scholarly journals Variability of Pestalotia spp. with special reference to the effect of media, temperature and light on their growth, sporulation and spore germination

2014 ◽  
Vol 12 (1) ◽  
pp. 141-151 ◽  
Author(s):  
A. N. Ibrahim ◽  
M. M. Satour ◽  
E. M. Elakkad
Keyword(s):  
Spore Germination ◽  
Mycelial Growth ◽  
Leaf Extract ◽  
Continuous Light ◽  
Storage Period ◽  
Morphological Characters ◽  
Optimum Temperature ◽  
Continuous Darkness ◽  
Agar Media ◽  
Host Tissues

Potalo dextrose and mango leaf extract agar media were found to be the most favourable for mycelial growth of <i>Pestalotia</i> spp. The optimum temperature for growth and sporulation was 25°C. Continuous light promoted mycelial growth and continuous darkness retarded it. The maximum percentage of germinated spores was obtained under intermittent daylight conditions. Germination of <i>Pestalotia</i> spores occurred at various stages of maturity. The percentage of germination decreased with the increase of the storage period in the host tissues, and after 12 months spores lost their viability completely. Mycelia in the same infected tissues, however, were found to be still alive and capable of producing new fructifications till 18 months. Morphological characters of the fungus, and mode of spore germination were also investigated.

Diversity of Botryosphaeriaceae species associated with Chinese hickory tree (Carya cathayensis) trunk cankers

Plant Disease ◽  
2021 ◽  
Author(s):  
C. J. Zhuang ◽  
Q. W. Wang ◽  
Q. Q. Wu ◽  
Z. L. Qiu ◽  
B. C. Xu ◽  
...  
Keyword(s):  
Spore Germination ◽  
Fungal Pathogen ◽  
Mycelial Growth ◽  
Optimum Temperature ◽  
Botryosphaeria Dothidea ◽  
Pathogen Diversity ◽  
New Information ◽  
Different Temperatures ◽  
Carya Cathayensis ◽  
Botryosphaeriaceae Species

Tree trunk cankers (TRC) represent serious fungal diseases that pose significant threats to Chinese hickory trees (Carya cathayensis). To characterize the pathogen diversity associated with, diseased tissues were collected between 2016 and 2018 from the primary Chinese hickory plantation regions. A total of 97 cultures were isolated from trees in six towns (Longgang, Qingliangfeng, Changhua, Tuankou, Taiyang Town, and Lin’an urban area) within the Linan district, where 60% of Chinese hickory tree yields originate. The isolated cultures caused cankers on Chinese hickory tree branches, but infections did not occur on fruits or leaves under tested conditions. Combined morphological observations and phylogenetic analysis of multiple genes (ITS, β-tublin, and EF) indicated that five Botryosphaeriaceae species were recovered, including 89 isolates of Botryosphaeria dothidea, four isolates of B. fabicerciana, one isolate of B. qingyuanensis, one isolate of B. corticis, and two isolates of Lasiodiplodia theobromae. B. dothidea was the most prevalent, and this is the first report of B. corticis, B. qingyuanensis, and L. theobromae infections in Chinese hickory trees. We investigated the mycelial growth, spore germination, and pathogenicity of these species at different temperatures. L. theobromae grew the fastest and B. cortices grew the slowest on PDA. The optimum temperature of spore germination for all species was 30°C. L. theobromae was the most virulent species, followed by B. dothidea and B. qingyuanensis, then B. fabicerciana, and finally B. cortices. These new insights into fungal pathogen diversity provide critical new information to understand and manage TRC of Chinese hickory.

scholarly journals Fungitoxicity of the Pyroligneous Extract in the Development in vitro of Colletotrichum gloeosporioides

2020 ◽  
Vol 8 (4) ◽  
pp. 82
Author(s):  
Cleverson Rodrigues ◽  
João Aguilar Massaroto ◽  
Grace Queiroz David ◽  
Dilânia Lopes de Matos ◽  
Walmor Moya Peres ◽  
...  
Keyword(s):  
Spore Germination ◽  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Tectona Grandis ◽  
Growth Speed ◽  
Randomized Design ◽  
Agar Media ◽  
Completely Randomized Design ◽  
Development In Vitro

