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1.
R.D. Kehr 《Forest Pathology》1991,21(4):218-233
Perennial cankers on trunks of Quercus rubra planted in Germany affect trees from age 30 onward. Symptoms and histopathology are presented and compared with other major causes of bark disorders on Red Oak in Europe. Infection trials with the causal agent, Pezicula cinnamomea (DC.) Sacc., are described and pathogenesis of the disease is discussed along with predisposing factors. 相似文献
2.
A study of lesion development in stems of Eucalyptus nitens following artificial inoculations with canker fungi was carried out on 16‐year‐old plantation trees. In a first trial cambium bark wounds on smooth‐ and rough‐barked trees were inoculated with the mycelium of nine species of canker fungi, including Endothia gyrosa. In a second trial spores or mycelium of E. gyrosa were applied directly onto undamaged or superficially wounded bark surfaces. Infection subsequent to artificial inoculation via wounding (whatever the wounding technique or type of inoculum) resulted in significantly larger external lesions (mean lesion area up to 35.6 cm2 20 months after inoculation) on smooth bark compared with those on rough bark (up to 19.0 cm2). Microscopic studies of infected rough and smooth bark suggest that, once smooth bark is compromised by wounding and artificial inoculation, the particular anatomical structure of smooth bark may offer less mechanical resistance to post‐penetration hyphal spread in comparison with rough bark. It is suggested that at a pre‐penetration stage under natural conditions spores of E. gyrosa more easily infect rough bark via cracks associated with this type of bark but not present in smooth bark. 相似文献
3.
Gry Alfredsen Halvor Solheim Rune Slimestad 《European Journal of Forest Research》2008,127(5):387-393
The inhibitory effect of methanol bark extracts from six deciduous and three coniferous European tree species were bioassayed
against eight fungi from the different damage categories, brown rot, white rot, canker and blue-stain. This is the first report
providing data on the antifungal activity of several Europaen tree species against fungi within these damage categories. Generally
the decay fungi were more inhibited by the bark extracts than the blue-stain fungi, while the lowest inhibition was found
among the cancer fungi. The main pattern found between the fungal groups in relation to the bark extracts in this study is
believed to be caused by the route of ingress. Acer platanoides bark extract proved to be the most efficient bark extract tested, significantly reducing the growth rate of all tested fungi.
Betula pubescens bark extract generally gave the weakest reduction in growth rate. In this study, the conifer bark extracts were in general
more active against the canker and blue stain ascomycete fungi than the deciduous trees extracts. 相似文献
4.
The chemical and anatomical host responses to natural fungal infection by Cytonaema sp. in the aerial bark of 3‐year‐old Eucalyptus globulus plantation trees were examined. The lesion margin (LM) of the canker‐infected bark was characterized by the formation of a layer of dark extractives visible to the naked eye. Chemical analysis of the LM by gas chromatography‐mass spectrometry (GC‐MS), high‐performance liquid chromatography (HPLC) with ultraviolet detection and HPLC‐MS using negative ion electrospray ionisation indicated the presence of a range of compounds including hydrolysable tannins, polymeric proanthocyanidins, flavonoid glycosides, formlyated phloroglucinol compounds and volatile terpenes. These compounds were either undetectable in healthy tissue or present at significantly lower concentrations than in the LM. The LM of the canker‐infected bark was morphologically distinct from healthy phloem, its characteristics varying depending on severity of canker infection. In superficial infections in which only the phloem was affected, the following LMs were observed: (i) a continuous wound periderm of multiple layers, or (ii) an incompletely differentiated and discontinuous wound periderm. In cases of severe canker infections in which the vascular cambium had been killed, the new phloem formed subsequently contained traumatic oil glands in addition to the responses observed for superficial canker infections. All LMs were characterized by the formation of new parenchyma cells that stained positive for the presence of polyphenols. The significance of the chemical and structural responses as defence mechanisms against fungi causing stem canker is discussed. 相似文献
5.
