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Studies of cytology and growth of different strains of Fomes annosus (Fr.) Cooke. I. Numbers of nuclei and DNA content in different isolations and stages of development. In cytological and cytophotometric studies, determinations were made of nuclear numbers and DNA contents of both conidia and basidiospores, of the primary mycelium and of mycelium after plasmogamy. Information was also obtained on parasexual phenomena in dikaryotic mycelium which can be held responsible for the great variability of the fungus.  相似文献   

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The effect of water extracts of leaf and needle litter from different forest trees on the mycelial growth and the germination rate of conidia of Fomes annosus (Fr.) Cke. Litter extracts from various forest trees and stands have distinct effects on mycelial growth and germination rate of conidia of Fomes annosus. The effects depend on concentration of the extract, period of extraction and on date of collecting the litter samples.  相似文献   

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SEM-Contribution to the attack of Chrysomyxa abietis teliospore-layers by larvae of a midge . Larvae of a non-identified midge (mycodiplosis group, Diptera Cecidomyidae) feed on spore layers of Chrysomyxa abietis, a parasite of spruce needles. This paper reports information about the biology and behaviour of that midge in connection with the fungus.  相似文献   

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Infection and Deterioration of Spruce Root Bark by Fomes Annosus . The paper describes the mode of infection and consequent deterioration of spruce root bark by the root rot fungus, Fomes annosus using light and electron microscope observations. Spread of fungal hyphae occurs through bore holes produced by enzymatic activity. Although a definte loss of wall substance occurs, the bark tissues primarily represent merely a pathway for the fungus before it colonieses the xylem.  相似文献   

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A method for examining Norway spruce (Picea abies Karst.) for susceptibility and resistance to the spread of Fomes annosus (Fr.) Cooke . An easily applied method is described for determining the results of infections and the reactions of young Norway spruce to Fomes annosus. By the use of genetically homogeneous material, e. g. clonal plants, the importance of environmental factors such as nutrient supply and also the varying virulence of different fungal strains can be studied.  相似文献   

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Natural pruning of branches and its biological conditions. VI. Survey of wood degradation by branch inhabiting fungi . Laboratory tests demonstrated that fungi occurring on decaying branches and probably associated with natural pruning of branches are capable of degrading wood. Most fungi tested positive for the Bavendamm-reaction and therefore produce phenol-oxidase. The inoculation of wood blocks caused a typical soft rot. Impact-resistance tests showed that fungi involved in natural pruning of branches can considerably reduce strength of wood.  相似文献   

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Hosts of Fomes annosus (Fr.) Cke in France. Records of Fomes annosus in France since 1875 are listed. They include several examples not given in Sinclair 's 1964 account and also include seven new hosts.  相似文献   

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Zusammenfassung Es wurden in Kiefernkulturen Untersuchungen über die Tagesdynamik des Harzdruckes und der Intensität der Harzabsonderung geführt und die Ergebnisse in Beziehung zum Befallsgrad des KiefernknospentriebwicklersRhyacionia buoliana Schiff. gesetzt.Im Verlauf eines Tages variierte der Harzdruck wenig, die Intensität der Harzabsonderung dagegen stark. Die höchste Harzfluß-Intensität fällt in den Zeitraum zwischen 13 und 16 Uhr. Die Flugzeit des Wicklers, nach 18 Uhr, liegt somit außerhalb der Zeit des stärksten Harzflusses.Weder der Index der Harzfluß-Intensität noch jener des Harzdruckes zeigten eine Beziehung zur Stärke des Wicklerbefalls. Sie sind daher als Kriterien der Widerstandsfähigkeit einer Kulturkiefer gegenRh. buoliana, zumindest unter den Verhältnissen der Süd-Ukraine, nicht verwendbar.
Summary Studies on the diurnal rhythm of resin pressure and resin secretion in connection with the degree of pine-infestation byRhyacionia buoliana Schiff.In the course of one day pines in the age of 15 years showed only a small variation in resin pressure but a great one in secretion of resin. The maximal intensity of secretion was observed early in the afternoon. The moths ofRh. buoliana are flying after this time when the secretion of resin is low.There was no connection between resin pressure and secretion of resin on the one hand and the degree of pine-infestation byRh. buoliana on the other. The two factors are not suitable for indicating the degree of pine-infestation by this tortricid.

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Zusammenfassung Bei der ertragskundlichen Bearbeitung der mittelschw?bischen Seegras-Fichtenforste ergaben sich drei Wuchsreihen mit unterschiedlichem Ertragsniveau auf verschiedenen Standortseinheiten. Weitgehend von physikalischen Bodenfaktoren, insbesondere vom Grad der Pseudovergleyung, h?ngt die Wuchsleistung der Fichte ab. Die physiognomisch ziemlich einheitlichen Seegras-Fichtenbest?nde entstammen verschiedenen natürlichen Waldgesellschaften mit unterschiedlicher ?kologie, Vegetationsdynamik, Verjüngungsbereitschaft und Leistungsf?higkeit. Sie k?nnen daher waldbaulich nicht einheitlich beurteilt werden. Auf den stabilen Standorten des artenreichen natürlichen Seegras-Eichen-Buchenwaldes mit vorherrschender Braunerdedynamik kann auch zukünftig die überdurchschnittlich leistungsf?hige Fichte den Bestandestyp pr?gen. Dagegen sind die labilen Standorte der artenarmen Gesellschaft auf stark ausgepr?gtem Pseudogley vordringlich zu meliorieren. Für diese Umbauschwerpunkte wird ein ausgewogen gemischter, biologisch wie betriebswirtschaftlich realisierbarer Bestandestyp aus Laubbaumarten (Stieleiche, Buche, Hainbuche, Winterlinde), Tanne, Kiefer (Japanl?rche) und Fichte vorgeschlagen.
Summary A yield study of Carex brizoides-Picea abies forests in Middle Schwaben showed the existence of three growth series with different yield levels. The physiognomically rather uniform Carex brizoides-Picea abies stands derive from different natural forest assoziations with a different degree of surface water influence (pseudo gley), different vegetation dynamics, regenerative capacity and yield potential. At stable sites of the Carex brizoides-Quercus-Fagus forests with an abundance of species and a predominant dynamic typical of gray-brown podzolic soils, spruce-showing an above average growth capacity-may determine the stand type in the future too. The unstable sites on predominant gleyic soils, with a scantiness of species are in urgent need of amelioration by mixed stand types of deciduous species (Quercus robur, Fagus silvatica, Carpinus betulus, Tilia cordata) and fir, pine, spruce (and possibly Larix leptolepis).
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Fomes annosus (Fr.) Cke. and other decay fungi in a Douglas fir stand, Pseudotsuga menziesii (Mirb.) Franco. 40% of the trees in a 40 years old Pseudotsuga menziesii stand showed butt rot. 85 trees were analysed for decay fungi. Fomes annosus, the most frequent fungus, also invaded the sap wood. Factors of the soil favourable to the rot and the possibility of transmission of the most frequent decay fungus, Fomes annosus, from (a) neighbouring spruce stands, (b) from the roots of Scots pine from the previous crop arc discussed. Caniophora puteana was isolated from about 10% of the butt rots. The importance of Calocera viscosa which grew out of the central decay of twelve trees as a decay fungus is still under investigation.  相似文献   

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Studies on the influence of nutrition on the susceptibility of plants to SO2 . The mineral nutrition of plants is of great importance for their susceptibility to air pollutants. Substrate media with ammonia as nitrogen source, deficiency of potassium and low pH-values reduce the buffer capacity and the cation contents. Buffer capacity and cation contents play important roles for the detoxification of SO2-borne products. Low cation contents and a reduced buffer capacity produce a severe increase of the SO2-effects. Decreased sulfur nutrition results in a considerable delay of the beginning of the SO2-injuries.  相似文献   

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The spread of Fomes annosus from artificial infections of stems, in relation to the chemical characteristics of timber of two spruce clones . Differences in the spread of Fomes annosus in two spruce clones (Picea abies Karst.), which were found by DIMITRI, may be attributed to differences in the properties of the wood from the two clones, detected in laboratory tests. Wood meal from the more resistant clone R inhibited Fomes annosus in bioassays more than wood meal from the more susceptible clone A. Wood from clne A-trees showed a higher nitrogen content than wood from clone R-trees.  相似文献   

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