Products derived from renewable sources have been studied for their use in agriculture enabling increments in the production of agricultural culture, such as in the case of the pyroligneous extract. The research aimed at evaluating the fungitoxic potential of the pyroligneous extract of teak (Tectona grandis L.) on mycelial growth, sporulation and spore germination of Colletotrichum gloeosporioides. The experiment was conducted in completely randomized design with five treatments and four replications. Five doses of pyroligneous extract were tested (0, 25, 50, 100, 150 mL L-1) following the pour-plate methodology in 10 mL of potato dextrose agar media and kept in the incubating room maintained at 25 ± 2 °C in a 12 hour-photoperiod for eight days. Mycelial growth variables (cm), mycelial index growth speed, growth inhibition (%), sporulation inhibition (%) and spore germination (%) were evaluated. There was a reduction for the mycelial growth as well as for the rate of mycelial growth, sporulation inhibition and spore germination as the doses were increased. The percentage inhibition of mycelial growth was 56 % for the highest dose (150 mL L-1). Pyroligneous extract of teak has a direct fungitoxic action on growth, sporulation and germination in vitro of the fungus C. gloeosporioides.

scholarly journals Effect of Temperature and Moisture on Various Aspects of Development, Growth, and Pathogenicity of Thielaviopsis paradoxa from Sugarcane in Puerto Rico

1969 ◽  
Vol 56 (2) ◽  
pp. 162-170
Author(s):  
Lii-Jang Liu ◽  
Amelia Cortés-Monllor
Keyword(s):  
Puerto Rico ◽  
Soil Moisture ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Sugarcane Variety ◽  
Optimum Temperature ◽  
Temperature Range

It was found that the optimum temperature range for mycelial growth and spore germination of Thielaviopsis paradoxa lies between 28° and 32° C, with the maximum above 36° C. and the minimum below 12° C. Neither mycelial growth nor spore germination was obtained at 8° or at 40° C. Pathogenicity of T. paradoxa to sugarcane variety P.R. 1059 was favored by temperatures between 28° and 32° C. No infection of sugarcane by this fungus occurred at 8° or at 40° C. The highest rate of infection of sugarcane by T. paradoxa was obtained at the lowest soil moisture with a maximum temperature up to 32° C. It thus appears that low soil moisture has a profound effect on rate of infection during summer months in Puerto Rico.

scholarly journals E-2-Hexenal Can Both Stimulate and Inhibit Botrytis Growth in Vitro and on Strawberry Fruit in Vivo

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 505E-506
Author(s):  
Elazar Fallik ◽  
Douglas D. Archbold ◽  
Thomas R. Hamilton-Kemp
Keyword(s):  
Volatile Compounds ◽  
Vapor Phase ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Storage Period ◽  
Strawberry Fruit ◽  
High Concentration ◽  
Fungal Cell

Some plant-derived natural volatile compounds exhibit antifungal properties and may offer a tremendous opportunity to control the causes of postharvest spoilage without affecting fresh produce quality or leaving a residue on the produce. E-2-hexenal has shown significant potential for use as a fumigant for controlling Botrytis cinerea in prior studies. In in vitro studies on the mode of action of E-2-hexenal, mycelial growth and percent spore germination were inversely proportional to concentrations of the compound. Spore germination was found to be more susceptible to the compound then mycelial growth. Much higher concentrations of E-2-hexenal were required to inhibit mycelial growth than spore germination. Lower concentrations of the compound significantly stimulated mycelial growth, especially when the volatile was added 2 days following inoculation. Light microscopy analysis revealed that a high concentration of the volatile damaged fungal cell wall and membranes. Treatment with a high vapor phase level of E-2-hexenal during postharvest storage of strawberry fruit at 2°C prevented botrytis development in a subsequent storage period at 15°C. However, treatment with a low vapor phase level enhanced botrytis development. The implications of these results with respect to the practical use of E-2-hexenal and other natural volatile compounds will be discussed.

scholarly journals Morphophysiological characterization of Ceratocystis fimbriata isolates from yerba mate

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Nícolas Manarim de Brito ◽  
Henrique da Silva Silveira Duarte ◽  
Caroline de Bastos Bühner ◽  
Celso Garcia Auer ◽  
Álvaro Figueredo dos Santos
Keyword(s):  
Mycelial Growth ◽  
Culture Medium ◽  
Morphological Characterization ◽  
Yerba Mate ◽  
Optimum Temperature ◽  
Ceratocystis Fimbriata ◽  
Agar Media

