What causes chestnut blight?
chestnut blight, plant disease caused by the fungus Cryphonectria parasitica (formerly known as Endothia parasitica). Accidentally imported from Asia, the disease was first observed in 1904 in the New York Zoological Gardens.
What is the disease affecting horse chestnut trees?
Bleeding canker is a disease that affects European horse chestnut trees (Aesculus hippocastanum) in Great Britain. It is characterised by the appearance of ‘bleeding cankers’, or lesions, on the stems (trunks) and branches.
What is Hypovirulence?
Hypovirulence in fungal plant pathogens refers to the reduced ability of selected isolates within a population of a pathogen to infect, colonize, kill, and (or) reproduce on susceptible host tissues and is often associated with fungal viruses and associated double-stranded RNA elements.
How does the chestnut blight work?
The fungus enters through wounds on susceptible trees and grows in and beneath the bark, eventually killing the cambium all the way round the twig, branch or trunk. The first symptom of C. parasitica infection is a small orange-brown area on the tree bark.
What is the ink disease?
1 : a destructive disease of the chestnut in Europe that is caused by a fungus (Phytophthora cambivora) and that produces dark cankers and a black exudate on the trunk. — called also black canker. 2 : a destructive disease of walnuts caused by a fungus (Phytophthora citrophthora)
What causes bacterial canker?
What is bacterial canker? Bacterial canker is a disease caused by two closely related bacteria that infect the stems and leaves of plums, cherries and related Prunus species. Cankers begin to form in mid-spring and soon afterwards shoots may die back. Shotholes appear on foliage from early summer.
What is killing horse chestnut trees?
The larvae of the horse chestnut leaf miner bores within horse chestnut leaves, eventually causing them to drop and harming the tree and leaving it vulnerable. The adult is a very small and difficult to identify moth. Brown spots on the leaves show where the leaf miner has fed.
What exotic species brought the chestnut blight?
Cryphonectria parasitica
Of the estimated four billion American chestnut trees that once grew from Maine to Georgia, only a remnant survive today. A ghost forest of blighted American chestnuts in Virginia. The species was nearly wiped out by chestnut blight, a devastating disease caused by the exotic fungal pathogen Cryphonectria parasitica.
Who introduced the chestnut blight?
This was taken as proof that Asian trees imported into the United States had brought the blight with them. G. H. Powell wrote in 1900 (9) that Japanese chestnut trees (Castanea crenata) were first imported in 1876 by nurseryman S. B.
How does Cryphonectria parasitica spread?
Chestnut blight, caused by Cryphonectria parasitica, is a devastating disease infecting American and European chestnut trees. The pathogen is native to East Asia and was spread to other continents via infected chestnut plants.
Where does Cryphonectria parasitica overwinter?
The pathogen overwinters as mycelium in lesions and other colonized bark. In spring, fruiting bodies called pycnidia develop on the surface of the canker, and yellow- orange spore tendrils may be observed on the bark as the emerge from the yellow-brown pycnidia .
What kind of disease does c.parasitica cause?
Typical killing canker, incited by C. parasitica, on smooth-barked American chestnut (Castanea dentata) stem with numerous stromata (yellowish spots) and cracking bark. Severe, swollen-butt disease canker, incited by C. parasitica, on scarlet oak (Quercus coccinea) with rough, irregular bark.
What’s the difference between Endothiella and Cryphonectria?
Both Cryphonectria and Endothia have Endothiella conidial states, but this name is seldom used for the chestnut blight fungus as both asexual and sexual states are typically present in the same stroma.
Where does c.parasitica live in the world?
C. parasitica is widespread throughout the eastern USA, in China and Japan, where it is native, and in many countries of Europe that have significant Castanea populations. See also CABI/EPPO (1998, No. 194).
Is the c.parasitica a tractable experimental organism?
C. parasitica is also a tractable experimental organism for both classical and molecular genetics. It can mate in the laboratory, which facilitates genetic linkage analysis, and can be transformed with high efficiency.