Publications by G. Laflamme

Efficacy of two Phlebiopsis gigantea formulations in preventing Heterobasidion irregulare colonization of red pin thinning stumps in Eastern Canada

Fri, 10 May 2013

Enzymatic interactions between Gremmeniella abietina var. abietina, European race, and two resistant hosts, Pinus banksiana and P. contorta.

Fri, 08 Feb 2013

Ultrastructural observations showed that the European race of Gremmeniella abietina var. abietina can secrete several cell wall–degrading enzymes that help the invasion of Pinus banksiana and P. contorta shoot tip tissues. Alterations in the content or distribution of cellulose were obvious, indicating that colonization might be achieved primarily through the action of glucanases. Polygalacturonases seemed more abundant in the cortex and the phloem of the stem, suggesting they are among the first enzymes secreted by the pathogen during infection. Production of laccases and peroxidases was also revealed but always close to fungal cells or in areas where host wall degradation was obvious. In places where there was an accumulation of phenolic compounds in the infected zones of the shoot, particularly in or near the transition zone, immunolocalization of both enzymes was limited or absent. Laccases and polygalacturonases were regularly detected over the extracellular sheath of G. abietina, and this indicates that the sheath could play a significant role during host wall degradation. Finally, examination of G. abietina wall constituents, such as chitin and β-1,3-glucans, suggests that the composition of the pathogen wall changes during the infection process. This change may be associated with the secretion of fungal enzymes but could also be linked to host reactions altering the integrity of pathogen cell walls.

Detection of an invisible foe: annosus root and butt rot. Branching out from the Canadian Forest Service. No. 78.

Thu, 20 Dec 2012

Annosus root and butt rot was first reported in Quebec in 1989. The causal fungus enters a pine stand by colonizing the surface of freshly cut stumps. The disease spreads through contact between the roots of infected stumps and the roots of healthy trees. After a few years, this radial spread, which occurs at a rate of about 1 m per year, results in a roughly circular patch of dead trees. The French common name of the disease, “maladie du rond,” comes from the circular areas of mortality. Annosus root and butt rot is spreading northward in Quebec at a rate of 10 km/year. Canadian Forest Service (CFS) researchers are working on methods to protect pines, the pathogen’s preferred host species, against this threat.

Maladie du rond : invisible, mais reconnaissable. L’éclaircie du Service canadien des forêts. No 78.

Thu, 20 Dec 2012

Pathogenicity trials with Gremmeniella fungi collected on conifers in Canada.

Tue, 24 Jul 2012

White pine needle diseases in Eastern Canada.

Tue, 24 Jul 2012

White pine blister rust: knowledge, control and innovation. Branching out from the Canadian Forest Service, Laurentian Forestry Centre. No. 73.

Tue, 26 Jun 2012

The essential link between Ribes spp. and blister rust.

Careful selection of planting sites.

Inspection and pruning to the rescue.

Planting blister rust-free seedlings: it's not that simple!

Increasing resistance through hybridization.

La rouille vésiculeuse du pin blanc : savoir, contrôle et innovation. L’éclaircie du Service canadien des forêts, Centre de foresterie des Laurentides. No. 73.

Tue, 26 Jun 2012

The essential link between Ribes spp. and blister rust.

Careful selection of planting sites.

Inspection and pruning to the rescue.

Planting blister rust-free seedlings: it's not that simple!

Increasing resistance through hybridization.

Gremmeniella balsamea sp. nov. on balsam fir in Canada.

Thu, 17 May 2012

Gremmeniella balsamea sp. nov. is described from specimens collected on balsam fir (Abies balsamea) in eastern Canada. This is a fungal pathogen specific to balsam fir. Until now, it was considered to be G. abietina var. balsamea, this variety including also a Gremmeniella fungus on spruces. Consequently, this new species causes changes in the taxonomy within the genus Gremmeniella.

In Brief from the Canadian Forest Service, Laurentian Forestry Centre. No. 28.

Tue, 27 Mar 2012

Does fire severity affect the decomposition of woody debris?

Scleroderris canker: reinterpreting the historical record

Silviculture and regeneration of eastern white-cedar in mixedwood stands

Growing hybrid poplars outside their comfort zone

Evolution of the boreal forest in the absence of fire

Hemlock looper: more eggs, more parasitism?

Les Brèves du Service canadien des forêts, Centre de foresterie des Laurentides. No 28.

Tue, 27 Mar 2012

Does fire severity affect the decomposition of woody debris?

Scleroderris canker: reinterpreting the historical record

Silviculture and regeneration of eastern white-cedar in mixedwood stands

Growing hybrid poplars outside their comfort zone

Evolution of the boreal forest in the absence of fire

Hemlock looper: more eggs, more parasitism?

Pathogenicity tests of Gremmeniella abietina var. balsamea isolated from balsam fir in Canada.

Wed, 18 Jan 2012

The pathogenicity of Gremmeniella abietina var. balsamea isolated from balsam fir (Abies balsamea) was tested on different conifer hosts, including A. balsamea. Pathogenicity of the fungus was positive on balsam fir only. This pathogen could not infect other conifers, not even spruce species which are reported as hosts for the taxon G. abietina var. balsamea. Also, isolates from spruces and pines were pathogenic only on their respective hosts. These results raise questions on the taxonomic status of the two pathogens classified as G. abietina var. balsamea.

New and updated information of scleroderris canker in the Atlantic provinces

Wed, 22 Jun 2011

This note reviews the status of the European race of Scleroderris canker (Gremmeniella abietina [Lagerb.] Morelet), an exotic pest, in the Atlantic provinces of Canada. The European race of Scleroderris canker is a disease of plant quarantine significance, and many reports have been written since it was initially recognized in New York State in 1975 and subsequently found in Quebec in 1978. The race testing methods have improved in the intervening three decades. This report clarifies the situation for regulatory authorities, the forest industry, and provincial officials in New Brunswick, Nova Scotia, Prince Edward Island, and Newfoundland. We are also reporting a breach of the quarantine zone of that disease in Newfoundland. A complete listing of isolates tested from New Brunswick and the known distribution for Newfoundland are included as tables and maps.

Solutions to the imbroglio over the nomenclature of Gremmeniella abietina

Mon, 24 Jan 2011

Root diseases in forest ecosystems

Wed, 01 Dec 2010

Silvicultural approaches for management of eastern white pine to minimize impacts of damaging agents

Wed, 08 Sep 2010

Earliest documented report of Scleroderris canker in North America: damage believed until now to be caused by summer frost.

Wed, 04 May 2011

In 1934, over 200,000 red pine(Pinus resinosa) seedlings were planted at Valcartier, near Quebec City. By 1939, more than 28% of these pines were dead. Fifteen years after plantation, red pine mortality reached 93% and the plantation was considered a total loss. Summer frost was thought to be the cause of red pine mortality, while white pine (Pinus strobus) trees planted at the same time were killed by white pine blister rust (Cronartium ribicola), without any trace of frost damage. However, while summer frost was not listed in insect and disease survey reports published from 1953 to 1993, it was reported in the Valcartier area. Analysis of archival documents and publications shows that Scleroderris canker caused by Gremmeniella abietina was responsible for this mortality. This disease was not known in Canada before 1960. Our diagnosis is based on the description of signs and symptoms, on photographs of damage and on samples collected on site. Gremmeniella abietina, North American race, was isolated and identified. The age of the trees confirms the identity of the plantation; the age of the cankers on residual pines shows that the disease reached the trunks around 1945. High snow depth - not frost - in topographic depressions created conditions conducive to the development of the disease at the epidemic level. This is the earliest documented report of Scleroderris canker in North America.

Biological control trials of beech bark disease under laboratory conditions.

Thu, 07 Jan 2010

Pathologie forestière

Thu, 07 Jan 2010

Fungi and diseases - natural components of healthy forests.

Thu, 07 Jan 2010

Outbreak of Scleroderris canker, European race, in Central Newfoundland: escape form quarantine.

Thu, 07 Jan 2010

Patterns of colonization and spread in the fungal spruce pathogen Onnia tomentosa.

Tue, 10 Nov 2009

The basidiomycetous fungus Onnia tomentosa is one of the most widespread root rot pathogens in North America. Although the disease is more severe on spruce and pine trees, this pathogen can infect several coniferous species. To study the population structure of O. tomentosa, we harvested 180 basidiocarps in a 45-year-old white spruce plantation in western Quebec in autumn 1997 and extracted DNA directly from individual basidiocarps. Using a combination of spatial coordinates and molecular data based on the analysis of two mitochondrial and three nuclear loci, we measured the average genet size and molecular diversity and assessed the relative contribution of basidiospores and vegetative growth to the stand colonization. Most of the sampled basidiocarps that clustered spatially belonged to the same genet. A total of 37 discrete multilocus genets of an average size of 3.42 m were obtained. The genet size distribution was skewed towards smaller genets (<3 m) that displayed higher diversity than the larger genets (>3 m). The nuclear loci were in Hardy–Weinberg equilibrium in the larger genets, but not in the smaller genets, which displayed a deficiency of heterozygotes. This suggests a Wahlund effect, whereby different colonization events resulted in expected heterozygosity higher than observed heterozygosity. Using an estimate of the growth rate of the fungus, only a few of the largest genets were approximately the age of the plantation. These observations are consistent with the colonization by basidiospores subsequent to site preparation and tree planting followed by secondary colonization events and vegetative spread.

