Factors affecting perithecial production in Gibberella (Fusarium) tricincta

1979 ◽  
Vol 57 (22) ◽  
pp. 2497-2500 ◽  
Author(s):  
N. E. El-Gholl ◽  
C. L. Schoulties ◽  
W. H. Ridings
Keyword(s):  
Mass Culture ◽  
Basal Medium ◽  
Continuous Light ◽  
Colony Growth ◽  
Constant Darkness ◽  
Continuous Darkness ◽  
Hedera Helix ◽  
Pigment Formation ◽  
Factors Affecting ◽  
Leaf Spots

Three pigmentation types (brown, red, and white) of Fusarium tricinctum (Corda) Sacc. were observed when an isolated mass culture from leaf spots on English ivy (Hedera helix L.) was single spored. Perithecia of the heterothallic fungus Gibberella tricincta El-Gholl were produced at 20 and 27 °C on stem pieces of Cynodon dactylan Pers. resting on water agar, under 12-h alternating light and dark when certain pigmentation types were paired. Pairing of red and brown pigmentation types yielded significantly (P < 0.05) more perithecia than red and white pairings at 20 and 27 °C. Perithecia were formed only in combinations of red with brown or white pigmentation types. In both sets of pairings, significantly (P < 0.05) more perithecia were produced at 27 than at 20 °C. No perithecia were formed in constant darkness. Occasionally, the red pigmentation type became white after subsequent transfers and never reverted to the red pigmentation on various media and failed to produce perithecia with any pigmentation type. Continuous darkness slightly favored red pigment formation over continuous light as detected by the Munsell color codes. Increasing temperatures from 20 to 32 °C decreased the colony growth diameter of the red-pigmented cultural type. At 32 °C a change in hue was noted with corresponding changes in color codes. Red mycelial pigmentation was intensified by the addition of copper, iron, manganese, and zinc to a basal medium. The addition of 0.1% yeast extract favored mycelial development and caused a more pronounced red mycelial pigmentation in the presence of heavy metals.

Regulation of shell growth in the pulmonate gastropod Helisoma duryi

1978 ◽  
Vol 56 (9) ◽  
pp. 1975-1980 ◽  
Author(s):  
S. C. Kunigelis ◽  
A. S. M. Saleuddin
Keyword(s):  
Shell Growth ◽  
Relative Proportion ◽  
Continuous Light ◽  
Continuous Darkness ◽  
Deposition Rates ◽  
Factors Affecting ◽  
Helisoma Duryi ◽  
Shell Deposition ◽  
Slow Growing ◽  
Pulmonate Gastropod

Photoperiod has a significant effect on linear shell deposition rates; animals maintained in continuous darkness (DD) deposit shell more rapidly than those held in continuous light (LL) or 12L: 12D. Shell deposition is endogenously governed and might be synchronized by photoperiod. Photoperiod also affects the relative proportion of shell occupied by different crystal layers.Injections of brain homogenates from fast-growing animals stimulate shell deposition in slow-growing animals. Supraoesophageal and suboesophageal brain fractions both have a greater effect than whole brain; both fractions may contain factors affecting shell growth. Suboesophageal fractions from shell-repairing donors show a reduced effect. A supraoesophageal factor may be involved in normal shell growth and a suboesophageal factor in shell repair.

The identification, induction of perithecia, and pathogenicity of Gibberella (Fusarium) tricincta n.sp.

1978 ◽  
Vol 56 (18) ◽  
pp. 2203-2206 ◽  
Author(s):  
N. E. El-Gholl ◽  
J. J. McRitchie ◽  
C. L. Schoulties ◽  
W. H. Ridings
Keyword(s):  
Mass Culture ◽  
Cynodon Dactylon ◽  
Hedera Helix ◽  
Leaf Spots ◽  
In Vitro Inoculation ◽  
Sexual State ◽  
Fusarium Tricinctum ◽  
English Ivy

Fusarium was consistently isolated from leaf spots on English ivy (Hedera helix L.). This Fusarium culture (mass culture) was single spored, and three distinct pigmentation types were evident: brown, red, and white. They appeared to be cultural variants of the mycelial type and were identified as Fusarium tricinctum (Corda) Sacc. Perithecia resulting from pairings of certain combinations of these single-spored cultures, or from the mass culture, were formed on water agar containing cold-sterilized dried stem pieces of coastal Bermuda hay (Cynodon dactylon Pers.). Gibberella tricincta n.sp. is proposed for the binomial of the heterothallic sexual state, which is heretofore undescribed. In vitro inoculation of detached English ivy leaves with ascospores or conidia of the pathogen reproduced the leaf spotting originally observed; however, pathogenicity was very limited under the conditions studied.

scholarly journals Adventitious plantlet regeneration from floral stem explants of Nerine bowdenii W. Watts.

