MORPHOGENESIS IN VERTICILLIUM: EFFECTS OF LIGHT AND ULTRAVIOLET RADIATION ON MICROSCLEROTIA AND MELANIN

1964 ◽  
Vol 42 (8) ◽  
pp. 1017-1023 ◽  
Author(s):  
W. H. Brandt
Keyword(s):  
Ultraviolet Radiation ◽  
Liquid Culture ◽  
Defined Medium ◽  
Potato Dextrose Agar ◽  
Complex Medium ◽  
Fluorescent Light ◽  
Melanin Formation ◽  
Near Ultraviolet ◽  
Solid Media ◽  
Microsclerotia Production

Delay or total suppression of microsclerotia and melanin formation by light seems general among Verticillium isolates of the microsclerotial form. White, fluorescent light delayed or prevented production of microsclerotia and melanin in 14 of 16 microsclerotial isolates on agar, and in 30 of 31 isolates which produced at least some microsclerotia and melanin in liquid culture. Most isolates produced more melanin and microsclerotia on a complex medium (potato dextrose agar) than in a defined medium (sucrose–nitrate liquid). Near-ultraviolet radiation (peak 3650 Å) suppressed melanin and microsclerotia production in one isolate (H-13) of Verticillium in both liquid and solid media. On agar, colonies of isolate H-13 grew larger in near-UV than in darkness. Isolate H-13 retained its ability to produce melanin and microsclerotia during 21 days suppression by near-UV. On some media, near-UV inhibits all steps in microsclerotia development. On others it inhibits only the final steps. There appear to be at least two places in the chain of events leading to melanin and microsclerotia production where near-UV can inhibit the process.

scholarly journals Pyrenochaeta terrestris Microsclerotia Production and Pigmentation on Onion Roots

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1213-1216 ◽  
Author(s):  
Charles L. Biles ◽  
Mel Holland ◽  
Mauricio Ulloa-Godinez ◽  
Dennis Clason ◽  
Joe Corgan
Keyword(s):  
New Mexico ◽  
Allium Cepa ◽  
Root Rot ◽  
Potato Dextrose Agar ◽  
The Other ◽  
Fluorescent Light ◽  
Pigment Synthesis ◽  
Pyrenochaeta Terrestris ◽  
Microsclerotia Production

Experiments were conducted to determine variation of in vitro microsclerotia production, pigmentation, and growth of five Pyrenochaeta terrestris (Hans.) Gorenz, Walker, and Larson isolates from Texas and New Mexico. Isolates of P. terrestris, the causal agent of pink root rot, were placed on agar with lo-mm-long sections of sterile onion (Allium cepa L.) roots. Microsclerotia were present after 20 days at 20, 25, 27, or 32C, with the number of microsclerotia dependent on the isolate. Microsclerotia were absent at 35C. One isolate produced few microsclerotia at all temperatures. Optimum temperatures for growth on potato dextrose agar for the isolates tested were 25 and 27C. Pigment production in roots on agar varied depending on isolate and temperature. Three isolates produced high levels of pigment in onion roots at 15, 20, 25, and 27C. A New Mexico isolate produced significantly less visible pigment than the other New Mexico and Texas isolates. One isolate produced very little pigment at all temperatures tested. Constant fluorescent light stimulated pycnidia production in one isolate and reduced microsclerotia production in all other isolates. Isolates varied significantly in microsclerotia production and pigment synthesis.

Ocular Effects of Near Ultraviolet Radiation

1977 ◽  
Vol 54 (8) ◽  
pp. 542-559 ◽  
Author(s):  
DONALD G. PITTS ◽  
ANTHONY P. CULLEN ◽  
PIERRETTE D. HACKER
Keyword(s):  
Ultraviolet Radiation ◽  
Near Ultraviolet

Near-Ultraviolet Radiation Suppresses Pineal Melatonin Content*

Endocrinology ◽  
1986 ◽  
Vol 119 (5) ◽  
pp. 2201-2205 ◽  
Author(s):  
GEORGE C. BRAINARD ◽  
PATRICIA L. PODOLIN ◽  
SANDER W. LEIVY ◽  
MARK D. ROLLAG ◽  
CURTIS COLE ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Pineal Melatonin ◽  
Near Ultraviolet

Pycnidium production by Botryodiplodia theobromae. I. The relation of light to the induction of pycnidia

1969 ◽  
Vol 47 (7) ◽  
pp. 1153-1156 ◽  
Author(s):  
J. A. Ekundayo ◽  
R. H. Haskins
Keyword(s):  
Light Intensity ◽  
Ultraviolet Radiation ◽  
Exposure Period ◽  
Fluorescent Light ◽  
Botryodiplodia Theobromae ◽  
Continuous Irradiation ◽  
Long Wave ◽  
Light Intensities ◽  
Glass Color ◽  
Color Filters

Cultures of Botryodiplodia theobromae Pat. produced pycnidia abundantly on several media under continuous irradiation with fluorescent light. The fungus did not sporulate when grown in darkness. Irradiation of cultures with a light intensity of 15 foot-candles for 4 days was sufficient to stimulate pycnidial production, but for appreciable sporulation to occur over the same exposure period, higher light intensities are required. Irradiation of cultures through glass color filters showed that long-wave ultraviolet radiation stimulated sporulation.

scholarly journals Penicillium Antibiotic Effect

2018 ◽  
Vol 80 (7) ◽  
pp. 530-535
Author(s):  
Jesse A. Lewis ◽  
Nadja Anderson
Keyword(s):  
Experimental Design ◽  
Natural Product ◽  
Penicillium Chrysogenum ◽  
Liquid Culture ◽  
Bacterial Culture ◽  
Fungal Spore ◽  
Culture Density ◽  
Solid Media ◽  
Antibiotic Effect ◽  
Laboratory Cultures

In this lesson students will use the Penicillium chrysogenum fungus, which naturally produces the antibiotic penicillin, to investigate the effect of naturally produced antibiotics on bacteria in laboratory cultures. Students co-culture P. chrysogenum with three species of bacteria to observe differences between penicillin-resistant and penicillin-sensitive bacteria. They will normalize fungal spore suspension and bacterial culture concentrations before inoculating co-cultures. After bacteria have been exposed to the antibiotic, students will quantify culture density to determine antibiotic effect in liquid culture and on solid media. Students will learn about natural product antibiotics as well as experimental design and application.

Activity of myxin against Ceratocystis ulmi

1969 ◽  
Vol 15 (1) ◽  
pp. 133-135 ◽  
Author(s):  
E. A. Peterson
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Liquid Culture ◽  
Inhibitory Concentration ◽  
In Vitro Tests ◽  
Strong Inhibition ◽  
Solid Media ◽  
Highly Sensitive ◽  
Paper Disc ◽  
Disc Assay

Eight strains of Ceratocystis ulmi originating from different locations and host species were found to be highly sensitive to the antibiotic myxin in in vitro tests. By paper disc assay, amounts as low as 0.5–1.0 μg caused strong inhibition of the fungus on solid media. The minimum inhibitory concentration in liquid culture was 0.2 μg/ml and levels of antibiotic above this concentration proved to be fungicidal.

scholarly journals Effect of Near-ultraviolet Radiation on the Responsibility of Antioxidative Function of Orchid Leaves

2005 ◽  
Vol 17 (4) ◽  
pp. 192-198
Author(s):  
Xiheng ZHAO ◽  
Jincai LI ◽  
Shuichiro MATSUI ◽  
Shigenori MAEZAWA
Keyword(s):  
Ultraviolet Radiation ◽  
Antioxidative Function ◽  
Near Ultraviolet
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