摘要:

AbstractOver 4000 records of the six EuropeanArmillariaspecies were compiled to give distribution maps and host lists for each species. Differences in geographical and altitudinal distribution, pathogenicity, dissemination and ecological role are discussed.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00814.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractReproductive rates of three North American isolates ofBursaphelenchus xylophilusand a Finnish isolate ofB. mucronatuswere compared by culturing the nematodes at constant and at daily fluctuating temperatures in the laboratory and in the field.Botrytis cinereaandPinus sylvestriswood were used as nutrient sources. In general, theB. xylophilusisolates reproduced better than theB. mucronatusisolate at constant temperatures, whereas the situation was reversed at fluctuating temperatures.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00815.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractChlorophyll fluorescence induction of Scots pine needles was measured under field conditions in the vicinity of an oil refinery, and in the greenhouse after a recovery period of 20 h. Pigment content of needles was also determined. Sulphur dioxide is discussed as a potential factor affecting the light reactions of photosynthesis.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00816.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractRoadside reconnaissance and aerial photo surveys were used to characterize the frequency and size of canopy gaps caused byArmillariaroot disease in 1763 stands ofPinusspp. in the eastern Transvaal, South Africa. Root disease occurred in 290 stands, most of which grew at altitudes 1000 m.Pinus elliottiiwas the most commonly infected host, followed byP. kesiya, P. roxburghii, P. caribaea, P. taeda, andP. patula. Disease severity (proportion of stand area with gaps) increased rapidly to age 3, remained nearly constant between ages 6–17, increased rapidly again between 17–28, and then decreased abruptly between ages 28–40. Gap incidence (proportion of all stands with gaps) rapidly increased to age 10, after which it remained nearly constant. Host species present in previous stands influenced whether disease developed in current s

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00817.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIncreased foliar N/K and N/Mg ratios are known to reduce the resistance ofPinus sylvestristo scleroderris canker caused byGremmeniella abietina. The aim of this work was to study how such changes in nutrient levels affect the growth of the pathogen in vitro. The mycelium of the pathogen was grown on artificial media adjusted to simulate the changes in inorganic N, K, Mg and Ca and free amino acid concentrations in the host with nutritional imbalance. Increased concentrations of K and Ca reduced the mycelial growth of the pathogen, whereas a modest increase in the concentration of inorganic N increased the growth. Tenfold concentrations (compared with normal host levels) of arginine and glutamic acid, and up to one hundred‐fold concentrations of proline increased the mycelial growth. The results suggest, that nutrient imbalances may enhance the colonization of host tissues by G.abietin

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00818.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effect of the growth phase of pine seedlings on the success ofGremmeniellainfection was studied in both simulated and natural growing seasons. Also the effect of cold and drought stress on the success of the infection was studied.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00819.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractIn a field experiment in central Sweden, the vigour of 25‐yr‐old Scots pines was manipulated by pruning, prior to inoculation withLeptographium wingfieldiiandOphiostoma minus, two blue‐stain fungi associated withTomicus piniperda. Our main purpose was to correlate fungus invasion and host defence reactions with host vigour. Both fungi invaded the inner bark and the sapwood at the points of inoculation.L. wingfieldiicaused larger lesions in the bark, but O.minustended to grow faster in the sapwood. The flow of primary resin was related to tree vigour, whereas carbohydrates present in needles and stem phloem were not. Lesion formation and the content or composition of resin acids in lesions did not differ between fungi or pruning treat

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00820.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractDifferent combinations of two decay fungi (Heterobasidion annosum, Stereum sanguinolentum), two non‐decay fungi (Nectria fuckeliana, Ascocoryne cylichnium), a yeast‐like fungus and two bacteria (Bacillus pumilus, Enterobacter agglomerans) all of spruce origin, were inoculated into stems of 16 healthy‐lookingPicea abies. Growth and survival of the microbes were followed over the subsequent five years. The rapid upward vertical spread of the decay fungi during the first two years was followed by a later regression and loss of these decay fungi by the fifth year.The stems were effectively colonized by the bacteria,A. cylichniumand/orNeobulgaria premnophilawhich then persisted over the whole experimental period. The endophytic fungi,N. premnophilaandA. cylichnium, were abundant in the stems of the experimental trees before inocul

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00821.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe spatial arrangement of discolouration and decay from artificial wounds inEucalyptus regnanswas consistent with the CODIT model of shigoand marx(1977) up to 2 years after wounding. Discolouration and decay had spread more from wounds which remained bark‐covered than from those where the bark was removed from the bol

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00822.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe winter activity of soil organisms and of the fungusPhacidium infestansinoculated on excised Scots pine shoots was monitored by measuring CO2concentrations under the snow cover. Other variables measured, relating to respiration, were the temperature under the shoot heaps and the depth of snow cover. The concentrations were highest when the temperature under the snow remained at a relatively high level during the whole winter which also favoured respiration fromP. infestans. When the soil was covered with a thin layer of snow, the conditions did not favor a high respiration rate until the snow melt period.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1993.tb00823.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY