bluuebunny/crossref_metadata_2025 huggingface dataset:
Observation de sensibilités differentielles de quelques organes de Platanus acerifolia vis‐à‐vis de Ceratocystis fimbriata f. platani
Authors: Vigouroux A. , Rouhani H.
Published: June 2007

Differences in susceptibility against Ceratocystis fimbriata f. platani between organs of Platanus acerifolia.

Artificial inoculations in various organs of young plane‐tree seedlings showed different degrees of susceptibility for different tissues. While herbaceous and slightly lignified parts (leaves, stem top) proved to be relatively resistant, rootlets were very effective sites of infection. The theoretical and epidemiological consequences of these findings are pointed out.
Ultrastructural modifications in Cupressus sempervirens tissues invaded by Seiridium cardinale
Authors: Mutto S. , Panconesi A.
Published: June 2007

Seiridium cardinale, inoculated in the bark of Cupressus sempervirens causes deterioration in the cell walls of parenchyma, parenchyma rays, sieve elements and cambium. The cytoplasm of the cells quickly aegeiierates. The wall of fibers and xylem elements seem not to be affected.
Investigations on epicuticular waxes of differently damaged spruce needles
Authors: Grill D. , Pfeifhofer H. , Halbwachs G. , Waltinger H.
Published: June 2007

Epicuticular waxes of spruce needles were studied with a scanning electron microscope (SEM). Needle samples originated from differently SO2‐polluted areas. The results show that the wax structures of the damaged trees are destroyed. The erosions of the waxes are not exclusively caused by air pollution; the wax structures are influenced also by the vitality of the individual tree.
Infection of Norway spruce by Armillaria under controlled conditions
Authors: Zollfrank U. , Hock B.
Published: June 2007

A method for the infection of Norway spruce by Armillaria under defined conditions is described. The joint culture of seedlings and Armillaria rhizomorphs on a Spbagnum‐Perlite substrate under a controlled light‐dark and temperature regime guaranteed a high yield of infections, which became visible in the root system within 6 months. The localisation of the fungus was achieved by means of immunofluorescent techniques using anti‐Armillaria antibodies raised in rabbits.
The in‐vitro‐mycorrhization of Pinus sylvestris L. and its dependence on the pH‐value
Authors: Metzler B. , Oberwinkler F.
Published: June 2007

Ectomycorrhizae of Pinus sylvestris with Cenococcum geophilum, Amanita muscaria, and Pisolithus tinctorius were synthesized in substrates of different acidity (pH 3‐6). The mycorrhizae which then formed were counted respectively. Morphology and ultrastructure are described and discussed. Meristematic abortion in root tips as an indicator of acidity in the substrate is presented in brief.
Fluctuation of temperature inside poplar stems in relation to air temperature
Authors: Diamandis S.
Published: June 2007

Two Euramerican poplar clones, ‘I‐214’and ‘I‐45/51′, were badly damaged by frost cracks in 1981 and 1985. Thermocouples attached to 12 trees showed that clone ‘I‐45/51’was more resistant to winter and late frosts, possibly due to its significantly thicker and rougher bark in comparison to ‘I‐214′.
Ultrastructure of mesophyll cells of spruce needles exposed to O3 alone and together with SO2
Authors: Sutinen Sirkka
Published: June 2007

Mesophyll cells of spruce [Picea abies (L.) Karst.] needles fumigated for two months with O3 alone and together with SO2 were studied with electron microscope. The observations showed the specific type of injuries for both pollutants, the dependency of severity of injuries both on the concentration of the pollutant and the duration of daily exposure as well as enhanced effects with combined O3 and SO2 in the older needles.
Change in forest structure in the boreal montane ecosystem of Mount Mitchell, North Carolina1
Authors: Bruck R. I. , Robarge W. P.
Published: June 2007

Surveys were undertaken on Mt. Mitchell, N. C. (USA) from Spring 1984 through 1987 to determine the extent and rate of decline and mortality of red spruce and Fraser fir ecosystems. Data indicate that regardless of cause and effect mechanisms the physical structure and integrity of the boreal montane forest has greatly deteriorated over the past 4 years. Along ridges, and particularly on west facing aspects greater than 80% of all mature stands are dead. No definitive conclusions can be made concerning etiological agents; however, current hypotheses include biotic factors, climatic abberations, and/or the acute or chronic stress from anthropogenic pollutants.
Tiarosporella parca (Berk. and Br.) Whitneyerster Nachweis in Österreich
Authors: Cech Von T. , Tomiczek C.
Published: June 2007

Tiarosporella parca (Berk. et Br.) Whitney—first record for Austria. In a diseased mixed stand of Norway spruce near Salzburg city Tiarosporella parca could be recorded the first time for Austria. Connections with the “Yellowing” of spruce needles and frequency of fructifications of the fungus are discussed.
Cercoseptoria needle blight of pines in nurseries: disease spread and control strategies
Authors: Singh Sujan , Khan S. N. , Misra B. M.
Published: June 2007

Studies on the epidemiology of Coroseptoria needle blight of Pinus roxburgbii are presented. Disease spread is related to high rainfall. An integrared approach for control of the disease is given.
Stump infection by Armillaria in first‐rotation conifers
Authors: Rishbeth J.
Published: June 2007

