scholarly journals Effect of photoperiod on the cultural morphology of Rhizoctonia solani isolates of maize from Yogyakarta and Central Java, Indonesia

2019 ◽  
Vol 20 (7) ◽  
Author(s):  
SRI WAHYUNI BUDIARTI ◽  
RUDY LUKMAN ◽  
CHRISTANTI SUMARDIYONO ◽  
ARIF WIBOWO ◽  
ACHMADI PRIYATMOJO
Keyword(s):  
Rhizoctonia Solani ◽  
Light Condition ◽  
Morphological Characteristics ◽  
Continuous Light ◽  
Dark Condition ◽  
Light Conditions ◽  
Continuous Darkness ◽  
Central Java ◽  
Special Region ◽  
Cultural Morphology

Abstract. Budiarti SW, Lukman R, Sumardiyono C, Wibowo A, Priyatmojo A. 2019. Effect of photoperiod on the cultural morphology of Rhizoctonia solani isolates of maize from Yogyakarta and Central Java, Indonesia. Biodiversitas 20: 2028-2038. Banded leaf and sheath blight (BLSB) caused by Rhizoctonia solani Kuhn is a significant constraint of maize production in Indonesia, especially within the last several years. R. solani is an important soil-borne necrotrophic fungal pathogen which is known to be sensitive to different environmental conditions. The differential response of fungi to light and dark is important to study, especially of those causing disease to crop plant as it helps to reveal the factors regulating the pathogenicity of the fungus. This study aims to determine the effect of light duration on the mycelial development and sclerotia formation of R. solani isolates obtained from different locations in Yogyakarta Special Region and Central Java, Indonesia. Ten isolates of R. solani collected from different geographic regions in Yogyakarta Special Region, and Central Java from maize (nine isolates) and rice (one isolate) were exposed to three different light conditions: 12 h alternating light/dark, continuous darkness, and continuous light. Cultural morphology and sclerotial characteristics were recorded for each isolate. All isolates revealed great diversity in terms of cultural and morphological characteristics after exposure to three different light conditions. Under complete darkness, the mycelial growth phase was extended, and a fluffy mass of mycelia was produced. All isolates showed abundant growth under the 12 h alternating light/dark condition than under the continuous dark and continuous light conditions. Sclerotia were initiated earlier under the 12 h alternating light/dark condition than under other conditions. The 12 h alternating light/dark condition also induced number and heavier weight of sclerotia compared with those produced under the continuous light and continuous dark conditions. The modifications in light condition exert a significant impact on some R. solani isolates.

scholarly journals Germination and seedling structure of Ruprechtia laxiflora Meissn. (Polygonaceae)

2017 ◽  
Vol 39 (2) ◽  
pp. 243
Author(s):  
Rafael Espanhol Müller ◽  
Luiz Antonio De Souza ◽  
Lindamir Hernandez Pastorini ◽  
Mariza Barion Romagnolo
Keyword(s):  
Experimental Design ◽  
Light Condition ◽  
Cotyledonary Node ◽  
Plant Anatomy ◽  
Light Conditions ◽  
Continuous Darkness ◽  
Germination Speed ◽  
Forest Remnants ◽  
Mean Time ◽  
Germination Parameters

Germination of diaspores and the seedling structure of Ruprechtia laxiflora Meissn. (Polygonaceae) which is a secondary species frequent in forest remnants are described. Seedlings were embedded in hydroxymethacrylate and sectioned in a rotary microtome according to usual techniques in plant anatomy. For bioassays of germination, the experimental design was completely randomized in a 3x2 bifactorial arrangement, corresponding to three temperatures (20, 25 and 30°C) and two light conditions (photoperiod and continuous darkness) for the diaspores newly harvested and in a 4x2 bifactorial arrangement, corresponding to four temperatures (15, 20, 25 and 30°C) and two light conditions (photoperiod and continuous darkness) for diaspores analyzed after storage. There was no interaction between the factors light condition and temperature for germination parameters analyzed. However, the temperature affected the germination and diaspores maintained at 25°C showed a shorter mean time and higher germination speed index. Seedlings are phanerocotylar and epigeal with tetrarch root, intermediate-low type of root-stem transition and trilacunar cotyledonary node.

scholarly journals Earthworm Depuration: Analysis of Coprophagy and Light Impacts

2021 ◽  
Vol 23 ◽  
Author(s):  
Katherine Messer ◽  
Ann C Wilkie
Keyword(s):  
Filter Paper ◽  
Eisenia Fetida ◽  
Continuous Light ◽  
Light Conditions ◽  
Gut Content ◽  
Continuous Darkness ◽  
Research Project ◽  
Filter Paper Disc ◽  
Prevention Method ◽  
Paper Disc

Earthworms are used as biomarkers to determine the bioavailability of contaminants. As such, their uptake of contaminants has been studied extensively. Protocols have been established to ensure that laboratory-obtained data are valid and comparable. However, the method of removing the organism’s gut content (depuration) before assessing the contaminant in the tissue is not standardized. The aim of this research project is to investigate some parameters for earthworm depuration: light conditions and coprophagy prevention. Eisenia fetida were depurated for 48 hours in two separate studies according to guidelines ASTM-E1676 and OECD Test No. 317. In one study, 2 frequencies of egesta removal were employed during depuration to prevent coprophagy and compared to the control (egesta and worms removed after 48 hours). In another study, the subjects and material egested were assessed under conditions of continuous darkness and the control (continuous light). The depuration methods that included egesta removal every 12 and 24 hours resulted in 62% and 10% more egested material per mg of earthworm than the control (filter paper disc change after 48 hours), respectively. The earthworms depurated in continuous darkness egested 94% more material per mg of earthworm than the control. The results indicate that depuration would be more total under continuous darkness and employing a coprophagy prevention method. These findings could lead to more efficient depuration methods.

scholarly journals Study on the in vitro growth of Lily Sorbonne bulblet

2017 ◽  
Vol 1 (T1) ◽  
pp. 35-47
Author(s):  
Thang Thanh Tran ◽  
Huong Thanh Tran
Keyword(s):  
Plant Hormone ◽  
Sucrose Concentration ◽  
Parenchyma Cell ◽  
Light Condition ◽  
Starch Accumulation ◽  
In Vitro Growth ◽  
Dark Condition ◽  
Continuous Darkness ◽  
Physiological And Biochemical

In this study, the effects of light and dark condition, sucrose concentration, and plant growth regulators on the in vitro growth of bulblet from Lily Sorbonne shoot were studied. Morphological, physiological and biochemical changes in the bulblet growth were analyzed. Shoots in the light condition developed into plant while shoots in continuous darkness formed bulblet. Sucrose (90 g/L) increased the size of scale and starch accumulation of bulb. 6-Benzylaminopurine (BA 1,5 mg/L) stimulated the divison of parenchyma cell. The combination of 90 g/L sucrose and 1,5 mg/L BA in dark condition stimulated the division and size of the parenchyma cells, which increase the number and size of scales and size and weight of the bulblet. Respiratory rate, zeatin content and starch accumulation were increased in the bulblet growth. The correlation of light condition, sucrose concentration, plant hormone, respiration rate, starch accumulation, and bulblet growth were discussed. The combination of 90 g/L sucrose, 1.5 mg/L BA and 0.5 zeatin mg/L in dark strongly induced the growth of in vitro Lily bulblet, especially the number of scale.

On the photoreactivity of some hardwood species studied by their leaf characteristics

1970 ◽  
Vol 23 ◽  
Author(s):  
M. Van Miegroet
Keyword(s):  
Morphological Characteristics ◽  
Vegetation Period ◽  
Forest Stand ◽  
Light Environment ◽  
Light Radiation ◽  
Light Conditions ◽  
Site Factors ◽  
Leaf Characteristics ◽  
Single Tree ◽  
Changing Light

A  certain number of measurable characteristics of tree leaves (morphological  characteristics, absorption of light radiation, intensity of respiration and  photosynthesis) are clearly linked with the presence of physiologically  active pigments in the leaves.     Leaf characteristics are highly and inequally influenced by changing  conditions of light environment, especially those related to light intensity,  light quality and duration of the daily illumination period. These  modifications do not only apply to light radiation as created under  laboratory conditions, but also to light conditions ensuing from the place in  the crown of a single tree, the social position of the tree in a forest stand  and the site factors in general.     There are also changes taking place due to the progression of the  vegetation period, at the end of which all species are less tolerant or more  light demanding. The reaction of the leaves towards light radiation out of  different regions of the spectrum is also different. The so-called blue light  radiation (λmax = 440 nm) seems to be of the greatest importance in this  relation, as species react quite different to its action.     The biggest variation in leaf characteristics due to changing light  environment was measured for oak and beech, which both react quickly and are  qualified as 'photolabile species'. No important variations occur in leaves  of ash and maple, which therefore are qualified as 'photostable species'.      As a consequence of variable reactions to changing light conditions, the  relationships between the species are continually modified, even in such a  way that their potential for dominance is not constant.     The classical division into tolerant and intolerant species or  classification of the species based upon the degree of light demand, is  highly inaccurate and it seems preferable to speak of relative light demands  and relative tolerance. All these observations and conclusions bring about a  clear confirmation of the necessity to recognize the individuality of the  single tree, the special character of each growth condition, the own  structure of each forest stand, the specific reaction to one sided  modifications of environmental factors. This is especially important for an  intensive sylvicultural practice.     They also prove the necessity for more physiological and biochemical  research to arrive at a better understanding of growth and its mechanism.      Sylviculture in fact must try to regulate, on an expanded scale, the  phenomens of growth, which is the exchange, absorption and transformation of  energy.     A practical interpretation and regulation of fundamental laws of physiology  and growth will be possible as soon as a clinical form of sylviculture is  created and the adequate instrumentarium developed.

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.

Control of browning during seed germination of Meizotropis pellita: a rare and an endangered plant

2021 ◽  
Vol 16 (8) ◽  
pp. 118-120
Author(s):  
Renu Chandola ◽  
Anshulika Upadhyaya
Keyword(s):  
Seed Germination ◽  
Culture Media ◽  
Light Condition ◽  
Endangered Plant ◽  
In Vitro Germination ◽  
Light Conditions ◽  
Low Intensity ◽  
Browning Reaction ◽  
Threatened Plant Species

Meizotropis pellita is a rare, endangered and threatened plant species found in Patwadanger forest. In nature this species grows from rootstock in precise and sensitive habitats. However, phenolic compounds provoke browning reaction which is responsible for lethal browning in plant tissue culture and hindering in vitro germination. The aim of this study was to minimize the effect of phenolic compound during seed germination. We evaluate different antibrowning treatments in Meizotropis pellita seeds. The seeds were pretreated in Polyvinylpyrrolidone and then treated seeds were cultured on MS media and sterilized seeds were directly inoculated on PVP containing MS media. These culture media incubate under dark and light conditions at different durations respectively. Our results showed that addition of antibrowning agent, PVP inhibit onset of browning. Dark and light condition also played a crucial role on onset of browning. Delayed and low intensity of browning were observed in case of seeds that were inoculated on MS media containing PVP and were kept in dark. The present research offers a positive in vitro seed germination protocol for Meizotropis pellita conservation.

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