1986 ◽  
Vol 34 (2) ◽  
pp. 217-223
Author(s):  
R.L.M. Pierik ◽  
H.H.M. Steegmans
Keyword(s):  
Basal Medium ◽  
Continuous Light ◽  
Plantlet Regeneration ◽  
Stem Explants ◽  
Free Medium ◽  
Continuous Darkness ◽  
Macro Elements ◽  
Full Strength ◽  
Half Strength ◽  
Micro Elements

Explants (1.5 mm thick) from the floral stems of cv. Favoriet were cultured on a basal medium (containing Murashige and Skoog micro-elements, half-strength macro-elements and 4% sucrose) with 1 mg/litre BA and 0.5 mg/litre NAA, at 18 degrees C in continuous darkness. Bulblet regeneration was strongly influenced by the age (length) of the original floral stem, optimal regeneration occurring with immature stems 2.5 to 10 cm in length. To obtain plantlets the regenerated bulblets were subcultured on a cytokinin-free medium (with macroelements increased to full strength) at 25 degrees in continuous light. Plantlets were easily transplanted into soil. (Abstract retrieved from CAB Abstracts by CABI’s permission)

EFFECTS OF PINEALECTOMY, CONSTANT LIGHT AND DARKNESS ON GROWTH HORMONE LEVELS IN THE PITUITARY AND PLASMA OF THE RAT

1972 ◽  
Vol 53 (2) ◽  
pp. 289-293 ◽  
Author(s):  
R. RELKIN
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
Plasma Concentrations ◽  
Continuous Light ◽  
Tail Length ◽  
Male Rats ◽  
Constant Light ◽  
Constant Darkness ◽  
Continuous Darkness ◽  
Plasma Gh

SUMMARY The effects of constant light, constant darkness, and diurnal lighting, in combination with pinealectomy or sham pinealectomy, on pituitary and plasma concentrations of radio-immunoassayable growth hormone (GH) were investigated in 23- to 24-day-old male rats. In addition, the effects on pituitary, accessory sex organ, testes, adrenal and body weights, as well as tail length, were measured. Three days after operation random groups of pinealectomized and sham-pinealectomized animals were placed in either continuous light, continuous darkness or diurnal light, and killed 28–29 days later. Analysis of the results revealed that the sham-pinealectomized group exposed to constant darkness differed from the other five groups by showing lower pituitary and plasma GH concentrations, body weight, tail length and accessory sex organ weight relative to body weight and testes weight. No statistically significant differences were found in pituitary or adrenal weights. It is concluded that increased pineal function occurring in darkness probably inhibits secretion of GH releasing factor, decreasing pituitary synthesis and release of GH.

scholarly journals Factors affecting adventitious root formation in isolated stem segments of Rhododendron.

1969 ◽  
Vol 17 (3) ◽  
pp. 203-208
Author(s):  
R.L.M. Pierik
Keyword(s):  
Mineral Nutrition ◽  
Adventitious Root ◽  
Culture Medium ◽  
Root Formation ◽  
Continuous Light ◽  
Adventitious Root Formation ◽  
Continuous Darkness ◽  
Factors Affecting ◽  
Stem Segments

Stem expiants of the rhododendron cultivar Catawbiense Album rooted more easily in vitro than those of Pink Pearl, agreeing with the experience of nursery practice. Rooting occurred only on segments of young soft shoots and was strongly promoted when the expiants were placed inverted on the medium. Continuous light inhibited, whereas continuous darkness promoted rooting. Rooting occurred only in the presence of an auxin together with a sugar in the culture medium. There was no evidence that mineral nutrition and temperatures between 21 degrees and 29 degrees C. play an important role.-Univ. Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Environmental and nutritional factors affecting the in vitro inhibition of the vegetative growth of Venturia inaequalis by five antagonistic fungi