Information about the entry of Armillaria into first‐rotation pine and spruce stands was obtained by searching for infected stumps, rhizomorph systems or trees that had been killed. In pines Armillaria foci were very rare. In pure Norway spruce Armillaria lutea and A. mellea were detected in stumps but rhizomorphs did not extend into the soil; in Norway spruce mixed with oak, by contrast, A. lutea sometimes produced extensive rhizomorph systems. In Sitka spruce small groups of trees had been killed by A. ostoyae. All foci investigated in conifers contained different genotypes of Armillaria and probably originated from spore infection of stumps created by thinning. Some implications of these findings are discussed.
Production d'hydrolases dégradant des polyosides pariétaux par Rigidoporus lignosus, un des agents du pourridié blanc de l'Hévéa
Authors: Lafitte C. , Barthe J.‐P. , Touzé A.
Published: June 2007

Cell wall‐degrading enzymes produced by Rigidoporus lignosus in vitro and in vivo. Secretion of 3 polysaccharide degrading enzymes (cellulase, xylanase, endopolygalacturonase) by R. lignosus, responsible for white root rot of Hevea, was studied in culture and during pathogenesis.
The response of Populus ‘NE 42’ (P. maximowiczii × P. trichocarpa) to infection by Ceratocystis fimbriata isolated from cacao‐tree and plane
Authors: Przybyl Krystyna
Published: June 2007

Shoots of a poplar clone susceptible to a Ceratocystis fimbriata strain from poplar were inoculated with strains of the fungus isolated from cacao‐tree and plane. Disease symptoms and pathological changes in shoots as well as the development of the fungus in tissues are reported.
Ecophysiological reactions of different provenances of European Silver fir (Abies alba Mill.) to SO2 exposure during winter
Authors: Larsen J. B. , Qian X. M. , Scholz F. , Wagner I.
Published: June 2007

Photosynthesis, transpiration and stomatal behavior were studied in different Abies alba provenances during and after SO2 exposure. Differences in SO2 sensitivity and regeneration ability between provenances could be demonstrated.
Studies of Marssonina castagnei in Australasia
Authors: Spiers A. G.
Published: June 2007

Comparative studies of conidium morphology and host range and pathogenicity tests of Australian and New Zealand isolates of Marssonina castagnei in the laboratory established their equivalence which was indicative of a common origin. It is speculated that trans‐Tasman dispersal is responsible for the introduction of M. castagnei into New Zealand and its widespread distribution. This is based on the prior recording of M. castagnei in Australia, the potential of M. castagnei conidia for long distance transport and the proven records of trans‐Tasman dispersal of other pathogens. Laboratory inoculations and field observations showed P. alba cv. Silver poplar and its hybrids to be highly susceptible to M. castagnei. Populus alba X P. glandulosa hybrids and Italian selections of P. alba showed high field resistance.
Growth and visible responses of Scots pine (Pinus sylvestris L.) seedlings to simulated summer frost
Authors: Holopainen K.
Published: June 2007

Scots pine seedlings, 20–30 days old, were exposed to simulated summer frost in controlled environment growth chambers. The responses observed showed extreme variation between individual seedlings; seedlings suffering from needle‐necrosis, healthy‐looking, and dead seedlings were found in the same treatment. Four days exposure to temperatures below –4.5°C caused multiple‐leaders maximally in 7.7 % of the pine seedlings and resulted in decreased shoot and root dry weight and shoot length.
Intracellular infection by fungi in mycorrhizae of damaged spruce trees
Authors: Haug I. , Weber G. , Oberwinkler F.
Published: June 2007

Intracellular infection was found in the vascular tissue and meristem of mycorrhizae of a severely damaged stand of spruce and fir trees in the Northern Black Forest. Two fungal species could be isolated from surface sterilized mycorrhizae: Mycelium radicis atrovirens and Cryptosporiopsis cf. abietina. Infection tests with spruce seedlings revealed that mainly Cryptosporiopsis cf. abietina must be held responsible for infection of the vascular tissue. Less infectious was Mycelium radicis atrovirens, which infected only cortex cells.
Production of phenols in the sapwood of Eucalyptus maculata after wounding and infection
Authors: Mireku E. , Wilkes J.
Published: June 2007

When the sapwood of Eucalyptus maculata Hook, was tested between 7 and 240 days after injury, increases were generally detected in both the concentration of phenols and activity of phenol oxidizing enzymes (peroxidase, tyrosinase and laccase). This effect was most pronounced in a narrow ‘marginal zone’ at the boundary of healthy and injured/infected tissues. It is probable that one or more enzymes stimulate production of antimicrobial phenols contributing to effective compartmenalization of microbial invasion in the sapwood.
Effect of suppression and felling on infection of oak and Scots pine by Armillaria
Authors: Davidson A. J. , Rishbeth J.
Published: June 2007

Armillaria mellea, A. ostoyae and A. bulbosa, but not A. tabescens, infected some of the heavily suppressed oaks that had been inoculated, whereas only A. mellea infected subdominant oaks. The same three species also infected suppressed Scots pines, but only A. ostoyae infected subdominant ones. Infections in stump roots of oak inoculated with A. mellea, A. ostoyae, A. bulbosa and A. tabescens were small unless roots had been weakened by severing; intact stump roots of pine were colonized more extensively than those of oak by the first three species.
Ultrastructural changes in mesophyll cells of spruce needles from a declining forest in northern Germany
Authors: Meyberg M. , Lockhausen J. , Kristen U.
Published: June 2007

Dilatation of thylakoids in mesophyll chloroplasts was found in needles from diseased Norway spruce. Additionally, the shape of the chloroplasts with extreme swellings of thylakoids had become spherical. These cytopathological symptoms are clearly distinct from structural changes observed in senescent needles from healthy trees.
Relative susceptibilities to Sphaeropsis sapinea of six Pinus spp. cultivated in South Africa
Authors: Swart W. J. , Wingfield M. J. , Knox‐Davies P. S.
Published: June 2007

