Le Linospora ceuthocarpa (Fr.) Munk ex Morelet,parasite foliaire des peupliers

Linospora ceuthocarpa (Fr.) Munk ex Morelet, a parasite of poplar leaves. Linospora ceuthocarpa (Fr.) Munk ex Morelet and its conidial stage Titaeosporina tremulae (Lib.) v. Luyk are experimentally connected and described. The life history of the disease on poplar leaves is studied.     

Biological control of Heterobasidion annosum (Fr.) Bref. (Fomes annosus) in Finland

Fresh stumps of Norway spruce (Picea abies) were inoculated with Peniophora gigantea (Fr.) Massee, Botrytis cinerea Pers. ex Fr., Gliocladium deliquescens Sopp, Trichoderma viride Pers. ex Fr. ex S. F. Gray aggr. and Verticicladiella procera Kendrick in order to study their effect on infection by Heterobasidion annosum (Fr.) Bref. The organisms colonizing spruce stumps under natural conditions were identified by collecting samples in the field. In addition, the effect of season of the year, air temperature, precipitation and relative air temperature on fungal colonization of the stumps was investigated.     

Morphologische und taxonomische Untersuchungen an Naemacyclus niveus (Pers. ex Fr.) Fuck. ex Sacc. und verwandten Arten

Morphological and taxonomical studies in Naemacyclus niveus (Pers. ex Fr.) Fuck. ex Sacc. and related species. Biometrical studies of apothecia, ascospores and pycnospores suggest that two species of Naemacyclus exist on pine needles; each has a characteristic host-relationship. One is Naemacyclus niveus (Pers. ex Fr.) Fuck. ex Sacc., the original species of Persoon ; the other is described here as Naemacyclus minor nov. spec.     

Death of bark in Acer pseudoplatanus associated with drought

Radially flattened fibres and parenchyma cells, together with buckled and constricted rays were interpreted as a drought ring in Sycamore (Acer pseudoplatanus L.). The damage was dated to late summer of 1972, an exceptional drought year in Scotland. Nectria coccinca (Pers. ex Fr.) Fr. and Verticillium tenerum (Nees ex Pers.) Link (Nectria inventa Pethybridge) were the two organisms found almost exclusively in bark and wood of lesions on stems and branches. These lesions were non perennating and had been formed at the end of the 1972 growing season.     

Notes on Ectotrophic Mycorrhizae of Pinus patula in South Africa

The discovery of ectotrophic mycorrhizae of Pinus patula Schlecht. et Cham. formed by Boletus edulis Bull, ex Fr., Amanita muscaria (L. ex Fr.) Pers. ex Hooker and possibly Tuber rapaeodorum Tul. et Tul. and Lycoperdon umbrinum Pers. is described. Aseptic culturing of mycorrhizae was carried out with A. muscaria and B. edulis, and chemical tests employed in agaricology, applied to these species and L. umbrinum to determine their association with natural mycorrhizae.     

A tree-ring study of Norway spruce infected with the wood-destroying fungus Armillaria mellea

A stand otPicea abies (L.) Karst. was studied using the method of tree-ring analysis. The stand involved non-infected trees and trees at different stages of infection by the wood-destroying fungus Armillaria mellea (Vahl. ex Fr.) Kummer [Armillariella mellea (Vahl.) Karst.].     

Stem-rot damage and the progress of causal fungi in old-aged Japanese larch trees at the foot of Mt. Fuji

Damage caused by stem-rot and the progress of the causal fungi in old-aged Japanese larch (Larix kaempferi (Lamb.) Carr.) was investigated at the foot of Mt. Fuji. Stem-rot was found in 75% of 108 trees investigated, and volume of rot was 6% of the total wood volume in the forest investigated. Stem-rot damage was much greater than the damage by butt-rot.Stereum sanguinolentum (Alb. and Schw. ex Fr.) Fr. infected larch trees at the greatest incidence (49.4%). However,Porodaedalea chrysoloma (Fr.) Imaz. caused the most volume loss to the trees.S. sanguinolentum infected larch stems mainly through stem wounds, and decay caused by the fungus progressed 9.75×10² cm³/year on average.P. chrysoloma infected larch stems mainly through dead branches and wounds, and the average rate of decay progress for the fungus was 2.74×10³ cm³/year.     

