Nature of the "black line" produced between different biological species of the Armillaria mellea complex

1986 ◽  
Vol 64 (11) ◽  
pp. 2588-2590 ◽  
Author(s):  
K. I. Mallett ◽  
Y. Hiratsuka
Keyword(s):  
Light Microscopy ◽  
Agar Medium ◽  
Biological Species ◽  
Malt Agar ◽  
Black Line ◽  
Armillaria Mellea

The zone of antagonism or black line, formed between the confronting margins of different biological species of the Armillaria mellea complex when paired on malt agar medium, was investigated. Light microscopy showed that the black line was composed of melanized hyphal cells from both species and was bordered on either side by the bladderlike cells of the pseudosclerotial plate of each species.

The use of L-DOPA to enhance visualization of the "black line" between species of the Armillaria mellea complex

1989 ◽  
Vol 67 (1) ◽  
pp. 15-17 ◽  
Author(s):  
A. A. Hopkin ◽  
K. I. Mallett ◽  
P. V. Blenis
Keyword(s):  
Black Line ◽  
Similar Treatment ◽  
Complex Species ◽  
Armillaria Mellea

The zone of antagonism, known as the "black line," that occurred between the confronting margins of diploid isolates of different Armillaria mellea complex species was enhanced by incubation in L-β-3,4-dihydroxyphenylalanine (L-DOPA). Intraspecific crosses and crosses of genetically identical isolates did not produce a black line after similar treatment with L-DOPA.

scholarly journals First Report of Umbel Browning and Stem Necrosis Caused by Diaporthe angelicae on Carrot in France

Plant Disease ◽  
2014 ◽  
Vol 98 (3) ◽  
pp. 421-421 ◽  
Author(s):  
L. Ménard ◽  
P. E. Brandeis ◽  
P. Simoneau ◽  
P. Poupard ◽  
I. Sérandat ◽  
...  
Keyword(s):  
Seed Production ◽  
White Light ◽  
Agar Medium ◽  
Malt Agar ◽  
Universal Primers ◽  
Conidial Suspension ◽  
First Report ◽  
Daucus Carota L ◽  
Cropping Seasons ◽  
Production Areas

In 2011, carrot (Daucus carota L.) seed production occurred on 2,900 ha, which accounts for approximately 25% of the area devoted to the production of vegetable fine seeds. Since 2007, symptoms of umbel browning have been regularly observed in carrot production areas located in the central region. Initially, triangular necrotic lesions appeared on carrot umbels that later spread to the entire umbels and often progressed to the stems. Diseased umbels became dried prematurely, compromising seed development. The loss in seed production was estimated at approximately 8% of the harvested carrot umbels during the cropping seasons of spring and summer 2007 and 2008 in France. In collaboration with seed companies, diseased carrot stems were collected from seven fields of seed production (eight plants per field) and a fungus was isolated from the tissue. The cultures were grown on malt (2%) agar (1.5%) medium and incubated for 2 weeks at 22°C in darkness. Young fungal colonies were white and a brownish green pigmentation developed when the colonies became older. The same color was observed from the top and on the reverse of the colonies. To induce sporulation, isolates were grown on water agar (1.5%) medium in the presence of carrot stem fragments for 1 week at 22°C in darkness, followed by 1 week at 22°C in white light under a 16-h photoperiod. Pycnidia were produced on stem fragments and contained alpha and beta conidia typical of the genus Diaporthe (2). Alternatively, pycnidia were also obtained on malt agar medium after 2 weeks of culture at 25°C in white light under a 12-h photoperiod. The size of alpha and beta conidia was 6.3 ± 0.5 × 2.3 ± 0.4 μm and 23.3 ± 1.8 × 0.9 ± 0.2 μm, respectively (n = 170). In order to confirm the identification at the genus level and determine the species, DNA was extracted from the mycelium of three representative isolates and the ITS regions of the ribosomal DNA were amplified using universal primers (1). The sequences of the amplified products (GenBank Accession Nos. KF240772 to KF240774) were 100% identical with the ITS sequence of a Diaporthe angelicae isolate deposited in the NCBI database (CBS 111592 isolate, KC343027). To confirm pathogenicity, the three isolates of D. angelicae were inoculated on carrot umbels in the greenhouse. A total of nine plants were inoculated (three plants per isolate). Using a micropipette, 10 μl of a conidial suspension containing alpha and beta conidia (105 conidia mL–1) were deposited at the base of the primary umbel and two secondary umbels, which were wounded before inoculation using a scalpel blade. Seven inoculated plants developed triangular, necrotic lesions that were typical umbel browning. D. angelicae was re-isolated on malt agar medium from the inoculated diseased carrot umbels. To our knowledge, this is the first report of D. angelicae in carrot cultivated for seed production in France. The disease resembles the lesions described in the Netherlands in 1951 on carrot inflorescence caused by Phomopsis dauci (3). In future experiments, it would be crucial to precisely determine if D. angelicae could be transmitted to the seeds. References: (1) M. A. Innis et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (2) J. M. Santos and A. J. L. Philips. Fungal Divers. 34:111, 2009. (3) J. A. von Arx. Eur. J. Plant Pathol. 57:44, 1951.

Intake of Ferritin by Armillaria mellea Hyphae

1971 ◽  
Vol 29 ◽  
pp. 364-365
Author(s):  
Arya K. Bal ◽  
Pritam Singh
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Picea Glauca ◽  
Nutrient Absorption ◽  
Malt Agar ◽  
Functional Aspect ◽  
Armillaria Mellea

Our earlier study on the fine structure of young hyphae of Armillaria mellea revealed the presence of numerous invaginations of the plasma-membrane - the so called lomasomes. Functions of these plasma-membrane modifications still remain ambiguous although suggestions have been made as to their involvement in nutrient absorption. With a view to clarifying this functional aspect, ferritin was employed as a marker to trace its path of intake into the hyphal cells.The fungus was isolated from mycelial fans present under the bark of infected roots of Picea glauca (Moench). Voss and maintained on 2% Malt agar. Periferal hyphae from 19 days old culture of A. mellea were exposed to 0.1 ml of a 0.5% aqueous ferritin (Pentax, Inc. 104 ug/ml) solution. The solution was injected into the agar containing the peripheral hyphae. Samples of hyphae were fixed 1-5 seconds after exposure and at 30 minutes, 3 hours, 10 hours, and 24 hours. Fixation, embedding and staining was followed according to the method described by Bal and Singh.

STIMULATION OF RHIZOMORPH DEVELOPMENT OF ARMILLARIA MELLEA BY AUREOBASIDIUM PULLULANS IN ARTIFICIAL CULTURE

1965 ◽  
Vol 11 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Gertrude D. Pentland
Keyword(s):  
Aureobasidium Pullulans ◽  
Indoleacetic Acid ◽  
Synthetic Medium ◽  
Potato Dextrose Agar ◽  
Malt Agar ◽  
Artificial Culture ◽  
Armillaria Mellea ◽  
Stimulation Of

In artificial culture, Aureobasidium pullulans (de Bary) Arnaud produced a stimulatory effect on rhizomorph development of Armillaria mellea (Fr.) Quél. Tests were carried out on malt agar, potato dextrose agar, and a chemically defined synthetic medium. The stimulatory substance (or substances) produced by A. pullulans was extracellular, diffusible in the medium and volatile. Tests indicated that the stimulation was caused by something other than ethanol or indoleacetic acid.

Biological Species of Armillaria mellea in North America

Mycologia ◽  
1979 ◽  
Vol 71 (2) ◽  
pp. 402 ◽  
Author(s):  
James B. Anderson ◽  
Robert C. Ullrich
Keyword(s):  
North America ◽  
Biological Species ◽  
Armillaria Mellea

Relation of colonial morphologies in soft agar to morphological and biological properties of the K-9 strain of Klebsiella pneumoniae and its variants

1977 ◽  
Vol 23 (4) ◽  
pp. 448-451 ◽  
Author(s):  
Masami Takahashi ◽  
Kosaku Yoshida ◽  
C. L. San Clemente
Keyword(s):  
Klebsiella Pneumoniae ◽  
Light Microscopy ◽  
Parent Strain ◽  
Agar Medium ◽  
Soft Agar ◽  
Biological Properties ◽  
Biochemical Properties ◽  
Volume Index ◽  
Compact Type ◽  
Rain Drop

During repeated subcultures of strain K-9 of Klebsiella pneumoniae, three variants, A, B, and C, were obtained showing different colonial morphologies in soft agar. The parent strain K-9 produced colonies that were large, smooth, and globular; variant A, wedged balloon forms somewhat elongate; variant B, rain-drop-like with some streaming; and variante, small compact rough globules. These colonial forms in soft agar medium correlated well with the size of capsule determined by cell volume index and light microscopy. Organisms exhibiting large globular colonies did possess extra large capsules while strains producing compact-type colonies in soft agar were lacking capsules. Capsular size of the strains correlated well with mouse virulence, but most biochemical properties, including the amount of endotoxic substance, were the same in all strains.

Comparison of malt agar with malt agar plus orthophenylphenol for isolating Armillariamellea and other fungi from conifer roots

1978 ◽  
Vol 8 (3) ◽  
pp. 348-351 ◽  
Author(s):  
R. D. Whitney ◽  
D. T. Myren ◽  
W. E. Britnell
Keyword(s):  
Agar Medium ◽  
Malt Agar ◽  
Fast Growing ◽  
Inhibiting Effect

Armillariamellea isolations from the roots of dead and dying conifer saplings increased by 40% when o-phenylphenol (OPP) was added to malt agar compared with isolations on malt agar alone; they were similar on the two media from the roots of larger, healthy trees. This is attributed largely to the inhibiting effect of the additive on fast-growing Hyphomycetes and other fungi which are far more abundant in the roots of dead or dying saplings than in the roots of healthy older trees. Decay-causing Basidiomycetes other than A. mellea were isolated less frequently, whereas bacteria and yeasts were isolated more frequently, when OPP was added to the malt agar medium. This suggests that the additive must be used with discretion.

Restriction Fragment Polymorphisms in Biological Species of Armillaria mellea

Mycologia ◽  
1987 ◽  
Vol 79 (1) ◽  
pp. 69 ◽  
Author(s):  
James B. Anderson ◽  
Dawna M. Petsche ◽  
Myron L. Smith
Keyword(s):  
Restriction Fragment ◽  
Biological Species ◽  
Armillaria Mellea

OBSERVATIONS ON THE CULTURE AND MAINTENANCE OF A FREE-LIVING AMOEBA

1956 ◽  
Vol 2 (5) ◽  
pp. 511-513
Author(s):  
A. Bakerspigel
Keyword(s):  
Pure Culture ◽  
Agar Medium ◽  
Sole Source ◽  
Malt Agar ◽  
Free Living ◽  
Gram Negative ◽  
Negative Bacillus ◽  
The Past ◽  
Gram Negative Bacillus ◽  
Free Living Amoeba

A free-living amoeba isolated from creek water could be grown at 24 °C. on a solid malt agar medium together with a pure culture of a motile Gram-negative bacillus, isolated from the same sample of water. The bacilli apparently served as the sole source of food for the trophozoites, the malt in the medium being-utilized by the bacilli for their own growth. In addition, the encysted form has been maintained on this medium at 24 °C. for the past 12 months and at 4 °C. for 10 months. Transfers to fresh medium of cysts from such cultures yielded numerous trophozoites after 12 hr. incubation at 24 °C, provided that metabolically active bacilli were present.

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