Orchidaceous rhizoctonias from roots of nonorchids: mycelial and cultural characteristics of field and pot culture isolates

1987 ◽  
Vol 65 (3) ◽  
pp. 598-606 ◽  
Author(s):  
M. J. Milligan ◽  
P. G. Williams
Keyword(s):  
Light Microscope ◽  
Cultural Characteristics ◽  
Natural Distribution ◽  
Rate Of Growth ◽  
Vesicular Arbuscular ◽  
Complex Carbohydrates ◽  
Synthetic Media ◽  
Septal Pores ◽  
Pot Culture ◽  
Growth Shape

This paper reports the field isolation of orchidaceous rhizoctonias similar to those found recently in pot cultures of vesicular–arbuscular endophytes. The paper describes the morphology and growth of field and pot-culture isolates on different natural and synthetic media and reports light microscope observations on the nuclei and septal pores of hyphal cells. All isolates were the same in regard to the utilisation of simple and complex carbohydrates and different forms of nitrogen. They were all multinucleate and had an inconspicuous septal pore. Consistent differences were found among isolates in the morphology and frequency of chlamydospores and monilioid hyphae and in the rate of growth, shape, type of margin, and colour of colonies. By using these criteria, the fungi were segregated into 10 entities. The observations are discussed in relation to the natural distribution of the fungi and their resemblance to other fungi in the form-genus Rhizoctonia.

The growth of Easter lily (Lilium longiflorum) as influenced by vesicular–arbuscular mycorrhizal fungi, Fusarium oxysporum, and fertility level

1978 ◽  
Vol 56 (21) ◽  
pp. 2773-2780 ◽  
Author(s):  
R. N. Ames ◽  
R. G. Linderman
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Mycorrhizal Fungi ◽  
Control Plant ◽  
Fertilizer Treatment ◽  
Fertility Level ◽  
High Inoculum ◽  
Easter Lily ◽  
Vesicular Arbuscular ◽  
Pot Culture

Easter lily bulbs were inoculated in the greenhouse with pot-culture inoculum containing a mixture of four vesicular–arbuscular (VA) mycorrhizal fungi as well as other fungi and bacteria, including pathogens. These organisms had multiplied in association with roots of lily, onion, and clover in pot cultures inoculated with sievings from lily field soils. Growth, as measured by bulb weight gain, root volume, and total leaf area, was determined on lily bulb plants inoculated at two inoculum levels and grown under three fertilizer regimes. Growth of plants inoculated with pot-culture inoculum was less than that of controls, especially in plants given the high inoculum (which included pot-culture plant roots) and the high rate of fertilization. The growth reduction apparently was due to the combined effect of greater incidence of Fusarium oxysporum root rot infections, damage to roots from fertilizer, and lower incidence of VA mycorrhizal infections. More mycorrhizal infections occurred in the low-fertilizer treatment than in the high- or no-fertilizer treatments at both high and low inoculum levels, but more F. oxysporum root rot occurred in the high-inoculum, high-fertilizer treatment.In a second experiment, lily seedlings that lacked bulb nutrient reserves were grown at a low fertilizer level and inoculated with Acaulospora trappei without any pathogens. Mycorrhizal plants were significantly larger than nonmycorrhizal control plants, and their tissues contained more N, P, K, Ca, and Mg than control plant tissues.

Competition between Eucalyptus melliodora and E. rossii at varying levels of exchangeable calcium

1961 ◽  
Vol 9 (1) ◽  
pp. 92 ◽  
Author(s):  
cWE Moore
Keyword(s):  
Plant Growth ◽  
Absolute Amount ◽  
Competing Species ◽  
Natural Distribution ◽  
Exchangeable Calcium ◽  
The Absolute ◽  
Log Ratio ◽  
Pot Culture

E. rossii and E. melliodora were grown in pot culture as competing species at varying levels of exchangeable calcium. Both height and yield of E. melliodora increased with increasing exchangeable calcium. Regressions of log ratio E. rossii / E. melliodora for both height and yield on exchangeable calcium were highly significant (P < 0.001) and there was no evidence of departure from linearity. The data indicate that plant growth is influenced by the degree of calcium saturation of the soil rather than by the absolute amount of exchangeable calcium. The implications of the results in relation to the natural distribution of the two species are discussed.

scholarly journals Prairie Remnant Soil as a Source of Mycorrhizal Inoculum

HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1015-1016 ◽  
Author(s):  
Ricky D. Kemery ◽  
Michael N. Dana
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Native Prairie ◽  
Vesicular Arbuscular ◽  
Nursery Production ◽  
Prairie Soil ◽  
Soil Mix ◽  
Prairie Plant ◽  
Plant Seedlings ◽  
Pot Culture ◽  
Better Than

Soil from four native prairie remnant sites was used as inoculum in pot culture to achieve vesicular–arbuscular mycorrhizal (VAM) infection of Sudangrass [Sorghum sudanense (Piper) Stapf]. The prairie sites varied in their management histories and degradation levels. Sudangrass plants that became infected with VAM grew better than those grown in standard pasteurized greenhouse mix or those grown in a pasteurized greenhouse–prairie soil mix. Soil from prairie remnants may serve as a beginning source of inoculum that can be increased via Sudangrass pot culture for inoculation of prairie plant seedlings in nursery production.