The relative susceptibilities to Sphaeropsis sapinea of six Pinus spp. cultivated in South Africa were investigated in growth chamber and field inoculations. The relative susceptibilities of the species tested, compare favourably with field observations by foresters over a number of years. There was some variation in pathogenicity among S. sapinea isolates on the different species.
Stem necrosis of Populus deltoides X P. trichocarpa in New Zealand caused by Xanthomonas campestris pv. Populi
Authors: Hawortharsen R. H. , Spiers A. G.
Published: June 2007

One‐year‐old nursery‐grown trees of Populus deltoides X P. trichocarpa parentage exhibited stem necrosis and lesioning during the unusually moist 1985–1986 growing season. A yellow‐pigmented, Gram negative, aerobic, monotrichous bacterium which utilized salicin was isolated from infected tissue almost in pure culture. The bacterium was identified as Xanthomonas campestris pv. populi and pathogenicity tests revealed it to be the causal organism. This is the first recorded outbreak in New Zealand of stem necrosis of poplars caused by X. campestris pv. populi. The bacterium appears to be an opportunistic pathogen.
Description et distribution du chancre scléroderrien sur Picea mariana (Mill.) B.S.P
Authors: Laflamme G.
Published: June 2007

Description and distribution of Scleroderris canker on Picea mariana (Mill.) B.S.P. The distribution of Gremmeniella abietina infecting black spruce in natural regeneration is restricted to an area, 100 km north of Quebec City, Canada. Even with high rates of infection in two studied stands (38 % and 80 %), the disease is not conspicuous; this fact may explain the actual small known distribution of scleroderris canker on natural spruce in North America. The fungus on spruce is morphologically identical to the same species on red pine, but it is different if we compare its sporulation behavior and its reaction to chemical treatments. Its race identification is problematic. A description of symptoms, signs and damages is given.
New types of damage to forest trees typical of the Mediterranean region
Authors: Clauser F. , Gellini R. , BUSSOTTI F. , Cenni E. , Bottacci A.
Published: June 2007

Since 1984 a new type of damage to the typical tree species growing in the mediterranean area has been observed. The pathological picture includes the typical features of “Waldsterben”. The new symptoms occurring in Pinus pinea, P. pinaster, P. halepensis and Qnercus ilex are described.
Identification of viruses from European beech (Fagus sylvatica L.) of declining forests in Northrhine‐Westfalia (FRG)
Authors: Winter S. , Nienhaus F.
Published: June 2007

Five different viruses isolated from degenerating European beech of different forest sites of West Germany could be identified as cherry leaf roll virus, brome mosaic virus, potex and potyviruses.
Effect of inoculum density of Macrophomina phaseolina on seedling susceptibility of six conifer species
Authors: McCain A. H. , Scharpf R. F.
Published: June 2007

The severity of charcoal root disease of conifer seedlings (Abies concolor, A. magnified, Pinus jeffreyi, P. lambertiana, and Pseudotsuga menziesii) was a power function of the sclerotial density of the fungus (Macrophomina phaseolina) in nursery soil.
Fungi on spruce needles in Norway II
Authors: Solheim H.
Published: June 2007

Tiarosporella parca has been found in different plots in Norway, mostly in small amounts. However, in Pasvik, East‐Finnmark, this species was rather common and replaced the otherwise most common species, Lophodermiumpiceae.
Histopathologie du chancre cortical du cypres à Seiridium cardinale
Authors: Et J. Ponchet , Andréoli Claudine
Published: June 2007

Histopathology of cankers on Cupressus caused by Seiridium cardinale. The purpose of this work was to understand host defense reactions of cypress trees against S. cardinale canker to improve selection of clones resistant to the disease. Following infection, bark recovery depends on the neophellogenic efficiency to build a necrophylactic periderm (NP) that compartmentalizes the diseased tissue. The thicker the NP the more resistant the bark. Neophellogenic activity can be estimated by measuring the thickness of constitutive phelloderm of the bark of trees from natural plantings or seedlings. Potentially resistant clones having phelloderms thicker than 100μm will be selected for further experiments.
Toxic effects of elm phytoalexin mansonones on Ophiostoma ulmi, the causal agent of dutch elm disease
Authors: Wu W. D. , Jeng R. S. , Hubbes M.
Published: June 2007

The toxic effect of elm phytoalexins (mansonones) on two isolates of Ophiostoma ulmiwas studied cytologically and physiologically. The effects included increasing ion leakage, reducing respiration rate and altering the structure of cellular organelles.
Lethal effects of Chloropicrin and Vorlex on Phellinus weirii and nine Trichoderma species
Authors: Nelson E. E.
Published: June 2007

Sublethal fumigation followed by introduction of biological control agents may offer a method of controlling laminated root rot [Phellinus weirii (Murr.) Gilb.]. To determine the tolerance of P. weirii and 9 Trichoderma spp. to 2 fumigants, culture tubes containing 47 isolates of these fungi were fumigated for 10 days with 12 concentrations of chloropicrin and Vorlex in sealed glass containers. Considerable variation occurred in tolerance to fumigant among isolates within a species and among species. Isolates of P. weirii, however, were more consistent and were less tolerant to the fumigants than were isolates of the other fungi. In general, isolates of all fungi appeared more tolerant of Vorlex than of chloropicrin.
Pollaccia blight of poplars in India
Authors: Khan S. N. , Misra B. M.
Published: June 2007

Detection of leaf and shoot blight of poplars has been reported from India. The causal organism,Pollaccia elegansServ. has been described as it occurs onPopulus ciliataWall. andP. nigraLinn. alongwith disease symptoms.

