Cytospora Canker Cytospora chrysosperma (Pers.:Fr.) Fr. PDF file. Hosts: Aspen, cottonwood, alder and other riparian species. Figure An expanding. Cytospora chrysosperma (Pers.:Fr.) Fr. is a fungus that causes a tree disease called Cytospora canker. It attacks several hardwoods, notably trees used for. Cytospora canker of poplars–including aspens and cottonwoods–and willows is caused by the fungus Cytospora chrysosperma (perfect or teleomorph state.

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This can be challenging since pathogens can remain dormant or have endophytic stages in the host tissues. We use cookies in a very limited number of scenarios that are all present to help the users to have an easier experience. The yellowish to reddish brown spore horns consist of masses of one-celled spores conidia in a gelatinous matrix. Google cookies and technologies Google Analytics: The perithecia of Valsa sordida form in the same stromata with pycnidia or in new stromata beginning in autumn and winter after the formation of pycnidia.

Cytospora canker Spore tendrils of C. Specimens and strains links: The perithecia are black, spherical, and several are arranged in a ring in the lower, outer part of the stroma.

Cookies mentioned in the last point are Google analytics cookies that are IP anonymized which means that we cannot trace single users. Other fungal links Bibliography links General links Molecular links Specimens and strains links. Since pathogens of poplars and pines tend to track their hosts worldwide better detection and surveillance are essential.

The stromata are shaped like short cones with flattened, gray-brown chrysos;erma black tips that break through the bark surface as small dark pimples or pustules Figure 3. The lesions enlarge during the winter, becoming dark brown to black and water-soaked with distinct margins. The Cytospora Valsa fungus overwinters as mycelia and conidia or ascospores in diseased bark and wood.


IPM : Reports on Plant Diseases : Cytospora Canker of Poplars and Willows

Balsam poplargolden weeping willow, largetooth aspenLombardy poplar, trembling aspenwillow. Specimen record 6. Other species of Valsaincluding Valsa abietis Fr.

This stem disease commonly kills Lombardy poplars Populus nigra cv. The disease is usually associated with trees growing outside their normal range or under unfavorable conditions due to a poor site, frost damage, periods of drought, extremely cold winter weather, transplant shock, or severe pruning pollarding. Shortly after the bark dies two types of black, pinhead-sized, spore-producing bodies form in stromata in the outer diseased bark Figure 2 and 3 ; the pycnidia of the asexual phase Cytospora chrysosperma i and the perithecia of the sexual state Valsa sordida Figure 4.

The pycnidia, under warm moist conditions, absorb water and swell, exuding long, thin, coiled, thread-like tendrils of microscopic spores, called spore horns.

The affected branches turned yellowish brown, and the inner bark turned black. Under the bark, the wood is discoloured, wet and foul-smelling. The initial infection is followed by the death of part of the bark and rarely by the formation of a true canker.

This opportunistic fungus often inhabits apparently healthy bark and buds and is thus in position to infect weakened tissue quickly and massively. Seedborne fungi, insect damage, adverse weather such as frostimproper storage, and physiological aging all reduce seed vigor and viability. Pairwise identification Polyphasic identification. The fungus spreads by producing conidia asexual spores within fruiting bodies pycnidia on the cankers.

First Report of Cytospora Canker Caused by Cytospora chrysosperma on White Poplar in Israel

Under moist conditions, spore masses oozed out in long, reddish brown, coiled tendrils. Matches exactly Value is undefined. It is replaced each time chtysosperma is a query done. No cankers developed on the control seedlings. Attacks by pathogens represent one of the most important threats to the sustainable growth of bioenergy trees in plantations.


Cytospora canker

Inoculation of eight 1-year-old seedlings of white poplar and willow Salix acmophylla Boiss proved the pathogenicity of several isolates of C. Any rough or excessive handling of dry or moist seeds at harvest or planting can cause cracked seedcoats and kill seed embryos. Highly susceptible trees, such as Lombardy poplars Figure 1may die within 2 to 5 years after becoming infected. Outbreak prevention depends largely on a better understanding of how pathogens infect trees so that resistance can be developed and on early detection, spread of the disease can be reduced through monitoring and surveillance.

These cookies allow us to see information on user website activities including, but not limited to page views, source and time spent on a website. Frequently, as the canker gradually enlarges, affected stems are girdled and killed. It attacks several hardwoods, notably trees used for bioenergy such as cottonwood, trembling aspen, and willows.

A, Section through a pycnidial stroma showing two chambers and a pore releasing spores conidia from the right chamber; B, section of the pycnidial wall showing conidiophores bearing conidia at their tips; C, six colorless, one-celled conidia. Sanctioned by Sanctioning name Validated by Type specimen or ex type More specimens Human pathogenicity code Plant pathogenicity code Code toxicity.

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This disease is rarely a problem of economic importance in natural stands, but can cause serious damage in forest nurseries, young plantations, and in horticultural settings. Pairwise sequence alignments Polyphasic identifications.

Cytospora chrysosperma Cytosspora v1.