1997 ◽  
Vol 75 (4) ◽  
pp. 632-639 ◽  
Author(s):  
A. Ouimet ◽  
O. Carisse ◽  
P. Neumann
Keyword(s):  
Venturia Inaequalis ◽  
Apple Scab ◽  
Carbon Sources ◽  
Continuous Light ◽  
Continuous Darkness ◽  
Cold Temperatures ◽  
Factors Affecting ◽  
Nutritional Conditions ◽  
Aureobasidium Sp

The environmental (temperature, pH, and light) and nutritional (carbon sources) factors that affect the inhibition of mycelial growth of Venturia inaequalis by five fungi (Aureobasidium sp. (P26A), unidentified fungus (P28A), Phoma sp. (P59A), Phoma sp. (P66A), and Ophiostoma sp. (P164A)) were evaluated. Cold temperatures slightly reduced the inhibition of V. inaequalis by Phoma sp. (P66A). A neutral pH increased the inhibition by the unidentified isolates and by a Phoma sp. (P66A). Continuous darkness enhanced the inhibition of the pathogen by the isolate Aureobasidium sp., and continuous light favored the inhibition by the Phoma sp. (P66A). The conidial germination of V. inaequalis was significantly reduced by all the isolates, and the inhibition was stronger closer to the fungal colony. Ophiostoma sp. inhibited 100% of the pathogen's growth regardless of temperature, pH, and light regime. Only the presence of peptone in the medium diminished the inhibition by 8%. Since Ophiostoma sp. strongly inhibited V. inaequalis (92–100% inhibition) and was not influenced by environmental and nutritional conditions, this fungal isolate could be considered in the development of a biocontrol agent against the apple scab pathogen. Key words: apple scab, biological control, environment, nutrition.

Control of nitrogen assimilation in Stichococcus bacillaris by growth conditions

1987 ◽  
Vol 65 (3) ◽  
pp. 432-437 ◽  
Author(s):  
Iftikhar Ahmad ◽  
Johan A. Hellebust
Keyword(s):  
Glutamine Synthetase ◽  
Nitrogen Assimilation ◽  
Continuous Light ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Dark Cycle ◽  
Continuous Darkness ◽  
Cell Carbon ◽  
Stichococcus Bacillaris ◽  
Mixotrophic Conditions

Stichococcus bacillaris Naeg. (Chlorophyceae) grown on a 12 h light: 12 h dark cycle divides synchronously under photoautotrophic conditions and essentially nonsynchronously under mixotrophic conditions. Photoassimilation of carbon under photoautotrophic conditions was followed by a decline in cell carbon content during the dark period, whereas under mixotrophic conditions cell carbon increased throughout the light–dark cycle. The rates of nitrogen assimilation by cultures grown on either nitrate or ammonium declined sharply during the dark, and these declines were most pronounced under photoautotrophic conditions. Photoautotrophic cells synthesized glutamine synthetase and NADPH – glutamate dehydrogenase (GDH) exclusively in the light, whereas in mixotrophic cells about 20% of the total synthesis of these enzymes during one light–dark cycle occurred in the dark. NADH–GDH was synthesized almost continuously over the entire light–dark cycle. In the dark, both under photoautotrophic and mixotrophic conditions, the alga contained more than 50% of glutamine synthetase in an inactive form, which was reactivated in vitro in the presence of mercaptoethanol and in vivo after returning the cultures to the light. The thermal stability of glutamine synthetase activity was less in light-harvested cells than in dark-harvested cells. The inactivation of glutamine synthetase did not occur in cultures growing either heterotrophically in continuous darkness or photoautotrophically in continuous light. This enzyme appears to be under thiol control only in cells grown under alternating light–dark conditions, irrespective of whether this light regime results in synchronous cell division or not.

The Daily Rhythm of Activity of the Cockroach, Blatta Orientalis L

1940 ◽  
Vol 17 (3) ◽  
pp. 267-277 ◽  
Author(s):  
D. L. GUNN
Keyword(s):  
Activity Rhythm ◽  
Continuous Light ◽  
Locomotory Activity ◽  
Continuous Darkness ◽  
Daily Cycle ◽  
Blatta Orientalis ◽  
Physical Stimuli ◽  
Inactive Phase ◽  
Set Up ◽  
Main Activity

