scholarly journals 100 ROLE OF LIGHT INTENSITY IN THE DEVELOPMENT OF OSTRICH FERN

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 442e-442 ◽  
Author(s):  
Matthew Donelan ◽  
Kenneth Corey
Keyword(s):  
Light Intensity ◽  
High Light ◽  
Silt Loam ◽  
Ambient Conditions ◽  
Light Levels ◽  
Shade Cloth ◽  
Growth Development ◽  
Role Of Light ◽  
Frond Length

Crowns of ostrich fern (Matteuccia struthiopteris L. Todaro) were field-planted in June 1993 on a Hadley silt loam in South Deerfield, Mass. Shade cloth was used to alter light intensity to determine if light intensity effects growth and development of fronds and crowns. Light levels were 22% (low), 45% (intermediate), 72% (high), and 100% (full) of ambient conditions. Survival of crowns decreased with increasing light intensity with only 22% survival under full light. Low, intermediate, and high light levels resulted in 89%, 75%, and 56%, respectively, of crowns producing shoots. Light intensity did not effect the number or length of fronds produced. Frond length reached a maximum after 2 months growth. Development of secondary crowns was enhanced at intermediate and high light intensities. Final crown weight was significantly correlated with initial crown weight regardless of light intensity. Crowns will be vernalized and forced hydroponically to determine effects of light intensity and crown size on growth of croziers.

The role of light intensity in mediating ascorbic acid content during postharvest tomato ripening: A transcriptomic analysis

2021 ◽  
Vol 180 ◽  
pp. 111622
Author(s):  
Yating Zhang ◽  
Nikolaos Ntagkas ◽  
Dimitrios Fanourakis ◽  
Georgios Tsaniklidis ◽  
Jiantao Zhao ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Light Intensity ◽  
Acid Content ◽  
Ascorbic Acid Content ◽  
Transcriptomic Analysis ◽  
Role Of Light

scholarly journals Role of light‐intensity‐dependent changes in thiol and amino acid metabolism in the adaptation of wheat to drought

2019 ◽  
Vol 205 (6) ◽  
pp. 562-570
Author(s):  
Mónika Gyugos ◽  
Mohamed Ahres ◽  
Zsolt Gulyás ◽  
Gabriella Szalai ◽  
Éva Darkó ◽  
...  
Keyword(s):  
Amino Acid ◽  
Light Intensity ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Role Of Light

Environmental Influence on Locomotor Activity in Nephrops Norvegicus (Crustacea: Decapoda)

1980 ◽  
Vol 60 (1) ◽  
pp. 103-113 ◽  
Author(s):  
T. H. Moller ◽  
E. Naylor
Keyword(s):  
Locomotor Activity ◽  
Light Intensity ◽  
Environmental Influence ◽  
Activity Patterns ◽  
Nephrops Norvegicus ◽  
Experimental Conditions ◽  
Emergence Patterns ◽  
Role Of Light ◽  
Trawl Catches

Diel variations in the emergence of the burrowing prawn Nephrops norvegicus (L.) have been investigated by direct field observations (Chapman & Rice, 1971; Chapman, Johnstone & Rice, 1975; Chapman & Howard, 1979; Atkinson & Naylor, 1976), and indirectly by sequential trawling during 24 h periods (Höglund & Dybern, 1965; Simpson, 1965; Hillis, 1971; Farmer, 1974; Atkinson & Naylor, 1976; Oakley, 1979). Peak emergence appears to be related to temporal and depth-dependent variations in daylight penetration, since Nephrops are apparently nocturnal in shallow waters, crepuscular as the depth increases, and diurnal at the greatest depths of their occurrence. This lends support to the suggestion that emergence occurs at an optimum light intensity (Hillis, 1971; Chapman, Priestley & Robertson, 1972; Chapman, et al., 1975; Chapman & Howard, 1979). However, additional factors influencing emergence of Nephrops from their burrows have also to be taken in account, since laboratory studies of locomotor activity in Nephrops have consistently revealed nocturnal activity patterns in light-dark (LD) regimes, with light inhibiting locomotor activity even at extremely low irradiance levels (Arechiga & Atkinson, 1975; Atkinson & Naylor, 1973, 1976; Naylor & Atkinson, 1976). Moreover, Hammond & Naylor (1977 a) have presented qualitative evidence that the nocturnal locomotor activity peak appears to be synchronized by falling light intensity at dusk. The differences between these experimental results and emergence patterns deduced from trawl catches and underwater observations of Nephrops have not been fully resolved by studies of the role of light intensity and of gradual light transitions (Arechiga & Atkinson, 1975; Hammond & Naylor, 1977 a, b). Thus the behavioural responses of Nephrops both in the field and in the laboratory need to be assessed in relation to more accurately quantified light changes. Also, despite earlier evaluation of the problem (Atkinson & Naylor, 1976; Hammond & Naylor, 1977a) it is necessary to reconsider the possibility that the patterns of locomotor activity recorded in the laboratory are influenced by experimental conditions, as has been demonstrated for minnows (Jones, 1956), and flatfish (Verheijen & de Groot, 1967).

The effects of handling time, ambient light, and anaesthetic method, on the standardized measurement of fish colouration

2011 ◽  
Vol 68 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Suzanne M. Gray ◽  
Francine L. Hart ◽  
Maude E.M. Tremblay ◽  
Thomas J. Lisney ◽  
Craig W. Hawryshyn
Keyword(s):  
Light Intensity ◽  
Spectral Reflectance ◽  
Handling Time ◽  
Ambient Light ◽  
Clove Oil ◽  
Ambient Conditions ◽  
Light Levels ◽  
Standardized Measurement ◽  
Colour Patterns ◽  
Reflectance Data

The effects of handling time, ambient light intensity, and anaesthetic method, on the collection of spectral reflectance data were assessed in two species of Malawi cichlids ( Melanochromis auratus and Metriaclima zebra ). Using spectrometry, colour patches were measured over 10 min, under increasing ambient light levels, and using three anaesthetic methods. As time elapsed, maximum percent reflectance (Rmax) decreased across all anaesthetic methods and species, suggesting that measurements should be taken immediately after capture and anaesthetization. With increasing light intensity, Rmax increased significantly, suggesting that measurements should be taken under natural ambient conditions when possible. Finally, we found that anaesthetizing fish using an ice bath produced significantly higher Rmax than using either MS-222 (tricaine methanesulphonate) or clove oil (eugenol). However, the highest proportion of ultraviolet (UV) colouration was recorded while fish were anaesthetized with clove oil. Our results highlight the variation involved in measuring fish colour patterns using two related species, and thus indicate the need for a standardized approach to collecting spectral reflectance data in fish.

scholarly journals The role of light as vital effect on coral skeleton oxygen isotopic ratio

2018 ◽  
Author(s):  
Anne Juillet-Leclerc
Keyword(s):  
Isotopic Ratio ◽  
Environmental Parameter ◽  
Data Series ◽  
Isotopic Ratios ◽  
Relative Distribution ◽  
Light Levels ◽  
Vital Effect ◽  
Oxygen Isotopic ◽  
Role Of Light

Abstract. Light, an environmental parameter playing a crucial role in coral aragonite growth and δ18O formulation, is always neglected in the geochemical literature. However, by revisiting already published studies, we demonstrated that light might be considered as a vital effect affecting coral aragonite oxygen isotopic ratios. Re-examining data series included in a publication by Weber and Woodhead (1972), we stressed that annual δ18O–annual temperature calibrations of all considered coral genera may be compared because their assessment assumes homogenous light levels. Temperature prevails on δ18O because it influences δ18O in two ways: firstly it acts as is thermodynamically predicted implying a δ18O decrease; and secondly it induces an enhancement of photosynthesis causing δ18O increase. When the highest annual temperature occurs simultaneously with the highest annual irradiation, the annual δ18O amplitude is shortened. The annual δ18O–annual temperature calibration is also explained by the relative distribution of microstructures, centres of calcification or COC and fibers, according to morphology, and in turn taxonomy. We also investigated monthly δ18O–monthly temperature calibrations of Porites grown at the same sites as by Stephans and Quinn (2002), Linsley et al. (1999, 2000) and Maier et al. (2004). Multiple evidence showed that temperature is the prevailing environment forcing on δ18O and that the mixture of temperature and light also determines the relative distribution of microstructures, explaining the relationships between Porites calibration constants. By examining monthly and annual δ18O–monthly and annual temperature calibrations, we revealed that monthly calibration results from the superimposition of seasonal and annual variability over time. Seasonal δ18O strongly impacted by seasonal light fluctuations, may be obtained by removing interannual δ18O only weakly affected by light. Such features necessitate the reconstitution of tools frequently utilised, such as the coupled δ18O–Sr / Ca or pseudo-coral concepts.

