Colonization of Pinus banksiana roots by Laccaria bicolor variants: structural characterization

1990 ◽  
Vol 28 (1-4) ◽  
pp. 557-561 ◽  
Author(s):  
Ken K.Y. Wong ◽  
Yves Piché ◽  
Diane Montpetit ◽  
J.André Fortin
Keyword(s):  
Structural Characterization ◽  
Pinus Banksiana ◽  
Laccaria Bicolor

Differences in the colonization of Pinus banksiana roots by sib-monokaryotic and dikaryotic strains of ectomycorrhizal Laccaria bicolor

1989 ◽  
Vol 67 (6) ◽  
pp. 1717-1726 ◽  
Author(s):  
Ken K. Y. Wong ◽  
Yves Piché ◽  
Diane Montpetit ◽  
Bradley R. Kropp
Keyword(s):  
Pinus Banksiana ◽  
Intraspecific Variability ◽  
Root Cell ◽  
Laccaria Bicolor ◽  
Cortical Cells ◽  
Aseptic Culture ◽  
Hartig Net ◽  
Cell Layers ◽  
The Mean ◽  
Root Surfaces

First-order laterals of Pinus banksiana seedlings were inoculated with variant strains of ectomycorrhizal Laccaria bicolor in an aseptic culture system. Macroscopic observations of 10 fungal strains indicated that 6 are mycorrhizal and 4 are apparently nonmycorrhizal. Furthermore, light microscopic examinations revealed significant intraspecific variation in mycorrhizal structures. The mean mantle thickness, mean mantle density, and mean Hartig net penetration of the six mycorrhizal strains ranged from 2.5 to 13.4 hyphae, 278 to 411 hyphae/mm and 2 to 2.8 root cell layers, respectively. Three of these strains formed fewer macroscopically observable mycorrhizae and developed significantly thinner mantles but their Hartig nets usually separated cortical cells more extensively. Three of the four apparently nonmycorrhizal strains showed infrequent and poor Hartig net development (mean penetration of 0.3 to 0.8 root cell layer), poor surface colonization, and no mantle development. These three strains were better able to colonize long roots. Only one strain could be considered truly nonmycorrhizal because it only colonized root surfaces poorly and never showed mantle or Hartig net formation. The observed intraspecific variability raises questions concerning the determinants of mycorrhiza development and structure.

A Petri dish technique for the aseptic synthesis of ectomycorrhizae

1989 ◽  
Vol 67 (6) ◽  
pp. 1713-1716 ◽  
Author(s):  
Ken K. Y. Wong ◽  
J. André Fortin
Keyword(s):  
Pinus Banksiana ◽  
Petri Dish ◽  
Microbial Interactions ◽  
Laccaria Bicolor ◽  
Larix Laricina ◽  
Hebeloma Cylindrosporum ◽  
First Order ◽  
Whole Plants ◽  
Improved Technique ◽  
Physiological And Biochemical

An improved technique was developed for the aseptic synthesis of ectomycorrhizae in Petri dishes. Within 2 weeks after inoculation of a first-order lateral, ectomycorrhizae were formed on Larix laricina and Pinus banksiana with Hebeloma cylindrosporum, Laccaria bicolor, and Pisolithus tinctorius. The technique should be useful for addressing physiological and biochemical questions concerning microbial interactions with roots of whole plants.

Variable loss of ectomycorrhizal ability in monokaryotic and dikaryotic cultures of Laccaria bicolor

1987 ◽  
Vol 65 (3) ◽  
pp. 500-504 ◽  
Author(s):  
Bradley R. Kropp ◽  
Brenda J. McAfee ◽  
J. André Fortin
Keyword(s):  
Mating Type ◽  
Pinus Banksiana ◽  
Laccaria Bicolor ◽  
Relative Ability

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 rootlets. Dikaryons formed soon after isolation from compatible mating type pairs were vigorous colonizers. A dikaryon formed after 12 months by pairing two competitive monokaryons formed abundant mycorrhizae. However, dikaryons formed after 12 months by using less competitive monokaryons showed a sharply reduced symbiotic ability. The isolation of one apparently nonmycorrhizal monokaryon is reported.

