J.-André Fortin

Laval University | ULAVAL · SBF

The acidity of peat-based substrates used in forest nurseries limits seedling mineral nutrition and growth as well as the activity of microorganisms. To our knowledge, no study has yet evaluated the use of granular calcite as a covering material to increase pH, calcium and CO2 concentrations in the rhizosphere and ectomycorrhizal development. The o...

We developed a method combining passive baiting (animals that are not trapped) with DNA meta-barcoding of the feces acquired, to study fungi in the diet of small mammals. Mammal and fungal species were identified using genomic DNA of 596 fecal samples collected in five regions of the eastern Canadian boreal forest. For identification of the small m...

Biofilm formation on abiotic and biotic surfaces was studied with two hyphobacteria, strongly attached to the surface of the arbuscular mycorrhizal fungus (AMF) Rhizoglomus irregulare (Ri) DAOM 197198 and two mycorrhizobacteria, loosely attached to the roots of different mycorrhizal plants. When the sparingly soluble igneous phosphate rock (PR) fro...

Fluorapatite-solubilizing bacteria were isolated from the hyphosphere of the ectomycorrhizal (ECM) fungus Wilcoxina sp., a dominant species in the Picea glauca rhizosphere. Hundreds of strains isolated from the ascomycete Wilcoxina sp. could dissolve tricalcium phosphate, while only 27 of them could produce clarification halos on fluorapatite-amend...

Canadian oil sands tailings are predominately sodic residues contaminated by hydrocarbons such as naphthenic acids. These conditions are harsh for plant development. In this study, we evaluated the effect of inoculating roots of Alnus viridis ssp. crispa and Alnus incana ssp. rugosa with ectomycorrhizal fungi in the presence of tailings compounds....

Avant-propos de la deuxième édition Avant-propos de la première édition 1. La vie en symbiose 2. Les symbioses végétales et leurs structures 3. Origine des symbioses végétales et leurs rôles dans l’évolution de la vie terrestre 4. Physiologie des mycorhizes 5. Les mycorhizes dans les écosystèmes 6. Biologie des champignons forestiers comestibles 7...

A simple method is described for trapping phosphate solubilizing bacteria (PSB) strongly attached to the hyphae of the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis (. Ri). Bacteria were isolated from the hyphosphere of mycorrhizal leek plants growing on Turface previously inoculated with soil suspensions, obtained from the mycorrhizo...

Despite the economic importance of chanterelles, much remains to be known about their habitat requirements. Cantharellus cibarius var. roseocanus Redhead, Norvell & Danell sporocarp productivity was measured during three growing seasons in two Pinus banksiana Lamb. stands of boreal forest. The objective was to determine how the variability in stand...

With the object of knowing the endophyte morphology, axenic root nodules of Alnus crispa var. mollis Fern. were studied by light microscopy. The nodule endophyte was present in three forms: the hypha, which was branched or unbranched, measured between 0.3 μ and 1.0 μ; the vesicle (3–5 μ), which was septate, developed at the hyphal tip; and the bact...

The ectomycorrhizal fungus Suillusgranulatus prevented the phytopathogenic fungus Myceliumradicisatrovirens from adversely affecting the growth of aseptically grown seedlings of Piceamariana. Disease symptoms caused by M. radicisatrovirens are summarized for aseptically grown pine and spruce seedlings.

Suillusgranulatus prevented the stunting effect of root pathogen Myceliumradicisatrovirens on Pinusresinosa (red pine) seedlings grown in gnotobiotic conditions. In these conditions, the presence of carbon dioxide also seems to have stimulated a better growth of the seedlings inoculated with Suillusgranulatus as compared with the controls. In the l...

Various methods were compared for surface sterilization of Alnuscrispa (Ait.) Pursh. seeds. A 20-min treatment with 30% hydrogen peroxide plus Tween 20 surfactant gave the highest percentage of normal axenic germinants.

White ash seedlings (Fraxinusamericana L.) were inoculated with five species of endomycorrhizal fungi. On the 2nd week after transplantation, growth of inoculated plants differed from control plants. Growth also differed between each fungal species used, but the difference decreased after 82 days of culture. Only dry mass remained higher in plants...

