Effect of low light intensity on the VRN-H1 and VRN-H2 vernalization response loci in barley ( Hordeum vulgare L.)

2008 ◽  
Vol 56 (1) ◽  
pp. 1-10
Author(s):  
I. Karsai
Keyword(s):  
Light Intensity ◽  
Developmental Regulation ◽  
High Light Intensity ◽  
Phenotypic Variance ◽  
Vernalization Response ◽  
Hordeum Vulgare L ◽  
Low Light ◽  
Photoperiod Regime ◽  
Low Light Intensity ◽  
Modifying Effect

The flowering characteristics of a facultative × winter barley mapping population were evaluated in a series of controlled environmental tests in order to study the effect of low light intensity in association with various photoperiod regimes. Functional QTL analysis was used to determine the effect of low light intensity on the functioning of the VRN-H1 and VRN-H2 vernalization response genes and on the allele interactions. Low light intensity exerted the strongest modifying effect on these genes under a 12-hour photoperiod regime, which was intermediate between short and long daylengths. With this photoperiod more than 50% of the phenotypic variance in flowering was explained by the VRN-H2 gene when high light intensity (340 μmol m −2 s −1 ) was applied, but at low light intensity (170 μmol m −2 s −1 ) the VRN-H1 gene became the most important source of variation. There were also significant changes in the interaction between the alleles of the two VRN-H genes, implying that in addition to their role in vernalization-driven regulation, they may also participate in and be subjected to circadian-driven developmental regulation.

Effect of combinations of light intensity and photoperiod on heading date of barley ( Hordeum vulgare L.)

2007 ◽  
Vol 55 (4) ◽  
pp. 397-405 ◽  
Author(s):  
I. Karsai ◽  
K. Mészáros ◽  
B. Kőszegi ◽  
Z. Bedő ◽  
O. Veisz
Keyword(s):  
Light Intensity ◽  
Growth Habit ◽  
Spring Barley ◽  
Heading Date ◽  
Short Photoperiod ◽  
Hordeum Vulgare L ◽  
Low Light ◽  
Photoperiod Regime ◽  
Low Light Intensity ◽  
Barley Germplasm

In order to evaluate the effect of light intensity and photoperiod on heading and to establish the reaction types of barley, a set of barley germplasm of various geographical origin and growth habit was examined in a series of controlled growth chamber experiments combining two levels of light intensity with long and short photoperiod regimes. Low light intensity contributed only a limited portion to the total variance of heading and this originated to a large extent from the genotype × light intensity interaction for both photoperiods. Under the long photoperiod regime the effect of low light intensity was only apparent in a significant delay in heading. Under a short photoperiod the type of sensitivity depended on the growth habit. Low light intensity hastened plant development in 15% of the spring barley varieties, while the flowering of 44% of the winter barley varieties was significantly delayed. Establishing the reaction types for photoperiod and low light intensity in this range of barley germplasm made it possible to identify the typical reaction types of the two growth-habit groups. In addition, it also became possible to identify genotypes with contrasting or unusual combinations of these traits.

Response of chlorina barley mutants to heat stress under low and high light

2003 ◽  
Vol 30 (5) ◽  
pp. 515 ◽  
Author(s):  
Katya Georgieva ◽  
Ivanka Fedina ◽  
Liliana Maslenkova ◽  
Violeta Peeva
Keyword(s):  
Heat Stress ◽  
Light Intensity ◽  
Photosynthetic Activity ◽  
High Light Intensity ◽  
High Light ◽  
O2 Evolution ◽  
Wild Type ◽  
Hordeum Vulgare L ◽  
Low Light ◽  
Low Light Intensity

Barley plants (Hordeum vulgare L.) of wild type and two chlorina mutants, chlorina 126 and chlorina f2, were subjected to 42°C for 5 h at light intensities of 100 and 1000 μmol photons m–2 s–1. The exposure of plants to heat stress at a light intensity of 100 μmol m–2 s–1 induced enormous proline accumulation, indicating that the effect of heat stress was stronger when it was combined with low light intensity. The functional activity of PSII, O2�evolution and flash-induced thermoluminescence B-band amplitude were strongly reduced when plants were exposed to heat at low light intensity. The results clearly showed that high light intensity had a protective effect on photosynthetic activity when barley plants were treated with high temperature. Comparison of the thermosensitivity of wild type plants and chlorina mutants revealed that O2 evolution in chlorina 126 and, especially, in chlorina f2 was more sensitive to heat than in wild type.

scholarly journals Light intensity regulates phototaxis, foraging and righting behaviors of the sea urchin Strongylocentrotus intermedius

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8001 ◽  
Author(s):  
Jiangnan Sun ◽  
Xiaomei Chi ◽  
Mingfang Yang ◽  
Jingyun Ding ◽  
Dongtao Shi ◽  
...  
Keyword(s):  
Light Intensity ◽  
Foraging Behavior ◽  
Sea Urchins ◽  
High Light Intensity ◽  
High Light ◽  
Strongylocentrotus Intermedius ◽  
Low Light ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Significant Difference

