bluuebunny/crossref_metadata_2025 huggingface dataset:
Short term effects of simulated acid mist on gas exchange of Eucalyptus globulus1
Authors: Valentini R. , Scarascia‐Mugnozza G. , De P. , Angelis  , Monaco R.
Published: June 2007

The effects of simulated acid mist treatment on net photosynthesis were determined on Eucalyptus globulus trees. Net assimilation decreased for all the three levels but after 3—4 days recovered only in the pH 3.5 one. Acidity effects are discussed in terms of morphological change to the leaves and as alteration of stomatal and mesophyll resistances. 1 Research work supported by C.N.R., Italy. Special grant I.P.R.A. sub‐project 1. paper N. 2014
Isolierung eines Potyviruses aus erkrankter Fichte im Bayerischen Wald
Authors: Ebrahim‐Nesbat F. , Heitefuss R.
Published: June 2007

Isolation of a Potyvirus from Norway Spruce in the Bavarian Forest. A flexuous filamentous virus was isolated from leaves of Nicotiana tabacum cv. Xanthi inoculated with Norway spruce sap from the Bavarian forest. The normal virus particle length was 800 nm and the diameter about 10–12 nm. According to cytological and immunoelectronmicroscopical studies and aphid transmission trials the virus particles belong to the potyvirus group.
Saprophytic growth of Heterobasidion annosum on silver‐fir logs interred in different types of forest soils1
Authors: Capretti P. , Mugnai L.
Published: June 2007

Heterobasidion annosumshows a greater colonization ability in wood interred in pastureland soil than in forest (beech and silver fir stand) soils. Its behaviour is studied in relation to wood colonization by other fungi present in the different soils.
The relative susceptibility of scots and lodgepole pine to western gall rust
Authors: van der Kamp B. J.
Published: June 2007

Scots pine was much less susceptible (percent of seedlings infected) to western gall rust from the coast of British Columbia than lodgepole pine. There was no difference in the virulence spectrum of rust collections from Scots and lodgepole pine. Scots pine could be readily divided into susceptible (heavily infected) and resistant (disease free) seedlings; infection on lodgepole pine varied in a continuous and unimodal fashion.
On the pigment content of Norway spruce needles infected with Chrysomyxa rhododendri, and the carotenoids of the fungus aeciospores
Authors: Pfeifhofer H. W.
Published: June 2007

Pigment patterns of Chrysomyxa rbododendri infected Norway spruce needles and carotene composition of Chrysomyxa rhododendri aeciospores were studied. In general, pigment content in rust infected spruce needles is diminished. Aeciospores of Chrysomyxa wododendri contain β‐ and γ‐carotene.
Virus contamination of soils in forest ecosystems of the Federal Republic of Germany
Authors: Büttner C. , Nienhaus E.
Published: June 2007

Investigations on virus contamination of soils in forests located in three federal states of West‐Germany have indicated that plant viruses are widely spread. From about one third of 284 samples mechanically transmissible viruses belonging to the potex‐, tobamo‐, tobacco necrosis‐ and potyvirus group were isolated by bait‐plant technique.
Intensity of dieback induced by Sphaeropsis sapinea in relation to site conditions
Authors: Zwolinski J. B. , Swart W. J. , Wingfield M. J.
Published: June 2007

Following a hail storm in the southern Cape Province of South Africa, Sphaeropsis sapinea infected about 2000 ha of pine plantations. A series of sample plots yielded information on symptom development in relation to site factors and stand characteristics. Aerial photography and ground inspection of the area showed that, although the intensity of disease was not affected by site quality or age, it was inversely proportional to altitude.
Thermal infrared detection of cavities in trees
Authors: Catena G. , Palla L. , Catalano M.
Published: June 2007

The authors present a Remote Sensing System for detecting internal cavities in trees, using a thermal infrared apparatus which combines the benefit of instant data with the additional advantages of not requiring scaffolding or crews and (above all) of not entailing any injury or damage to the tree.
An intersterility group of Heterobasidion annosum specialized to Abies alba
Authors: Capretti P. , Korhonen K. , Mugnai L. , Romagnoli C.
Published: June 2007

A third intersterility group of H. annosum in Europe has been identified from Italy. It is specialized to Abies alba., and hence is called the F (fir) group. It is closely related to the European S group, but is sexually incompatible with the geographically adjacent S population occurring in the Alps.
Inland spruce cone rust of black spruce: Effect on cone and seed yield, and seed quality
Authors: Singh Pritam , Carew G. C.
Published: June 2007

This paper is a follow‐up of an earlier article on inland spruce cone rust published by the author in 1981. It discusses the impact of the disease on cone and seed production, and seed quality, including seed viability. The cone and seed production and seed viability were reduced to a lesser or greater degree depending on the severity of infection; in severely infected cones practically no seeds were produced.
Sources of inoculum of Lophodermium seditiosum on Pinus sylvestris1
Authors: Diwani S. A. , Millar C. S.
Published: June 2007

A survey of the incidence of Lophodermium seditiosum, L. pinastri and L. conigenum in plantations of Pinus sylvestris in north‐east Scotland showed that L. seditiosum predominated on fallen cones and on young needles which tell prematurely in early summer. L. pinastri predominated on old senescent needles which fell in autumn. The incidence of L. conigenum was low on fallen cones and needles and it is not thought that tins species could effectively replace L. seditiosum. It is concluded that the main source of L. seditiosum inoculum for infections in plantations and nearby nurseries is young infected fallen needles on which ascocarps form in late summer and autumn.
Growth of Heterobasidion annosum through bark of Picea abies
Authors: Lindberg M. , Johansson M.
Published: June 2007