Rasterelektronenmikroskopische Abbildungen von Hyphen des Birkenporlings (Piptoporus betulinus) im Holz von Betula pendula

Scanning electron micrographs of the hyphae of Piptoporus betulinus in timber of Betula pendula. Hyphae of Piptoporus betulinus (Bull, ex Fr.) Karst. were photographed in naturally infected timber of Betula pendula Roth by means of scanning electron microscopy. The hyphae had an average diameter of 3μm and a cell wall thickness between 0.4 and 0.7 μm. The dissolution of the cell wall by specific fungal enzymes can be extremely well studied using scanning electron microscopy.     

Detection of early stages of wood decay by acoustic emission technique

Acoustic emissions of pine wood samples (Pinus sylvestris L.) previously infected with the soft-rot fungi (Chaetomium globosum Kunze) and brown-rot fungi (Coniophora puteana (Schum. ex Fr.) Karst.) were measured in the perpendicular to grain compression test, in the radial direction. It was found that even a minimum mass loss (below 1%) caused by enzymatic deterioration of the wood substance resulted in an increase in acoustic emission level in the compression test measured perpendicular to grain in the radial direction. A particularly sensitive indicator of wood enzymatic destruction were cumulative counts of acoustic emission related to the value of the applied compression load. Received 4 March 1997     

Infection strategy of Hymenochaete tabacina

The infection courts of Hymenochaete tabacina (Sow. ex Fr.) Lév. were studied in stands of Corylus avellana and on stems of Sorbus aucuparia and Syringa vulgaris. The fungus was able to spread through tight contacts between stems that were bound together by fungal tissue. H. tabacina could spread from a dead to a living stem within and between different stools of hazel and from one tree species to another.     

The effect of Trifluralin on the formation of ectotrophic mycorrhizae in some pine species I. Toxicity to mycorrhiza forming fungi

Laboratory experiments were conducted to test the effect of various concentrations of Trifluralin on certain fungi. The ectotrophic mycorrhizal fungi tested were: Amanita citrina Schaefer, Tricholoma pessundatum (Fr.) Quel., and Tricholoma saponaceum (Fr.) Qtiel. All exhibited sensitivity to Trifluralin concentrations. The consequence of such fungitoxicity was discussed.     

Effect of an ectomycorrhizal fungus,Laccaria laccata,on Fusarium damping-off in Pinus banksiana seedlings

Damping-off caused by Fusarium oxysporum Schlecht in Pinus banksiana Lamb, was reduced significantly when inoculated with an ectomycorrhizal fungus, Laccaria laccata (Scop. ex Fr.) Berk. and Br. In paired culture, growth of F. oxysporum was significantly reduced by L. laccata. The number of colony forming units of F. oxysporum was reduced significantly in the rhizosphere of P. banksiana seedlings when inoculated with L. laccata. Spore germination and germ tube length of F. oxysporum was inhibited strongly by culture filtrate of L. laccata and root exudate of P. banksiana inoculated with L. laccata. Mycorrhizal seedlings had significantly higher amount of total soluble phenols than nonmycorrhizal ones.     

Fertilizer levels and fungal strain influence the development of ectomycorrhizae on Sitka spruce seedlings

Effects of low, medium, and high applications of solid, controlled-release fertilizers on ectomycorrhizal formation of containerized Sitka spruce (Picea sitchensis (Bong.) Carr.) seedlings with a nursery or forest isolate of either Thelephora terrestris (Ehrh.) Fr., Laccaria laccata (Scop. ex Fr.) Cooke, or the E-strain fungus was evaluated 14 weeks after inoculation. The influence of fungal species and isolate source on seedling growth and nutrient status was also evaluated through an analysis of variance. Seedlings receiving the low level of fertilization were significantly smaller than those receiving the medium or high level. Fungal species and isolate source did not affect seedling size and was significant only for the percentage of short roots colonized which tended to be highest in the low fertilizer treatment. Analyses of foliage revealed that concentrations of nitrogen and phosphorus did not differ significantly by fertilizer level or fungal type whereas potassium was significantly higher at the low level of fertilization and magnesium was significantly lower at the low level of fertilization.     