The absorption of phosphate ions by long lateral nonmycorrhizal roots and by four of the most prevalent types of ectomycorrhizae of Abiesbalsamea was followed over one season of growth. For each experiment, the excised roots were bathed for 2.5 h in a buffered nutrient solution containing 100 μg•L−1 of KH2PO4 and 100 μCi•L−1 (1 Ci = 37 GBq) of KH23...

Containerized jack pine (Pinusbanksiana Lamb.) seedlings were grown in a peat moss – vermiculite substrate and inoculated at sowing with pure cultures of three ectomycorrhizal fungi. After 18 weeks of growth in the greenhouse, seedlings inoculated with Laccariabicolor had 97% of their short roots mycorrhizal, while those inoculated with Hebelomacyl...

The effects of H2SO4 watering on the competitive interactions of outplanted mycobionts was studied in a jack pine plantation in Quebec. Ectomycorrhizal jack pine seedlings produced in growth pouches and inoculated with either Pisolithustinctorius (Pers.) Coker and Couch or Laccariabicolor (Maire) Orton as well as noninoculated seedlings were expose...

Picea mariana seedlings were grown in containers under nitrogen fertilization (6,8,5, and 15 mg/seedling per season). Seedlings were inoculated at sowing with Laccaria bicolor and Hebeloma cylindrosporum. After 20 wk in the greenhouse, seedlings fertilized with 8.5 mg N and inoculated with L. bicolor had the highest percentage of ectomycorrhizal sh...

The potential allelopathic (phytotoxic or beneficial) effect of barley, oat, and wheat straw mulches was evaluated on growth, mineral nutrition, and mycorrhizal status of black spruce seedlings, under greenhouse conditions. The various straws did not affect spruce seedling height growth over a 2-month growth period. The newly formed fine roots of t...

This paper reports the effects of Glomus intraradices (Schenck & Smith) external mycelium, mycorrhizal, and nonmycorrhizal transformed carrot roots (alone or in interaction with Pseudomonas aeruginosa (Schroeter) Migula, Pseudomonas putida (Trevisan) Migula, or Serratia plymuthica (Dyar) Bergey et al.) on phosphorus solubilization and pH changes of...

The interactions between arbuscular mycorrhizal fungi and bacteria may affect the nutrient dynamics in the environment. To study these changes, assays were conducted in a two-compartment Petri plate system. A NO3--N medium containing an insoluble phosphate (P) source was used to evaluate the effect of Glomus intraradices (Schenck & Smith) external...

Diarimella laurentidae, a new species occurring on dead bark and decorticated twigs of American beech (Fagus grandifolia Ehrh.), is reported from the Muir's Wood ecological reserve, located in the centre of the Haut-Saint-Laurent region in the province of Quebec. Diarimella laurentidae is characterized by stromatic, pulvinate, black, setose fructif...

Cuttings of Picea mariana (Mill.) B.S.P. and Larix decidua Mill, were rooted in a peat moss – vermiculite substrate inoculated with vegetative mycelium of two ectomycorrhizal fungi. The fungal influence on rooting was compared with auxin-treated cuttings. The symbionts stimulated rhizogenesis of P. mariana, resulting in significantly increased root...

The rooting pattern of tamarack hypocotyl cuttings produced under the influence of the ectomycorrhizal fungus Laccaria bicolor (Maire) Orton was assessed and compared with the rooting patterns induced by three plant growth regulators. No callus was produced in fungal and control treatments, and the rooting percentages were 93 and 100%, respectively...

The ectomycorrhizal fungus Pisolithus tinctorius secreted a metabolite that lysed hypha and conidia and inhibited the germination of conidia in a range of phytopathogenic fungi. The optimum incubation period for the production of the metabolite by P. tinctorius in liquid culture was 42–56 days. Dilutions of the culture filtrate with fresh medium ca...

The ability of 28 monokaryons and 78 reconstituted dikaryons of Pisolithus sp. from South Africa to form mycelial strands in association with Pinus pinaster was tested under aseptic and non-aseptic conditions. All monokaryotic and some dikaryotic cultures failed to form mycelial strands either on agar medium or in growth pouches. The remaining dika...

Ectomycorrhizal macrofungus communities were classified across a sequence of four forest associations in the Laurentide Mountains. Cluster analysis was used to delimit two types of coenological units: grouping and sociological group. Three macrofungal groupings and two subgroupings, which vary with physiognomic and floristic–edaphic parameters of t...

Container-grown jack pine (Pinus banksiana) seedlings were inoculated with a wild strain of the ectomycorrhizal fungus Laccaria bicolor. Seedlings were raised for 24 weeks and were given various nitrogen fertilization levels as well as long and short day regimes. Basidiomes occurred from week 16 up to the end of the experiment (24 weeks) depending...

The effect of the mycorrhizal fungus Glomus intraradices on disease development caused by Fusarium oxysporum f.sp. dianthi in the nonmycorrhizal species Dianthus caryophyllus was studied by co-culture of carnation plants with the mycorrhizal species Tagetes patula. Presence of VAM T. patula plants more than doubled the survival of D. caryophyllus,...

Endogone pisiformis is described in pure culture on various normal mycological media. The usually coenocytic mycelium is characteristically coloured yellow and bears numerous lipid-fllled hyphal swellings. Under axenic conditions, hyphae are attracted to Sphagnum, but the fungus has neither sporulated on nor parasitized the Sphagnum. Endogone pisif...

Stages in ectomycorrhizal development between the fungus Pisolithus tinctorius (Pers.) Coker & Couch and short roots of Pinus strobus L. were followed in growth pouches. Short roots from preinoculation through Hartig net formation were processed for light and electron microscopy. Fungal hyphae approaching the surface of roots have Thiéry-positive s...

Greenhouse experiments were conducted to compare the growth of mycorrhizal and nonmycorrhizal plants in a calcined montmorillonite clay (Turface) supplied with nutrient solutions of different P concentrations. Apple (Malus pumila Mill., var. Beautiful Arcade), leek (Allium porrum L., var. American Flag), and marigold (Tagetes patulus L., var. Golde...

Greenhouse experiments were performed to compare the nutrient uptake of mycorrhizal and nonmycorrhizal plants grown in a calcined montmorillonite clay (Turface) supplied with nutrient solution containing different amounts of P. The host plants used were apple (Malus pumila Mill., var. Beautiful Arcade), leek (Allium porrum L., var. American Flag),...

A lectotype is designated for Glomus macrocarpum Tul. & Tul. from the original Tulasne collections. As a consequence of the examination of type materials of previously proposed synonyms of this species, three new combinations are made: Glomus australe (Berk.) Berch, Glomus versiforme (Karst.) Berch, and Glomus tenebrosum (Thaxter) Berch.

The known geographic distributions of Endogone pisiformis, Endogone incrassata, Endogone lactiflua, Glomus macro-carpum, Glomus radiatum, and Glomus vesiculifer (Endogonaceae) are extended into the northwest of mainland Canada. Descriptions and observations of taxonomic and ecological features of these collections are provided. Morphologically, the...

The interaction between Glomus intraradices Schenck & Smith, a vesicular–arbuscular mycorrhizal fungus, and Fusarium oxysporum Schlecht f.sp. radicis-lycopersici Jarvis & Shoemaker and its effect on tomato plants were investigated over a 12-week period. The root colonization by Glomus was not affected by the presence of Fusarium. The number of Fusa...

A rapid field method to evaluate the competitive performance of selected ectomycorrhizal isolates is presented. Ectomycorrhizal jack pine seedlings and noninoculated controls produced in growth pouches were outplanted in diverse stations 1 month after inoculation. Photographs taken prior to outplanting and at the time of excavation permitted compar...

Protoplasts were released from dikaryotic mycelium of the ectomycorrhizal basidiomycete Laccaria bicolor using the lytic enzyme preparation NovoZyme 234. Protoplast release depended strongly on mycelium age, osmotic stabilizer, and temperature. The protoplasts could regenerate to form both monokaryotic and dikaryotic cultures capable of forming nor...