Small sea urchins Strongylocentrotus intermedius (1–2 cm of test diameter) are exposed to different environments of light intensities after being reseeded to the sea bottom. With little information available about the behavioral responses of S. intermedius to different light intensities in the environment, we carried out an investigation on how S. intermedius is affected by three light intensity environments in terms of phototaxis, foraging and righting behaviors. They were no light (zero lx), low light intensity (24–209 lx) and high light intensity (252–2,280 lx). Light intensity had obvious different effects on phototaxis. In low light intensity, sea urchins moved more and spent significantly more time at the higher intensity (69–209 lx) (P = 0.046). S. intermedius in high light intensity, in contrast, spent significantly more time at lower intensity (252–690 lx) (P = 0.005). Unexpectedly, no significant difference of movement (average velocity and total distance covered) was found among the three light intensities (P > 0.05). Foraging behavior of S. intermedius was significantly different among the light intensities. In the no light environment, only three of ten S. intermedius found food within 7 min. In low light intensity, nine of 10 sea urchins showed successful foraging behavior to the food placed at 209 lx, which was significantly higher than the ratio of the number (two of 10) when food was placed at 24 lx (P = 0.005). In the high light intensity, in contrast, significantly less sea urchins (three of 10) found food placed at the higher light intensity (2,280 lx) compared with the lower light intensity (252 lx) (10/10, P = 0.003). Furthermore, S. intermedius showed significantly longer righting response time in the high light intensity compared with both no light (P = 0.001) and low light intensity (P = 0.031). No significant difference was found in righting behavior between no light and low light intensity (P = 0.892). The present study indicates that light intensity significantly affects phototaxis, foraging and righting behaviors of S. intermedius and that ~200 lx might be the appropriate light intensity for reseeding small S. intermedius.

Influence of Fluridone on Chlorophyll Content of Wheat (Triticum aestivum) and Corn (Zea mays)

Weed Science ◽  
1978 ◽  
Vol 26 (5) ◽  
pp. 432-433 ◽  
Author(s):  
R. M. Devlin ◽  
C. N. Saras ◽  
M. J. Kisiel ◽  
A. S. Kostusiak
Keyword(s):  
Triticum Aestivum ◽  
Zea Mays ◽  
Light Intensity ◽  
Chlorophyll Content ◽  
High Light Intensity ◽  
Carotenoid Content ◽  
Low Light ◽  
Low Light Intensity ◽  
Chlorophyll Production ◽  
Effect Of Light

Chlorophyll content of wheat (Triticum aestivum L. ‘Mericopa’) and corn (Zea mays L. ‘Merit’) treated with the herbicide fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)-phenyl]-4(1H)-pyridinone} and grown under high light intensity (10.8 klux), was markedly reduced. Corn and wheat germinated from seeds treated with 10 uM fluridone and grown for 6 days were almost completely bleached. Under low light intensity (108 lux) the influence of fluridone on chlorophyll production was greatly reduced. Under very low light intensity (21.5 lux) this influence was almost completely lost. The effect of light on the activity of fluridone suggests that the inhibition of carotenoid production may represent the mode of action of this herbicide. This study shows that the carotenoid content of wheat or corn drops dramatically when these plants are treated with fluridone.

scholarly journals Light, Temperature, and Moisture Effects on Apothecium Production of Sclerotinia sclerotiorum

Plant Disease ◽  
2000 ◽  
Vol 84 (12) ◽  
pp. 1287-1293 ◽  
Author(s):  
P. Sun ◽  
X. B. Yang
Keyword(s):  
Light Intensity ◽  
Sclerotinia Sclerotiorum ◽  
High Light Intensity ◽  
High Light ◽  
Moisture Level ◽  
Optimal Temperature ◽  
Degree Days ◽  
Low Light ◽  
Low Light Intensity ◽  
The Relationship

The purpose of this study was to quantify the effects of light, moisture, and temperature on apothecium production of Sclerotinia sclerotiorum. Sclerotia were placed in sand beds in crispers and exposed to two light intensities. For each light intensity, sclerotia were subjected to five temperature levels and three moisture levels. The results showed that the optimal temperature and temperature range for germination of sclerotia were affected by both light intensity and the moisture level of the sand. At light intensity of 80 to 90 mol m-2 s-1 (low light intensity treatment), the optimal temperatures were in the range of 12 to 18°C regardless of moisture level. At light intensity of 120 to 130 mol m-2 s-1 (high light intensity treatment), the optimal temperature was shifted to 20°C when the soil moisture level was high. Under high light intensity, only a few days were needed for initials to develop into apothecia. Under low light intensity, several weeks were needed for initials to develop into apothecia. The frequency with which initials developed into apothecia was high under high light intensity (80%) but low under low light intensity. The initials produced at low light intensity and high temperature (25 to 30°C) were thinner and longer. The apothecia also were smaller at low light intensity than those produced at high light intensity at any temperature. The periods for apothecium production were longer under lower temperature treatments. The relationship between apothecium production and degree days was analyzed. Apothecium production began at about 160 degree days and ceased at about 900 degree days at high light intensity. However, production began at about 760 degree days and ceased at 1,720 degree days at low light intensity. Nonlinear regression equations which describe the relationship between cumulative formation of apothecia and degree days were highly significant. The deviation between the observed value and the predicted value increased as degree days increased.

Selection for light preference during ovipositing in Drosophila pseudoobscura

1983 ◽  
Vol 25 (5) ◽  
pp. 446-449 ◽  
Author(s):  
Marvin B. Seiger ◽  
Amelia Broach Sanner
Keyword(s):  
Light Intensity ◽  
Genetic Variability ◽  
High Light Intensity ◽  
High Light ◽  
Drosophila Pseudoobscura ◽  
Low Light ◽  
Original Population ◽  
Low Light Intensity ