Die Wirkung wäßriger Streuextrakte verschiedener Waldbäume auf Mycelwachstum und Konidiosporenkeimung von Fomes annosus (Fr.) Cke.

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.     

Influence of acidity on the growth of Trichoderma viride Pers. ex Fr. and on the inhibitory effect of its filtrates against Fomes annosus (Fr.) Cke. in artificial cultures

This work reports results of observations on mycelial dry weight yield, pH changes and the inhibitory effect of filtrates of Trichoderma viride on linear growth of the mycelium of Fomes annosus. The maximum mycelial yield of T. viride, derived from spores was obtained within the pH range 2,5–3,1. The greatest inhibitory effect of filtrates on the mycelial growth of F. annosus occurred at an initial pH of the Trichoderma cultures from 2,0-3,5. At other pH-values, no inhibition was found.     

Effects of monoterpenes on Fomes annosus (Fr.) Cooke and its phenol oxidase activity

Fomes annosus was cultivated subject to vapours of monoterpenes. Three monoterpenes were tested separately: α-pinene, β-pinene and 3-carene. The terpenes inhibited the dry matter production of the fungus but extracellular phenol oxidase activity was increased, particularly when the fungus was exposed to vapours of β-pinene and 3-carene.     

Studies on Ectomycorrhizae of Pine

As a gas phase all the monoterpenes and the sesquiterpene longifolene used in the present study inhibited the extension growth of Phytophthora cinnamomi and Fomes annosus. The forementioned compounds are constituents of ectomycorrhizal root systems of Scots pine. It is suggested that compounds of host origin play an important role in the disease resistance of ectomycorrhizal root systems.     

Fomannoxin production by different spruce isolates of Fomes annosus

In vitro production by five isolates of Fomes annosus obtained from diseased spruce trees in Irish Forestry plantations is compared. Identification of these isolates as five distinct strains is based on quantitative differences in fomannoxin production, differences in linear growth rate and mycelial interaction between isolates in paired culture.     

Inhibitory effect of Trichoderma viride Pers. ex Fr. filtrates on Fomes annosus (Fr.) Cke. In relation to some carbon sources

The mycelial yield of Trichoderma viride on a number of carbon sources and the inhibitory effect of its filtrates on Fomes annosus were investigated. d-Xylose and d-glucose as carbon sources in the media gave the highest degree of inhibition when their filtrates were directly tested against F. annosus mycelium. The protection of pine wood blocks with filtrates was most effective when these were derived from cellulose and d-xylose.     

Zum Vorkommen von Fomes annosus (Fr.) Karst. im Boden von Fichtenbeständen (Picea abies Karst.)1

Occurrence of Fomes annosus in the soil of spruce stands (Picea abies Karst) . In stands of spruce Fomes annosus was found to occur in a viable state in the litter and soil to a depth of 25 cm. Successful isolations were obtained from 153 samples out of a total of 216. In ca. 40% of the 153 samples Fomes annosus could be isolated from 9 mg of soil; in the remaining samples it was found either in 90 mg, 230 mg or in 900 mg. The results raise the possibility of direct infection of the roots of spruce by Fomes annosus from the soil.     

Fomannoxin,a phytotoxic metabolite of Fomes annosus: in vitro production,host toxicity and isolation from naturally infected Sitka spruce heartwood

The effect of different culture conditions on growth and production of fomannoxin and the sesquiterpene phytotoxin fomannosin by a single isolate of Fomes annosus was studied. Whereas fomannoxin was produced by actively growing hyphae, fomannosin production was associated with the declinning growth phase of the fungus. The presence of fomannoxin in chloroform extracts from the stained stein heartwood zone of Fomes annosus diseased Sitka spruce trees was established. Fomannosin however was not detected. Toxicity of fomannoxin to germinating seeds and young seedlings of Sitka spruce was demonstrated.     

Über die Infektion von Fichtenwurzeln (Picea abies Karst.) durch Forties annosus (Fr.) Cke.

Infection of roots of spruce (Picea abies Karst.) by Fomes annosus present in the soil. 108 roots of spruce were severed at approximately 50 cm from the base of the tree. The resulting wounds were invaded by Fomes annosus originating as mycelium or basidiospores in the soil. Infection rate on limestone soils was 41 %, on other soils 10 %. Odontia bicolor also grew into spruce roots from the soil.     

