摘要:

SummaryPinus contorta, logs with occluded cankers caused by the pathogenGremmeniella abietina, as well as logs from unaffected trees were sampled from a 23‐year‐old plantation in Sweden and compared in terms of their paper properties. Damaged wood gave kraft pulp with poor paper properties: it required a larger amount of beating energy and resulted in paper with low tear strength, air permeability, tensile stiffness, burst strength, and poor light‐scattering properties. However, small amounts of damaged wood mixed in with a large amount of healthy wood can pass almost unnoticed. The use of trees with a larger content of damaged wood will lead to serious processing problems and give a pulp with poor paper properties. Thus, wood damaged byGremmeniellashould be sorted out and classed as low‐grade raw m

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1996.tb00716.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryPolygalacturonase was found to be one of the first enzymes secreted by a pathogen during infection. The polygalacturonic‐acid hydrolysing activity was compared between the North American and the European race ofGremmeniella abietina in vitro. Isolates were grown in pure pectin media from which the enzyme activity was analysed. Altogether, 29 isolates were tested in five experiments (experimental runs in a growing chamber). The data were analysed using variance‐component models that included fixed‐race effects and random‐experiment, isolate, flask and measurement effects. The European race secreted more polygalacturonic‐acid hydrolysing enzyme than the North American race and the mycelial dry weight produced was smaller for the European race. The differences between races were of the same order of magnitude as the variation between isolates within races; variance components relating to experimental errors were quite large. No correlation was found between the activity and mycelial dry‐matter production within the races. Logarithmic transformation removed the apparent racial differences in the variability of the activity and mycelial dry weight. Results from the additionally tested A‐ and B‐type of Finnish isolates indicated differences in dry‐

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1996.tb00717.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryThe susceptibility of oak seedlings (Quercus palustris, Quercus robur, Quercus rubra) and chestnut seedlings (Castanea sativa) toPhytophthora cinnamomiwas tested. The dynamics of infection was examined in plant material raised in a rhizotron. In the oak species, primary root tissues were susceptible whereas secondary cortical tissues showed some resistance toP. cinnamomi. Secondary cortical tissues of the tap root inC. sativawere susceptible. Inoculations withP. cinnamomiwere performed bothin situand on excised roots of matureQ. rubra. In both cases, the resistance ofQ. rubraroots and shoots was negatively correlated with diameter at the inoculation point. Small roots (l–5‐cm diameter) were resistant, whereas collar and trunk were susceptible. In contrast to oak, small excised roots of matureC. sativa(0.7–2‐cm diameter) were susceptible toP. cinnamomi. This may explain whyP. cinnamomidoes not induce a decline of the attacked oaks, but rather a trunk

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1996.tb00718.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryChanges in soluble phenol contents of Scots‐pine (Pinus sylvestris) phloem were studied after inoculation withOphiostoma brunneo‐ciliatum, a fungus associated withIps sexdentatus. They were compared to the length of the fungus‐induced reaction zone of the phloem, taken as an estimation for the trees' response efficiency against aggression.Five clones consisting of 14 trees were studied, and eight soluble phenolic metabolites were analysed in detail in reaction zones and in unwounded phloem sampled 3 weeks after inoculation.The stilbenes pinosylvin and pinosylvin monomethylether, and the flavonoid pinocembrin, were detected in reaction zones only. Concentrations of two p‐coumaric‐acid esters and an acetophenone glycoside decreased after inoculation. Variations of the flavonoids taxifolin and 3' taxifolin glucoside were inconsistent.One tree had longer reaction zones and a phenolic content different from the others. In unwounded phloem, concentrations of some phenolic compounds and in particular the ratio between the two p‐coumaric‐acid esters could be markers for trees' response efficiency. In the reaction zone, markers could be the ratios between concentrations of certain preformed compounds and concentrations of newly synthesized pinosylvin an

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1996.tb00719.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryA novel method, Random Amplified Microsatellites (RAMS, due to the nature of amplified markers as two randomly amplified microsatellites with the intervening sequence), was applied to generate DNA markers in a variety of fungi (Armillaria cepistipes, Gremmeniella abietina, Heterobasidion annosum, Pbytophthora cactorum, Phlebiopsis gigantea, andStereum sanguinolentum). It is based on the polymerase chain reaction (PCR), and uses primers containing microsatellite sequences and degenerate anchors at the 5' end. The method is highly reproducible, applicable to all tested fungal species including members of the Phycomycetes, Ascomycetes and Basidiomycetes, and allows detection of interspecific and intraspecific DNA‐polymorphism

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1996.tb00720.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Book Reviews in this article:Manka, M. (ed.):Environmental Biotic Factors in Integrated Plant Disease Control.Scheiner, M.S.; Gurevitch, J. (eds.):Design and Analysis of Ecological Experiments.Bormann, F.H.; Likens, G.E.;Pattern and Process in a Forested Ecosystem. Disturbance, Development and the Steady State Based on the Hubbard Brook Ecosystem Study.Perrin, R.; Sutherland, J.R. (eds.):Diseases and insects in forest nurseries.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1996.tb00721.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY