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.

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.

INHIBITION OF FUNGAL GROWTH BY BACTERIA DURING CELLULOSE-DECOMPOSITION

1961 ◽  
Vol 7 (6) ◽  
pp. 857-863 ◽  
Author(s):  
Y. Henis ◽  
Paulina Keller ◽  
A. Keynan
Keyword(s):  
Bacterial Growth ◽  
Filter Paper ◽  
Vegetative Growth ◽  
Pure Culture ◽  
Carboxymethyl Cellulose ◽  
Agar Medium ◽  
Fungal Growth ◽  
Fungal Development ◽  
Cellulose Decomposition ◽  
Cellulose Filter

The cellulose-decomposing flora developing from soil crumbs on filter paper placed upon an agar medium was studied. Under these conditions fungal development was significantly inhibited by bacterial growth. When cellophane was substituted for filter paper, no inhibition of fungal growth was observed. A pure culture of Cellvibrio inhibited the vegetative growth of Stachybotrys when inoculated simultaneously on media containing carboxymethyl-cellulose, filter paper, or glucose up to 0.1%. This inhibition was shown to be caused by competition for available carbohydrates.

scholarly journals Antibacterial Activities of Actinomycete Isolates Collected from Soils of Rajshahi, Bangladesh

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Md. Ajijur Rahman ◽  
Mohammad Zahidul Islam ◽  
Md. Anwar Ul Islam
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Inhibitory Activity ◽  
Pure Culture ◽  
Agar Medium ◽  
Antibacterial Activities ◽  
Soil Samples ◽  
Indicator Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative

This study was performed to isolate actinomycete colonies having antibacterial activity from soil samples collected from different places around Rajshahi, Bangladesh. Thirty actinomycete colonies were isolated in pure culture from five soil samples using Starch-casein-nitrate-agar medium. The isolates were grouped in five color series based on their aerial mycelia color and screened for their antibacterial activity against a range of test bacteria. Sixteen isolates (53.3%) were found to have moderate to high activity against four gram-positive and four gram-negative bacteria. Since many isolates showed inhibitory activity against indicator bacteria, it is suggestive that Bangladeshi soil could be an interesting source to explore for antibacterial secondary metabolites.

On the relation of colony variants to the time dependency of colony formation during adaptive mutation of Escherichia coli FC40

1997 ◽  
Vol 43 (9) ◽  
pp. 884-886 ◽  
Author(s):  
Patricia R. MacLeod ◽  
Robert A. MacLeod
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Pure Culture ◽  
Colony Formation ◽  
Agar Medium ◽  
Selective Medium ◽  
Adaptive Mutation ◽  
Time Dependency ◽  
Colony Type ◽  
Selective Agar

When Escherichia coli FC40 formed adaptive Lac+ revenants on a selective agar medium containing lactose as the carbon source, the colonies which accumulated over several days were of two readily distinguishable types. Colonies of both types appeared both early and late on the plates. Cells of colonies that appeared early and late on the plates, irrespective of the type, when grown in liquid medium and replated, all formed colonies on the selective medium within 48 h. Cells of each colony type gave rise to colonies of both types and attempts to isolate cells of each type in pure culture were unsuccessful. It was concluded that the presence of two colony types in the cultures plated did not contribute to the observed time dependency of colony formation during adaptive mutation. The proportions of the two colony types arising from cultures of the Lac+ revertants varied from culture to culture.Key words: Escherichia coli FC40, variants, adaptive mutation, colony accumulation.

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.

STUDIES OF SOIL FUNGI: II. A NEW SPECIES OF SPHAEROSPORA WITH A BOTRYTIS-LIKE STAGE

1956 ◽  
Vol 34 (3) ◽  
pp. 360-376 ◽  
Author(s):  
Roy F. Cain ◽  
Nancy A. Hastings
Keyword(s):  
New Species ◽  
Pure Culture ◽  
Pinus Banksiana ◽  
Soil Fungi ◽  
Conidial Production ◽  
Conidial Stage ◽  
A New Species

A new species, Sphaerospora minuta Cain, is described from soil collected under Pinus banksiana, Algonquin Park, Ontario. Growth in pure culture is rapid on various media. Conidia are produced in Botrytis-like clusters on long, dichotomously branched conidiophores. The conidial stage resembles that of Patella abundans (Karsten) Seaver except for the fewer conidia which have a broader attachment to the ampullae. The method of conidial production in both of these species is described in detail and illustrated. Monoconidial cultures of S. minuta produce mature apothecia which are globose, light-brown, and enclosed in an excipulum covered with numerous slender brown septate hairs. The excipulum remains intact until the apothecium is nearly mature and then splits irregularly to expose the nearly white hymenium. The ascospores are hyaline, globose, smooth, and each contains a single large refractive oil globule. Consideration is given to the validity of the genus Sphaerospora as separate from Humaria (Patella).

Evidence and characterization of temperate bacteriophage inStreptococcus salivariussubsp.thermophilusSt18

1992 ◽  
Vol 59 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Domenico Carminati ◽  
Giorgio Giraffa
Keyword(s):  
Dna Analysis ◽  
Phage Genome ◽  
Agar Medium ◽  
Optimal Dose ◽  
Streptococcus Salivarius ◽  
Temperate Bacteriophage ◽  
A Genome ◽  
Phage Dna ◽  
Contractile Tail

SummaryLysogenic strains ofStreptococcus salivariussubsp.thermophiluswere studied using induction with mitomycin C (MC). The induction and presence of temperate phage were investigated carrying out tests on sensitive strains, electron microscopy and phage DNA analysis. Forty-fiveStr. salivariussubsp.thermophilusstrains were subjected to induction with MC and growth of the various cultures was evaluated. Only one strain of those tested showed lysis after adding MC, thus indicating a possible lysogenic state, 0·5μg MC/ml being the optimal dose. Two Φ18 phage-sensitive strains out of 45 were isolated in which this phage behaved as virulent, causing lysis of the culture in broth, but no lysis plaques on agar medium were detected. The St18 strain was cured by u.v. irradiation but no mutants sensitive to the Φ18 phage were found among the clones non-inducible by MC. The presence of phages having a hexagonal isometric head and a long non-contractile tail in the lysate obtained after inducing the St18 strain was confirmed by examination under the electron microscope. Study of the phage DNA showed a genome size of 40·9 ± 0·5 kb without cohesive end fragments. In addition, the restriction map of the phage genome was constructed. This study has demonstrated lysogeny inStr. salivariussubsp.thermophilusand also that several phage infections ofStr. salivariussubsp.thermophilusstarters may have an ‘endogenous’ origin.

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