The ability of tamarack to form ectomycorrhizae with different fungi was investigated by using a pouch technique. Ninety-one out of 109 fungal isolates from 25 different species formed ectomycorrhizae on larch seedlings. Tamarack displays strong specificity for ectomycorrhizal fungi identified as sporocarp-specific to larch under field conditions:...

The relative ability of sibling monokaryotic and reconstituted dikaryotic cultures of Laccaria bicolor (Maire) Orton to colonize short roots of Pinus banksiana Lamb. was studied using two different methods at 4, 8, and 12 months after isolation. Monokaryotic isolates varied in their ability to form ectomycorrhizae. Some lost the ability to colonize...

The incompatibility system of four Laccaria bicolor collections was studied and found to be bifactorial with multiallelic mating type factors. One of the collections studied was a biological species of L. bicolor that was intersterile, but morphologically identical, with the others. Seedling growth parameters and ectomycorrhiza formation were measu...

The ability of Populus tremuloides Michx. to form ectomycorrhizae with identified species of fungi was investigated using a pouch technique. Twenty-nine out of 54 fungus species formed ectomycorrhizae on aspen seedlings. Aspen seems to display little specificity for ectomycorrhizal fungi. Only epidermal Hartig nets were observed in the synthesized...

Growth pouches were used to establish ectomycorrhizae of Pinus strobus using Pisolithus tinctorius as inoculum. An epi-illumination technique was used to follow changes in external morphology of short roots as they became colonized by hyphae and dichotomized. Apices became broader and flatter before an obvious dichotomy was apparent. Secondary dich...

Flat, transparent polyester growth pouches were used for synthesis of ectomycorrhizae on Pinus strobus seedlings. Typical ectomycorrhizae with mantle and Hartig net were obtained within 5 days after inoculation with Pisolithus tinctorius. An extensive extramatrical network of hyphae and hyphal strands could be observed within 15 days after ectomyco...

A culture medium promoting the in vitro nodulation of Alnus crispa var. mollis Fern. was established. Under well-defined growth conditions, a minimum inoculum of about 1 μg of fresh nodule per plant was sufficient to promote good nodulation of the host plant. Using the suspension–dilution technique combined with inoculation tests, it was possible t...

Antifungal activity of three different Rhizobium isolates was tested against eight different fungi. Some of these fungi are potential phytopathogens on legumes. Inhibition zones were observed in several cases. Similar results were obtained with the cell-free extract of the media on which Rhizobium had been grown.

Mycelium radicis atrovirens is known as a sterile fungus colonizing the surface of rootlets of trees in the boreal forest. Microscopic examination of 41 isolates conforming in vegetative morphology to the type description of this fungus revealed the presence of phialoconidia corresponding to Phialocephala dimorphospora in 15.

A method of growing excised root cultures of leguminous plants was modified for the culture of excised roots of Pinus sylvestris L. The inclusion of a portion of hypocotyl on the expiants from the seedlings was found essential to obtain sustained growth of the root. With such explants, typical ectotrophic mycor-rhizae were obtained upon inoculation...

Mechanisms involved in post-fire morel fructification remain unclear. A new undescribed belowground vegetative structure of Morchella tomentosa in a burned boreal forest was investigated north of Fairbanks, Alaska. The name "radiscisclerotium" is proposed to define this peculiar and elaborate below-ground vegetative structure of M. tomentosa. Bayes...

Four different light intensities exerted distinctly different effects on the formation, reproduction and influence of vesicular-arbuscular mycorrhiza on onion plants. Over a growth period of 100 days, the rate of infection under low light intensities (5 and 10 klux) was more rapid and the percentage of infection higher than on mycorrhizal plants cu...

The effects of vegetative inoculum of Laccaria bicolor (Maire) Orton, Pisolithus tinctorius (Pers.) Coker & Couch and Hebeloma cylindrosporum (Bull. & St. Am.) Quél. and addition of fine soil suspensions to jack pine (Pinus banksiana Lamb) and American larch [Larix larcina (DuRoi) K. Koch] seedlings were studied under controlled environmental condi...