Formation and regeneration of protoplasts from the ectomycorrhizal basidiomycete Laccaria bicolor

1986 ◽  
Vol 64 (6) ◽  
pp. 1224-1226 ◽  
Author(s):  
Bradley R. Kropp ◽  
J. A. Fortin
Keyword(s):  
Pinus Banksiana ◽  
Enzyme Preparation ◽  
Lytic Enzyme ◽  
Laccaria Bicolor ◽  
Dikaryotic Mycelium ◽  
Osmotic Stabilizer

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 normal ectomycorrhizae with Pinus banksiana.

Vegetative interactions among mycelia of Laccaria bicolor in pure culture and in symbiosis with Pinus banksiana

1995 ◽  
Vol 73 (11) ◽  
pp. 1768-1779 ◽  
Author(s):  
Paul Y. de la Bastide ◽  
Yves Piché ◽  
Bradley R. Kropp
Keyword(s):  
Pure Culture ◽  
Pinus Banksiana ◽  
Dna Analysis ◽  
Agar Medium ◽  
Intraspecific Variability ◽  
Nuclear Migration ◽  
Laccaria Bicolor ◽  
Soil Medium ◽  
Mycelial Interactions ◽  
Ectomycorrhizal Colonization

Mycelial interactions of Laccaria bicolor strains were studied in pure culture and after inoculation onto mycorrhizal hosts. Monokaryon–monokaryon and dikaryon–monokaryon crosses were performed on an agar medium that enhanced nuclear migration to study mating events. The first observance of clamped hyphae, their location, evidence of nuclear migration, and the occurrence of dikaryon–monokaryon matings varied among crosses. One monokaryon–monokaryon and two dikaryon–monokaryon combinations were selected for seedling inoculation to compare their mycorrhizosphere interactions with those observed on agar medium. Seedlings of Pinus banksiana were grown for 20 weeks in a mycelium inoculated soil medium. Three seedlings from each treatment were selected at harvest and ectomycorrhizae reisolates were subject to randomly amplified polymorphic DNA analysis to identify genotypes. This analysis was also done for mycelial samples of the same crosses on agar medium. Variation in the mycobiont genotype was observed for different root isolates from the same seedling, which had been initially inoculated with a compatible monokaryon–monokaryon or a dikaryon–monokaryon strain combination. Root isolates from seedlings receiving the latter treatment included a new dikaryotic genotype produced by a dikaryon–monokaryon mating. Seedling growth was reduced with ectomycorrhizal colonization, most likely because of the photosynthate requirements of the mycobiont during this study. The nature of mycelial interactions and the potential value of a genetically variable mycobiont are discussed. Key words: Buller phenomenon, ectomycorrhizae, intraspecific variability, mycelial interactions, RAPD analysis.

Effects of nitrogen fertilization and photoperiod on basidiome formation of Laccaria bicolor associated with container-grown jack pine seedlings

1992 ◽  
Vol 70 (1) ◽  
pp. 181-185 ◽  
Author(s):  
Christian Godbout ◽  
J. André Fortin
Keyword(s):  
Nitrogen Fertilization ◽  
Pinus Banksiana ◽  
Host Plants ◽  
Wild Strain ◽  
Jack Pine ◽  
Culture Conditions ◽  
Ectomycorrhizal Fungus ◽  
Laccaria Bicolor ◽  
Pine Seedlings ◽  
Respective Host

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 on the culture conditions. Frequency of fruiting reached a maximum with the addition of 5 – 6 mg of nitrogen per seedling. The response of fruiting to nitrogen was enhanced with a short photoperiod. The biomass of the basidiomes was positively correlated with the biomass of their respective host plants with proportions ranging from 10 to 35% and with a mean of 20%. Key words: basidiome, Laccaria bicolor, fertilization, photoperiod, ectomycorrhiza.

Phase behavior of cationic and anionic surfactants at low concentrations

1992 ◽  
Vol 50 (1) ◽  
pp. 694-695
Author(s):  
E. Naranjo
Keyword(s):  
Phase Behavior ◽  
Structural Characterization ◽  
Dynamic Systems ◽  
Anionic Surfactants ◽  
Intermolecular Forces ◽  
Stable Form ◽  
Surfactant Mixtures ◽  
Low Concentrations ◽  
Cationic And Anionic Surfactants ◽  
General Method

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

The original basal stem section influences rooting in Pinus banksiana cuttings

1992 ◽  
Vol 86 (1) ◽  
pp. 1-5
Author(s):  
Bruce E. Haissig ◽  
Don E. Riemenschneider
Keyword(s):  
Pinus Banksiana ◽  
Stem Section
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