scholarly journals Environment and Sporulation in Phytopathogenic Fungi Li. Conidia Formation in Peronospora Tabacina Adam as a Function of Temperature

1961 ◽  
Vol 14 (2) ◽  
pp. 198 ◽  
Author(s):  
IAM Cruickshank
Keyword(s):  
Incubation Period ◽  
Environmental Temperature ◽  
Phytopathogenic Fungi ◽  
Leaf Disk ◽  
Peronospora Tabacina ◽  
Response To Temperature

Using a leaf-disk technique an analysis was carried out to study the effect of environmental temperature on the length of the incubation period and sporulation intensity of P. tabacina. An analysis was also made of the sporulation response to temperature treatments prior to and during sporulation. The following points were demonstrated:

scholarly journals The antagonistic activity of marine actinomycetes from mangrove ecosystem against phytopathogenic fungi Colletotrichum sp. KA

2021 ◽  
Vol 22 (2) ◽  
Author(s):  
Qonita Gina Fadhilah ◽  
Iman Santoso ◽  
Yasman YASMAN
Keyword(s):  
Growth Inhibition ◽  
Incubation Period ◽  
Culture Method ◽  
Mangrove Ecosystem ◽  
Phytopathogenic Fungi ◽  
Antagonistic Activity ◽  
Dual Culture ◽  
Marine Actinomycetes ◽  
Mangrove Ecosystems ◽  
Incubation Periods

Abstract. Fadhilah QG, Santoso I, Yasman. 2021. The antagonistic activity of marine actinomycetes from mangrove ecosystem against phytopathogenic fungi Colletotrichum sp. KA. Biodiversitas 22: 642-649.  Marine actinomycetes from mangrove ecosystems are known to be potential antifungal-producing isolates against phytopathogenic fungi. The aim of this research was to obtain potential marine actinomycetes isolates against the phytopathogenic fungi Colletotrichum sp. KA. Screening of 15 marine actinomycetes isolates using a dual culture method with a plug technique showed that 80% of isolates have antagonistic activity, represented as a percentage of growth inhibition range from 47.96% to 84.94%. Among 12 potential isolates, six isolates (SM4, SM11, SM14, SM15, SM18, and SM20) were evaluated for delayed antagonistic activity with incubation periods of 6, 9, and 12 days using the plug and streak techniques. The results showed that the percentage of growth inhibition of selected isolates inclined to increase along with the incubation period prior to inoculation of Colletotrichum sp. KA. Delayed antagonist assays using the streak technique resulted in higher inhibition results compared to the plug technique. Furthermore, the non-delayed assays of the two selected isolates, SM11 and SM15, also inhibited Colletotrichum sp. KA 57.99% and 59.88%, respectively. The delayed antagonist assay with a shorter incubation period of the two selected isolates also showed an increased percentage of growth inhibition of Colletotrichum sp. KA. According to our research, the delayed antagonistic assay of marine actinomycetes isolates with a 12-day incubation period using a plug technique was representative to evaluate the percentage of growth inhibition.

Effect of inoculum spore load, length of infection period, and leaf washing on occurrence of Peronospora tabacina Adam, (blue mould) of tobacco

1966 ◽  
Vol 17 (2) ◽  
pp. 133 ◽  
Author(s):  
AV Hill
Keyword(s):  
Incubation Period ◽  
Similar Increase ◽  
Spore Concentration ◽  
Peronospora Tabacina ◽  
Infection Period ◽  
Spore Number ◽  
Limited Series ◽  
Series Of Experiments ◽  
Different Strains ◽  
Spore Load