During evaluation of diseases of poplars in Jammu and Kashmir State in May 1986, an outbreak of a very serious leaf and shoot blight ofPopulus ciliataWall. andP. nigraLinn. was detected in Kamraj and Baramulla Forest Divisions. In the present publication the symptoms of the disease and the pathogen as it occurs on poplars in India were described.
Differential reaction in Pinus spp. to inoculation by various isolates of Ascocalyx (Gremmeniella) abietina
Authors: Capretti P. , Dorworth C. E.
Published: June 2007

Stem inoculations of 3 species of pole‐size pines with 4 diverse isolates of Ascocalyx (Gremmeniella) abietina revealed Pinus pinea to be more susceptible than either P. pinaster or P. nigra in terms of canker length. Isolate type and geographical aspects considered more briefly, also have some effect.
Effects of Douglas‐fir parentage on Swiss needlecast expression
Authors: Nelson E. E. , Silen R. R. , Mandel N. L.
Published: June 2007

Densities of pseudothecia on Douglas‐fir needles infected with Phaeocryptopus gaeumanni and needle retention on Christmas trees were related to male and female parentage in a 4 by 5 factorial mating in replicated plantings in western Oregon. Interactions of families by plantation and of male parentage by plantation were highly significant. The additive proportion of variation calculated from variance components due to male and female parentage was greater than 1.00; hence, no evidence was found of nonadditive genetic variance.
Influence of environmental, host and cultural factors on conidium morphology of Marssonina species pathogenic to poplars
Authors: Spiers A. G.
Published: June 2007

Laboratory studies investigating the influence of environmental, host and cultural factors on conidium morphology of isolates of Marssonina brunnea, M. castagnei and M. populi established that conidial features (length and breadth dimensions, shape, conidium ratios, L:B, LS:B and septum location) were remarkably stable. Significant differences in length and breadth dimensions and ratios were induced by culture media and host but not by media pH, incubation temperature, photoperiod, leaf age, leaf surface and infection severity. Significant differences in conidial dimensions and ratios of M. brunnea were observed following examination of monthly collections from a single field‐grown tree. The variation in conidial features induced by environmental, host and cultural factors in no instance obscured taxonomic differences between species.
Factors influencing the incidence of Rosellinia necatrix Prill. in poplars1
Authors: Anselmi N. , Giorcelli A.
Published: June 2007

Tests were carried out in controlled environments to ascertain the effects of some physical, chemical and biological characteristics of soil on the spread of Rosellinia necatrix and on the development of its infection in poplars. Following the results obtained, cultivation techniques have been suggested which could prevent the diffusion of the fungus or reduce the damage it causes.
Chemical and structural characteristics of conifer needles exposed to ambient air pollution
Authors: Kim Yoon Soo , Lee Jae Ki
Published: June 2007

Conifer needles exposed to ambient air pollutants were observed by a scanning electron microscope (SEM). Predominant changes on needles were the breakdown and the aggregation of wax structures on stomatal chambers. However, the mode of destruction in stomatal wax structures was dependent on the pollutants. Ginkgo biloba seemed to be resistant to air pollutants despite higher amounts of sulfur in the foliage.
Zur Feinstwurzelentwicklung sauer beregneter Jungfichten (Picea abies Karst.)
Authors: Kattner Doris
Published: June 2007

After simulating acid rain on 2‐year‐old spruce seedlings (Picea abies. Karst.), potted in soil of a damaged stand, no signs of stunted roots or mycorrhizal injury could be achieved. Liming had some effect on the status of the Hartig net. The findings must be seen as a result of changes in soil chemistry and successful competition of the established mycorrhiza.
Monoterpene composition of the preformed and induced resins of Scots pine, and their effect on bark beetles and associated fungi
Authors: Delorme Lucile , Lieutier F.
Published: June 2007

Inoculations of fungi or introductions of insects were performed on Scots pines. The monoterpene composition of the induced resin differed from that of preformed resin, but did not depend on the nature of the aggression on a same tree. There were variations in the composition of induced resin according to tree. Mycelial growth was strongly limited, more by the increase in resin quantity and total monoterpene quantity than by the qualitative changes of the monoterpene composition. Monoterpenes appeared very toxic for Tomicus piniperda, but not for Ips sexdentatus.
Relation between wilt rate and obstruction of water flow in stems of two families of loblolly pine affected by pitch canker
Authors: Solel Z. , Bruck R. I.
Published: June 2007

Movement of water forced through stem segments of two half‐sib families of loblolly pine (Pinus taeda), infected by Fusarinum subglutinans, was monitored. Wilt rate of the two families was shown to be correlated with obstruction of water flow through stem segments of similar disease severity.
Stump colonization by Armillaria in Wisconsin aspen stands following clearcutting
Authors: Stanosz G. R. , Patton R. F.
Published: June 2007

The frequency and degree of aspen stump colonization by undetermined Armillaria sp. was quantified by examination of 185 bulldozed stumps in two Wisconsin aspen stands, 2or5 years after cutting. Rhizomorphs were associated with all stumps examined. All of the 5‐year‐old stumps and 94 % of the 2‐year‐old stumps were colonized. Armillaria had colonized >50 % of the root‐collar area of 98 % of the 5‐year‐old stumps, but only of 13 % of the 2‐year‐old stumps. Mycehal fans and decay extended from stumps into roots.
A cut‐shoot bioassay for assessment of Pinus pinaster susceptibility to Melampsora pinitorqua
Authors: Desprez‐Loustau Marie‐Laure
Published: June 2007

