摘要:

SummaryChanges in the level of phenolic compounds in needles of young Scots‐pine (Pinus sylvestristrees of various provenances were studied in an environment polluted by sulphur dioxide and fluorine compounds, and in a control environment. An increase in the content of ortho‐diphenols (o‐dPh) and total phenols (TPh) was found in the First year of needle development. This increase was significantly greater in the plants from the polluted environment. Relative to levels in the control environment, the highest level of phenols in the polluted environment was found in 2‐year‐old needles, followed by 3‐year‐old and then 1‐y

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01345.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryA range of fungi was screened for the ability to suppress symptoms of Dutch elm disease in European and hybrid elms under UK and Italian field conditions. The efficacy of the preventative inoculations varied Considerably between elm clones of differing resistance to the causal fungusOphiostoma novoulmi. On susceptible English elm,Ulmus procera, preventative inoculations with conidia ofVerticillium dahlias, Opbiostoma ulmiorOphiostoma piceae(OPH form) caused no reduction in final disease levels. OnU. x bollandicacv.‘Commelin’, pretreatment withV. dabliaeorO. ulmireduces final disease levels, but not significantly, On the elm clone Ca06 ofU. carpinifolia, and on the hybrid clones FL025 and 196–6, significant (p0.05) symptom suppression occurred in trees pretreated withO. ulmiorV. dahliae. On the more resistant elm clones 3–14 and Lobel, onlyV. dahliaewas an effective pretreatment (p0.05). Certain pretreatment fungi alone caused symptoms in some of the elm clones. Major difficulties in using this approach to control Dutch elm disease are discussed.The technical assistance by F. C. Baldwin, R. Brooker, S. A. Kirkand J. Roseat the Forest Research Station, Alice Holt, and by A. Fagnaniand F. Ferriniat CNR, Florence, as well as statistical advice from A. J. Peaceat Alice Holt, is gratefully acknowledged.The authors would like to thank the Pilkington Charitable Trust for funding the research in the UK and lsotron plc, Swindon, Berkshire, for gamma irradiating the conidial suspensions. The Italian contribution was supported by the National Research Council of Italy, special project RAISA, subproject no. 2, paper no. 2133. The authors also thank John GIBBS for helpful comments on the man

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01346.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryGastrodia elata was collected from July to August 1992 in Hokkaido forests. A total of 22 diploid isolates were paired with haploid testers of the biologicalArmillariaspecies reported in Hokkaido. One isolate was identified asA. ostoyae, 10 asA. gallica, three asA. jezoensis, three asA. sinapina, and five asA. singula. These isolates were compatible with the respective Hokkaido testers of these species. With the exception of A. ostoyae, these species are known as saprophytes, which form abundant rhizomorphs in soil.Clear isozyme profiles of esterases were obtained with all isolates except one. Interspecific variations were more important than intraspecific variations. The esterase profiles could be used for identification of theArmillariaspecies in Hokkaido as a useful complement to the mating‐type metho

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01347.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryTwo devices were evaluated for the inspection of wood decay caused byUstulina deusta (Hypoxylon deustum, the‘Metriguard’stress‐wave timer for decay detection, and the‘Fractometer’, a sample corebreaking gauge, for measurement of the loss of strength. The stress‐wave timer failed to detect decay caused by the fungus in naturally infected trees or jinoculated wood blocks, but detected decay in wood blocks from various tree species inoculated with the white‐rot basidiomycetesFomes fomentarius, Ganoderma pfeifferi, andPolyporus squamosus, and the brown‐rot basidiomyceteLeatiporus sulphureus. The Fractometer showed large losses of strength in inerement cores incubated with all the test fungi, includingU. deusta, even at an early stage of decay. The patterns of cell‐wall degradation, as shown by light microscopy, were consistent with the observed brittle nature of deeay caused byU. deustaand with the results of testing the two devices. Both in naturally infected trees and in wood bloeks, early degradation took the form of a soft‐rot, with cavity formation in the S2 layer of the secondary cell walls. A white‐rot supervened, but with prolonged persistence of a brittle, lignin‐iich 'skeleton’that appeared to transmit stress‐waves with li

