Summary Since the arrival to North America of Cronartium ribicola , management eastern white pine has been driven by need avoid actual or, in many areas, perceived damage caused blister rust. Although lost much its former dominance, it remains a valuable species for biotic diversity, aesthetics, wildlife habitat and forest products. Understanding silvics damaging agents provides sound basis silvicultural activities site selection, regeneration stand tending. The can be successfully grown...

A comparative study of isolates and their corresponding herbarium specimens Gremmeniella spp. from pine, spruce, balsam fir, Ascocalyx laricina larch, abietis fir was conducted using morphological cultural characteristics as well electrophoresis tests on 12 10 – 15% gradient polyacrylamide gels. In addition, the conidia ascospores were treated with 4′,6-diamino-2-phenylindole to determine number nuclei per cell. is quite distinct in morphology its anamorph all other samples studied. The...

The nature and distribution of the endophytic mycoflora isolated from healthy needles Pinus banksiana resinosa growing in plantations or natural stands infected with Scleroderris canker were investigated. Overall colonization rates 68 89% for P. resinosa, respectively, generally higher closed canopy stands. For a given tree, increased foliage age but not influenced by twig orientation. Colonization more than one fungal species 17% 76% resinosa. Two different could be found inside up to seven...

Forest health is described and perceived in different ways by the general public, land owners, managers, politicians, scientists, depending on their values objectives. Native tree pathogens diseases are often associated with negative impacts even though damage limited or not widespread. Too often, concepts of forest used interchangeably related to scale. Similar fire, occurrences disease outbreaks focus effects. However, native exist equilibrium natural communities so critical ecological...

ABSTRACT A histological study was conducted to provide insights into the defense mechanisms of Pinus banksiana resistant European (EU) race Gremmeniella abietina in naturally infected sites. At time sampling, only apparent symptom a blight induced at tip shoots. The identity G. during microscopic examinations confirmed by an immunogold labeling method. Once fungus had succeeded penetrating bracts through stomata, it invaded stem cortex and phloem cells attained vascular cambium. progression...

Summary In field tests conducted on freshly cut red pine ( Pinus resinosa ) logs, the antagonistic fungus Phaeotheca dimorphospora formulated as pre‐colonized rye grains reduced colonization of wood tissue by Heterobasidion annosum to less than 2% over 2 months following inoculation. However, compared controls, a water suspension P. did not reduce infection, but rather promoted H. after 2‐month exposure. Production antifungal metabolites in and better logs antagonist were observed with grain...

The epiphytic mycoflora isolated from healthy needles of Pinus banksiana and resinosa was investigated. Approximately 75% the fungi were present on less than 5% needles. number different per needle increased with age both species, but more found P. most frequently species common primary saprophytes nonspecific to Pinus: Alternaria alternata, Botrytis cinerea, Cladosporium cladosporioides, herbarum, Epicoccum purpurascens, Hormonema dematioides. Aureobasidium microstictum, Penicillium...

The presence of the European (EU) race Gremmeniella abietina var. abietina, causal agent Scleroderris canker conifers, was first reported in North America 1975 northeastern United States and subsequently southern Quebec Newfoundland during late 1970s, where it quickly became established. We analyzed DNA profiles samples from a historic collection G. that included some isolates EU to test hypotheses concerning epidemic America. Genetic diversity partitioned by an analysis molecular variance...

Phaeotheca dimorphospora, which was first isolated from elm wood and found to be antagonistic in vitro against the Dutch disease pathogen Ophiostoma ulmi, tested for antifungal activity other tree pathogens by a variation of agar layer technique. dimorphospora produced compounds that were strongly inhibitory wide range addition O. such as Gremmeniella spp., Armillaria Septoria musiva, Verticillium albo-atrum, Cylindrocladium floridanum, Phytophthora sp., Nectria galligena, Heterobasidion...

Information on eastern Canadian tree species vulnerability to windthrow is scarce. Some statements relative have been made but they rely empirical observations, which are often difficult generalize. In this context, a study was conducted compare the overturning resistance of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) mesic site. To establish characteristics would best explain critical turning moment, simple linear regressions were calculated using...