Field survey,isolation, identification and pathogenicity of Phytophthora species associated with a Mediterranean‐type tree species 
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下载免费PDF全文 L. Croeser T. Paap M. C. Calver M. E. Andrew G. E. St J. Hardy T. I. Burgess 《Forest Pathology》2018,48(3)
Corymbia calophylla (marri), a keystone tree species in the global biodiversity hot spot of southwestern Australia, is suffering decline and mortality associated with a canker disease caused by the endemic fungus Quambalaria coyrecup. Phytophthora species are frequently isolated from the rhizosphere of C. calophylla, and a hypothesis is that Phytophthora root infection is predisposing C. calophylla to this endemic canker pathogen. Field surveys were conducted in both anthropogenically disturbed and undisturbed C. calophylla stands, from where a total of 100 rhizosphere soil samples, from both healthy and cankered trees, were collected. Phytophthora species were isolated from 26% of the samples collected, with Phytophthora incidence significantly higher on disturbed stands than in natural forests (73% and 27%, respectively). Five Phytophthora species were recovered, including P. cinnamomi, P. elongata, P. multivora, P. pseudocryptogea and P. versiformis. Under‐bark inoculations with the Phytophthora isolates caused significant lesion lengths in excised C. calophylla stems. Corymbia calophylla response to pot infestation trials in the glasshouse varied between Phytophthora species and isolates, with isolates of P. cinnamomi and P. multivora causing a significant reduction in seedling root volume and often leading to seedling death. This study demonstrates that root disease caused by Phytophthora species, especially P. cinnamomi and P. multivora, has the ability to adversely affect C. calophylla health. This study leads the way to do a dual inoculation trial with the canker pathogen Q. coyrecup, and different Phytophthora species to investigate if Phytophthora root infection predisposes C. calophylla to this canker disease. 相似文献
6.
Several Aegean (Greece) and Anatolian (Turkey) cypress provenances were studied for resistance variability to bark canker, a disease caused by the fungal pathogen Seiridium cardinale. The investigation also examined whether the low disease rate within the natural area of cypress was due to genetic or geographic‐climatic reasons. Results demonstrated strong variability for the ‘bark canker resistance’ character, in particular for trees within families. As trees from the provenances studied were not found to have genetic superiority for bark canker resistance, the above‐mentioned low disease rate could be due to geographic‐climatic barriers that inhibit the development of the fungus or its ability to infect the host. Several half‐sib progenies exhibited high resistance, suggesting that this character is totally inherited through the maternal line. Should this finding be confirmed by further research, it would facilitate the task of genetic improvement for resistance, allowing progenies of resistant trees to be obtained. 相似文献
7.
A multiplex PCR‐based technique for identification of Biscogniauxia mediterranea and Obolarina persica causing charcoal disease of oak trees in Zagros forests 下载免费PDF全文
下载免费PDF全文 Zagros oak (Quercus spp.) forests (ZOF) cover approximately 4 million hectares of the Zagros Mountains in Iran. Oak charcoal disease caused by Biscogniauxia mediterranea and Obolarina persica has recently increased in some regions of ZOF. Detection of these fungi in host tissue and identification of the anamorphs by traditional methods have limitations and difficulties which were overcome using two primers, OP1 and OP2, based on rDNA sequences of O. persica and used along with the specific primers MED1 and MED2 for B. mediterranea to develop a multiplex PCR. This method was used to correctly identify 1 pg of fungal DNA per 1 mg of inner bark tissues of Quercus brantii, Q. infectoria and Q. libani. 相似文献
8.
Pinus patula and high-elevation (HE) sources of P. tecunumanii exhibit intermediate levels of resistance to pitch canker (Fusarium circinatum), compared to extremely resistant species such as P. oocarpa, and extremely susceptible species such as P. radiata. Seedlings from 20 P. patula provenances and 15 HE P. tecunumanii provenances were artificially inoculated with the pitch canker fungus at 21 and 12 weeks of age, respectively, and assessed
for resistance 12–20 weeks later. There was important provenance variation in pitch canker resistance for both species. The
20-week LiveStem percentage ranged from 70.3% to 43.6% among the P. patula provenances and 59.6% to 11.7% among HE P. tecunumanii provenances. There was a geographic pattern to the provenance variation, and in both species, low altitude sources demonstrated
more resistance than those from high elevation. Provenance variation in pitch canker resistance could be useful when making
selection and breeding decisions with these species. 相似文献
9.