1. In an aktograph at 25.5°C., at upwards of 75% relative humidity and with food present, the average locomotory activity of the cockroach per day does not depend on whether there is continuous light for weeks, or continuous darkness, or a daily alternation of light and darkness. 2. When temperature and humidity do not vary during the day and other factors are kept as constant as possible, the cockroach's activity can be largely concentrated into any desired half of the day, simply by suitably adjusting the time of onset of the half-day's darkness. A rhythm can thus be set up, so that the main activity occurs at the same hours each day. 3. This activity rhythm persists for some days in continuous light or continuous darkness, but eventually activity becomes much more evenly spread over the whole day, leaving only a slight residual rhythm which is unrelated to the previous conspicuous one. A new conspicuous rhythm can then be started at once by alternation of light and darkness. 4. There are indications that animal responses to physical stimuli may depend to a considerable extent on whether the animal is in the active or the inactive phase of its daily cycle. A method is suggested for making it possible to study the nocturnal phase during the daytime.

Light-induced suppression of the rat circadian system

1995 ◽  
Vol 268 (5) ◽  
pp. R1111-R1116 ◽  
Author(s):  
P. Depres-Brummer ◽  
F. Levi ◽  
G. Metzger ◽  
Y. Touitou
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Prolonged Exposure ◽  
Light Exposure ◽  
Continuous Light ◽  
Circadian System ◽  
Short Exposure ◽  
Complete Suppression ◽  
Continuous Darkness

In a constant environment, circadian rhythms persist with slightly altered period lengths. Results of studies with continuous light exposure are less clear, because of short exposure durations and single-variable monitoring. This study sought to characterize properties of the oscillator(s) controlling the rat's circadian system by monitoring both body temperature and locomotor activity. We observed that prolonged exposure of male Sprague-Dawley rats to continuous light (LL) systematically induced complete suppression of body temperature and locomotor activity circadian rhythms and their replacement by ultradian rhythms. This was preceded by a transient loss of coupling between both functions. Continuous darkness (DD) restored circadian synchronization of temperature and activity circadian rhythms within 1 wk. The absence of circadian rhythms in LL coincided with a mean sixfold decrease in plasma melatonin and a marked dampening but no abolition of its circadian rhythmicity. Restoration of temperature and activity circadian rhythms in DD was associated with normalization of melatonin rhythm. These results demonstrated a transient internal desynchronization of two simultaneously monitored functions in the rat and suggested the existence of two or more circadian oscillators. Such a hypothesis was further strengthened by the observation of a circadian rhythm in melatonin, despite complete suppression of body temperature and locomotor activity rhythms. This rat model should be useful for investigating the physiology of the circadian timing system as well as to identify agents and schedules having specific pharmacological actions on this system.

scholarly journals Влияние масс-медиа на сознание человека в пьесах Александра Марданя

2018 ◽  
pp. 153-164
Author(s):  
Maria Sibirnaya
Keyword(s):  
Mass Media ◽  
Mass Culture ◽  
Real Life ◽  
Point Of View ◽  
Contemporary Culture ◽  
Modern Culture ◽  
Factors Affecting ◽  
The Mass Media ◽  
Music Information ◽  
Modern Mass

Nowadays the influence comprehension of the mass media as one of the most significant factors affecting contemporary culture, acquires the special significance. All kinds of new information receiving by media channels obtain the stereotyped, frequently repeatedly cultural and axiological orientations, which become fixed in people's consciousness. Skillful manipulation of information makes the power of suggestion from mass media practically unlimited. Therefore, the public opinion is created by the mass media. Being so closely intertwined with the mass media, the modern mass culture is coming through all elements of people's lives. Moreover, it appears in the literary works, which reflect the influence of the mass media on the consciousness, mentality, point of view and decisions of the literature characters, using their set example in the literature. Odessian playwright Aleksander Mardan presents his characters in the context of the events, which entails new circumstances both due to the characters decisions and out of more extensive economic and political changes. One may notice the presence of mass media in the form of music, information broadcasts and press almost in all Mardan's play. One may track out the influence on the character’s consciousness and reveal the difference between the official version and what happened in the real life. Using the performance tool, there is the action in the play showing the influence of the stereotypes implicated by the mass media. The performance reveals not only the stereotypes affection influencing the mentality of the characters, but also the viewers whose interpretation of the play’s direction is not always critical enough. Therefore, the question about the relationship between the society and mass media, about the level of freedom in mass media from the society and concerning the influence exerted by mass media on the modern culture and the human's consciousness is repeatedly presented in Alexander Mardаn’s plays.

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