Interaction between mycorrhizal Basidiomycetes and pine roots in presence of indol-3yl-acetic acid. — La croissance de deux Basidomycètes mycorrhizateurs, Suillus variegatus (Sw. ex Fr.) et S. granulatus (L. ex Fr.) O. Kuntze a été rendue possible dans un milieu contenant au départ des quantités d'acide indol-3yl-acétique (AIA) inhibitrices pour ce...

La croissance en milieu liquide de quelques champignons mycorhizateurs a étéétudiée en présence d'acide 3-indlolyl-acétique (AIA). Les champignons suivants ont été utilisés: Amanita muscaria (L. ex Fr.) Quél., A. rubscens (Pers. ex Fr.) Quél., Suillus granulatus (L. ex Fr.) O. Kuntze et S. variegatus (Sw. ex Fr.) O. Kuntze. Tous ont été inhibés, à...

Preface Part I State of the Art 1 In vitro culture of mycorrhizas J.A. Fortin, S. Declerck & D.G. Strullu Part II Systematics 2 The Monoxenic culture of arbuscular mycorrhizal fungi as a tool for germplasm collection S. Declerck, S. Seguin & Y. Dalpe 3 The Monoxenic culture of arbuscular mycorrhizal fungi as a tool for systematics and biodiversity...

Market dobalization, demographic pressure, and environmental degradation have led us to reconsider many of our current agricultural systems. The heavy use of chemical inputs, including fertilizers and pesticides, has resulted in pollution, decreased biodiversity in intensively-farmed regions, degradation of fragile agro-ecosystems, and prohibitive...

The study of arbuscular mycorrhizal (AM) fungi and the AM symbiosis formed with host plant roots is com- plicated by the biotrophic and hypogeous nature of the mycobionts involved. To overcome this, several attempts have been made during the last three decades to obtain this symbiosis in vitro. The use of root-organ cultures has proved particularly...

This work addresses the symbiotic culture of the arbuscular mycorrhizal (AM) fungus Glomus intraradices with Daucus carota hairy roots transformed by Agrobacterium rhizogenes, in two submerged culture systems: Petri dish and airlift bioreactor. AM fungi play an active role in plant nutrition and protection against plant pathogens. These fungi are o...

 A reliable inoculum, free from other microorganisms, to produce arbuscular mycorhizal (AM) plants is of the greatest importance when studying the interaction between AM plants and soil microorganisms. We investigated the colonization of leeks from monoxenic in vitro-produced Glomus intraradices spores. The isolated spores were produced using a two...

Arbuscular mycorrhizal (AM) fungi can reduce the incidence and importance of plant root diseases caused by pathogens. The mechanisms involved are not well characterized. We used an in vitro experimental system to test the hypothesis that the extraradical mycelium of AM fungi can interfere directly with microorganisms in the mycosphere and directly...

Polynema muirii sp. nov. is described and illustrated from Fagus grandifolia collected in the Muir's Wood, Québec, Canada. It is compared with known Polynema species. This is the second report of a species of Polynema from North America.

Lamhamedi, M. S., Fortin, J. A., E1 Ammari, Y., Benjelloun, S., Poirier, M., Fecteau, B., Bougacha, A., Godin, L. 1997. Evaluation des composts, des substrats et de la qualité des plants (Pinus pinea, Pinus halepensis, Cupressus sempervirens & Quercus suber) élevés en conteneurs. Projet Banque mondiale N3601. Direction Générale des Forêts, Tunisie...

The influence of different N sources on medium pH variation and the effect of the external mycelium of arbuscular mycorrhizal fungi on nutrient dynamics were studied using a two-compartment, aseptic Petri plate system. VA mycorrhizal, transformed roots of carrot (Daucus carota L.) were cultured in the proximal compartment and external mycorrhizal m...

Arbuscular mycorrhizal (AM) fungi are ecologically important for most vascular plants because they benefit plant growth and survival. The obligate biotrophic nature of AM fungi imposes limitations in inoculum production which could be used in the management of the symbiosis in field crops. Glomus intraradices was grown on genetically transformed Da...