Leaves of tobacco plants cv. Virginia Gold were spray-inoculated with different concentrations of spores of Peronospora tabacina strain APT1 and kept wet for 2 to 16 hr. Incubation period and occurrence of the disease on leaves were related to spore concentration, length of the infection period, temperature, and leaf position. The length of the incubation period increased from approximately 3 to 8 days with decrease in spore number. There was a similar increase with decrease in the length of the infection period and with low temperatures. The number of disease lesions increased with spore number in the inoculum and with increase in the length of the infection period up to 8 hr; it was about 100% higher on washed than on unwashed leaves. All leaves of washed plants had the same number of lesions but with unwashed plants, the lowest leaf had the most lesions and the uppermost the least. In a limited series of experiments with APT2 on cv. Virginia Gold and cv. Sol, the results were similar to those reported for APT1. The host–pathogen reaction was modified by spore load and temperature, the result being a range of symptoms; this indicates the need for caution in the use of symptoms as a means for distinguishing between different strains of the pathogen and between levels of resistance. High spore concentrations and infection periods of 4 hr or longer were necessary for extensive occurrence of the pathogen in leaves.

scholarly journals Origin of the mechanism of phenotypic plasticity in satyrid butterfly eyespots

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Shivam Bhardwaj ◽  
Lim Si-Hui Jolander ◽  
Markus R Wenk ◽  
Jeffrey C Oliver ◽  
H Frederik Nijhout ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Temperature ◽  
Butterfly Species ◽  
Bicyclus Anynana ◽  
Comparative Framework ◽  
Response To Temperature ◽  
Molecular Components

Plasticity is often regarded as a derived adaptation to help organisms survive in variable but predictable environments, however, we currently lack a rigorous, mechanistic examination of how plasticity evolves in a large comparative framework. Here, we show that phenotypic plasticity in eyespot size in response to environmental temperature observed in Bicyclus anynana satyrid butterflies is a complex derived adaptation of this lineage. By reconstructing the evolution of known physiological and molecular components of eyespot size plasticity in a comparative framework, we showed that 20E titer plasticity in response to temperature is a pre-adaptation shared by all butterfly species examined, whereas expression of EcR in eyespot centers, and eyespot sensitivity to 20E, are both derived traits found only in a subset of species with eyespots.

Environment and sporulation in phytopathogenic fungi. III. Peronospora tabacina Adam: Field environment, sporulation, and forecasting

1961 ◽  
Vol 12 (6) ◽  
pp. 1119 ◽  
Author(s):  
NE Rider ◽  
IAM Cruickshank ◽  
EF Bradley
Keyword(s):  
Phytopathogenic Fungi ◽  
Basic Information ◽  
Peronospora Tabacina ◽  
Laboratory Findings ◽  
Blue Mould ◽  
Field Environment ◽  
Germination Characteristics ◽  
Temperature And Humidity ◽  
Trial Basis ◽  
Spore Dissemination

An account is given of measurements of temperature and humidity at a number of positions and heights within a tobacco crop during a 4 day period. Measurements of the intensity of sporulation of Peronospora tabacina Adam were made at the same time. It is shown that the capacity of P. tabacina to sporulate is controlled not only by nocturnal humidity but also by day temperature. The observations confirm that Cruickshank's laboratory findings hold in the field. The implications of the observations reported here, together with those of other workers on such factors as the spore dissemination and germination characteristics of P. tabacina, are discussed. It is concluded that the basic information necessary to initiate, on a trial basis, a blue mould forecasting and spray warning service is now available.

scholarly journals Environment and Sporulation in Phytopathogenic Fungi I. Moisture in Relation to the Production and Disoharge of Conidia of Peronospora Tabaoina Adam

1958 ◽  
Vol 11 (2) ◽  
pp. 162 ◽  
Author(s):  
IAM Cruickshank
Keyword(s):  
Water Relations ◽  
Phytopathogenic Fungi ◽  
Peronospora Tabacina ◽  
Tobacco Leaf ◽  
Leaf Disks

In an investigation into the effects of water relations on sporulation of Peronospora tabacina Adam in tobacco leaf disks the following results were obtained:

The response of growing pigs to amino acids as influenced by environmental temperature. 1. Threonine

2000 ◽  
Vol 70 (2) ◽  
pp. 287-297 ◽  
Author(s):  
N.S. Ferguson ◽  
G.A. Arnold ◽  
G. Lavers ◽  
R.M. Gous
Keyword(s):  
Food Intake ◽  
Environmental Temperature ◽  
Live Weight ◽  
Fat Content ◽  
Growing Pigs ◽  
Similar Response ◽  
Large White ◽  
Total Heat Loss ◽  
Body Protein ◽  
Response To Temperature

AbstractTwo similar experiments (1 and 2) were conducted to measure the effects of a range of dietary threonine concentrations and environmental temperatures on the performance of pigs grown from 13 to 25 kg live weight. In both experiments 48 Large White x Landrace entire male pigs were assigned at 13 kg to one of six dietary threonine treatments (8·9 (T1), 7·6 (T2), 6·2 (T3), 4·9 (T4), 3·6 (T5) g/kg and T5 + supplemented threonine (T6)) and one of four temperature treatments (18, 22, 26 and 30°C). Animals were given ad libitum access to food until 25 kg live weight. There were significant interactions (P < 0·05) between temperature and threonine content on the rate of growth (ADG) with the highest gains on T1 and at 22°C. Similarly the response in food intake (FI) to dietary threonine was significantly (P < 0·01) modified by the ambient temperature. An increase in the supply of threonine in the diet resulted in significant increases (P < 0·001) in the gain per unit of food (FCE). A similar response to temperature occurred with the highest FCE recorded at 26°C and the lowest at 18°C. There was a 0·20 proportional reduction in body protein content at 25 kg live weight in pigs given T5 compared with those given T1 and similarly, excluding T6 because threonine may not have been the most limiting amino acid, the fat content was 1·37 higher for pigs on T5 versus T1, which had the lowest fat content. Similar trends occurred in protein and lipid growth rates with maximum protein deposition recorded on T1 (86 (s.e. 3·5) g/day) and maximum lipid deposition on T5 (108 (s.e. 5·8) g/day), over all temperatures. The response in total heat loss was similar to that observed in FI with the effect of decreasing threonine content being dependent on the environmental temperature. Linear regression of daily empty body threonine accretion on daily digestible threonine intake showed an average efficiency of threonine utilization for pigs between 12 kg and 25 kg live weight of 0·59 (s.e. 0·03). There were no differences in efficiency between temperatures. In conclusion, decreasing the threonine concentration below the requirement of the animal ‘resulted in a significant decrease in ADG, reduced FCE and fatter animals. Pigs given a diet deficient in threonine will attempt to maintain threonine intake as the concentration declines by increasing food intake but this compensation is dependent on the environmental temperature. Pigs are able to compensate better for a deficiency in threonine at 18°C and 22°C than at higher temperatures due to the animals being able to dissipate more heat at the lower temperatures.

scholarly journals Blood Glukose Response of Giant Gouramy (Osphronemus gaouramy, Lac.) to the Stress of Environmental Temperature Changes

2007 ◽  
Vol 2 (2) ◽  
pp. 73 ◽  
Author(s):  
S. Hastuti ◽  
Eddy Supriyono ◽  
Ing Mokoginta ◽  
. Subandiyono
Keyword(s):  
Body Weight ◽  
Blood Glucose ◽  
Environmental Temperature ◽  
Environmental Changes ◽  
Glucose Response ◽  
Temperature Changes ◽  
Stress Effects ◽  
Response To Temperature ◽  
Post Stress