Although the suberized rhytidome and phellem of Norway spruce bark appeared to be the strongest barriers against penetration by Heterobasidion annosum, artificial inoculations on standing trees showed that the living phelloderm and phloem bark were also able to contain the fungus. Thickened cell walls and excretions in the lumen of necrotic cells, as well as morphological changes in the infecting hyphae, indicated that this protection is of both mechanical and chemical character. Rate of wound pcriderm formation was correlated to bark thickness and tree age.
An overview of root dieback and its causes in Swedish forest nurseries
Authors: Beyer‐Ericson Liselotte , Damm Eva , Unestam Torgny
Published: June 2007

The authors present an overview of fungal pathogens attacking roots of containerized conifer seedlings in Swedish nurseries. Special emphasis is put on the rhizospheric fungus Cylindrocarpon destructcms and its biology. The predisposing effect of stress is discussed, as well as the protective effect from soil microflora and mycorrhiza. Practical advice is given.
Infection strategy of Hymenochaete tabacina
Authors: Stenlid J. , Holmer Lillian
Published: June 2007

The infection courts of Hymenochaete tabacina (Sow. ex Fr.) Lév. were studied in stands of Corylus avellana and on stems of Sorbus aucuparia and Syringa vulgaris. The fungus was able to spread through tight contacts between stems that were bound together by fungal tissue. H. tabacina could spread from a dead to a living stem within and between different stools of hazel and from one tree species to another.
Hypoxylon mammatum and its toxins‐recent advances in understanding their relationships with canker disease of poplar
Authors: Pinon J. , Manion P.D.
Published: June 2007

Present knowledge relative to Hypoxylon mammatum toxins is reviewed: bioassays methods for toxin detection, in vitro secretion, urification and identification and the relationships between toxins, pathogenicity and host resistance, assessed.
Variation in foliage resin composition within the Italian cypress (Cupressus sempervirens L.) species complex and its relation to canker diseases1
Authors: Schiller G. , Madar Z.
Published: June 2007

The foliage resin composition of Cupressus sempervirens var. pyramidalis showed significant differences between healthy trees and trees infested with Diplodia pinea f. sp. cupressi and/or Seiridium cardinale. However, no relationship was found between the resin composition and the specific pathogen.
Laboratory evaluation of the efficacy of antiblue and biocide in the control of sapstain and mould fungi on Pinus elliottii
Authors: Masuka A.
Published: June 2007

Results of a test on the effects of Antiblue and Biocide at various concentrations and times of immersion on the growth sapstain and mould fungi are presented. Antiblue (active ingredient, sodium pentachlorophenate) was the better chemical providing complete control at the lowest concentration of 1.5%. Biocide, a chlorinated derivative and local substitute for Antiblue, pro‐vided 55% control at 4 and 8% concentrations and 74% control at the highest concentration of 12%. The time of immersion did not have a significant effect on the incidence of stain and mould.
Vegetative compatibility and conversion to hypovirulence among isolates of Cryphonectria parasitica from northern Italy
Authors: Garbelotto M. , Frigimelica G. , Mutto‐Accordi S.
Published: June 2007

Isolates of Cryphonectria parasitica from chestnut trees in forest stands and commercial orchards were tested for virulence, distribution in vegetative compatibility (v‐c) groups, and capacity of being converted to hypovirulence through acquisition of double‐stranded RNA determinants from five hypovirulent isolates. Even though 77% of the virulent isolates were converted to hypovirulence, the low retrieval of hypovirulent isolates and the relatively high v‐c diversity in our study area warrant further investigation.
Intersterility groups of Heterobasidion annosum in some spruce and pine stands in Byelorussia, Lithuania and Estonia
Authors: Korhonen K. , Bobko I. , Hanso S. , Piri T. , Vasiliauskas A.
Published: June 2007

Heterobasidion annosum isolates were collected from spruce, pine and mixed stands growing on forest and former agricultural soils. Intersterility groups of the isolates were identified. Pine was attacked by the P group only and spruce mostly by the S group. Frequency of the P group on spruce was higher on old forest soils and in mixed spruce and pine stands. Based on its in vitro compatibility with the F group, the S population in Byelorussia and Lithuania is more closely related to the Finnish S population than to the Alpine S population of H. annosum.
The effect of site preparation and fertilization on the severity of Phaeoseptoria eucalypti on Eucalyptus species
Authors: Nichol Nicola S. , Wingfield M. J. , Swart W. J.
Published: June 2007

The effect of site preparation and fertilization on the susceptibility of Eucalyptus species to Phaeoseptoria eucalypti was examined. There was no significant difference in disease rating between plough and terrace treatments which consistently yielded trees that attained greater heights and possessed a denser foliage. These trees were also less susceptible to P. eucalypti than those associated with other forms of site preparation. Trace element application reduced the incidence of disease as did the application of 50 % fertilizer at planting and 50 % when trees were 6 months old as opposed to the second half being applied when trees were 3 months old.
Identification and partial characterization of an extracellular manganese‐dependent peroxidase in Armillaria ostoyae and Armillaria mellea
Authors: Robene‐Soustrade I. , Lung‐Escarmant B. , Bono J. J. , Taris B.
Published: June 2007