Les ectomycorrhizes naturelles de Betula pendula + Cortinarius armillatus

Naturally occurring ectomycorrhizae of Betula pendula + Cortinarius armillatus. Ectomycorrhi-zae of Betula pendula Roth. +Cortinarius armillatus (Fr.) Fr. are described for the first time. Ecological data of Cortinarius armillatus are briefly reviewed.     

Aspect of herbicidal effects on the ectosymbiotic microorganism of the forest plants

Experiments were conducted under laboratory conditions to establish the sensitivity or otherwise of the following mycorrhizal fungi: Tricholoma saponaceum (Fr.) Quel., Tricholoma pessundatum (Fr.) Quel. and Amanita citrina Schaefer to the herbicides Dalapon and Aminotriazole. Various reactions were shown by the fungi. In general, the rareness of growth stimulation coupled with significant inhibition of mycelial growth are indications of the fungitoxicity of the herbicides.     

Variation in relative resistance to spread of Fomes annosus in four clones of Picea abies

The stems of 160 cuttings including 32 controls of four clones of Picea abies (L.) H. Karst., grown for two seasons in the nursery, were inoculated with Fomes annosus (Fr.) Cke. No differences in resistance to spread of the pathogen were observed after 5 weeks, but after 13 weeks the fungus had spread (P < 0.10) less in one of the clones.     

Comportement in vitro du Sparassis crispa Wulf. ex Fr. et du Sparassis laminosa Fr

Behaviour in vitro of Sparassis crispa Wulf. ex. Fr. and Sparassis laminosa Fr . Sparassis crispa and S. laminosa are described in culture following the method used by Nobles. S. crispa is a very active wood destroying fungus in blocks of Douglas fir (sapwood and heartwood) in laboratory tests. The cauliflower-like fructifications are easily produced on malt-agar and could be produced on a large scale.     

Heterobasidion annosum infection of Picea abies following manual or mechanized stump treatment

Heterobasidion annosum (Fr.) Bref. s. l. colonization following thinning was studied in 1246 stumps of Picea abies (L.) Karst. trees from 14 previously unthinned stands in Sweden. Treatments included mechanized and manual application of (1) 35% urea solution, (2) Phlebiopsis gigantea (Fr.) Jül. spores, and (3) 5% solution of disodium octaborate tetrahydrate (DOT), and untreated stumps, cut in the summer and winter. Compared with untreated stumps cut in the summer, all stump treatments and winter cuttings significantly reduced the colonized stump area 6–7 weeks after thinning by 88–99%. Mechanized stump treatment provided as good protection as manual treatment against H. annosum infections. The probability of spore infection (p _ij ) was reduced by 53–83% in mechanized treatment and 79–98% in manual treatment compared with untreated summer thinning. In terms of p _ij , urea had significantly higher control efficacy than P. gigantea and manual treatment performed better than mechanized treatment.     

Rhizina undulata. A review of research in the Netherlands1

Research on killing of coniferous trees caused by the fungus Rhizina undulata Fr. ex Fr. in the Netherlands is reviewed. Aspects of the fungus’ pathogenicity, its biology and pyrophilous nature, and means to restrict or avoid damage in young plantations and older stands are discussed.     

Fungal symbionts of siricid woodwasps: isolation techniques and identification

European woodwasps of the genera Sirex and Urocerus have symbiotic relationships with basidiomycetes, Amylostereum chailletii (Pers. : Fr.) Boid. and Amylostereum areolatum (Fr.) Boid. The fungal symbionts of siricid woodwasps are contained in a pair of mycangia located at the top of the ovipositor. A technique used for isolating the fungal symbionts from mycangia is described and illustrated using Urocerus gigas L. and Sirex juvencus L., and isolation of the fungi from wood and fruitbodies is described briefly. Some characteristics are given of the involved fungi, A. chailletii and A. areolatum.