Cypress Canker Disease Research Articles

Cyclopaldic acid, a major phytotoxic metabolite of Seiridium cupressi, the pathogen of a canker disease of cypress

A phytotoxic substance was produced in vitro in a relatively high concentration (c. 40 mg/1) by Seiridium cupressi, a fungus that causes a canker disease of cypress (Cupressus sempervirens) and other Cupressaceae in Greece and in other parts of the world. Structural investigations demonstrated that the substance was identical with cyclopaldic acid, an antibiotic known to be a metabolite of some species of Penicillium, Aspergillus and Pestalotiopsis. Absorbed by severed twigs of three species of Cupressus and by cuttings of two herbaceous non‐host plants (tomato and mung bean), cyclopaldic acid at concentrations of 10‐100 ug/ml induced leaf chlorosis and necrosis. Oat seed germination and root growth of oat seedlings were also reduced to about 50% at 75 and 100 jig/ml, respectively. The compound showed antifungal activity towards species of Botrytis. Fusarium and Geotrichum when assayed at a concentration range from 10 to 100 /ug ml. We believe this to be the first report of cyclopaldic acid as a non‐selective fungal phytotoxin. However, its possible role in the pathogenesis of the cypress canker disease has not been established.

Seiricardine A, A phytotoxic sesquiterpene from three Seiridium species pathogenic for cypress

Isolates of Seiridium cardinale, S. cupressi (a Greek strain) and S. unicorne, three species associated with canker disease of cypress ( Cupressus sempervirens) in the Mediterranean area, were found to produce phytotoxic substances in culture. Besides already known toxins (seiridin, iso-seiridin and seiricuprolide), four structurally related metabolites were found in small amounts in the culture filtrates of the three species. The major metabolise was characterized as a new bicyclic sesquiterpene, which we have called seiricardine A. The structures of the metabolite and of some key derivatives were established by spectral studies. When absorbed by severed twigs of cypress, a 0.3 mgml −1 solution of seiricardine A produced leaf yellowing and browning. Subperidermal injection of a 0.1 mg ml t1̄ solution into young cypress trees caused necrotic lesions on the stem and a diffuse yellowing of adjacent twigs. In the agar diffusion assay, seiricardine A at concentration of 100 μg ml −1 showed a fungistatic ettect on three test fungi.

Seiricuprolide, a new phytotoxic macrolide from a strain of Seiridium cupressi infecting cypress

A strain of Seiridium cupressi, a fungus causing a canker disease of cypress ( Cupressus sempervirens) in Greece, produces several phytotoxins in culture. Two of them were identified as seiridin and iso-seiridin, the butenolides previously isolated from another cypress pathogen, S. cardinale. A third phytotoxin, which is present in small amounts in the culture filtrates of S. cupressi and is not produced by S. cardinale, was identified as a new macrolide which we have called seiricuprolide. Its structure was established by spectroscopic analysis of the metabolite and of some key derivatives.

New phytotoxic butenolides produced bySeiridium cardinale, the pathogen of cypress canker disease

Two new butenolides, seiridin andiso-seiridin, were isolated from culture filtrates ofSeiridium cardinale, the pathogen of cypress canker, a destructive disease ofCupressus and relatedConiferae These metabolites were characterized as 3-methyl-4-(2-hydroxyheptyl)-2(5H)-furanone and its 4-(3-hydroxyheptyl) isomer, respectively. Chlorotic, and necrotic symptoms were produced on leaves of either host or non-host test plants by absorption of 0.3 mg/ml solutions of either compound. These also showed antibacterial activity.

The influence of some chemical treatments on cypress canker disease development

AbstractSix fungicides were applied for 32 months prior to inoculating Cupressus sempervirens L. with Seiridium cardinale (Wag.) Sutton and Gibson. Benomyl and Benomyl + Captafol were partly effective in preventing infection but none of the tested fungicides prevented spread of established infections.

A distribution map for Seiridium cardinale causing the cypress canker disease in Greece

AbstractThe first distribution map of Seiridium (Coryneum) cardinale (Wag.) Sutton and Gibson which causes the cypress canker in Greece is given. A recent survey all over the country has shown that S. W. Greece and the Ionian islands are already under heavy attack whereas in central and N. Greece and the island of Krete only restricted spots have been found. Strict sanitation measures are imposed to prevent building up and diffusion of the disease.

Pathogenicity of some isolates of Seiridium (Coryneum) cardinale, agent of cypress canker disease

AbstractRamets of 200 clones of Cupressus sempervirens were inoculated with 6 isolates of Seiridium cardinale. No significant differences were found among isolates, while there were highly significant differences among clones when length and width of canker were assumed as discriminating traits.

Further studies on cypress canker disease in east Africa caused by Monochaetia unicornis (Cookie & Ellis) sacc.

The relationship that exists between height and diameter growth increments of Cupressus lusitanica was found to be stochastic, with an overall correlation coefficient of 0.979 for the entire plantation population. Maxima of up to 8.91 m in height and 12.50 cm in diameter were achieved after a growth period of about 5 years. Incidence of canker infection appeared higher in faster growing progeny classes than in the slower growing ones when individual trees were considered but this trend was not strongly reflected when the results were pooled. The highest recorded canker attack in a single progeny class was about 60% while the lowest was 8%. Peak infection was recorded at a plantation age of about 3 years after which the infection started to decline. Some “Plus Trees” were found to be unacceptable for inclusion in the future genetic improvement programme and there is a case for a second selection pressure on seed orchards already established from siblings of these “Plus Trees”.

Cypress canker disease in Italy: biology, control possibilities and genetic improvement for resistance

AbstractThe life cycle of Seiridium cardinale, the principal symptoms of the cypress canker disease, the results of chemical control, and the research directed toward genetic improvement of Italian cypress for resistance to the canker are described.

The Incidence of Cypress Canker Disease in East Africa

The Incidence of Cypress Canker Disease in East Africa