Resistance to Gremmeniella abietina (European race, large tree type) in introduced Pinus contorta and native Pinus sylvestris in Sweden

Thu, 19 Feb 2009

Un siècle de pathologie forestière au Québec, sur fond de grands pins.

Thu, 07 Jan 2010

In Brief from the Canadian Forest Service, Laurentian Forestry Centre. Number 15.

Tue, 29 Dec 2009

A model for evaluating the impact of temperature increases on the carbon cycle of forest soil

Canadian forests - New understandings of carbon sequestration

Estimating biomass with satellite imagery

Lodgepole pine - Resistance of the European breed to scleroderris canker

Weevil infestation of Norway spruce - Lumber quality and quantity not affected

Which sites are sensitive to biomass harvest?

Les Brèves du Service canadien des forêts, Centre de foresterie des Laurentides. Numéro 15.

Fri, 30 Jan 2009

A model for evaluating the impact of temperature increases on the carbon cycle of forest soil

Canadian forests - New understandings of carbon sequestration

Estimating biomass with satellite imagery

Lodgepole pine - Resistance of the European breed to scleroderris canker

Weevil infestation of Norway spruce - Lumber quality and quantity not affected

Which sites are sensitive to biomass harvest?

Inferences on the phylogeography of the fungal pathogen Heterobasidion annosum , including evidence of interspecific horizontal genetic transfer and of human-midiated, long-range dispersal.

Wed, 21 Jan 2009

Fungi in the basidiomycete species complex Heterobasidion annosum are significant root-rot pathogens of conifers throughout the northern hemisphere. We utilize a multilocus phylogenetic approach to examine hypotheses regarding the evolution and divergence of two Heterobasidion taxa associated with pines: the Eurasian H. annosum sensu stricto and the North American H. annosum P intersterility group (ISG). Using DNA sequence information from portions of two nuclear and two mitochondrial loci, we infer phylogenetic relationships via parsimony, Bayesian and median-joining network analysis. Analysis of isolates representative of the entire known geographic range of the two taxa results in monophyletic sister Eurasian and North American lineages, with North America further subdivided into eastern and western clades. Genetically anomalous isolates from the Italian presidential estate of Castelporziano are always part of a North American clade and group with eastern North America, upholding the hypothesis of recent, anthropogenically mediated dispersal. P ISG isolates from Mexico have phylogenetic affinity with both eastern and western North America. Results for an insertion in the mitochondrial rDNA suggest this molecule was obtained from the Heterobasidion S ISG, a taxon sympatric with the P ISG in western North America. These data are compatible with an eastern Eurasian origin of the species, followed by dispersal of two sister taxa into western Eurasia and into eastern North America over a Beringean land bridge, a pattern echoed in the phylogeography of other conifer-associated basidiomycetes.

Resistance of Pinus contorta and P. sylvestris to Gremmeniella abietina (European race) in Sweden.

Tue, 20 Jan 2009

Resistance of Pinus contorta to the European race of Gremmeniella abietina. For. Pathol.

Fri, 18 Aug 2006

Pinus contorta seedlings, together with Pinus resinosa and Pinus banksiana seedlings, were planted adjacent to 25-year-old red pine trees infected by the European (EU) race of Gremmeniella abietina. Resistance to this race was assessed over 5 years. All P. resinosa seedlings were dead after that period while 65% of P. contorta and 86% of P. banksiana seedlings appeared resistant to the disease. The tip blight that occurred on P. contorta was slightly longer than that observed on P. banksiana. In microscopy, one, two, or even more suberized boundaries were seen to be initiated near the surface of the shoot at the base of healthy needles where they extended downward in the direction of the vascular cambium. Suberized boundaries occasionally crossed the xylem and joined together in the pith region to form continuous barriers around necrotic tissues. However, in most cases, these suberized barriers were not continuous across the shoot and compartmentalization was then completed by other barriers mainly constituted of parenchyma cells and xylem tracheids that accumulated phenolic compounds. Meristematic-like cells were observed adjacent to the necrophylactic periderm. Tissue regeneration, restoration of cambial activities and formation of traumatic resin canals also seemed to be associated with the defence system of P. contorta against the EU race of G. abietina.

Les pourridiés des arbres : un secret bien gardé.