Laccase and manganese‐dependent peroxidase (Mn peroxidase) activities were detected in the culture media of Armillaria ostoyae and A. mellea. Mn peroxidase was produced in significantly higher quantity by the A. ostoyae isolates and was purified by chromatography from one isolate of this species. Some properties of the purified enzyme were examined (absorption spectrum, H2O2 and MnSO4 optimal concentrations, pH optimum and lactate stimulation). Enzymes of potential importance in the lignin degradation (especially Mn peroxidase) by Armillaria sp. are compared to those of other root‐rotting fungi. The possible role of Mn peroxidase in modulating the pathogenicity of Armillaria sp. is discussed.
Effect of endophytic fungi from oak (Quercus robur L.) on mortality of leaf inhabiting gall insects
Authors: Butin H.
Published: June 2007

Observations in the field suggest that certain species of endophytic fungi which occur, but are normally dormant, in the leaves ofQuercus roburcan be stimulated to pathogenic development by the feeding activity of certain gall insects. As a result of the death of leaf tissue the gall is also killed. This antagonistic relationship between endophytic fungi and gall insects is illustrated in the following three examples:Kabatiella apocrypta / Trioza remota, Gloeosporium quercinum / Neuroterus numismalisandDichomera saubinetii / Polystepha panteli.
Field evidence for the large pine weevil, Hylobius abietis as a vector of Heterobasidion annosum
Authors: Kadlec Z. , Starý P. , Zumr V.
Published: June 2007

Mycological analysis of the excrements of adult weevils (Hylobius abietis L.), trapped in the baited pitfall traps in South Bohemia, Czechosovakia, demonstrated the presence of viable spores which suggest a positive role of the weevils as vectors of H. annosum.
Gremmeniella abietina, Phacidium infestans, and other causes of damage in alpine, young pine plantations in Norway
Authors: Roll‐Hansen F. , Roll‐Hansen Helga , Skroppa T.
Published: June 2007

Field studies of damage and mortality were carried out through 16 years in six young plantations, mostly of Pinus contorta, but also P. sylvestris and P. sibirica. Differences between pine species, P. contorta provenances, sites, and soil treatments are reported and discussed, as are influences of environment, climatic conditions, snow cover, and nutrient deficiency. Gremmeniella abietina was by far the most important cause of mortality; there were great differences between the sites as to development and seriousness. Other important causes of mortality and damage were Phacidium infestans, elk (Alces alces L.), voles, and snow pressure.
Resistance of Picea abies seedlings to infection by Heterobasidion annosum in relation to drought stress
Authors: Lindberg M. , Johansson M.
Published: June 2007

Norway spruce (Picea abies) seedlings, 2–4 years old, were subjected to different degrees of stress. Drought stress affected the predisposition to infection by Heterobasidion annosum in the same way in root wood, stem wood and stem bark. At high water potentials (−3 to −5 bar) resistance was high, at intermediate levels (‐ 5 to ‐ 15 bar) it was low but increased again at water potentials below ‐ 8 to ‐ 15 bar. Neither light nor oxygen deficiencies appeared to have adverse effects on resistance. Total length of unsuberized roots was a sensitive indication of strain on the seedlings.
Fungal succession in sapwood of Norway spruce infested by the bark beetle Ips typographus
Authors: Solheim H.
Published: June 2007

Fungal invasion of Norway spruce sapwood was investigated during a period of 130 weeks fol‐lowing attack by the spruce bark beetle Ips typographus. Heavy beetle attack tended to overwhelm the trees quickly and no secondary resinosis was produced. Nonetheless, fungal penetration in the sapwood was initiated only slowly, although it accelerated during the fourth week after attack. Typically the leading edge of fungal penetration was a few millimeters in advance of the visible blue‐stain during the sapwood colonization. Fungi invaded the sapwood in a successional pattern with the most pathogenic species Ophiostoma polonicum first, followed by other beetle‐transmitted Ophiostoma and Graphium species. The later succession was probably influenced by sapwood moisture. Strong decaying white‐rotters invaded near the base of the trees, where sapwood moisture remained favourable, while cf. Trichoderma viride dominated in the drier parts or the trees.
The susceptibility of Scots pine seedlings to Gremmeniella abietina: effect of growth phase, cold and drought stress
Authors: Petäistö Raija‐Liisa , Kurkela T.
Published: June 2007

The effect of the growth phase of pine seedlings on the success of Gremmeniella infection was studied in both simulated and natural growing seasons. Also the effect of cold and drought stress on the success of the infection was studied.
Detection of the endophyte Discula umbrinella in buds and twigs of Fagus sylvatica
Authors: Toti L. , Viret O. , Horat Gisela , Petrini O.
Published: June 2007

Endophytic fungi have been isolated from buds and twigs of beech trees collected at four different sites in Switzerland. Discula umbrinella. was recovered at high frequencies from the bud scales and the twig pieces contiguous to the buds, but was virtually absent from the rolled up leaves enclosed by the scales. In addition to infection by air‐borne inoculum, thalli of D. umbrinella may grow from the twigs into the leaf tissues.
Requirements and biological aspects of Fusarium eumartii and its possible role in oak decline in North‐eastern Italian oak forests
Authors: Ragazzi A. , Mugnai Laura , Moricca S. , Vagniluca S. , Dellavalle Irene
Published: June 2007

To determine a possible role of Fusarium eumartii in oak decline in different zones of Italy some requirements (temperature, substrates, pH) and some biological aspects (ability to produce phytotoxic metabolites, and pathogenicity) were studied in vitro and by inoculation tests on oak seedlings.
Stimulation of growth, sporulation, and potential staining capability in Ceratocystiopsis falcata
Authors: Kawchuk L.M. , Hutchison L.J. , Reid J.
Published: June 2007