T. J. Wardlaw 《Forest Pathology》1999,29(3):199-208
Severe stem cankers in Eucalyptus nitens, from a 14-year-old mixed provenance plantation, were associated with infection by Endothia gyrosa, present in its teleomorph state. Surveys of incidence among canker severity classes were carried out in a thinned and pruned stand and an adjacent unthinned and unpruned stand within the affected plantation. No differences in incidence among the canker severity classes were found between the thinned/pruned and unthinned/unpruned stands or between different crown dominance classes within the unthinned/unpruned stand. However, the incidence among canker severity classes was strongly associated with bark roughness with 97% of rough-barked trees developing either annual cankers or cankers causing cambial damage. Stem cankers were found on only 11% of trees with smooth bark. Bark roughness in E. nitens was shown to differ significantly between provenances. Deployment of provenances prone to rough bark in routine plantation establishment may pose a risk of damaging stem canker outbreaks. 相似文献
10.
Since 2001, the incidence of bleeding canker of horse chestnut (Aesculus hippocastanum) has increased markedly in western Europe. The causal agent, the bacterium Pseudomonas syringae pv. aesculi, originally isolated from foliar lesions on Indian horse chestnut (Aesculus indica) in India, is a bark killing pathogen on A. hippocastanum. In this study, P. syringae pv. aesculi was found as a foliar epiphyte on both A. hippocastanum and A. indica trees growing in the UK. When Aesculus leaves were challenged with cell suspensions (109 CFU ml?1) of Pseudomonas syringae pv. aesculi, a high level of asymptomatic infection occurred in all the species tested. The degree of re‐isolation of the bacterium after surface sterilization of leaves ranged from 33% (A. pavia) to 84 and 97% for A. hippocastanum and A. chinensis, respectively. The studies suggest both epiphytic and intrafoliar populations of P. syringae pv. aesculi could play a role in the incidence and spread of bleeding canker of horse chestnut. Growth–temperature responses of P. syringae pv. aesculi indicated a minimum of approximately ?4°C and a maximum of approximately 35°C, with an optimum of approximately 25°C. These findings show that P. syringae pv. aesculi is not restricted to bark lesions but is likely to be widespread in the environment. It is also capable of causing foliar infection of several Aesculus species and could persist under extremes of weather in the UK. 相似文献
11.
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. 相似文献
12.
A new canker disease causing mortality of golden chinquapin trees [Chrysolepis chrysophylla (Dougl.) Hjelmqvist], in Oregon was recently observed. Most of the symptomatic or dead trees were located near roads. The cankers on the lower boles of trees are similar to those caused by species of Phytophthora on other trees in western North America. The cankers in the inner bark were reddish‐orange in colour and extended upward from necrotic roots. Phytophthora cambivora (Petri) Buisman was isolated from the cankers; identity was confirmed by morphological comparison with known isolates and internal transcribed spacer sequence analysis. Pathogenicity was confirmed by inoculation of chinquapin seedlings and mature trees. Seven of nine isolates from chinquapin were A2 mating type; 27 of 28 isolates from other hosts in Oregon and Washington were A1 mating type. 相似文献
13.
H. Zycha 《European Journal of Forest Research》1970,89(1):349-355
Zusammenfassung Im Holz der in der Bundesrepublik angebauten Roteichen (Quercus borealis) treten h?ufig braune Flecken mit gest?rter Holzstruktur auf. Ursache sind Spechte, welche die Rinde durch zahlreiche Einschl?ge
im Frühjahr besch?digen. Die typischen Narben in der Rinde lassen auf die Sch?den im Inneren des Stammes schlie?en.
Summary The wood of Red Oak (Quercus borealis) grown in Western Germany, frequently shows brown spots with disturbed texture. This is caused by woodpeckers, which breaks the bark in springtime. From typical scars on the bark we can conclude the damage inside the stem.
Résumé Le bois du chêne rouge souvent montre des taches brunes avec une structure anormale. C'est causé par des pics, qui blessent l'écorce. Des cicatrices de l'écorce indiquent les dommages dans le bois.相似文献
14.