Depuis 1955, le champignon Heterobasidion annosum , cause de la maladie du rond, n'était présent, dans l'est Canada, que sud l'Ontario. En 1968, fut identifié plus au nord, près des frontières Québec. À partir 1983, un groupe quatre plantations pins rouges ( Pinus resinosa ) ayant déjà été éclaircies a fait l'objet d'un programme surveillance, ce qui nous permis détecter H. plantation Mayo en 1989. Cette détection constitue première mention présence 1993, on observé une autre groupe, à...

In 2009 unusual white pine needle discoloration was observed in eastern Canada and northeastern USA. While the symptoms were similar most stands, disease diagnosed as Canavirgella banfieldii several locations Dooks blight caused by Lophophacidium dooksii others. Because of similarities symptom development morphological characters causal agents, it suspected that C. L. are either same or closely related species. To test this hypothesis we examined collections representing dooksii, including...

Abstract Purpose of Review Gremmeniella abietina is a destructive forest pathogen responsible for Scleroderris canker, shoot dieback, defoliation, and tree death in forests nurseries. This review aimed at providing complete description the fungus, its distribution, conditions spread, impact climate change summarising relevant management methods. Due to worldwide importance pathogen, retrospective required summarise lessons learned relation disease, considering application future outbreaks....

Heterobasidion irregulare is the scientific name for North American fungal species that was previously known as H. annosum (P-type) and Fomes annosus . In eastern Canada, pathogen found mainly in red pine plantations southern Ontario Quebec, where it causes tree mortality. There no registered control method currently available this disease Canada. Phlebiopsis gigantea a saprophytic basidiomycete successfully used biological agent several European countries. order to register product its...

The basidiomycetous fungus Onnia tomentosa is one of the most widespread root rot pathogens in North America. Although disease more severe on spruce and pine trees, this pathogen can infect several coniferous species. To study population structure O. tomentosa, we harvested 180 basidiocarps a 45-year-old white plantation western Quebec autumn 1997 extracted DNA directly from individual basidiocarps. Using combination spatial coordinates molecular data based analysis two mitochondrial three...

Abstract The root system is an important part of a tree, but being inconspicuous it does not attract much attention. Therefore, diseases are often invisible during the pathogens' life cycle. Nevertheless, they cause losses due to mortality and reduced growth, also components forest ecosystems. For example, complex Armillaria diseases, frequently associated with ostoyae, attacks stressed trees can kill seedlings or reduce growth decades while hidden in roots. Inonotus tomentosus common...

La maladie du chancre scléroderrien des pins est causée par le Gremmeniella abietina . Cette étude porte sur la race européenne de cet ascomycète qui, une fois introduite en Amérique Nord, s'est révélée plus destructrice que indigène nord-américaine, car elle peut tuer grands arbres. Comme il n'existait pas moyen lutte efficace contre cette plantation, un traitement élagage systématique a été mis à l'essai dans plantation rouges ( Pinus resinosa ) située Kazabazua (Québec). Les quatre...

The ascospore release of G. abietina var. balsamea was measured every hour for a period 1339 hours; it analyzed with regard to microclimatic factors, such as rain, relative humidity, air temperature, wind speed, and leaf wetness, which were also recorded on an hourly basis. spore dispersal started in the middle July ended October, peak during first 3 weeks August. Leaf wetness measurements best correlated dispersal. Relative humidity rain showed good correlation but not wetness. Dew...

Specific polymerase chain reaction (PCR) primers were developed for the internal transcribed spacer (ITS) region of rDNA gene Inonotus tomentosus, causal agent tomentosus root rot conifers. The designed to specifically amplify DNA from I. and allow its differentiation leporinus Phellinus pini s.l., which are morphologically very similar in culture. PCR amplification was carried out successfully extracted fruiting bodies cultures can potentially be used detect pathogen environmental samples...