Vesicular arbuscular mycorrhizal fungi can reduce plant disease symptoms and populations of pathogens through mechanisms that are not well understood. Glomus intraradices was grown on Daucus carota transformed roots in a two-compartment in vitro system. One compartment contained mycorrhizal roots on a complete growth medium, while the other contain...

Herbicides are increasingly used in orchards. Since apple trees strongly depend on mycorrhizae, the effects of three commonly used herbicides on the host plant and endophyte were examined. Symbiosis between tissue-cultured P16 apple rootstocks and Glomus versiforme (Karsten) Berch was established under greenhouse conditions. Simazine (1, 2, 10, and...

A 12-week greenhouse experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal fungi on four apple ( Malus domestica Borkh) rootstock cultivars: M.26, Ottawa 3 (Ott.3), P.16, and P.22. The plants were grown in soil from an apple rootstock nursery, containing high levels of extractable P (644 kg Bray/1 ha ⁻¹...

Development of the Laccariabicolor (Maire) Orton basidiome in association with container-grown Pinusstrobus L. seedlings was influenced by photosynthetic photon flux densities (PPFD). Three growth patterns were observed. At a PPFD of 330 μmol•m−2•s−1, basidiome growth was rapid, and complete development was achieved after 16 days. At a very low PPF...

Reconstituted dikaryons of Pisolithus sp. (Pers.) Coker & Couch from South Africa influenced growth parameters (shoot length, shoot/root ratio and leaf area), nutrition and physiological indicators (transpiration rate, stomatal conductance and xylem water potential) of maritime pine (Pinus pinaster Ait.) seedlings during drought and recovery from d...

La culture d'un champignon endomycorhizien à vésicules et arbuscules, #Gigaspora margarita$ en association avec des racines transformées en carotte, en conditions axéniques et sur un même milieu, a permis d'obtenir un inoculum de qualité selon un modèle simple et reproductible. Ce système de culture permet de produire massivement des hyphes mycélie...

Nineteen agricultural and sylvicultural plant species cultivated in Zaire were tested under field conditions for their response to endomycorrhizal fungi. All plant species, except amaranth, showed various degrees of root colonization in non-fumigated and fumigated soil. African yam bean, wild mung, acacia, leucaena, onion, sweet potato, tomato and...

Liquid culture media in which homokaryons of Pisolithus arhizus from Australia and South Africa, and synthesized heterokaryons from South Africa had grown, were assayed for inhibition of the germination of conidia of the seedling pathogen, Truncatella hartigii. Ten homokaryons from an Australian strain displayed a wide-range of variability, with on...

The antibiotic compounds p-hydroxybenzoylformic acid [2-(4′-hydroxyphenyl)-2-oxoethanoic acid, pisolithin A] and (R)-(−)-p-hydroxymandelic acid [(R)-(−)-2-(4′-hydroxyphenyl)-2-hydroxyethanoic acid, pisolithin B] were isolated from the growth culture of Pisolithus tinctorius. Both of these metabolites, and a few structurally related compounds, were...

Des cultures monocaryotiques et dicaryotiques de Pisolithus sp. issues d’Afrique du Sud diffèrent dans leur pouvoir à coloniser les racines de Pinus pinaster. Contrairement aux monocaryons, les dicaryons ont stimulé la croissance des semis de P. pinaster. Aucun des monocaryons n’a formé des cordons mycéliens en présence ou en absence de la plante-h...

E-strain fungi form ecto- and ectendomycorrhizal associations with many trees, and are important mycorrhizal symbionts in disturbed forest habitats and conifer nurseries. Unlike the majority of mycorrhizal fungi, which are basidiomycetes, E-strain fungi are ascomycetes belonging to the genus Wilcoxina (Pezizales). We analysed variation in the nucle...

A fungus-biotope and a cluster analysis of macrofungal communities were done across a sequence of four forest associations in the Laurentide Mountains of Qubec. Comparison between different scales of sampling indicated that the cohesion and individuality of macrofungal clusters tend to increase from the whole mycoflora of a site toward trophic grou...

Two antifungal compounds isolated from the liquid culture medium of Pisolithus arhizus were identified as p-hydroxybenzoylformic acid and (R)-(-)-p-hydroxymandelic acid and given the trivial names pisolithin A and pisolithin B, respectively. The efficacy of the compounds to inhibit the germination of conidia of Truncatella hartigii was compared wit...