A procedure is described for the rapid extraction from the hyphomycete Gliocladiumroseum of a compound that stimulates growth, perithecial formation, and pigmentation in the mycelium of the wood‐inhabiting ascomycete Ceratocystiopsis falcata.
Factors influencing mansonone induction in elm callus by culture filtrate elicitors of Qphiostoma ulmi
Authors: YangIB D. , Jeng R.S. , Hubbes M.
Published: June 2007

Mansonone F (phytoalexin) production in elm callus induced by elicitors of Ophiostoma ulmi is affLited by cultural and experimental conditions. These factors include different fun gal isolates, fungal culture age, elicitor concentration, the time of elicitor treatment, the callus cu Ytured with or without light and the callus subculturing frequency.
Variation in Heterobasidion annosum detected by Random Amplified Polymorphic DNAs
Authors: Fabritius Anna‐Liisa , Karjalainen R.
Published: June 2007

The production of Random Amplified Polymorphic DNAs (RAPDs) by Polymerase Chain Reaction (PCR) was used to detect variation in the isolates of Heterobasidion annosum with various geographical origins. Specific RAPD products were detected for each of the intersterility groups: the European S, F, P and the North American S group. There was considerably more polymorphism found among European S than P isolates. The analysis of RAPDs was shown to be a simple and a fast way to generate DNA markers specific to the previously established intersterility groups and thus useful for diagnostic purposes.
The effect of wood moisture on infection of Sitka spruce stumps by basidiospores of Heterobasidion annosum
Authors: Redfern D. B.
Published: June 2007

In an inoculation experiment to test the effect of wood moisture content on infection of Sitka spruce (Picea sitchensis) stumps by basidiospores of Heterobasidion annosum, exposure to high rainfall increased infection in the heartwood and reduced sapwood infection compared to covered stumps. This was associated with a greater moisture content in both wood types. Within‐treatment variation in the amount of infection was high and it is suggested that endogenous factors in stumps may have a greater influence on infection than the environment or the availability of spores.
Dieback of poplar and willow caused by Pseudomonas syringae in combination with freezing stress
Authors: Ramstedt M. , ÅRström B. , von Fircks H. A.
Published: June 2007

Dieback of poplar and willow, grown in short‐rotation forestry plantations, was shown to be a result of Pseudomonas syringae infections in combination with freezing stress. Bacteria isolated from damaged poplar and willow trees at several sites in Sweden, identified as P. syringae, showed ice nucleationactive (INA) properties in laboratory tests. To confirm the effect of bacterial infection, five different P. syringae isolates were reinoculatcd into stems of Salix viminalis, S. dasyclados and Populus spp. in the greenhouse before application of sub‐zero temperature stress. Subsequent dieback of the shoots was observed. It is concluded that P. syringae is a Potentiall severe pathogen of willow and poplar.
A rapid method for screening potential biological control agents of wood decay
Authors: Schoeman M. , Webber J. , Dickinson D.
Published: June 2007

Sixteen isolates of microfungi, obtained from freshly felled pine, were screened for inhibitory activity on a number of wood‐decay basidiomycetes. The screening procedure employed a bi‐layer test which involved growing the potential biocontrol isolates on either agar medium or irradiated pine discs. The influence that the two different substrata had on subsequent inhibition of decay fungi may have important implications for the screening of isolates for biocontrol activity. The use of such techniques for screening biocontrol agents is discussed.
Susceptibility of Eucalyptus grandis provenances to a root rot associated with Ganoderma sculptrutum in Zimbabwe
Authors: Masuka A. J. , Nyoka B. I.
Published: June 2007

Widespread cankering, gummosis, wilting and death of Eucalyptus grandis were first observed in Zimbabwe in 1956. Recent investigations have revealed the symptoms and deaths to be associated with infection by Ganoderma sculptrutum. Indigenous tree species, in particular Brachystegia spiciformis and Julbernardia globiflora, provide inoculum source for the fungus.

A total of 170 half‐sib families in 23 provenances were assessed for symptoms and death associated with G. sculptrutum infection. There were statistically significant differences (p ≤ 0.001) in observed symptoms among families in a provenance. Provenance differences were not significant (p > 0.05). There were significant differences among provenances (p ≤ 0.05) and families (p ≤ 0.001) for death associated with G. sculptrutum. Differences among the four blocks were significant for both symptoms (p ≤ 0.01) and death (P ≤ 0.001). Family heritability estimates ranged from 0.00 (±0.82) to 0.79 (±0.13) for symptoms and from 0.00 bb (±0.82) to 0.75 (±0.14) for death.
Mycoflora associated with slash‐pine seeds from cones collected at seed orchards and cone‐processing facilities in the south‐eastern USA1
Authors: Fraedrich S. W. , Miller T.
Published: June 2007

A diverse mycoflora was associated with slash‐pine seeds from cones obtained at seed orchards and cone‐processing facilities in the southeastern USA. Potentially pathogenic fungi, including Lasiodiplodia tbeobromae, Sphaeropsis sapinea, and Fusarium spp., were isolated from seeds of cones obtained at all locations. Fusarium proliferatum and F. semitectum were the Fusarium spp. most often associated with seeds; F. subglutinans was rarely isolated. Many other species of fungi were associated with seeds from all locations. Incidence of fungus‐damaged seeds ranged from 2 to 11% among collection sites. Disease incidence was found to increase during cone storage. Types of fungi and the incidence of fungus‐damaged seeds were similar for damaged/discoloured cones and apparently healthy cones. The potential for slash‐pine seeds to become colonized by pathogenic fungi, such as S. sapinea and the various Fusarium spp., could have important implications for the establishment of these fungi in forest‐tree nurseries, as well as their introduction into foreign countries.
Comparison of Gremmeniella abietina isolates from Pinus sylvestris and Pinus contorta in terms of conidial morphology and host colonization
Authors: Hellgren M.
Published: June 2007

