically very significant.
- 3.1 harmful effect 3.1.1 infection
- 3.1.2 Disease
- 3.1.3 combating
- 6.1 Literature
- 6.2 Notes and references
Features
Macroscopic characteristics
The fruiting bodies of the root sponge can be used as flat hats, halbresupinat or resupinat ( adjacent to the substrate ) may be formed. The hats have a sharp edge ( not rounded ) and are often irregularly intergrown. They reach a width of 5 to 15 centimeters and a length of 1-8 inches (measured from the substrate to Hutkante ); in the middle they are one to two inches thick. The ranges in color from gray to red to dark brown; Growth edges are white.
The top is wrinkled feinfilzig, verkahlt later, however; and can also be zoned. It consists of a thin black crust, which can be easily bruised. When dried fruiting bodies, they appear as dark, shining line; the Trama is in contrast to whitish tint to wood color and has a corky - tough, in the dried state a woody consistency. She turns with Melzer's reagent dark reddish brown.
On the bottom are the tubes, the layering is quite difficult to see. The small, rounded pores are cremeweißlich colored yellowish to ocher. The spore powder is white.
Microscopic characteristics
The generative hyphae are hyaline. You have buckleless septa ( partitions ). The Skeletthyphen are also hyaline and usually unbranched. They change color in Melzer's reagent or Lugol wine red ( dextrinoid ) and their cell walls with cotton blue violet ( cyanophil ).
The basidia are hyaline, clavate in shape and have no basal buckle; each form four spores. These are also hyaline, broadly ellipsoid to globose, and measure 4-7 × 3-5 micrometers. They have a feinwarzige surface and a thin outer wall, which slightly change color in Melzer's reagent (weakly amyloid ).
If no fruiting bodies are present, the fungus can be seen on fresh, moist wood in the numerous conidia that are formed at the inflated hyphae.
Artabgrenzung
The root sponge is characterized by its rather inconspicuous and small fruiting bodies that grow low to the trunk, generative usually difficult to find, although it must be vegetatively called extremely often. Pale brownish copies can be confused with the row Tramete ( Antrodia serialis ), but which has no Hutkruste and generates its mycelium in the wood a cubical brown rot.
Ecology
The root sponge can be found in virtually all types of forests. Due to its " preference " for he spruce is particularly common in spruce forests. Occasionally, the fungus is also found in parks, gardens and similar installations. However, on standing, individually or in smaller groups of trees it is rare.
The root sponge lives parasitically on the trunk base, on roots or stumps of various coniferous and deciduous trees. All phases of Holzvermorschung its mycelium causes one by one. The spores are capable of germination usually over 90 percent. You can in cold and humid conditions to germinate much better than drought.
The fruiting bodies are perennial and can be found throughout the year. The growth and sporulation place in southern Germany shortly after the beginning of spring and keep the whole year through. This process is largely independent of temperature and only interrupted by extremely cold or dry conditions for a short time. Even an abrupt freezing to -18 degrees Celsius, the fruiting bodies and spores survive in a moist environment. The spore production is cyclical, with the maximum at midnight and the minimum is during lunch time.
Harmful effect
Especially in young spruce monocultures can cause major damage that can amount to millions of root sponge. In contrast, natural mixed forests he presents no serious threat dar. For this reason, the fungus on the part of forest economists as a pest and of conservationists was seen as " beneficial insect ". Consequently, the root sponge came again and again in discussions regarding his role in the forest ecosystem.
Infection
Trees are usually infected via the roots, either by the ingress into the ground basidiospores or by root contact with already infected neighboring trees. The basidiospores can also very easily make a non-protected from bark wood body, eg attacked on the fresh cut surfaces of the stumps of felled trees. Are mostly affected stumps with a diameter of about ten centimeters, which corresponds to a wood aged 15 to 20 years.
An opposite Wurzelverwachsungen very significantly accelerated infection of other trees is done by peeling.
Particularly at risk are afforestation on former agricultural whitewashed surfaces, with a high pH ( > 5.5 ) favors the disease. Further increase a -carbonate soil, densely packed, flat enigmatic, alternating wet and sandy soils, the risk of infestation.
Disease
The mycelium penetrates in spruce before after infection in the root and grows upward. It can rise within a year up to half a meter and penetrate to a height of sixteen feet. The fungus causes a white rot in wood in the heartwood, which is called because of their reddish -brown color as red rot. As a result, the wood is so decomposed that it is - in contrast to a cube-shaped brown rot - receives a längsfaserige consistency.
In pines, the fungus does not spread from the root upwards. He decomposed instead the roots, causing the tree dies. Since this phenomenon occurs mainly on formerly agricultural land, it is also referred to as arable death.
Combat
An effective treatment of infected trees is not possible. It can only take preventive measures to prevent new infections. This can be applied to freshly cut surfaces saturated solution of urea ( 37 percent ), which prevents the penetration of the fungus. A promotion or vaccination of stumps with antagonistic fungi such as Phlebia gigantea (giant mushroom beef ) or Trichoderma viride is also possible. Due to the competition of the root sponge can not settle then. With the help of P. gigantea, the infection rate can be reduced by 80 percent. The sodium nitrite formerly used is harmful to the environment and is therefore no longer used today.
Dissemination
The root sponge is particularly widespread in the Holarctic, where mostly he temperat to boreal occurs. It can also occur meridional. In addition, the fungus is found in Australia and New Zealand as well as in India, Pakistan and Central America.
In the Holarctic the root sponge is widely used and seems to be lacking only in China and Japan, where instead H. is to be found in the insular coastal areas. In North America, the fungus in the United States, distributed along with Alaska, and Canada; in Asia, he is in the northern part of the Middle East (Asia Minor, Iran) and the Caucasus, Siberia, Central Asia and the Far East before.
In Europe, the root sponge from the coast of the Mediterranean Sea and the Atlantic Ocean, is widely used to the eastern border of the continent, the Urals; to the north, the area extends to the Hebrides and the north Fennoskandinaviens. In the latter region, the fungus is, however, quite rare. In Central Europe, and especially in the coniferous forest areas it is common.
In Germany the root sponge is everywhere, often and almost completely represented on the islands. In the Alps, the fungus can sometimes penetrate to the forest boundary.
Related species
- Fir root fungus ( Heterobasidion abietinum ) Niemelä & Korhonen 1998
- Pine root fungus ( Heterobasidion annosum ) (Fr.) Bref. 1888
- Spruce root fungus ( Heterobasidion parviporum ) Niemelä & Korhonen 1998
- Heterobasidion araucariae P.K. Buchanan 1988
- Heterobasidion arbitrarium ( Corner) T. Hatt. 2001
- Heterobasidion insular ( Murrill) Ryvarden 1972