Antifungal properties of terpenoids in Picea abies against Heterobasidion parviporum

The antifungal properties of 14 major oleoresin‐constitutive terpenoids of Norway spruce (Picea abies) against Heterobasidion parviporum were evaluated in vitro at three gradient concentrations, 0.1, 0.2 and 0.4 μmol/cm², on potato dextrose agar medium. Eight monoterpene hydrocarbons (+)‐ and (?)‐α‐pinene, (?)‐β‐pinene, (+)‐3‐carene, myrcene, (+)‐ and (?)‐limonene, terpinolene; four oxygenated monoterpenes α‐terpineol, terpinen‐4‐ol, 1,8‐cineole, bornyl acetate; and two resin acids abietic acid and dehydroabietic acid were selected. Abietic and dehydroabietic acids showed the highest antifungal activities at all concentrations. Among oxygenated monoterpenes, bornyl acetate and α‐terpineol showed antifungal activity at the highest concentration. Among monoterpene hydrocarbons, (+)‐α‐pinene showed similar activity to terpinen‐4‐ol and 1,8‐cineole at the highest concentration; however, it was lower than α‐terpineol and bornyl acetate. Other monoterpene hydrocarbons inhibited mycelial growth by <10%. Re‐extraction of medium surfaces after the test period revealed that most α‐terpineol and terpinen‐4‐ol remained unchanged on the surface but monoterpene hydrocarbons completely disappeared. However, notable fungal transformed products were observed on surfaces applied with 1,8‐cineole and bornyl acetate. Thus, mycelial growth inhibition of monoterpenoids might be caused by complex functions such as biodegradation and/or detoxification by interaction between mycelium and compound. These results provide a basis for future studies considering the role of chemodiversity in the comprehensive chemical defence of P. abies.     

Beziehungen zwischen dem Ernährungszustand der Fichte (Picea abies Karst.), ihrem Kernfäulebefall und der Pilzhemmwirkung ihres Basts1

Relationships between nutrition and heart rot attack of Norway spruce (Picea abies Karst.) and the fungistatic effect of its inner bark . The fresh inner bark of Norway spruce stems and roots inhibits mycelium growth of Fomes annosus on malt agar. Nearly all fungistatic substances of the inner bark can be extracted with chloroform and acetone. The acetone-soluble fraction, which amounts to 13–27% of bark dry matter, was analysed. Up to now 12 phenolic substances have been identified, 5 of them have proved to inhibit Fomes annosus in vitro. Open-air-experiments showed, that desiccation of the root-zone, manganese deficiency and nitrogen hypertrophy decrease the inhibitory effect of the inner bark as well as its content of fungistatic substances. The degree of heart rot attack in older spruce stands was found to be negatively correlated with the N-, Fe- and Mn-concentrations in needles.     

Infektion und abbau der Wurzelrinde von Fichte durch Fomes annaus1

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.     

Genetic variation in Picea abies (L.) Karst. and Fomes annosus (Fr.) Cke. shown by growth of the fungus on wood dust

Growth of Fomes annosus is studied by a test based on growth of previously starved hyphae on sawdust of heartwood of Picea abies as the only nutrition. Our observations show that the method can be used to distinguish beween different spruce individuals or clones, between different Fomes annosus strains and between different growing sites of the trees.     

Fichten-Mykorrhizen auf Standorten der Schwäbischen Alb und ihre Beziehung zum Befall durch Fomes annosus

Spruce mycorrhizac and heart rot incidence caused by Fomes annosus in southwestern Germany. Naturally occurring spruce mycorrhizac on calcareous soils of southwestern Germany were investigated and classified. These soils are characterized by a relatively high incidence of heart rot caused by Fomes annosus. On comparable sites stand history (former woodlands versus former sheep pastures), though influencing heart rot incidence, had no effect on the overall distribution of mycorrhizal types. The occurrence of rare types, however, varied between sites with different stand history. For all mycorrhizal types found, isolation of the fungal symbiont was attempted. Where isolation was successful, the isolates showed no antibiotic activity against Fomes annosus.     

The effect of L-threonine on oxalic acid synthesis by Fomes annosus

Addition of 1 mM L-threonine to the growth medium of Fomes annosus inhibited its glyoxylate deliydrogenase activity and the synthesis of oxalic acid. Malate synthetase was synthesized de novo in the presence of L-threonine. Lignosulfonate completely blocked the effect of the amino acid in both glucose or cellobiose-containing medium.     