Gremmeniella abietina isolates from Pinus contorta in northern Sweden produced, in vitro, shorter conidia with fewer septa compared with isolates from Pinus sylvestris in the southern part of the country. After mycelial inoculation of shoots with G. abietina isolates from both host species, the resulting necroses were longer in P. sylvestris than in P. contorta. Keeping seedlings in artificial mild winter climate or detaching shoots from the seedling before inoculation caused longer necroses. No host specificity in colonization was found. Isolates from P. sylvestris caused longer necroses than did isolates from P. contorta, and both types of isolates caused longer necroses in P. sylvestris than in P. contorta. The differences found between the two G. abietina populations probably reflect regional variation in the fungus.
The ecology of fungal cankers on Cupressus macrocarpa in southern England
Authors: Sánchez M. E. , Gibbs J. N.
Published: June 2007

Bark isolations from cankers on Cupressus macrocarpa in southern England yielded Seiridium cardinale, Pestalotiopsis funerea and Pestalotiopsis monochaetioides. The recovery pattern of the three fungi indicated that only S. cardinale was a primary pathogen; the two Pestalotiopsis species being secondary. Pathogenicity data obtained following the inoculation of C. macrocarpa branches with mycelium of the three fungi confirmed this view.

No evidence of vegetative incompatibility was found in S. cardinale, but five vegetative‐compatibility (vc) groups were found in P. funerea and six in P. monochaetioides. Different vc groups of the two Pestalatiopsis species were often found in the same S. cardinale lesion, suggesting that a number of separate colonization events were involved. It is possible that this sometimes leads to complete replacement of the pathogen.
First report of Mycosphaerella dearnessii in Switzerland
Authors: Holdenrieder O. , Sieber T. N.
Published: June 2007

Brown‐spot needle blight caused by Mycosphaerella dearnessii [syn. Scirrbia acicola; anamorphic state: Lecanosticta acicola (syn. Septoria acicola)] was observed for the first time in Switzerland. So far, the disease seems to be confined to planted Pinus mugo and Pinus uncinata near Zurich. Pinus sylvestris adjacent to diseased P. uncinata did not show any disease symptoms.
Fungi colonizing Scots‐pine cone scales and seeds and their pathogenicity
Authors: Lilja A. , Hallaksela A. M. , Heinonen R.
Published: June 2007

Fungi were isolated from the cone scales and seeds of Scots pine using plating on malt‐extract agar and/or the standard blotter method in a Jacobsen's apparatus.

Alternaria alternata, Epicoccum purpurascens and Ulocladium atrum were isolated from damping‐off seedlings germinating on agar or filter paper, but, in pathogenicity tests with peat‐sand (1:3) growth substrate, they were not pathogenic. All the Fusarium species isolated were pathogenic in growth substrate. Some F. avenaceum colonies formed no aerial hyphae and they proved to be a mixed culture of the fungus, a fluorescent Pseudomonas sp., and a gram‐negative bacterium. The bacterial associates appeared to increase the pathogenicity of F. avenaceum. All the micro‐organisms tested were more pathogenic in sterilized than in unsterilized peat‐sand substrate.
Sugar‐beet chitinase inhibits the growth of a spruce pathogen
Authors: Susi A. , Mikkelsen J. D. , von Weissenberg K. , Nielsen K. K.
Published: June 2007

The inhibiting effect of sugar‐beet chitinase, a defence enzyme in plants, on the growth of the fungi Heterobasidion annosum and Gremmeniella abietina was examined. The enzyme inhibited the growth of H. annosum, but had no effect on G. abietina. The role of hydrolytic enzymes in defence is briefly discussed.
Changes in the level of phenols during needle development in Scots‐pine populations in a control and polluted environment
Authors: Kareolewki P. , Giertych M. J.
Published: June 2007

Changes in the level of phenolic compounds in needles of young Scots‐pine (Pinus sylvestris trees of various provenances were studied in an environment polluted by sulphur dioxide and fluorine compounds, and in a control environment. An increase in the content of ortho‐diphenols (o‐dPh) and total phenols (TPh) was found in the First year of needle development. This increase was significantly greater in the plants from the polluted environment. Relative to levels in the control environment, the highest level of phenols in the polluted environment was found in 2‐year‐old needles, followed by 3‐year‐old and then 1‐year‐old needles.
Evaluation of superficial canker instability for hypovirulent Cryphonectria parasitica inoculated on American chestnut trees
Authors: Griffin G. J. , Griffin S. L.
Published: June 2007

Hypovirulent strains of Cryphonectria parasitica produced superficial cankers on American chestnut (Castanea dentata) that were unstable for superficiality after one winter. Some unstable cankers yielded C. parasitica isolates that had high virulence on American chestnut trees and were vegetatively incompatible with the original inoculated hypovirulent strain, whereas other unstable cankers yielded isolates that had low virulence and were vegetatively compatible with the original hypovirulent strain.
Influence of the Phytophthora isolate and the seed source on the development of beech (Fagus sylvatica) seedling blight
Authors: Werres S.
Published: June 2007