THE DISTRIBUTION OF MYCELIA IN EUROPEAN LARCH BARK, IN RELATION TO THE DEVELOPMENT OF CANKER 总被引：1，自引：0，他引：1
The paper presents fully evidence to support the following conclusions.
- The living bark of European larch (Larix decidua Mill.) maybe expected to be infected with a microflora which containsboth fungi and bacteria and which may sometimes include Dasyscyphawillkommii (Hart.) Rehm.
- The necrotic areas which constitutecankers can be found tocontain a similar flora including Cytosporaabietis Sacc., C.curreyi Sacc., and Coniotbyrium fuckelii Sacc.This flora mayinclude D. wilkommii but it is not necessarilythe most abundantnor is its presence necessary for the developmentof larch canker.
- Inoculation experiments at Mynydd Ddu, wherecanker and die-backof branches is severe, with the above speciesof fungus, showthat inoculations stimulate extensions of deadbark. Under differentsite conditions and in a canker-free plantationat Southmoor,similar inoculations only produced extensionsgreater than thoseobserved in control treatments, where thetrees inoculated hadbeen partially girdled.
- A mass of myceliumof the usual species inhabiting living larchbark may, undersuitable conditions, have an influence whichfavours cankerextension but some special stimulus, of whichthe conditionof the tree may be an important factor, is neededto enablethem to influence the living bark of the host adversely.Muchmore careful study is needed before conditions which accompanycanker development are accurately known.
15.
Colonisation of native and exotic conifers by indigenous bark beetles (Coleoptera: Scolytinae) in France 总被引：1，自引：0，他引：1
Coralie Bertheau Aurlien Salle Jean-Pierre Rossi Stphanie Bankhead-dronnet Xavier Pineau Graldine Roux-morabito Franois Lieutier 《Forest Ecology and Management》2009,258(7):1619-1628
Planting exotic conifers offers indigenous forest insects an opportunity to extend their host range and eventually to become significant pests. Knowing the ecological and evolutionary modalities driving the colonisation of exotic tree species by indigenous insects is thus of primary importance. We compared the bark beetle communities (Coleoptera: Curculionidae, Scolytinae) associated with both native and introduced conifers in France. The aim of our study was to estimate the influence of both host- and insect-related factors on the beetles’ likelihood to shift onto new hosts. We considered the influence of host origin (i.e. native vs. exotic), host tree species identity, tree bark thickness and tree taxonomic proximity, as well as insects’ host specificity. A field inventory using trap trees was carried out in two regions in France (Limousin and Jura) during two consecutive years (2006 and 2007) on three European native conifer species [Norway spruce (Picea abies); Scots pine (Pinus sylvestris) and European Silver-fir (Abies alba)] and five North American [Sitka spruce (Picea sitchensis); Eastern white pine (Pinus strobus); Grand fir (Abies grandis); Douglas fir (Pseudotsuga menziesii) and Western red cedar (Thuja plicata)]. A total of 18 indigenous and 2 exotic bark beetle species were collected. All exotic conifer species were colonised by indigenous bark beetle species and no significant difference was observed of the cumulated species richness of the latter between native and exotic tree species (13 vs. 14, P < 0.05). The ability of indigenous bark beetles to shift onto exotic conifers appeared to strongly depend on host species (significantly structuring bark beetle assemblages), the presence of phylogenetically related native conifer species and that of similar resources, in combination with insect host specificity. Host tree species status (native or exotic) also seemed to be involved, but its effect did not seem as essential as that of the previous factors. These findings are discussed in terms of adaptation, plasticity and practical aspects of forest management. 相似文献
16.
A new disease of Maackia amurensis var. buergeri was recently found on the northern island of Hokkaido, Japan. Affected trees were heavily damaged and had cankers on both trunks and branches. After natural infection, a series of swellings on the bark surface developed longitudinally. These swellings burst and coalesced to become long cankers. It is proposed that the disease be designated ‘bacterial canker of Maackia’. The causal pathogen was isolated and characterized tentatively as Pseudomonas syringae on the basis of laboratory tests. Pathogenicity of the bacterium was confirmed by inoculation into the host. 相似文献
17.