Effect of different nitrogen and carbon sources and concentrations on the mycelial growth of ectomycorrhizal fungi under in-vitro conditions

Effect of different nitrogen and carbon sources and their concentrations in liquid media on the mycelial growth of six different ectomycorrhizal (ECM) fungal species was studied. Differences were found in the utilization of the different nitrogen and carbon sources between the fungal species. All the species showed better mycelial growth in the medium containing ammonium as nitrogen source. Growth was low in all species in medium in which nitrogen was supplied in nitrate form. All the ECM isolates investigated showed reduced growth in the medium containing maleic acid as the carbon source. The effect of glucose and di-ammonium hydrogen orthophosphate concentrations on mycelia growth of all the six fungal species was studied with ranges for glucose of 2–40 g/l, and for di-ammonium hydrogen orthophosphate of 2–20 g/l. Cortinarius fulvoconicus and Cortinarius flexipes showed maximal mycelial growth at a glucose concentration greater than 20 g/l. Suillus luteus, Scleroderma citrinum, Laccaria laccata, and Tricholoma aurantium showed maximal growth at a glucose concentration of 20 g/l. All six species showed maximal mycelial growth at 5–10 g/l of di-ammonium hydrogen orthophosphate concentration and with increased concentration mycelial growth in all species decreased.     

Toxicity of monoterpenes from Pinus radiata cortical oleoresin to Diplodia pinea spores1

The effect on spore germmation and germ tube growth of Diplodia pinea produced by (+)- α-pinene, (?)-β-pinene, (+)-Δ³-carene, (?)-limonene, β-phellandrene, and terpinolene was determined over a range of vapour concentrations. Spore germination was most inhibited by A³-carene; germ tube growth was inhibited by all these monoterpenes except (?)-limonenc and ß-phellandrene. In contrast to the low toxicity of (?)-limonene, (+)-limonene (not known to be present in Pinus radiata cortical oleoresin) was extremely toxic to both spore germination and germ tube growth. The results arc discussed in rotation to an earlier observation that trees free of dieback in the field had high levels of certain monoterpenes.     

Phytoalexin production by Aspen (Populus tremuloides Michx.) in response to infection by Hypoxylon mammatum (Wahl.) Mill and Alternaria spp.

Freshly wounded stem sections of P. tremuloides Michx. produce phytoalexin when inoculated with mycelium of Hypoxylon mammatum (Wahl.) Mill., and Alternaria sp. These exudates are inhibitory against spore germination of these two fungi and, although inhibitory against mycelial growth of Alternaria sp., have no effect on the mycelial growth of H. mammatum. It was possible to correlate the amount of phytoalexin elicited by different strains with the inhibitory activity.     

Tree-to tree variation on Picea abies in growth inhibition against Fomes annosus

The spread of Fomes annosus was measured on a set of 20 mature trees which were artificial inoculated. These observations were compared with growth observations and laccase activity of F. annosus grown on wood dust from the same 20 trees. Although variation between Fomes strains as well as between trees was recorded, correspondance between field and laboratory observations was absent in the present material.     

Effects of oleoresins and monoterpenes on in vitro growth of fungi associated with pine decline in the Southern United States

As a means of exploring pine resistance to root disease and declines, the effects of host plant secondary metabolites on the growth of root colonizing fungi associated with three diseases/declines of southern pines – loblolly pine decline, littleleaf disease and annosum root rot were tested. The associated fungi –Leptographium huntii, L. serpens, L. terebrantis, L. procerum, Heterobasidion annosum and Phytophthora cinnamomi– were grown in saturated atmospheres or in direct contact with, pure monoterpenes and crude oleoresin collected from the four southern pines (Pinus taeda, P. eschinata, P. palustris and P. elliotti) for 7 day. Fungal growth was measured at 3, 5 and 7 day. Root‐infecting fungi differed significantly in sensitivity to crude oleoresin and pure monoterpenes. All fungi tested were inhibited, to some extent, by the resins tested. H. annosum and P. cinnamomi were strongly inhibited by all the monoterpenes tested. The ophiostomatoid fungi were significantly less affected by the compounds tested. L. huntii and L. serpens were less inhibited by monoterpenes than either L. terebrantis or L. procerum. These fungal growth studies show that the kind and amount of secondary metabolite produced by the host plant have a profound effect on tree pathogens. Alterations of tree physiology may have implications for defenses against tree pathogens as well as to the ecology and management of forest ecosystems. Difference in incidence of root disease observed in the field may be explained by the ability of the fungus to tolerate these host defense mechanisms.