Phytophthora cactorum, the causal agent of beech seedling blight, can kill Fagus sylvatica seedlings within a few days. Eight isolates of Phytophtbora cactorum and one isolate of Phytophtbora citricola were tested for their pathogenicity towards beech seedlings derived from eight different registered stands. The P. citricola isolate proved to be more aggressive than all the P. cactorum isolates, although there were significant differences among the latter. The influence of the seed source was less sever than that of the fungi. Regions of provenance generally had less influence on disease development than fungal isolate but differences in susceptibility among sources were important in the interaction between isolate and source.
Distribution of clones of Phellinus noxius in a windbreak on Ishigaki Island
Authors: Hattori T. , Abe Y. , Usugi T.
Published: June 2007

The distribution of clones of Phellinus noxius, the causal agent of brown root rot, was studied in a windbreak on Ishigaki Island of Japan. In total, 99 isolates obtained from infected trees of Calopbyllum inophyllum, Casuarina equisetifolia and Bauhinia racemosa were analysed by means of a somatic compatibility test on a sawdust‐rice‐bran medium, an antagonism test on PDA with guaiacol solution, and by esterase analysis with isoelectric focusing. Results obtained from the three methods were almost identical, although the somatic compatibility test was less precise than the other methods. Isolates from neighbouring infected trees belonged to the same clone in many cases. On plots of 150–400 m2, 1–5 clones were found. Single clones covered an area of up to 20 × 20 m. A total or 25 different clones were recognized within the sample sites. This suggested that multiple basidiospore infection existed in the site, although infection centres spread by vegetative growth across root contacts of neighbouring trees.
Fast methods for DNA extraction for PCR analyses from Heterobasidion annosum mycelium and Endocronartium pini aeciospores
Authors: Pappinen A. , Kasanen R. , Möykkynen T. , von Weissenberg K.
Published: June 2007

The extraction of DNA from mycelium of Heterobasidion annosum or aeciospores of Endocronartium pini could be done rapidly by homogenizing the fungal material in PCR‐compatible buffer in Eppendorf tubes with a disposable pestle mounted on an electric drill. The DNA yield with this method was relatively low but sufficient for PCR analysis with ITS‐specific primers. For large series of fungal samples this protocol provides a quick and cheap method of determining the intersterility groups of H. annosum or for specific primer studies on E. pini populations. The time needed for DNA isolation from E. pini aeciospores and H. annosum mycelium could be reduced by nearly 85% compared to the mortar‐and‐pestle protocol.

By using a disposable pestle mounted on an electric drill and phenol‐chloroform as extraction solution, the yield of DNA was higher than with the mortar‐and‐pestle method with phenol‐chloroform as extraction solution. The quality of DNA was sufficient for both specific‐primer and RAPD analyses, but the more complicated extraction method with phenol was needed.
Changes in phenolic metabolites of Scots‐pine phloem induced by Ophiostoma brunneo‐ciliatum, a bark‐beetle‐associated fungus
Authors: Lieutier F. , Sauvard D. , Brignolas F. , Picron V. , Yart A. , Bastien C. , Jay‐Allemand C.
Published: June 2007

Changes in soluble phenol contents of Scots‐pine (Pinus sylvestris) phloem were studied after inoculation with Ophiostoma brunneo‐ciliatum, a fungus associated with Ips sexdentatus. They were compared to the length of the fungus‐induced reaction zone of the phloem, taken as an estimation for the trees' response efficiency against aggression.

Five clones consisting of 14 trees were studied, and eight soluble phenolic metabolites were analysed in detail in reaction zones and in unwounded phloem sampled 3 weeks after inoculation.

The stilbenes pinosylvin and pinosylvin monomethylether, and the flavonoid pinocembrin, were detected in reaction zones only. Concentrations of two p‐coumaric‐acid esters and an acetophenone glycoside decreased after inoculation. Variations of the flavonoids taxifolin and 3' taxifolin glucoside were inconsistent.

One tree had longer reaction zones and a phenolic content different from the others. In unwounded phloem, concentrations of some phenolic compounds and in particular the ratio between the two p‐coumaric‐acid esters could be markers for trees' response efficiency. In the reaction zone, markers could be the ratios between concentrations of certain preformed compounds and concentrations of newly synthesized pinosylvin and pinocembrin.
Random amplified microsatellites (RAMS) — a novel method for characterizing genetic variation within fungi
Authors: Hantula J. , Dusabenyagasani M. , Hamelin R. C.
Published: June 2007

A novel method, Random Amplified Microsatellites (RAMS, due to the nature of amplified markers as two randomly amplified microsatellites with the intervening sequence), was applied to generate DNA markers in a variety of fungi (Armillaria cepistipes, Gremmeniella abietina, Heterobasidion annosum, Pbytophthora cactorum, Phlebiopsis gigantea, and Stereum sanguinolentum). It is based on the polymerase chain reaction (PCR), and uses primers containing microsatellite sequences and degenerate anchors at the 5' end. The method is highly reproducible, applicable to all tested fungal species including members of the Phycomycetes, Ascomycetes and Basidiomycetes, and allows detection of interspecific and intraspecific DNA‐polymorphisms.
F group of Heterobasidion annosum found in Poland
Authors: Lakomy P.
Published: June 2007

The F intersterility group of Heterobasidion annosum, specialized to Abies species and earlier reported from southern parts of Europe, was identified from Abies alba and Picea abies in the Carpathian Mountains in southern Poland, close to northern limit of the natural distribution of A. alba. However, the fungus is not common in this area and seems to be primarily a saprophyte, growing on stumps and dead trees.
Structure‐activity relationships of some congeners of 4‐phenyl‐3‐butenoic acid against aspen decay and stain fungi
Authors: Trifonov L. S. , Ayer W. A. , Chakravarty P. , Hiratsuka Y.
Published: June 2007