The disease known as pitch canker results from infection of Pinus species by the fungus Fusarium circinatum. This fungus also causes a serious root disease of Pinus seedlings and cuttings in forestry nurseries. Pinus radiata and P. patula are especially susceptible to the pathogen, but there are no records of pitch canker on P. patula in established plantations. To date, only planting material of this tree species in nurseries or in plantations at the time of establishment have been infected by F. circinatum. Symptoms of pitch canker have recently emerged in an established P. patula plantation in South Africa and this study sought to determine whether the symptoms were caused by F. circinatum. Isolates from cankers were identified as F. circinatum using morphology and DNA-based diagnostic markers. Microsatellite markers were then used to determine the genetic diversity of a collection of 52 isolates. The entire population included 17 genotypes representing 30 alleles, with a greater number of genotypes collected from younger (three- to six-year-old) than older (12- to 19-year-old) trees. Both mating types of F. circinatum were present, but no evidence of sexual recombination was inferred from population genetic analyses. This is the first record globally of pitch canker on P. patula trees in managed plantations. It is of significant concern to South Africa, where P. patula is the most important Pinus species utilised for plantation forestry. 相似文献
18.
This study describes the first observation of Botryodiplodia canker in the Western Carpathians in south‐eastern Poland caused by Botryodiplodia hypodermia (Sacc.) Petr. (syn. Sphaeropsis hypodermia, S. ulmicola). The canker occurred on an approximately 17‐year‐old Ulmus glabra sapling in a mixed conifer/deciduous stand with elm trees severely damaged by Dutch elm disease. This paper describes disease symptoms and provides information on the macro‐ and micromorphology of the fungus isolated from the cankered tissues. The results of BLAST search using DNA sequences obtained for our cultures and subsequent phylogenetic positioning of the fungus among closely related Botryosphaeriaceae indicate that the species is much more closely related to Phaeobotryon than to the other Botryodiplodia or Sphaeropsis species. Moreover, a total of 16 polymorphisms within the ITS region were detected between S. ulmicola associated with Botryodiplodia canker in North America and B. hypodermia associated with the canker observed in Poland. Thus, the “European” variant of “Sphaeropsis” ulmicola can now be easily identified with our barcode sequences. The Botryodiplodia canker is much less prevalent in Europe than in North America. Differences in virulence of “American” and “European” linages and differences in susceptibility of various elm species may be the reason for the higher prevalence of the disease in North America. 相似文献
19.
Teratosphaeria stem canker is an important disease of Eucalyptus species in many parts of the world where these trees are intensively propagated in plantations. Symptoms similar to those of Teratosphaeria stem canker were observed on Eucalyptus grandis and a E. grandis × E. camaldulensis hybrid clone in the Central Highlands of Kenya. Symptomatic bark samples were collected from two sites and the associated fungus isolated and identified using DNA sequence analyses of multiple gene regions. The pathogen was identified as Teratosphaeria gauchensis. This represents the first report of the disease and the pathogen in Kenya. 相似文献
20.
Eutypella canker of maple, caused by Eutypella parasitica (which is native to North America), is reported for the first time from Germany. From 2013 to 2015, this perennial canker disease was recorded on 105 maple trees in Munich. Six maple species were affected: Acer pseudoplatanus, A. campestre, A. platanoides, A. cappadocicum, A. heldreichii ssp. trautvetteri and A. hyrcanum. Occurrence on the latter three species represents new host records for E. parasitica. In Austria, Eutypella canker was newly discovered on two trees at a second locality in 2011, and it is now known to occur on seven A. pseudoplatanus trees at two localities, which are separated nearly 150 km. A. pseudoplatanus was the most frequent host of E. parasitica in Munich and Austria, which is in agreement with previous studies in Europe. The identity of the causative pathogen as E. parasitica was verified by ITS rDNA sequencing of fungal cultures obtained from cankers in Munich and at both Austrian localities. The presence of large and old cankers in both countries suggests that introduction of E. parasitica dates back a long time, probably several decades. The new records of Eutypella canker in Germany and Austria show that the disease is more widely distributed in central Europe than previously recognized. 相似文献