Fri, 13 Apr 2012

Root and butt rots are hidden tree diseases. During a long part of their life cycle, these pathogens are mostly invisible in spite of their catastrophic final impact on trees. In Quebec, data on wood volume loss caused by root and butt rots are sketchy. A report from the Canadian Forest Service divided forest loss caused by diseases from that caused by insects in Quebec to respectively 36 and 64%, without mentioning root and butt rots. In comparison with data from Ontario where root and butt rots have been studied, the percentage of losses caused by diseases is around 65%, which is the opposite of the situation reported in Quebec. Moreover, losses through root and butt rots in Ontario could be underestimated as they are often reported under defoliators or windthrows. Forest treatments may increase the impact of root rot pathogens. For example, pre-commercial thinning in conifer stands has promoted the development of root rot pathogens on residual trees with a result opposite to the one expected. By cutting these trees, we are creating a new ecological niche that does not occur naturally, i.e., stumps. These stumps are colonized by several fungi including pathogens. For example, thinning of red pine stands favours stump colonization by Heterobasidion annosum if these stumps are not treated. Spruces can become infected by Inonotus tomentosus if these trees are under stress, e.g., in a stand of high stem density or because they are planted on a low quality site. Finally, Armillaria root rot on stumps of hardwood may kill conifer seedlings planted nearby.

Modelling the vulnerability of balsam fir forests to wind damage.

Thu, 12 Apr 2012

Wind causes significant damage to forests in central Québec, and with the current move to more refined silvicultural practices, concerns are increasing. This study investigates the mechanisms of windthrow resistance in stands dominated by balsam fir (Abies balsamea (L.) Mill.) with a minor component of white spruce (Picea glauca (Moench) Voss.), representing the dominant feature of a large section of the Eastern Canadian boreal forest. The aim was to compare the stability of trees of both species on mesic and rich mesic sites and then to compare the windthrow vulnerability of the entire stands on the same sites. Stability was measured by static tree-pulling tests. The resulting critical turning moments were calculated at the base of the stem and were related to a series of tree descriptors. Stem mass and tree mass were the variables showing the highest correlation coefficients. The effects of the site and the species on the critical turning moments were non-significant (P > 0.05). Influence diagnostics did not reveal the need for separating the stability of the pulled trees from their mode of failure. A similar analysis also showed that the amount of rot at the base of the stem did not affect significantly the vulnerability to windthrow in this study. Windthrow vulnerability was modelled using the methodology developed for the British GALES model. By using the relationship between the drag of the air on a surface and its aerodynamic roughness, the wind speed over a forest canopy was transformed into a resulting turning moment at the base of the stem. Critical wind speeds at which trees would overturn or snap could then be inferred for typical balsam fir stands growing on two site indices corresponding to those where the treepulling study was conducted. The immediate effect of a thinning operation was simulated by reducing the number of stems in the stands. The critical wind speeds were invariably higher for stem breakage than for overturning. In the later case, they were close to 20 m s-1 on both sites before declining at senescence. A thinning treatment removing 30% of the basal area would reduce this speed by approximately 4 m s-1.

L'armillaire, agent pathogène mondial : répartition et dégâts.

Fri, 18 May 2007

A framework for poplar plantation risk assessments

Mon, 26 Sep 2005

A simple effective tool for controlling white pine weevil and blister rust on Norway spruce and Eastern white pine

Tue, 31 May 2011

Un outil de contrôle simple et efficace contre le charançon et la rouille vésiculeuse du pin blanc

Tue, 31 May 2011

Evidence of resistance in Pinus contorta to Gremmeniella abietina, European race

Tue, 05 Apr 2005

Les Brèves du Service canadien des forêts, Centre de foresterie des Laurentides. Septembre 2004 [No 5].

Fri, 03 Dec 2004

For healthy red ash populations

For rapid detection of root rot

Harvesting method affects soil quality

Ozone affects cold hardening in sugar maple

Predicting the effectiveness of B.t. spraying operations

Pruning to control scleroderris canker

In Brief from the Canadian Forest Service, Laurentian Forestry Centre. September 2004 [No 5].

Fri, 03 Dec 2004

For healthy red ash populations

For rapid detection of root rot

Harvesting method affects soil quality

Ozone affects cold hardening in sugar maple

Predicting the effectiveness of B.t. spraying operations

Pruning to control scleroderris canker

Chancre scléroderrien du pin rouge : Traitement réussi! L’éclaircie du Service canadien des forêts, Centre de foresterie des Laurentides. No. 12.

Fri, 03 Dec 2004

Scleroderris canker, a disease caused by the European strain of the fungus Gremmeniella abietina, is highly virulent in red pine (Pinus resinosa) plantations. When nothing is done to eradicate the disease, the survival of infected plantations is compromised.

A successful treatment for scleroderris canker in red pine. Branching out from the Canadian Forest Service, Laurentian Forestry Centre. No. 12.