Glomus epigaeus sp.nov., a useful fungus for vesicular–arbuscular mycorrhizal research

1979 ◽  
Vol 57 (5) ◽  
pp. 539-542 ◽  
Author(s):  
Barbara A. Daniels ◽  
James M. Trappe
Keyword(s):  
Simple Technique ◽  
Soil Surface ◽  
Arbuscular Mycorrhizal ◽  
Transmitted Light ◽  
Bright Yellow ◽  
Vesicular Arbuscular ◽  
Thin Walled ◽  
Pot Culture ◽  
Glass Chips

A new endomycorrhizal species, Glomus epigaeus, produces abundant chlamydospores in sporocarps on the soil surface. This species has been maintained for more than 1 year in pot culture on various hosts and produces 8–15 sporocarps monthly from each pot. A simple technique of shaking sporocarps in water with broken glass chips is described for the separation of spores from sporocarps.The epigeous habit, narrow, thin-walled, inserted hyphal attachment, and bright yellow to yellow–brown wall color in transmitted light separate G. epigaeus from Glomus macrocarpus, which normally does not fruit epigeously and has a much broader, thick-walled, noninserted hyphal attachment and brown wall color in transmitted light.

Orchidaceous rhizoctonias in pot cultures of vesicular–arbuscular mycorrhizal fungi

1985 ◽  
Vol 63 (7) ◽  
pp. 1329-1333 ◽  
Author(s):  
P. G. Williams
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Pasture Legumes ◽  
Affected Plant ◽  
Symbiotic Germination ◽  
Terrestrial Orchids ◽  
Vesicular Arbuscular ◽  
Orchid Seed ◽  
Sebacina Vermifera ◽  
Pot Culture

The paper reports that previously undescribed, sterile, septate fungi (Rhizoctonia) with affinity to and attributes of orchid mycorrhizal fungi, commonly occur in pot cultures of vesicular–arbuscular (V–A) mycorrhizal fungi. Seventeen pot cultures of V–A endophytes from several sources were studied. The endophytes included unidentified organisms as well as species of Glomus, Acaulospora, and Gigaspora. A Rhizoctonia was present in every pot culture. In different cases, Rhizoctonia isolates were obtained from sporelike cells in intramatrical vesicles, extramatrical hyphae, and chlamydospores or roots of pot culture plants. In pure culture, the rhizoctonias formed pale or yellow–brown, submerged colonies composed of narrow, irregularly septate hyphae. Monilioid hyphae and terminal or intercalary, spherical chlamydospores about 12 μm in diameter developed in older mycelia. Fruiting experiments by J. H. Warcup indicated that the teleomorph of three Rhizoctonia isolates is related to Sebacina vermifera Oberwinkler, a mycorrhizal endophyte of certain Australian terrestrial orchids. Positive tests for symbiotic germination of orchid seed with one isolate are described. Pasture legumes and ryegrass plants were inoculated with mycelia of Rhizoctonia strains in the presence or absence of V–A mycorrhizal fungi. Inoculation affected plant growth only when V–A mycorrhizal fungi were present: in steamed soil containing residual inoculum of a V–A endophyte, the growth response following infection by the V–A endophyte occurred in inoculated plants several weeks earlier than in uninoculated plants; in different natural soils, inoculation increased, decreased, or had no effect on growth, depending on the strain of Rhizoctonia used.

A SEM and Light Microscope Study of the Epidermal Leaf Structures of the Carnivorous Plant, Sarracenia purpurea, L.

1971 ◽  
Vol 29 ◽  
pp. 358-359
Author(s):  
B. J. Panessa ◽  
J. F. Gennaro
Keyword(s):  
Methylene Blue ◽  
Toluidine Blue ◽  
Outer Surface ◽  
Microscope Study ◽  
Light Microscope ◽  
Carnivorous Plant ◽  
Sarracenia Purpurea ◽  
Inner Surface

Tissue from the hood and sarcophagus regions were fixed in 6% glutaraldehyde in 1 M.cacodylate buffer and washed in buffer. Tissue for SEM was partially dried, attached to aluminium targets with silver conducting paint, carbon-gold coated(100-500Å), and examined in a Kent Cambridge Stereoscan S4. Tissue for the light microscope was post fixed in 1% aqueous OsO4, dehydrated in acetone (4°C), embedded in Epon 812 and sectioned at ½u on a Sorvall MT 2 ultramicrotome. Cross and longitudinal sections were cut and stained with PAS, 0.5% toluidine blue and 1% azure II-methylene blue. Measurements were made from both SEM and Light micrographs.The tissue had two structurally distinct surfaces, an outer surface with small (225-500 µ) pubescent hairs (12/mm2), numerous stoma (77/mm2), and nectar glands(8/mm2); and an inner surface with large (784-1000 µ)stiff hairs(4/mm2), fewer stoma (46/mm2) and larger, more complex glands(16/mm2), presumably of a digestive nature.