A simple bioassay for testing susceptibility of excised maritime pine shoots to twisting rust is described. Using this method, it was possible to follow the development of shoot susceptibility throughout the spring.
Economic impact of a post‐hail outbreak of dieback induced by Sphaeropsis sapinea
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, about 2000 ha of pine plantations were infected by Sphaeropsis sapinea. The timber loss due to S. sapinea infection in compartments prematurely clearfelled was about 28% of volume and 55% of value of potential production. Total predicted volume of timber lost in compartments not felled prematurely was an average of 11.4%. Percentage volume lost increased with age, with the greatest losses being recorded on good quality sites.
Nitidulids as vectors of the oak wilt fungus and other Ceratocystis spp. in Texas
Authors: Appel D. N. , Kurdyla T. , Lewis R.
Published: June 2007

Sap‐feeding nitidulid beetles were trapped for 15 months at four oak wilt centers in central Texas and assayed for the presence of Ceratocystis fagacearum. Levels of contamination with the pathogen ranged 0.3% (Kerrville) – 2.0% (Austin); also detected were C. piceae at slightly higher levels and a low number of beetles carrying C. pluriannulata. The percentages of contaminated beetles were similar to those reported for other parts of the oak wilt range in the USA, but probable species differences in Texas were detected.
Changes in needle retention associated with the spread and establishment of Phaeocryptopus gaeumannii in planted Douglas fir
Authors: Hood I. A. , Sandberg C. J. , Barr C. W. , Holloway W. A. , Bradbury P. M.
Published: June 2007

The needle‐infecting fungus Phaeocryptopus gaeumannii (Rohde) Petrak spread to stands of Douglas fir [Psendotsuga menziesii (Mirb.) Franco] in most parts of New Zealand following its first detection in the central North Island in 1959. At Hanmer Forest in the South Island, the percentage of infected needles rose more rapidly in a provenance from northern inland California than in one from Kaingaroa Forest in the North Island. Increase in infection was accompanied by a significant decrease in the proportion of needles retained on shoots of certain age classes, the reduction in the Californian seedlot being greater than in that from Kaingaroa. More older foliage was retained in the Kaingaroa provenance at Hanmer Forest, when infection averaged under 30 %, than at two other locations where mean infection exceeded 90 %. It is suggested that heavily infected production stands of Douglas fir suffer some premature casting of older needles, even when crowns appear healthy.
A new method to produce numerous uncontaminated alder seedlings
Authors: Brunner Franziska , Brunner I.
Published: June 2007

Seeds of four species of Alnus were surface sterilized and placed on plates containing water agar. After seedlings had been produced, they were, without the seed coats attached, transferred onto malt agar plates. On such media, possible contaminants grew quickly and contaminated seedlings could be detected and discarded. With this method, numerous uncontaminated seedlings can be produced and used for synthesis experiments.
Studies on conidial germination of Cylindrocladium quinqueseptatum, causing leaf blight of Eucalyptus in India1
Authors: Sharma J. K. , Mohanan C.
Published: June 2007

In vitro germination of conidia of Cylindrocladium quinqueseptatum Boedijn & Reitsma, a cause of leaf blight of Eucalyptus spp., began after 4.5 h of incubation and attained approx. 95 % within 8 h; germination was optimal at 25°C. Conidial germination on the intact leaves of 2‐month‐old E. grandis occurred after 3 h of incubation. Formation of appressorium over the epidermal cells was recorded first on the abaxial surface of leaves at 6 h and later on the adaxial surface. Formation of appressorium over the stomata was found only very rarely and most leaf penetrations occurred directly through epidermal cells.
Die natürliche Astreinigung und ihre biologischen Voraussetzungen
Authors: Butin Von H. , Kowalski T.
Published: June 2007

Natural pruning of branches and its biological conditions. V. The fungal flora of spruce, pine and larch. The of dead branches from Pica, Pinus sylvestris and larix decidua was investigated. Each tree species is characterized by a host specific fungal flora. Most of the species belong to the and Deuteromycetes.
La Nécrose du Phloème du Tronc de l'Hévéa en Côte d'lvoire: 1. Symptomatologie et caractéristiques biochimiques
Authors: Nandris D. , Chrestin H. , Noirot M. , Nicole M. , Thouveneland J. C. , Geiger J. P.
Published: June 2007

Phloem Necrosis of the trunk of the rubber tree in Ivory Coast: 1. Symptomatology and biochemical characteristics. External and internal symptoms of this disease affecting the lower part of the trunk of Hevea brasiliensis are described. Data on necrosis spread in the tissue and on comparative biochemical characteristics of latex are given and discussed.
Preliminary investigations on phenolics as a response of Scots pine phloem to attacks by bark beetles and associated fungi1
Authors: Lieutier F. , Yart Annie , Jay‐Allemand Ch. , Delorme Lucile
Published: June 2007

Two fungus and one bark beetle species were introduced into Scots pine phloem. The phenolic composition of the induced reaction zone in the phloem, studied by two dimensional thin layer chromatography, greatly differed from that of the uninjured phloem. The concentration of three compounds increased, one of them considerably, while the concentration of four others decreased. These modifications were the same irrespective of the nature of the aggressor.
Testing Fraxinus excelsior, Fraxinus americana, and Fraxinus pennsylvanica for resistance to Pseudomonas syringae subsp. savastanoi pv. fraxini
Authors: Van Dam B. C. , Van Der Voet H.
Published: June 2007

Eight clones ofFraxinus excelsior, one clone ofF. americanaand one clone otF. pennsylvanicawere tested for their susceptibility to bacterial knot disease by artificial inoculations. Parametric and non‐parametric methods of statistically analysing their resistance were compared.
Effects of ammonium and nitrate on mycorrhizal seedlings of Pinus sylvestris1
Authors: Termorshuizen A. J. , Ket Petra C.
Published: June 2007