Fri, 03 Dec 2004

Controlling white pine blister rust

Tue, 31 May 2011

Lutte contre la rouille vésiculeuse du pin blanc

Tue, 31 May 2011

Root and Butt Rots of Forest Trees. 10th International Conference on Root and Butt Rots

Fri, 29 Aug 2003

Field tests on biological control of Heterobasidion annosum by Phaeotheca dimorphospora in comparison with Phlebiopsis gigantea

Fri, 29 Aug 2003

DNA polymorphism and molecular diagnosis in Inonotus spp.

Tue, 17 Apr 2012

Specific polymerase chain reaction (PCR) primers were developed for the internal transcribed spacer (ITS) region of the rDNA gene of Inonotus tomentosus, the causal agent of tomentosus root rot of conifers. The primers were designed to specifically amplify DNA from I. tomentosus and allow its differentiation from Inonotus leporinus and from Phellinus pini s.l., which are morphologically very similar to I. tomentosus in culture. The PCR amplification was carried out successfully from DNA extracted from fruiting bodies and cultures and can potentially be used to detect the pathogen from environmental samples for survey and management purposes. The PCR assay was validated with 42 samples from seven coniferous hosts originating from eight provinces or states across the North American continent. No cross reaction was observed with DNA of several other species of the same genus, with Phellinus pini or with white spruce (Picea glauca), a conifer host of I. tomentosus. Phylogenetic analysis of the ITS region for six species of Inonotus suggests that these resulted from the adaptation of a generalist ancestor to different ecological niches. It also appears that divergent evolution of an ancestor occupying different ecological niches has driven the speciation process, which subsequently conferred specificity to either coniferous or deciduous trees.

Nucleotide polymorphisms in three genes support host and geographic speciation in tree pathogens belonging to Gremmeniella spp.

Fri, 15 Apr 2011

We detected nucleotide polymorphisms within the genus Gremmeniella in DNA sequences of β-tubulin, glyceraldehyde phosphate dehydrogenase, and mitochondrial small subunit rRNA (mtSSU rRNA) genes. A group-I intron was present in strains originating from fir (Abies spp.) in the mtSSU rRNA locus. This intron in the mtSSU rRNA locus of strains isolated from Abies sachalinensis (Fridr. Schmidt) M.T. Mast in Asia was also found in strains isolated from Abies balsamea (L.) Mill. in North America. Phylogenetic analyses yielded trees that grouped strains by host of origin with strong branch support. Asian strains of Gremmeniella abietina (Lagerberg) Morelet var. abietina isolated from fir (A. sachalinensis) were more closely related to G. abietina var. balsamea from North America, which is found on spruce (Picea spp.) and balsam fir, and European and North American races of G. abietina var. abietina from pines (Pinus spp.) were distantly related. Likewise, North American isolates of Gremmeniella laricina (Ettinger) O. Petrini, L.E. Petrini, G. Laflamme, & G.B. Ouellette, a pathogen of larch, was more closely related to G. laricina from Europe than to G. abietina var. abietina from North America. These data suggest that host specialization might have been the leading evolutionary force shaping Gremmeniella spp., with geographic separation acting as a secondary factor.

Résistance comparée de l'épinette blanche et du sapin baumier au renversement

Thu, 28 Aug 2003

Formation of ligno-suberized tissues in jack pine resistant to the European race of Gremmeniella abietina

Mon, 04 Mar 2002

PCR detection of Gremmeniella abietina, the causal agent of Scleroderris canker of pine

Thu, 08 Aug 2002

Scleroderris canker of conifer is caused by Gremmeniella abietina var. abietina, which comprises several taxa, including races, varieties, and biotypes. The European race of G. abietina var. abietina was introduced into North America early in the century, most likely on asymptomatic infected pine seedlings, and is currently widespread in eastern North America. In order to detect latent infections and differentiate the North American and European races of the fungus, we developed oligonucleotide primers to amplify by PCR portions of the ITS of the ribosomal DNA of G. abietina var. abietina. The 417 bp amplified DNA fragment comprises two Msp I restriction sites in the NA race but only one in the EU race. DNA extractions directly from infected asymptomatic needles, or from single fruiting bodies, followed by PCR amplification and Msp I digestion allowed the detection and race identification of both races of G. abietina var. abietina from seedlings and branches of Pinus resinosa and P. banksiana. A nested PCR assay was sensitive enough to detect the equivalent of a single infected seedling in a bulk sample of 1000 healthy seedlings. Validation tests were conducted by comparing PCR and isolation assays with 104 fascicles. All samples for which the fungus was isolated yielded a positive PCR assay and there was no false negative, i.e. samples for which the fungus was isolated but not detected by PCR. Among the samples from which the fungus was not isolated, most yielded a negative PCR assay (71 %), but a proportion (29%) yielded positive PCR assays. In several of those cases, aggressive contaminants had apparently overgrown the pathogen. The method described here can lead to the detection and race identification of the NA and EU races of G. abietina var. abietina directly from infected tissues without the need to culture the fungus and should and applications in nursery inspection and quarantine.