<p>This experiment was conducted to investigate blood glucose performance of giant gouramy <em>(Osphronemus gouramy, </em>Lac.) to environmental changes. Fish with body weight of about 52,15 g was used in the experiment. A hundred and twenty fish were subjected to stress by moving them to another aquarium containing cooler water for 5 minute before put them back to the origin aquarium. The stress treatments were Δ 0°C (A), Δ-3°C (B), Δ-6°C(C), and Δ-9°C(D). Blood glucose was measured at 0, 1, 2, 3, 4 and 5 hours post stress, each for 5 fish. During stress treatment, the survival offish were recorded. To study the role of insulin activation on reducing the stress effects, thirty fish were injected with insulin 2 IU/100 g body weight before subjected them to stressar. Blood glucose level of fish subjected to temperature stress of Δ-9°C was the greatest. The blood glucose response to temperature changes was linear, Y = 4,4543 X + 35,553 with R2 = 0,09976. The survival rate of fish was 100% for all treatments. Injected of insulin 2 IU/100 g body weight was able to reduce hyperglycemia that caused by stress.</p> <p>Key words: Blood glucose, giant gouramy, <em>Osphronemus gouramy, </em>stress</p> <p> </p> <p>ABSTRAK</p> <p>Penelitian ini dilakukan dengan tujuan untuk mengetahui performa glukosa darah ikan gurami <em>(Osphronemus gouramy, </em>Lac.) dalam merespon perubahan suhu lingkungan. Ikan berbobot rata-rata 52,15 g sebanyak 120 ekor diberi stres dengan cara diangkat dan dipindahkan ke suatu wadah yang bersuhu lebih dingin selama 5 menit dan dikembalikan lagi ke wadah mula-mula. Perlakuan stres perubahan suhu dingin tersebut adalah A (Δ 0°C), B (Δ- 3°C), C (Δ-6°C) dan D (Δ-9°C). Glukosa darah diukur dari 5 ekor ikan pada jam ke 0, 1, 2, 3, 4 dan 5 jam pascastres. Kelangsungan hidup dihitung pada saat perlakuan stres. Untuk melihat peran aktivasi insulin dalam menekan efek stres, ikan sebanyak 30 ekor diinjeksi insulin 2 iu/100 g bobot badan sebelum diberi stres. Kadar glukosa darah ikan gurame yang diberi stres perubahan suhu dingin sebesar Δ-9°C mengalami peningkatan paling besar. Respon glukosa darah terhadap stres perubahan suhu tersebut berpola linier Y= 4,4543 X + 35,553, dengan R2 = 0,9976. Perlakuan tersebut menghasilkan kelangsungan hidup yang sama yaitu 100%. Injeksi insulin 2 IU/100 g bobot badan mampu menekan hiperglisemia akibat stres.</p> Kata kunci: Glukosa darah, ikan gurami, <em>Osphronemus gouramy, </em>stres

Effect of Temperature on ADP-Induced Platelet Aggregation

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Incubation Period ◽  
Room Temperature ◽  
Important Variable ◽  
Practical Significance ◽  
Effect Of Temperature ◽  
Induce Platelet Aggregation ◽  
Cuvette Holder ◽  
Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

Colchicine Uptake and Binding by Human Platelets

1975 ◽  
Vol 34 (03) ◽  
pp. 780-794 ◽  
Author(s):  
Dianne M Kenney ◽  
Francis C Chao ◽  
James L Tullis ◽  
Gail S Conneely
Keyword(s):  
Time Dependence ◽  
Incubation Period ◽  
Binding Sites ◽  
Silicone Oil ◽  
Cold Treatment ◽  
Human Platelets ◽  
Temperature Dependent

SummaryThe uptake and binding of antimitotic alkaloid colchicine has been demonstrated in washed preparations of human platelets. A silicone oil technique was adapted so that both uptake and binding of 14C-colchicine were examined in the same platelet preparations. The time dependence and amount of colchicine taken up and bound by different platelet preparations during a 90 to 120 min incubation period were highly reproducible. Both colchicine uptake and binding by intact platelets, and colchicine binding by preparations of lysed platelets were specific and temperature dependent. Colchicine uptake was slowly reversible. Magnesium and GTP enhanced colchicine binding by lysed platelet preparations but calcium decreased binding.Exposure of platelets to either cold (4° C) or to thrombin, which disrupt platelet microtubules, produced significant increases in colchicine uptake and binding. The thrombin effect was maximal at 37° C and resulted in a greater increase in uptake and binding than that produced by either cold treatment alone or, by cold treatment followed by incubation with thrombin at 37° C. The amount of increase in uptake and binding produced by thrombin was independent of both thrombin (1–5 Units/109 platelets) and colchicine concentrations (1–50 × 10−6M).It is postulated that thrombin may initiate the formation, or make available, colchicine binding sites (microtubule subunits) within platelets.

Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran
Keyword(s):  
Environmental Temperature ◽  
Extreme Temperature ◽  
Effect Of Temperature ◽  
Maximum Speed ◽  
Locomotor Performance ◽  
Extreme Temperatures ◽  
Physiological Limits ◽  
Fitness Consequences ◽  
Thermal Maximum ◽  
Environmental Temperatures

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.

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