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01348.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryIn central Italy,Pseudomonas syringaepv.morsprunorumwas isolated from wild cherries (Pranus avium) that had been planted for timber production. Biochemical tests were consistent with those characterizing the pathovar. Pathogenicity tests yielded necrotic lesions, shot holes on the leaves and decoloration of the tissues beneath the twig periderm, but no symptoms on inoculated lilac and pear leaves. In addition, whole‐cell protein profiles of the isolates and reference strains were remarkably homogenous when analysed by cluster analysis. All isolates were negative in ice‐nucleation activity and in antifungal‐compound production. The main symptoms observed in the field were cankers on twigs, branches and trunks, as well as withering of the shoots. Evalution of the field susceptibility of 18 clones indicated that the following selections must be considered susceptible to the pathogen: Montemignaio, Piantata Catenaia, Puzzolo, Raggiolo, Pozzacce 2, Pozzacce I, Paradision. Alpe 2 seems to be less suscep

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01349.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryHypovirulent strains ofCryphonectria parasiticaproduced superficial cankers on American chestnut (Castanea dentata) that were unstable for superficiality after one winter. Some unstable cankers yieldedC. parasiticaisolates that had high virulence on American chestnut trees and were vegetatively incompatible with the original inoculated hypovirulent strain, whereas other unstable cankers yielded isolates that had low virulence and were vegetatively compatible with the original hypovirulent strain.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01350.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryInfection of Norway spruce (Picca abies) by Heterobasidion annosum in relation to tree ageThe presence ofH. annosumin stems and roots of youngPicea abiesof different age classes was determined in four heavily infected stands in Southern Germany. The frequency of infected trees increased with age (0% in age class I (I‐10 years), 7,5% in class 2 (11‐20 years), 33,3% in class 3 (21‐30 years)). Only the S‐type was found. An additional investigation of 1‐10‐year‐old trees growing on stumps withH. annosumdecay or tightly surrounded by carpophores yielded an infection rate of 20% (mainly S‐type).H. annosumwas confined to very small regions in the host tissue

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01351.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryChanges in composition of the monoterpene fraction in damaged roots of Norway spruce and the potential significance for resistance against Heterobasidion annosumThe composition of monoterpenes in undamaged and wounded roots of Norway spruce (Picea abics) was investigated, α‐ and β‐Pinene comprised at least 85%. of the total content in undamaged roots. The variation of the monoterpene fraction within roots and between roots of an individual tree was relatively small. Variations of the monoterpene fraction between trees were found. There were no qualitative differences between stem and roots except for sabinene, which was found in small amounts in the stem. Large quantitative differences between stem and roots were found in α‐ and β‐pinene content. In almost all trees, damaging the sapwood of roots caused an increase in the α‐pinene content combined with a decrease in the relative content of β‐pinenc and limonenc/β‐phellandrene. Two different types of traumatic reaction in heartwood could be distinguished. The possible significance of the traumatic reaction in the roots of spruce with respect to their resistance toH.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01352.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryPhytophthora cactorum, the causal agent of beech seedling blight, can killFagus sylvaticaseedlings within a few days. Eight isolates ofPhytophtbora cactorumand one isolate ofPhytophtbora citricolawere tested for their pathogenicity towards beech seedlings derived from eight different registered stands. TheP. citricolaisolate proved to be more aggressive than all theP. cactorumisolates, although there were significant differences among the latter. The influence of the seed source was less sever than that of the fungi. Regions of provenance generally had less influence on disease development than fungal isolate but differences in susceptibility among sources were important in the interaction between isolate and source.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01353.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe history of damage caused byGremmeniella abietinaon 10 Scots‐pine trees (Pinus sylvestris) was studied near a nickel smelter in Tsuna, Russia. The most severely damaged area was located alongside a river. According to the results of branch analysis, the first sign ofG. abietinainfection occurred in 1937. During the following 4 decades, annual signs were few and they occurred at random. Most of the damage had appeared during the 1980s and the early 1990s. In terms of cankers, the peak occurred in the mid‐1980s, and in terms of scars and leader changes, the peak was in the late 1980s and early 1990s. Branch mortality and secondaryTomicusspp. attacks increased in the late 1980s and were at their highest level in the early 1990s. The high number of matureG. abietinapycnidia on shoots formed in the years 1989–1991 suggests that the epidemic will continue in the near f

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1995.tb01354.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY