Hymenoscyphus pseudoalbidus

From Chalara fraxinea infested ash trees

The Wrong White Stengelbecherchen ( Hymenoscyphus pseudoalbidus ) is a newly described species of fungus in 2010 from the division of the Real Ascomycota. Studies of herbarium material, however, show that Hymenoscyphus pseudoalbidus in 1978 occurred in Central Europe. Hymenoscyphus pseudoalbidus lives on the blade spindles of discarded ash leaves. His addition to fruit shape Chalara fraxinea triggers the ash dieback of Common ash and narrow-leaved ash.

The fruiting bodies of falsity white stem cup Lings are white cup-shaped apothecia with a size of 2 to 7 mm. The spores, ascospores formed in the asci are sticky and will be larger ( 15-22 microns ) than in the related species Hymenoscyphus albidus with a spore length of 8-20 microns. They should be spread through the air.

In addition to fruit shape Chalara fraxinea

In the search for the causative agent of ash dieback fungus Chalara fraxinea was discovered in 2006 in Poland as by fruit shape of an unknown fungus. Since 2008 he was considered the by Fruit of the White Stengelbecherchens ( Hymenoscyphus albidus ). This ascomycete is known since 1851 and has never come as a harmful parasite in appearance. Since 2010 it is known that Hymenoscyphus pseudoalbidus is the teleomorph of C. fraxinea.

Chalara fraxinea lives parasitically in the tissues of leaves, shoots and woody parts of ash trees and is according to some researchers the increased death of these trees involved in Europe. Any dissemination strategy of Chalara fraxinea date, nothing is known.

Chalara fraxinea affects young and old trees. There are suspicions that the fungus was able to prevail due to the increased average temperatures in Central Europe. Its distribution probably began in the Baltics. Proved he is now in Scandinavia, Great Britain, Poland, the Czech Republic, Slovenia and propagated in Germany, Austria and Switzerland. The symptoms of infestation are sparse crowns and dried up leaves and branches. As the fungus infects the pathways, the tree dies from the top manufactures. Yellowish or reddish- brown necrotic form on the bark.

The ash dieback due to the infestation with Chalara fraxinea is to be settled by the type initially a disease of the leaves and green shoots, and later the woody parts, from the inner tissues not primarily the vessels, but esp. the parenchyma of the Rays and the Mark. The showy bark necroses, sometimes also remember a cow fire disease, are more of a secondary damage of living through the dying bark and the cambium. The disease is also known as " ash dieback " or " ash wilt ".

Features

In culture, the fungus forms a moderately growing aerial mycelium, which is initially white, but later reddish-brown discolored to grayish or black. The vegetative hyphae are translucent to olive brown with just a few thickened. In older cultures appear thickened, pigmented cells. The phialides are solitary, the vegetative hyphae and 20 to 40 microns long.