scholarly journals 613 P3 287 LIGHT PENETRATION AFFECTS COLOR AND FLAVOR OF'RED DELICIOUS' APPLES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 520a-520
Author(s):  
T.W. Miller ◽  
D.S. Mattinson ◽  
B.C. Bostick ◽  
E. Fallahi ◽  
J.K. Fellman
Keyword(s):  
Fruit Color ◽  
Anthocyanin Content ◽  
Anthocyanin Accumulation ◽  
Light Penetration ◽  
Shade Cloth ◽  
Apple Peel ◽  
Fruit Maturity ◽  
Harvest Data ◽  
Role Of Light

Light has long been known to stimulate anthocyanin accumulation in apple peel, but changes in apple flavor as a result of fruit shading is poorly understood. Some growers maintain that the redder the strain, the less flavorful the fruit. An experiment was conducted to help characterize the role of light in biosynthesis of color versus flavor molecules in apple peel. Bags fashioned from 3 meshes of shade cloth were fastened around fruitlets of red delicious strains `Starkrimson' and `Topred' on M26, MM106, and MM111 by 21 DAFB to produce average light ranges of 100%. 41-68%, 12-30%, and < 1% of full sun incident upon the fruit. Observations from the 1993 harvest indicate that anthocyanin content of peel increased with fruit maturity and level of sunlight. Concentrations of flavor molecules were higher with low and moderate shade than with full sun, and also increased with fruit maturity. From this harvest data, it appears that apple flavor can be enhanced by lightly shading fruit without substantially reducing fruit color.

scholarly journals Substrate Acidification by Geranium: Light Effects and Phosphorus Uptake

2008 ◽  
Vol 133 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Matthew D. Taylor ◽  
Paul V. Nelson ◽  
Jonathan M. Frantz
Keyword(s):  
Light Intensity ◽  
Phosphorus Uptake ◽  
Dry Weight ◽  
P Uptake ◽  
High Light Intensity ◽  
High Light ◽  
P Deficiency ◽  
Light Levels ◽  
Direct Light ◽  
Substrate Ph

Sudden pH decline (SPD) describes the situation where crops growing at an appropriate pH rapidly (within 1–2 weeks) cause the substrate pH to shift downward one to two units. ‘Designer Dark Red’ geraniums (Pelargonium ×hortorum Bailey) were grown in three experiments to assess possible effects of light on SPD and phosphorous (P) uptake. The first experiment tested the effect of four light intensities (105, 210, 575, and 1020 ± 25 μmol·m−2·s−1) on substrate acidification. At 63 days, substrate pH declined from 6.0 to 4.8 as light intensity increased. Tissue P of plants grown at the highest two light levels was extremely low (0.10%–0.14% of dry weight). P stress has been reported to cause acidification. Because plants in the two lowest light treatments had adequate P, it was not possible to determine if the drop in substrate pH was a direct light effect or a combination of light and P. The second experiment used a factorial combination of the three highest light levels from Expt. 1 and five preplant P rates (0, 0.065, 0.13, 0.26, or 0.52 g·L−1 substrate) to assess this question. When tissue P concentrations were deficient, pH decreased by 0.6 to 1.0 pH units within 2 weeks and deficiency occurred more often with high light intensity. These data indicated that P deficiency caused substrate acidification and indicated the possibility that P uptake was suppressed by high light intensity. The third experiment was conducted in hydroponics to determine the direct effect of high light intensity on P uptake. In this experiment, cumulative P uptake per gram root and the rate of P uptake per gram root per day both decreased 20% when light intensity increased from 500 to 1100 μmol·m−2·s−1. It is clear from this study that P deficiency causes geraniums to acidify the substrate and that high light suppresses P uptake.

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