Expansion of the European race of Gremmeniella abietina in Newfoundland, Canada

Thu, 08 Aug 2002

Resistance of Pinus banksiana to the European race of Gremmeniella abietina

Thu, 08 Aug 2002

Traitement réussi d'une plantation de pins rouges affectée par le Gremmeniella abietina, race européenne

Tue, 22 Aug 2000

Molecular evidence of distinct introductions of the European race of Gremmeniella abietina into North America

Tue, 22 Aug 2000

The presence of the European (EU) race of Gremmeniella abietina var. abietina, the causal agent of Scleroderris canker of conifers, was first reported in North America in 1975 in the northeastern United States and subsequently in southern Quebec and Newfoundland during the late 1970s, where it quickly became established. We analyzed DNA profiles in samples from a historic collection of G. abietina var. abietina that included some of the first isolates of the EU race reported in the United States to test hypotheses concerning the G. abietina var. abietina epidemic in North America. Genetic diversity was partitioned by an analysis of molecular variance with haplotype frequencies and distances. Genetic differentiation was high between populations in continental North America and Newfoundland (between region differentiation, Ф = 0.665, P < 0.001). This result was not consistent with the hypothesis of a single introduction of the pathogen into the northeastern United States followed by secondary spread into northeastern Canada. In contrast, small levels of genetic differentiation were observed among continental North American populations (Ф = 0.047, P = 0.079), suggesting gene flow among these populations. A single haplotype of G. abietina var. abietina dominated the continental populations (80% of the isolates) but was absent from Newfoundland and Europe. Five haplotypes were found in the Newfoundland population, all of which were either absent or very rare on the continent. Populations from continental North America clustered together and were distinct from a second cluster composed of European and Newfoundland populations. A phylogenetic analysis of the haplotypes indicated that some of the rare haplotypes may have derived from somatic mutations, whereas others probably occurred as the result of new introductions. The results are consistent with a scenario of distinct primary introductions of this pathogen into Newfoundland and continental eastern North America followed by secondary asexual propagation.

Foliage, shoot and stem diseases of trees

Tue, 22 Aug 2000

This meeting was attended by 56 scientists and researchers from 11 countries in North America, Europe and Asia. A total of 35 scientific papers were presented in 7 oral sessions and 16 posters were on display. Two field trips had been planned and proved to be very popular among the participants. As well, they got to stroll through Old Quebec to observe the success the campaign against Dutch elm disease was having in the city. The following includes most of the contributions that were presented at the meeting with the exception of papers from authors who did not want them published or did not provide their text. In addition, a few manuscripts were included from members of our working parties who were not able to attend the meeting. The papers' contents are the responsibility of the author(s).

Status of the European race of Scleroderris canker in Canada

Tue, 22 Aug 2000

Control of Cronartium ribicola in Pinus strobus plantations

Tue, 22 Aug 2000

Status of the european race of scleroderris canker in Canada

Fri, 21 Jul 2000

Ultrastructure and cytochemistry of early stages of colonization by Gremmeniella abietina in Pinus resinosa seedlings

Tue, 22 Aug 2000

Genetic differentiation within the European race of Gremmeniella abietina

Tue, 22 Aug 2000

Twelve random amplified polymorphic DNA markers were variable within the European race of Gremmeniella abietina var. abietina (GAA-EU) in Europe. Three distinct DNA amplification profiles (amplitypes) appeared to be correlated with ecotypic origin. The northern amplitype was present exclusively in northern Europe in plantations and natural stands of Pinus sylvestris and in plantations of P. contorta and apparently was adapted to the presence of deep, long-lasting snow cover in the winter. An alpine amplitype was found exclusively in the Alps at altitudes above 2000 m on P. cembra, P. mugo, P. sylvestris and Larix lyalli and also appears to represent an ecotype adapted to conditions of deep snow cover. The third amplitype, the European amplitype, was present throughout Europe and ranged from the Scandinavian countries and extended south to the Apennine mountains of northern Italy. Most of the GAA-EU samples tested from North America had RAPD profiles identical to those of the European amplitype indicating that the origin of this introduced pathogen could be central Europe. However, some of the samples from North America had RAPD profiles that did not match any found in Europe. The internal transcribed spacers of the ribosomal DNA repeat subunit were amplified and digested with restriction enzymes Hae I11 and Msp I. These restriction sites were polymorphic between the North American (GAA-NA) race and the EU race of G. abietina but were homogeneous among the three amplitypes described above. The rDNA restriction and RAPD profiles also indicated that GAA-NA was absent from the samples from Europe and that symptoms resembling those caused by GAA-NA were attributable to the northern and alpine amplitypes.