Phellinus tremulae is the most important decay fungus on Populus tremuloides. In forest industries using aspen wood chips, two blue‐stain fungi Ophiostoma crassivaginatum and Ophiostoma piliferum cause considerable reduction in the value of the end product. Thirty‐eight homologues and analogues of 4‐phenyl‐3‐butenoic acid were studied against P. tremulae, O. crassivaginatum, and O. piliferum. Varied inhibition of the in vitro growth of these fungi was observed at 1–1000 μg/ml. The wood‐chip colonization by P. tremulae was not affected by the six most active compounds at 1 μg/ml, however, at 10 and 100 μg/ml the growth of P. tremulae on wood chips was totally arrested. 4‐Phenyl‐3‐butenoic acid and 4‐phenyl‐3‐butynoic acid prevented blue‐stain development on wood chips at 1 μg/ml.
A trial of disodium octaborate tetrahydrate for the control of Heterobasidion annosum
Authors: Pratt J. E. , Quill K.
Published: June 2007

The extent of heartwood infection of Sitka spruce Picea sitchensis stumps following inoculation with basidiospores of Heterobasidion annosum was significantly reduced by application of 2% and 4% solutions of disodium octaborate tetrahydrate (DOT) immediately after felling. Infection of sapwood was so rare in all treatments, including controls, that the effectiveness of DOT in this tissue could not be judged. The results of this trial suggest that DOT may be toxic to H. annosum at lower levels of borate loading than previously thought possible. Over the 10 months of the experiment the borate loading in the stumps appeared to reach an equilibrium that was independent of the initial concentration applied. Stump‐surface fruiting of Melanotus proteus, a potential fungal competitor of H. annosum, was not inhibited by these treatments.
Growth and ultrastructural modifications to chestnut calli induced by culture filtrates of virulent and hypovirulent Cryphonectria parasitica strains
Authors: Piagnani C. , Faoro F. , Sant S. , Vercesi A.
Published: June 2007

Callus cultures of two susceptible Castanea sativa cultivars, ‘Garrone rosso’ and ‘Clone 71’ were grown on culture medium supplemented to 50% with culture filtrates (CFs) from E4 virulent (E4‐V) or E13 hypovirulent (E13‐H) Cryphonectria parasitica strain, respectively. E13‐H CFs caused a reduction in fresh weight and an increase in dry weight on calli of both genotypes. E4‐V CFs did not induce any modification of these parameters compared with the control, but fresh weight of ‘Clone 71’ was reduced. Light and electron microscopy observation showed the presence of large osmiophilic aggregates in the vacuoles and, sometimes, the ruptured tonoplast in the E4‐V treated calli. Calli grown on El 3‐H CFs had a meristematic‐like appearance, with small, scarcely vacuolated cells containing altered mitochondria and plasmalemma proliferations.
Interactions between Agrobacterium tumefaciens and coniferous defence compounds α‐pinene and trans‐stilbene
Authors: Aronen T. S.
Published: June 2007

The ability of Agrobacterium species to infect gymnosperms is generally poor, but as a gene transfer vector Agrobacterium would have several advantages. This study characterizes interactions between coniferous defence compounds, a monoterpene α‐pinene and a phenolic constituent trans‐stilbene, and Agrobacterium tumefaciens. Of the chemical constituents studied, α‐pinene in doses equal to the concentrations found in wounded trees prevented the growth of A. tumefaciens. Neither α‐pinene nor trans‐stilbene inhibited virulence gene induction in A. tumefaciens, but both compounds caused a reduction in the frequency of gall formation in susceptible woody model plants (birch seedlings) when applied after the vir‐induction. This effect was smaller with the strain A281(pTVK291) containing extra copies of the virA, virB, virG, and virC genes than with the wild‐type strain A28l. The efficiency of Agrobacterium‐mediated transformation in a model gymnosperm, Scots pine, could not be enhanced by using the strains containing a constitutive mutant of virG gene or extra copies of virA and virG. The results suggest that the inefficiency of Agrobacterium spp. in infecting many conifers is not the result of insufficient vir‐gene induction but rather is the result of interference by chemical defence compounds during the later stages of T‐DNA‐transformation.
Phytopbthora cactorum on walnut seedlings in Italian nurseries
Authors: Belisario A. , Caciola S. O. , Magnano Disan Lio G.
Published: June 2007

Phytophthora cactorum was consistently isolated from basal stem tissues of walnut seedlings affected by collar and root rot. The isolates were identified on the basis of morphological and cultural characteristics and of electrophoretic patterns in polyacrylamide slab gels of total native mycelial proteins and isozymes (arylesterase, malate dehydrogenase, acid and alkaline phosphatase). The electrophoretic phenotypes of walnut isolates were identical or very similar to those of P. cactorum isolates from different hosts (apple, loquat, pineapple‐guava and strawberry). In pathogenicity tests, P. cactorum isolates from walnut proved to be highly pathogenic for seedlings of English walnut (Juglans regia) and moderately pathogenic for seedlings of eastern black walnut (Juglans nigra); moreover, they did not rot apple seedlings, suggesting host‐specificity. Poor soil drainage and excessive irrigation can be considered as predisposing factors to collar and root rot incited by P. cactorum.
Leaf necrosis and sucker and twig dieback of Alnus glutinosa incited by Pseudomonas syringae pv. syringae.
Authors: Scortichini M.
Published: June 2007