Epoxy Resin Embedment

1968 ◽  
Vol 26 ◽  
pp. 100-101
Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Epoxy Resin ◽  
Light Microscope ◽  
Epoxy Resins ◽  
Image Contrast ◽  
Tissue Preservation ◽  
Resin System ◽  
Excellent Quality

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).

Selective Staining of Acid Mucopolysaccharides By Ruthenium Red

1968 ◽  
Vol 26 ◽  
pp. 38-39
Author(s):  
J. H. Luft
Keyword(s):  
Electron Microscope ◽  
Light Microscopy ◽  
Light Microscope ◽  
Osmium Tetroxide ◽  
Single Cells ◽  
Ruthenium Red ◽  
Collagen Fibers ◽  
Selective Staining ◽  
Pectic Substances ◽  
Solid Tissues

Ruthenium red is one of the few completely inorganic dyes used to stain tissues for light microscopy. This novelty is enhanced by ignorance regarding its staining mechanism. However, its continued usefulness in botany for demonstrating pectic substances attests to selectivity of some sort. Whether understood or not, histochemists continue to be grateful for small favors.Ruthenium red can also be used with the electron microscope. If single cells are exposed to ruthenium red solution, sufficient mass can be bound to produce observable density in the electron microscope. Generally, this effect is not useful with solid tissues because the contrast is wasted on the damaged cells at the block surface, with little dye diffusing more than 25-50 μ into the interior. Although these traces of ruthenium red which penetrate between and around cells are visible in the light microscope, they produce negligible contrast in the electron microscope. However, its presence can be amplified by a reaction with osmium tetroxide, probably catalytically, to be easily visible by EM. Now the density is clearly seen to be extracellular and closely associated with collagen fibers (Fig. 1).

4-dimensional, high-resolution imaging of living cells

1992 ◽  
Vol 50 (1) ◽  
pp. 416-417
Author(s):  
Shinya Inoué
Keyword(s):  
Light Microscope ◽  
Living Cells ◽  
Live Cells ◽  
Video Tape ◽  
Active Living ◽  
High Resolution Imaging ◽  
3 Dimensional ◽  
Dynamic Architecture ◽  
Resolution Imaging ◽  
Disk Memory

This paper reports progress of our effort to rapidly capture, and display in time-lapsed mode, the 3-dimensional dynamic architecture of active living cells and developing embryos at the highest resolution of the light microscope. Our approach entails: (A) real-time video tape recording of through-focal, ultrathin optical sections of live cells at the highest resolution of the light microscope; (B) repeat of A at time-lapsed intervals; (C) once each time-lapsed interval, an image at home focus is recorded onto Optical Disk Memory Recorder (OMDR); (D) periods of interest are selected using the OMDR and video tape records; (E) selected stacks of optical sections are converted into plane projections representing different view angles (±4 degrees for stereo view, additional angles when revolving stereos are desired); (F) analysis using A - D.

High-resolution measurement of birefringent fine structure in living cells using a new polarized light microscope

1995 ◽  
Vol 53 ◽  
pp. 54-55
Author(s):  
Rudolf Oldenbourg
Keyword(s):  
Light Microscope ◽  
Fluorescent Dyes ◽  
Polarized Light ◽  
Processing System ◽  
Video Camera ◽  
Molecular Organization ◽  
Computer Assisted ◽  
Image Recording ◽  
Birefringent Crystal ◽  
Technological Advances

The recent renaissance of the light microsope is fueled in part by technological advances in components on the periphery of the microscope, such as the laser as illumination source, electronic image recording (video), computer assisted image analysis and the biochemistry of fluorescent dyes for labeling specimens. After great progress in these peripheral parts, it seems timely to examine the optics itself and ask how progress in the periphery facilitates the use of new optical components and of new optical designs inside the microscope. Some results of this fruitful reflection are presented in this symposium.We have considered the polarized light microscope, and developed a design that replaces the traditional compensator, typically a birefringent crystal plate, with a precision universal compensator made of two liquid crystal variable retarders. A video camera and digital image processing system provide fast measurements of specimen anisotropy (retardance magnitude and azimuth) at ALL POINTS of the image forming the field of view. The images document fine structural and molecular organization within a thin optical section of the specimen.

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