ABSTRACT: This study aimed to morphologically characterize the isolates of Ceratocystis fimbriata from yerba mate and to evaluate the effect of culture medium and temperature on mycelial growth and sporulation of C. fimbriata. For the morphological characterization of the 11 monosporic isolates of the fungus, slides were prepared to determine the dimensions of the sexual and asexual structures of the fungus. Four experiments were conducted to evaluate the mycelial growth and to evaluate the sporulation of C. fimbriata in different culture mediums and temperatures. The isolates of C. fimbriata from yerba mate showed perithecia with brown to black necks, divergent ostiolar hyphae, hatshaped hyaline ascospores, single-celled, cylindrical endoconidia, and globular to ovoid aleurioconidia. PDA and V8-agar media showed the highest mycelial growth. The average optimum temperature for mycelial growth and sporulation of isolates of C. fimbriata of yerba mate were 22.5 and 22.4 ºC, respectively.

Peanut Web Blotch: I. Cultural Characteristics and Identity of Causal Fungus1

1984 ◽  
Vol 11 (2) ◽  
pp. 109-114 ◽  
Author(s):  
R. A. Taber ◽  
R. E. Pettit ◽  
G. L. Philley
Keyword(s):  
South Africa ◽  
Cultural Studies ◽  
Mycelial Growth ◽  
Fungal Species ◽  
Optimum Temperature ◽  
Cultural Characteristics ◽  
Foliar Disease ◽  
The Usa

Abstract A foliar disease of peanuts, previously unreported in the USA, was found in Texas in 1972. The pathogen was identified as a species of Ascochyta. Further cultural studies have revealed this fungus to be Phoma arachidicola Marasas, Pauer, and Boerema. Pycnidia form profusely at 20 C and 25 C. Pycnidiospores are borne on short pycnidiosphores and are predominantly one-celled in culture. Spores produced in pycnidia on infected leaflets become 1 septate. Large 1-septate spores, as well as an occasional 2-septate spore, may form in culture. Optimum temperature for mycelial growth in 20 C; little or no growth occurs at 5 C or above 30 C. The teleomorphic state develops in the field on fallen leaflets and can be induced to form in the laboratory on sterilized peanut leaflets between 15 and 20 C. Cultures derived from single ascospores form pseudothecia. Pycnidiospores, ascospores, and chlamydospores are all infective units. Because this fungus produces hyaline ascospores and pseudoparaphyses, it has been transferred to the genus Didymella as Didymella arachidicola (Choch.) comb. nov. Comparisons with 15 isolates causing web blotch of peanut in the USA, Argentina, and South Africa indicate that web blotch symptoms are produced by the same fungal species.

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 Mutation in neurospora crassa with leaf extract of citrus aurantifolia and their soluble protein content

1970 ◽  
Vol 19 (2) ◽  
pp. 151-155
Author(s):  
Apurba Lal Ray ◽  
Mahbuba Akhter Jahan ◽  
Tahsina Rahim
Keyword(s):  
Neurospora Crassa ◽  
Protein Content ◽  
Soluble Protein ◽  
Mycelial Growth ◽  
Leaf Extract ◽  
Mutagenic Effect ◽  
Wild Type ◽  
Soluble Protein Content ◽  
Citrus Aurantifolia ◽  
Morphological Mutants

Leaf extract of Citrus aurantifolia exhibited remarkable inhibitor effect on the radial mycelial growth of Neurospora crassa. The extract also showed mutagenic effect and atleast six morphological mutants of the fungus were detected including albino (al 243), vigorous (vg 117), fluffy (fl 220), colonial (cl 232), conidial band (con. band 171) and dirty (dir 83). The mutants were used for estimation of soluble protein in comparison with the wild type (Ema). The soluble protein content increased to some extent in case of the mutants con. band 171 (192.86 μg/ml), cl 232 (188.57 μg/ml) and vg 117 (186.43 μg/ml) as compared to the wild type (182.14 μg/ml). On the other hand, the soluble protein content was remarkably decreased in case of the mutant al 243 (94.28 μg/ml), which was about 50% less than the control. This indicates that the leaf extract not only effect colony morphology but possesses profound effect on growth and metabolism of the fungus. Key words: Neurospora crassa; Mutation; Leaf extract; Soluble protein DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8958 DUJBS 2010; 19(2): 151-155

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