The mitochondrial DNA (mtDNA) from 25 Laccaria bicolor, 8 L. laccata, 3 L. proxima and 2 L. amethystina isolates was examinated by restriction fragment length polymorphism (RFLP) analysis. Whole-cell DNA from Laccaria isolates was digested with Bam HI, Bgl II and Hind III and probed in Southern hybridizations with cloned mitochondrial fragments fro...

We used the polymerase chain reaction (PCR) to amplify specific regions of the nuclear and mitochondrial genomes of fungi using DNA extracted from pure cultures as well as that directly from ectomycorrhizal rootlets. The internal transcribed spacer (ITS) of the nuclear ribosomal repeat unit and a portion of the mitochondrial large subunit ribosomal...

Container-grown Pinus strobus seedlings inoculated with a wild strain of the ectomycorrhizal fungus Laccaria bicolor, were raised under the same controlled growth conditions for 14 wk after which conditions were varied. Lowering the temperature from 24/18 °C (day/night) to 18/12° inhibited the fruiting of L. bicolor associated with P. strobus. A sh...

Seedling roots of Pinus banksiana were coinoculated under aseptic conditions with pairs of isolates of the ectomycorrhizal fungus Laccaria bicolor. Fungal cultures reisolated from second-order lateral roots were identified using isozyme patterns in combination with other phenotypic characters. There were examples where both inoculants persisted on...

summaryThe ability of 28 monokaryons and 78 reconstituted dikaryons of Pisolithus arhizus (Scop, pers Pers.) Rauchert [Syn.: Pisolithus tinctorius (Pers.) Coker & Couch] to form ectomycorrhizas on Pinus pinaster (Ait.) Sol. and Pinus banksiana (Lamb.) was studied using the growth pouch method. The ability to form mycorrhiza and promote growth of P....

Time course experiments were used to study the colonization of Pinus banksiana roots by 4 variants of Laccaria bicolor (d1 and d2 being dikaryons made by crossing the 2 sib-monokaryons, m4 and m10, on two separate occasions). Hyphal-root contact was first observed 4 or 5 d after inoculation. In the 2 d time required for the completion of the thick...

A comparison of cultures of E-strain fungi isolated from mycorrhizal roots and cultures isolated from ascocarps of the teleomorph genus Wilcoxina indicates that the majority of E-strain fungi can be accommodated in two taxa, Wilcoxina mikolae and Wilcoxina rehmii. Comparisons were based upon restriction fragment polymorphisms within the nuclear rib...

Eleven specimens of basidiospores of Pisolithus arhizus of various provenances were assayed for their ability to germinate. Three incubation amendments were tested for their basidiospore germination induction value. Two amendments were made in combination, using different seedlings on differently amended media. An additional assay was made using tw...

Eleven specimens of basidiospores of Pisolithus arhizus of various provenances were assayed for their ability to germinate. Three incubation amendments were tested for their basidiospore germination induction value. Two amendments were made in combination, using different seedlings on differently amended media. An additional assay was made using tw...

Hyphal growth from germinating spores of Gigaspora margarita was monitored under several conditions: with or without roots, root colonization, or removal of the spore. The results indicate that roots stimulate fungal growth by different mechanisms. Before colonization, roots provide inductive factors which promote fungal growth when the nutrients i...

The cell free culture media of 16 ectomycorrhizal fungi were tested for their ability to inhibit the growth of 23 phytopathogens and one ectomycorrhizal fungus. Extracellular metabolites of seven (44%) ectomycorrhizal fungi, Amanita citrina, Laccaria bicolor, Laccaria Iaccata, Pisolithus tinctorius, Suillns brevipes, Trircholomo flavovirens and Tri...

The macrofungal flora of the deciduous forest was composed mainly of many infrequent species, whereas coniferous forests had few, but very frequent, macrofungi. Total frequency was significantly lower (15%) in open stands of the spruce-Cladina association. Species richness decreased gradually (from 125 to 34 species) towards the N and with increasi...