Host preference of two Gremmeniella abietina varieties on balsam fir, jack pine, and black spruce in eastern Canada

Tue, 22 Aug 2000

Cherry tree black knot.

Wed, 01 Jun 2011

Ultrastructural and cytochemical results on scleroderris canker infection of red pine seedlings

Thu, 05 Dec 2002

Antagonistic tests between endophytic fungi of red pine and Gremmeniella abietina

Wed, 04 Dec 2002

Le nodule noir du cerisier

Tue, 22 Aug 2000

Cherry tree black knot

Tue, 22 Aug 2000

Détection du Heterobasidion annosum au Québec

Tue, 22 Aug 2000

Cross infectivity of scleroderris canker on native and exotic conifers in Newfoundland

Tue, 22 Aug 2000

The earliest report of scleroderris canker in North America

Tue, 22 Aug 2000

Phaeotheca dimorphosa as a potential biocontrol agent for shoot blight caused by Gremmeniella abietina

Tue, 22 Aug 2000

The distribution and control of scleroderris disease in Ontario. Frontline Technical Note 21.

Fri, 21 Jul 2000

Tree diseases of eastern Canada

Tue, 22 Aug 2000

This publication is the result of collaboration between the Canadian Forest Service, Laurentian Forestry Centre and other agencies.

Many of the more frequently encountered tree diseases can be recognized readily through the 96 descriptions and 276 color photographs presented in this field guide. Topics in each description include host, distribution, effects on the hosts, identifying features, life history, control, and a selected bibliography. Hosts and distribution of causal agents pertain to eastern Canada, although many of them are also found in western Canada and the United States. Guidelines for selection and handling of samples to send to experts and suggestions on how to prevent, manage, and control the disease are also provided.

Maladies des arbres de l'est du Canada

Tue, 22 Aug 2000

This publication is the result of collaboration between the Canadian Forest Service, Laurentian Forestry Centre and other agencies.

La maladie du rond causée par Heterobasidion annosum

Tue, 22 Aug 2000

Annosus root rot caused by Heterobasidion annosum

Tue, 22 Aug 2000

Molecular epidemiology of Gremmeniella abietina (abstract).

Tue, 22 Aug 2000

Methods for scleroderris canker inoculation under controlled conditions

Tue, 22 Aug 2000

SEPPIR© expert system: expert system for red pine plantations, version CFL 1.0

Tue, 22 Aug 2000

Le système expert SEPPIR© : système expert pour les plantations de pins rouges, version CFL 1.0

Tue, 22 Aug 2000

Diagnostic des cas de dépérissement

Tue, 22 Aug 2000

La maladie du rond. Formation continue. Cours no. 28. (Encart)

Tue, 22 Aug 2000

Symptoms of Gremmeniella spp. on pine, spruce, fir and larch

Tue, 22 Aug 2000

Scleroderris canker, North American and European strains in Canada

Tue, 22 Aug 2000

Pruning red pine to control scleroderris canker : 8 years of trials

Tue, 22 Aug 2000

Evaluation of a fungal antagonist, Phaeotheca dimorphospora, for biological control of tree diseases

Tue, 22 Aug 2000

Pruning as a tool to control scleroderris canker

Tue, 22 Aug 2000

Evaluation of a fungal antagonist, Phaeotheca dimorphospora, for biological control of tree diseases

Tue, 22 Aug 2000

Première mention de l'Heterobasidion annosum au Québec

Tue, 22 Aug 2000

Damage caused by Gremmeniella laricina on Larix spp.

Tue, 22 Aug 2000

Pinus contorta and Gremmeniella disease situation in northern Sweden

Sat, 26 Aug 2000

Guide de prise de données sur le terrain : SEPPIR--Version CFL 1.0

Tue, 22 Aug 2000

Field data acquisition manual: SEPPIR -- CFL 1.0 version

Tue, 22 Aug 2000

Le chancre scléroderrien des pins

Tue, 22 Aug 2000

Scleroderris canker on pine

Tue, 22 Aug 2000

Evaluation of microclimatic factors affecting ascospore release of Gremmeniella abietina var. balsamea

Thu, 23 Jan 2003

Susceptibility of jack pine from Quebec seed sources to scleroderris canker (abstract).

Tue, 22 Aug 2000

Climatic factors causing ascospore release of Gremmeniella abietina var. balsamea

Tue, 22 Aug 2000

North American and European races of G. abietina in Quebec: their presence in plantations and individual trees (abstract).