The effects of ammonium sulphate and sodium nitrate on Pinus sylvestris seedlings inoculated with Paxillus involutus and Suillus bovinus were investigated. Weekly fertilization (26 weeks) positively affected the plant dry weight, but inhibited the mycorrhizal formation and decreased the root length/weight ratio. Ammonium treatments affected the seedlings more positively and the mycorrhizas more negatively than nitrate did. The effects on seedlings inoculated with P. involutus were more pronounced than on those inoculated with S. bovinus. The possible mechanisms of the effects of nitrate and ammonium on mycorrhizas are discussed.
Cryphonectria cubensis, a potential pathogen of Psidium guajava in South Africa
Authors: Swart W. J. , Conradie E. , Wingfield M. J.
Published: June 2007

The pathogenicity of an isolate of Cryphonectria cubensis was tested in artificial inoculations on Eucalyptus grandis, Psidium guajava and Syzygium cordatmn. The isolate was able to colonize host tissue of all three species following inoculations of branch sections. It rapidly colonized the tissue of potted guava plants of the important commercial cultivar, Fan Relief and resulted in the death of a number of inoculated branches. Pathogenicity was also proven on mature guava trees in the field. An important implication of these findings is that the cultivation of guavas in South Africa could be confronted with a potentially severe disease problem in the future.
Occurrence of mycoplasma‐like organisms in diseased and non‐symptomatic alder trees (Alnus spp.)
Authors: Lederer W. , Seemüller E.
Published: June 2007

Mycoplasma‐like organisms (MLOs) were detected in almost all examined trees of Alnus glutinosa and A. incana older than approximately 5 years. The minority of trees showed symptoms of decline while the others appeared healthy. MLOs were also found in A. glutinosa var. barbata, A. hirsuta, A. rubra, A. rugosa, A. subcordata, and A. tenuifolia.
Effect of an ectomycorrhizal fungus, Laccaria laccata, on Fusarium damping‐off in Pinus banksiana seedlings
Authors: Chakravarty P. , Hwang S. F.
Published: June 2007

Damping‐off caused by Fusarium oxysporum Schlecht in Pinus banksiana Lamb, was reduced significantly when inoculated with an ectomycorrhizal fungus, Laccaria laccata (Scop. ex Fr.) Berk. and Br. In paired culture, growth of F. oxysporum was significantly reduced by L. laccata. The number of colony forming units of F. oxysporum was reduced significantly in the rhizosphere of P. banksiana seedlings when inoculated with L. laccata. Spore germination and germ tube length of F. oxysporum was inhibited strongly by culture filtrate of L. laccata and root exudate of P. banksiana inoculated with L. laccata. Mycorrhizal seedlings had significantly higher amount of total soluble phenols than nonmycorrhizal ones.
Bacteria wilt of Casuarina equisetifolia in India
Authors: Ali M. I. Mohamed , Anuratha C. S. , Sharma J. K.
Published: June 2007

Pseudomonas solanacearum (Smith) was consistently isolated from the wilted plants of Casuarina equisetifolia. The isolate gave positive reaction to oxidase, catalase and gas production from nitrate and negative reaction for arginine dihydrolase and acid was produced from various carbohydrates. Wilt produced on tomato, egg plant and capsicum indicated that the pathogen belongs to Race I and Biovar III of P. solanacearum which is a new record from India.
Chestnut blight (Cryphonectria parasitica) north of the Swiss alps
Authors: Bissegger M. , Heiniger Ursula
Published: June 2007

Chestnut blight (Cryphonectria parasitica) was found in several stands in the Swiss plateau. At each site only one or two compatibility (vc) groups were present. The vc‐group I was the most common. At a heavily infested site also young oaks (Quercus petraea) were infected.
Detection of xylan hydrolyzing activity in culture extracts of Gremmeniella abietina
Authors: Petäistö R.‐L. , Talvinen J. , Kajander E. O.
Published: June 2007

Hemicellulose xylan is a major non‐cellulose component of wood. Xylan hydrolyzing activity was detected in culture media of G. abietina. G. abietina grew well on xylan. Pine needle extract decreased xylanase activity.
Antagonism of two decay fungi, Peniophora polygonia and Phellinus tremulae associated with Populus tremuloides
Authors: Chakravarty P. , Hiratsuka Y.
Published: June 2007

Interactions between the two most common decay fungi of Populus tremuloides, Peniophora polygonia and Phellinus tremulae were studied. Pe. polygonia inhibited the growth of Ph. tremulae when grown in paired culture. The presence of a culture of Pe. polygonia reduced the growth of Ph. tremulae in a volatile metabolite test. A culture filtrate of Pe. polygonia reduced the growth of Ph. tremulae in liquid culture. The growth of both the fungi was inhibited, and they formed a dark brown line at contact point when grown on a Po. tremuloides block.
Tannase activity associated with growth of Cryphonectria parasitica on American and Chinese chestnut extracts and properties of the enzyme
Authors: Farias Graciela M. , Elkins J. R. , Griffin G. J.
Published: June 2007

Cryphonectria parasitica grew on American and Chinese chestnut total aqueous and tannin extracts from winter and summer bark. Differences in the amount of conidial germination and growth on extracts of the two species were small. C. parasitica tannase (tannin acyl hydrolase) was found to be more abundant intracellularly, had a pH optimum of 5.5, and a temperature optimum for activity of 30°C. Total tannase activities on American chestnut total aqueous and tannin extracts were higher than on the respective Chinese extracts.
Mating system and apothecia production in Gremmeniella abietina
Authors: Uotila A.
Published: June 2007

