Japanese oak wilt (also called mortality of oak trees in Japan) is a fungal disease caused by ''
Raffaelea quercivora
''Raffaelea quercivora'' is a species of fungus in the family Ophiostomataceae
The Ophiostomataceae are a family of fungi in the Ascomycota, class Sordariomycetes. The family was circumscribed by J.A. Nannfeldt in 1932. Species in the f ...
'' fungus affecting by
oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
trees. In 1998, Japanese plant pathologists group was isolation, inoculation and reisolation the dead tree.
[Ito S., Kubono T., Sahasi N., Yamada T.(199]
Associated fungi with the mass mortality of oak trees
''Journal of the Japanese Forestry Society 80(3), 170-175.'' It is the first disease known that ''Raffaela'' fungus cause plant disease.
Symptoms
The first obvious symptom was that the leaves wilted, and many small holes appeared on the trunk. The leaves turned to red and died back quickly (1 or 2 weeks), and finally the tree died. If you cut the dead tree, you would discover the xylem had been discolored to brown.
Mechanism
The oak trees react plugging their
xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
with gum and
tylose
Tyloses are outgrowths/extragrouth on parenchyma cells of xylem vessels of secondary heartwood. When the plant is stressed by drought or infection, tyloses will fall from the sides of the cells and "dam" up the vascular tissue to prevent furth ...
s for blocking the fungus spreading.
[{{cite journal, url=http://ci.nii.ac.jp/naid/110002830776/en, author1=Kuroda, K. , author2=Yamada, T. , year=1996, title= Discoloration of sapwood and blockage of xylem sap ascent in the trunks of wilting ''Quercus'' spp. following attack by ''Platypus quercivorus'', journal=Journal of the Japanese Forestry Society, volume= 78, issue=1, pages= 84–88] It's the same reaction of elm vs. ''Opiostoma'' fungus at
Dutch elm disease
Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America ...
.
Treatment
JOW treatment is resemble other fungus insect vector diseases such as Dutch elm disease or Pine wilt.
Exterminate beetle
The majority of this disease treatment is cut down the dead oak trees, and killed the vector ambrosia beetles by burned timber or infused insecticide.
Exterminate fungus
Some fungicide are developing and trying to inoculation.
See also
*
Bark beetle
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the ...
,
Ambrosia beetle
Ambrosia beetles are beetles of the weevil subfamilies Scolytinae and Platypodinae ( Coleoptera, Curculionidae), which live in nutritional symbiosis with ambrosia fungi. The beetles excavate tunnels in dead, stressed, and healthy trees in wh ...
''Raffaelea'' disease
*
Laurel wilt
Laurel wilt, also called laurel wilt disease, is a vascular disease that is caused by the fungus ''Raffaelea lauricola'', which is transmitted by the invasive redbay ambrosia beetle, ''Xyleborus glabratus''. The disease affects and kills membe ...
- caused by ''R. lauricola'', and ''R. canadensis''
* Korean oak wilt - caused by ''R. quercus-mongolicae''
Several tree wilt disease in the world
*
Dutch elm disease
Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Although believed to be originally native to Asia, the disease was accidentally introduced into Americas, America ...
*
Pine wilt
''Bursaphelenchus xylophilus'', commonly known as pine wood nematode or pine wilt nematode (PWN), is a species of nematode that infects trees in the ''Pinus'' genus of coniferous trees and causes the disease pine wilt.[Oak wilt
Oak wilt is a fungal disease caused by the organism ''Bretziella fagacearum'' that threatens ''Quercus'' spp. The disease is limited to the Midwestern and Eastern United States; first described in the 1940s in the Upper Mississippi River Val ...]
*
Sudden oak death
James Green aka "Sudden" is a fictional character created by an English author Oliver Strange in the early 1930s as the hero of a series, originally published by George Newnes Books Ltd, set in the American Wild West era. Oliver Strange died i ...
References
Further reading
*Kamata, Naoto; Esaki, Koujiro; Kato, Kenryu; Oana, Hisahito; Igeta, Yutaka; Komura, Ryotaro 2007
Japanese oak wilt as a newly emerged forest pest in Japan: why does a symbiotic ambrosia fungus kill host trees? In: Gottschalk, Kurt W., ed. Proceedings, 17th U.S. Department of Agriculture interagency research forum on gypsy moth and other invasive species 2006; Gen. Tech. Rep. NRS-P-10. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 1-3.
Fungal tree pathogens and diseases