Tue, 22 Aug 2000

Diseases of Scots pine in Canada

Tue, 22 Aug 2000

Mycoflora of Pinus banksiana and Pinus resinosa needles. II. Epiphytic fungi

Tue, 22 Aug 2000

Mycoflore des aiguilles de Pinus banksiana et Pinus resinosa. I. Champignons endophytes

Tue, 22 Aug 2000

Recovery of endophytes of Abies balsamea from needles and galls of Paradiplosis tumifex

Tue, 22 Aug 2000

Taxonomic position of Gremmeniella abietina and related species: a reappraisal

Tue, 22 Aug 2000

Description and symptoms of Gremmeniella abietina on Picea mariana

Tue, 22 Aug 2000

Description et distribution du chancre scléroderrien sur Picea mariana (Mill.) B.S.P

Tue, 22 Aug 2000

Vérification de la qualité des travaux de contrôle du chancre scléroderrien en plantation

Tue, 22 Aug 2000

Observations on the quality of interventions against the scleroderris canker were noted in 22 7- to 15-year-old red pine plantations located in the Ottawa region. Eight peculiarities have been identified for supervision during investigations. Verification of the quality of work is a necessary step towards successful interventions.

Outbreak of Gremmeniella abietina, European race in the province of Quebec, Canada

Tue, 22 Aug 2000

Le chancre scléroderrien en plantation

Tue, 22 Aug 2000

Trial to control scleroderris canker in red pine plantations

Tue, 22 Aug 2000

Précisions sur la taxonomie des genres Gremmeniella et Ascocalyx

Tue, 22 Aug 2000

Current research on scleroderris canker in North America

Tue, 22 Aug 2000

La protection des forêts papillonnes

Tue, 22 Aug 2000

Large infection center of scleroderris canker (European race) in Quebec Province

Tue, 22 Aug 2000

Gremmeniella abietina on Pinus griffithii and P. koraiensis in Québec

Tue, 22 Aug 2000

Essais de lutte au chancre scléroderrien au plantation de pin rouge (résumé).

Tue, 22 Aug 2000

Problems of scleroderris canker on black spuce

Tue, 22 Aug 2000

Symptôme inusité du chancre scléroderrien en plantation de pin rouge au Québec

Tue, 22 Aug 2000

Endophytic fungi in pine needles and their relation to epiphytic fungi and scleroderris canker

Tue, 22 Aug 2000

Current research on scleroderris canker in Quebec

Tue, 22 Aug 2000

Endophytic and epiphytic fungi from pine needles in relation to scleroderris canker in Quebec, Canada

Tue, 22 Aug 2000

Identification des champignons endophytes des épinettes noires et relations possibles avec certaines maladies des aiguilles et des rameaux

Tue, 22 Aug 2000

Test de résistance du pin gris à la maladie du chancre scléroderrien

Tue, 22 Aug 2000

Étude mycosociologique de quelques érablières du comté de l'Islet

Tue, 22 Aug 2000

La mycosociologie : ses origines, ses méthodes, ses applications au Québec

Tue, 22 Aug 2000

Le chancre scléroderrien menace les plantations de pin

Tue, 22 Aug 2000

Nouveau foyer d'infestation du chancre scléroderrien du pin, race européenne, au Québec (résumé).

Tue, 22 Aug 2000

Insectes et maladies des arbres - Québec 1984

Tue, 22 Aug 2000

Distribution de trois champignons fréquemment observés parmi la microflore des aiguilles du pin (résumé).

Tue, 22 Aug 2000

Insectes et maladies des arbres - Québec 1983

Tue, 22 Aug 2000

Nectria cinnabarina (Tode ex Fr.) Fr. trouvé sur des conifères au Québec

Tue, 22 Aug 2000

Insectes et maladies des arbres - Québec 1982

Tue, 22 Aug 2000

L'élagage

Tue, 22 Aug 2000

La maladie hollandaise de l'orme au Québec en 1982 (résumé)

Tue, 22 Aug 2000

Relevé des insectes et des maladies des arbres au Québec : rapport mi-saison

Tue, 22 Aug 2000

Les chancres sur les peupliers au Québec

Tue, 22 Aug 2000

Insectes et maladies des arbres, Québec 1981

Tue, 22 Aug 2000

Insectes et maladies des arbres - Québec 1980

Tue, 22 Aug 2000

Insectes et maladies des arbres - Québec 1979

Tue, 22 Aug 2000

Deterioration of Balsam Fir Damaged by the Eastern Hemlock Looper in Newfoundland

Fri, 21 Jul 2000

Reference Culture Collection of Fungi Maintained at the Newfoundland Forest Research Centre

Fri, 21 Jul 2000

Wood Defect and Density Studies of Living Trees: I - Field Guide

Fri, 21 Jul 2000

Micro-organismes dans les tissus colorés et cariés du peuplier faux-tremble

Tue, 22 Aug 2000

Relation entre la carie du bois, les défauts extérieurs et différents clones du Populus tremuloides Michx

Tue, 22 Aug 2000