Mycelia of Gremmeniella abietina isolated from the same ascus were paired in seedlings of Pinus sylvestris and the production of apothecia determined. G. abietina was found to be a heterothallic fungus in which mating is controlled by a single locus composed of at least two mating allcles. Independent of climatic conditions isolates of type B produced greater number of apothecia than those of type A.
Isolation of Xanthomonas campestris pv. populi from stem lesions on Salix matsudana X alba ‘Aokautere’ in New Zealand
Authors: Haworth R. H. , Spiers A. G.
Published: June 2007

A yellow‐pigmented, Gram‐negative, aerobic, salicin utilising bacterium‐identified as Xanthomonas campestris pv. populi was isolated from one year old stems of S. matsudana X alba‘Aokautere’ willows exhibiting stem necrosis. Although the bacterium was isolated from necrotic stem tissue almost in pure culture it was not pathogenic to vigorously growing material of S. matsudana X alba‘Aokautere’ in field inoculations. Stress and predisposing climatic conditions during winter (frost, rain, wind, mild temperatures) are thought to have favoured the initial infections of this opportunistic pathogen. This disease is not considered serious.
Relative susceptibility of Eucalyptus provenances to Cylindrocladium leaf blight in Kerala, India1
Authors: Sharma J. K. , Mohanan C.
Published: June 2007

Susceptibility of 46 provenances belonging to 16 species of Eucalyptus to Cylindrocladium leaf blight caused by Cylindrocladium quinqueseptatum, C. clavatum and C. ilicicola differed significantly in detached leaf inoculations. Generally, susceptibility of a provenance to the three species of Cylindrocladium showed significant differences; only a few provenances gave either equally resistant or susceptible reactions to all the three species. C. clavatum was the most virulent species, C. ilicicola the least and C. quinqueseptatum intermediate.
Seasonal changes of soluble carbohydrates in mycorrhizas of Norway spruce and changes induced by exposure to frost and desiccation
Authors: Niederer M. , Pankow W. , Wiemken A.
Published: June 2007

Mycorrhizas of six spruces of a stand were collected over two years and were analysed for soluble carbohydrates (sucrose, raffinose, glucose, trehalose and mannitol). The level of these carbohydrates was high during winter and low during summer. Upon exposure of excised mycorrhizas to frost or desiccation, the content of trehalose roughly doubled. A positive correlation was found between the trehalose content of mycorrhizas and their ability to survive frost or desiccation as determined by the electrolyte leaching method.
Susceptibility of Eucalyptus grandis to Cryphonectria cubensis
Authors: Conradie E. , Swart W. J. , Wingfield M. J.
Published: June 2007

Artificial inoculation of rooted Eucalyptus grandis cuttings with Cryphonectria cubensis in the glasshouse showed that significant differences exist in the susceptibility of various Eucalyptus clones to the pathogen. A 61.3% difference in susceptibility was observed between the most resistant and susceptible group of clones. Results appeared, however, to have been influenced by genotype × environment interaction.
Clonal response in Salix to Melampsora rusts in short rotation coppice plantations
Authors: McCracken A. R. , Dawson M.
Published: June 2007

The appearance of Melampsora spp. rust on a range of Salix spp. clones used for short rotation coppice was recorded. The progress of the disease and its subsequent effect on leaf fall was also recorded. Rust pustules from all the clones described were examined using the Stereoscan Elec‐tron Microscope. This revealed no differences in uredospore architecture which could be consis‐tently related to host.
S and P intersterility groups in Heterobasidion annosum; Infection frequencies through bark of Picea abies and Pinus sylvestris seedlings and in vitro growth rates at different oxygen levels
Authors: Lindberg M.
Published: June 2007

Seedlings of Norway Spruce and Scots Pine were inoculated with S and P strains of the root rot fungus Heterobasidion annosum. Infection frequencies through the living bark layers were not related to subgroup affiliation in neither spruces nor pines. Growth rates in vitro were not related to growth rates in vivo. Oxygen concentration had a stronger effect on the growth rates of P than on S strains.
Trunk inoculations of Phytophthora cinnamomi in red oaks
Authors: Robin Cécile
Published: June 2007

Trunks of northern red oaks were inoculated with Phytophthora cinnamomi. To study lesion growth in bark tissues over several years, lesion assessment methods were perfected and tested. Koch's postulates were demonstrated. Development and longevity of lesions were studied. Intra‐specific variability of red oak susceptibility was investigated.
Die natiirliche Astreinigung und ihre biologischen Voraussetzungen VI. Versuche zum Holzabbau durch Astreiniger‐Pilze
Authors: Von Butin H. , Kowalski T.
Published: June 2007

Natural pruning of branches and its biological conditions. VI. Survey of wood degradation by branch inhabiting fungi. Laboratory tests demonstrated that fungi occurring on decaying branches and probably associated with natural pruning of branches are capable of degrading wood. Most fungi tested positive for the Bavendamm‐reaction and therefore produce phenol‐oxidase. The inoculation of wood blocks caused a typical soft rot. Impact‐resistance tests showed that fungi involved in natural pruning of branches can considerably reduce strength of wood.
Der pH‐Wert und das Vorkommen niedermolekularer Fettsäuren im Naßkern der Buche (Fagus sylvatica L.)
Authors: Von Walter M.
Published: June 2007

The pH‐value and the occurrence of fatty acids in wetwood of European Beech (Fagus sylvatica L.). At the border of the wetwood area pH‐value of the capillary liquid was altered from acid to neutral conditions. Fatty acids frequently occurred in wetwood. Probes with pH‐values higher than 6.8 often were deeply black stained.
Potential impacts of a climate change on forest ecosystems
Authors: Kräuchi N.
Published: June 2007