In central Italy, Pseudomonas syringae pv. syringae was isolated from Alnus glutinosa that showed, in spring, leaf necrosis and also sucker and twig dieback. The trees were located near a lake and a stream. Biochemical tests were consistent with those characterizing the pathovar. Pathogenicity tests yielded necrotic lesions on A. glutinosa and Syringa vulgaris leaves and also on lemon and orange fruits. In addition, whole‐cell protein profiles of the isolates and P. s. pv. syringae reference strains were identical. Some isolates showed positive ice‐nucleation activity. This is the first record of this pathogen on black alder.
Characterization of Cryphonectria parasitica strains by random amplified polymorphic DNA (RAPD) technique and conventional methods
Authors: Wronski R. , Kudera U. , Wlhelm E.
Published: June 2007

In recent years damage to Austrian Castanea sativa populations caused by Cryphonectria parasitica has increased. A total of 34 isolates out of 13 observation plots of this phytopathogen in the south‐east of Austria were examined for laccase activity, virulence, number of vegetative compatibility groups and for the existence of hypovirulence associated dsRNA. Furthermore, the applicability of the random amplified polymorphic DNA (RAPD) technique for investigating population structure was tested. Small dsRNA fragments were found in two Austrian strains. The same two strains exhibited reduced virulence. Seven vegetative compatibility groups were found in the areas examined. RAPD analysis proved to be an efficient method for distinguishing between different C. parasitica genotypes.
The effect of acid rain treatments on the susceptibility of Pinus sylvestris to Gremmeniella abietina
Authors: Vuorinen M. , Uotila A.
Published: June 2007

Scots pine (Pinus sylvestris) seedlings were planted in a nursery bed 20 cm thick. The substrate had been removed from an illuvial horizon in the soil underlying a stand of Scots pine in Finland, which had suffered from severe infection by Gremmeniella abietina. The seedlings were irrigated for 3 years, applying three pH levels (2.5, 3.5, and 4.5) using sulphuric acid, nitric acid, and a 3:1 mixture of sulphuric and nitric acid. The pH of the pure water used in the control treatment was 6.1–6.4. The seedlings were inoculated with the conidiospores of G. abietina to find out their susceptibility to infection with the Scleroderris canker disease.

Because to the adequacy of its buffering capacity, the soil was observed to become more acidic only in the treatments at pH 2.5. The concentrations of extractable Ca and Mg cations decreased while the concentration of Al and Fe increased with soil acidification during the 3‐year experiment. Acidification did not increase the susceptibility of Scots pine to infection by the Scleroderris canker. Seedling growth was at its maximum in the acidification treatments where most nitrogen was added.
Susceptibility of different provenances ofPinus sylvestris, Pinus ContortaandPicea abiestoGremmeniella abietina
Authors: Hansson P.
Published: June 2007

In a randomized block factorial experiment, 1200 seedlings from four provenances, each ofPinus sylvestris, Pinus contortaandPicea abieswere inoculated with conidia (2 × 104and 1 × 106conidia/seedling) ofGremmeniella abietina (Brunchorstia pinea), isolated fromP. contortaplantations in northern Sweden. A further 600 seedlings were left as controls. The occurrence of symptoms and the extension of dead tissues on the annual shoots were recorded 13 months after inoculation. Only the higher spore dose resulted in significant infection.P. sylvestrisandP. contortaseedlings were equally susceptible (53% infected), and significantly more infected thanP. abiesseedlings (39%). The annual shoots ofP. sylvestrisandP. abieswere affected to 43% and 37% of their length, which was significantly more than 15% of the length of P.Contortashoots. The frequency of affected seedlings differed between the most southern and northern provenances ofP. sylvestrisandP. abies, and between the northwestern and the south‐eastern provenance of P.contortaTwenty‐six months after inoculation, a higher proportion ofP. contortaseedlings thanP. sylvestrisandP. abiesseedlings had recovered, and a lower proportion ofP. contortathanP. sylvestrisandP. abiesseedlings had died. This paper discusses whyP. sylvestriswas found to be more susceptible toG. abietinathanP. contortain this experiment, while the reverse is found in plantations in northern Sweden.
Tree vigour and the susceptibility of Douglas fir to Armillaria root disease
Authors: Rosso P. , Hansen E.
Published: June 2007

In this study the effects of thinning, fertilization and pruning on the vigour of Douglas fir (Pseudotsuga menziesii) and its susceptibility to Armillaria root disease were explored. Tree vigour was defined as the relative capacity for tree growth, expressed as the above‐ground biomass increment per unit of photosynthetic tissue, or growth efficiency (GE). It has been hypothesized that trees with higher GE can better resist pathogen attack, and that GE can be used as a predictor of tree susceptibility to disease. In a previous study, four Douglas fir plantations were thinned, fertilized and pruned in all combinations, and the effects of these treatments on tree vigour were measured after 10 years. Root disease was not a factor in the initial study design, and mortality was ignored until 8 years after the treatments were applied. The results of an earlier study were utilized and the correlation between Armillaria root disease incidence and the effects of earlier stand treatments on tree growth was tested. Armillaria ostoyae was the primary mortality agent in the study area. Disease incidence on infested subplots ranged from 2 to 20%. Armillaria ostoyae incidence was the highest at medium tree density (6.1%), slightly lower on the low density (5.6%), and lowest on the unthinned plots (3.8%). There were no significant correlations between disease incidence and previous tree growth. The vigour of trees that became symptomatic or died by 1993 was not significantly different in 1983–85 from the vigour of trees that remained asymptomatic. On these sites, in areas of infestation, A. ostoyae is killing the largest, fastest growing trees, as well as less vigorous trees. Armillaria continues to cause mortality, regardless of the growth efficiency or growth rate of the host.