Cryphonectria

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Cryphonectria
Chestnut blight.jpg
Cankers caused by the Cryphonectria parasitica cause the bark to split.
Scientific classification
Kingdom: Fungi
Phylum: Ascomycota
Subphylum: Pezizomycotina
Class: Sordariomycetes
Order: Diaporthales
Family: Cryphonectriaceae
Genus: Cryphonectria
(Sacc.) Sacc. & D. Sacc. 1905
Species

See text.

Cryphonectria is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is Cryphonectria parasitica, the species which causes chestnut blight. The genus was, for a time, considered synonymous with Endothia, but the two are now recognised as distinct. Taxonomic studies in 2006 limited the genus to four species, but a fifth, Cryphonectria naterciae, was described in 2011 from Portugal.[1]

Species[edit]

According to [(Murr) (And.et And.)] Cryphonectria P.was first discovered in N-Amerika in 1904, on Castanaea Dentata,Quercus Stelata and - Q.Virginiana.A barkparasit That can cause the trees to die out. Its origin is South EastAsia(valsceae)imported to South Europe in 1938, to infect Castnaea Sativa in Italy, South of France and Spain.

The infection takes place by Asco, and Konidiaspora through bark wounds. Symptoms, in the early stage: Clear yellow-brown spots appear on the young twigs, the bark then splits open, sinks in at these spots and dies out. In the next stage the Cambium layer is infected, the tree trunk becomes disformed, the split barkparts start to swell as parasitic fungus produces more Peridermia and yellow coloured-Pyknidia start to appear on the bark-outside. The release of these spores lasts through the whole vegetation season long. Between the bark an the wood, Crémewhite fan-shaped Mycelstrings start to grow. After the leaves have started wilting, the branches start dying off, caused by a wilttoxin. To stop or battle this decline more resistant trees are bred within the genus.

References[edit]

  1. ^ Helena Bragançaa, Daniel Riglingb, Eugénio Diogoa, Jorge Capeloa, Alan Phillipsd and Rogério Tenreiroc (2011). "Cryphonectria naterciae: A new species in the Cryphonectriae-Endothia complex and diagnostic molecular markers based on microsatellite-primed PCR". Fungal Biology 115 (9): 852–861. doi:10.1016/j.funbio.2011.06.014.