Review of literature indicates that many uncertainties and assumptions exist in predicting the impacts of a climate change on forest ecosystems. However, current knowledge is sufficient to encourage any measures that are combating climate change, that is to reduce first and foremost the release of harmful substances to the atmosphere, lithosphere and biosphere.
Reproductive success of Bursaphelenchus xylophilus and B. mucronatus under Finnish summer temperature conditions
Authors: Tomminen Jyrki
Published: June 2007

The objectives of this study were to determine the reproductive potential and the time required for completion of the life cycle of Bursaphelenchus xylophilus under Finnish summer temperature conditions. The reproductive success of B. xylophilus was compared with the potential of a Finnish isolate of B. mucronatus. The latter appeared more successful in reproduction particularly when cultured on Finns syhestris wood.
Genetics of field resistance to Melampsora in Salix viminalis
Authors: Gullberg U. , Ryttman H.
Published: June 2007

The inheritance of resistance to Melampsora. spp. on Salix viminalis, the variation in resistance over space and time, and rust infection rate in relation to the geographic origin of the host was studied. The analysis showed that there was considerable additive genetic variation for rust resistance, that the results did not have high repeatability over space and time, and that the material from southernmost Sweden was most sensitive to the rusts occurring in south Sweden.
Variation of virulence of white pine blister rust
Authors: Hoff R. J. , Mcdonald G. I.
Published: June 2007

According to the literature the following evidence suggests racial variation in white pine blister rust: changes over site in general level of resistance; interaction of needle spot color types with crosses of western white pine; neutralization of specific resistance reactions; bark reactions and normal cankers on the same tree.
Effect of nitrogen and carbon sources on lignin and cellulose degradation by Armillaria ostoyae
Authors: Entry J. A. , Donnelly PaulaK. , Cromack K.
Published: June 2007

Lignin has been hypothesized to be the primary mechanism of resistance to fungal pathogens in plant tissue. Degradation of lignin and cellulose by Armillaria ostoyae cultured for six weeks in Melin‐Norkrans medium containing various nitrogen and carbon sources was measured radiometrically. No consistent pattern of lignin or cellulose degradation was found, regardless of A. ostoyae isolate, nitrogen source and concentration, or carbon concentration. More lignin was degraded as the concentration of glucose and fructose increased but not when the concentration of sucrose increased.
Effects of some seed‐borne fungi on Picea glauca and Pinus strobus seeds
Authors: Mittal R. K. , Wang B. S. P.
Published: June 2007

Effects of inoculations of nine fungi to prechilled and nonchilled seeds of Picea glauca and Pinus strobus were studied in unsterilized and sterilized nursery soils, and a peat‐vermiculite‐perlite mixture. All the fungi demonstrated weak pathogenicity to seeds.
Susceptibility of different Eucalyptus genotypes to artificial leaf‐inoculations with Cylindrocladium scoparium and C. clavatum
Authors: Blum L. E. B. , Dianese J. C.
Published: June 2007

Young plants of 38 Eucalyptus seed sources were inoculated in the laboratory with conidia of Cylindrocladium scoparium and C. clavatum. Susceptibility was principally assessed in terms of the severity of leaf spotting.
A method for axenic sampling of wood from standing trees
Authors: Delatour C.
Published: June 2007

A method is described to collect wood samples axenically from standing trees by the use of a Pressler borer in conjunction with protective sterile jackets.
Sur un cas de variabilité chez Sphaeropsis sapinea
Authors: Morelet M. , Chandelier P.
Published: June 2007

A case of variability in Sphaero sis sapinea. Two isolates (type I and type II) of Sphaeropsis sqinea were isolated from the co lar of a declining Cedrus deo daa in the South of France. Cultural characteristics on PDA and MEA as well as conidial dimensions were compared with those of types A and B of S. sapinea described to occur in North America.

Type II was similar to type A in respect to cultural aspects and growth but distinctly different in conidial dimensions. Slower growing type I was similar to type B. However, type I grew faster on PDA, had smaller conidia and lacked microconidia. Single‐conidia isolates obtained from the four types showed stability of these characteristics.
Impact of molecular biology on forest pathology: A literature review
Authors: Hubbes M.
Published: June 2007

Rapid developments in the field of molecular biology have produced a number of very powerful analytical tools by unifying techniques of genetics, biochemistry and cell biology. As reviewed in the present paper, these tools will become important and indispensable in forest pathology studies of the genetic machinery and regulatory mechanisms that control fungal products implicated in the complex tree‐pathogen interactions. Understanding these interactions will enhance the development of efficient control methods of forest pathogens.
Pathogenicity studies with Bursaphelenchus mucronatus in Scots pine in Finland
Authors: Tomminen Jyrki
Published: June 2007

The objective of the study was to determine the role of FinnishBursaphelenchus mucronatusas a possible pathogen in Scots pine,Pinus sylvestris, under Finnish ambient weather conditions. Small seedlings and young field grown trees were used as inoculation targets. The results suggested the nematode being of minor importance as a tree pathogen in Finland.
Mycorrhizal associations of Sitka‐spruce seedlings propagated in Irish tree nurseries
Authors: Grogan H. M. , O'Neill J. J. M. , Mitchell D. T.
Published: June 2007

The mycorrhizas of Sitka‐spruce seedlings propagated in two bare‐root nurseries and one container nursery in Ireland are identified and compared. In the bare‐root nurseries, Piceirhiza horti‐inflata was the most frequent mycorrhizal association during the first year of growth but appeared to be replaced by Hebeloma sp. and Amphinema byssoides in 2‐year‐old seedlings. There was a greater diversity of mycorrhizas on container‐grown seedlings which included Thelepbora terrestris, Hebeloma sp. and Piceirhiza guttata.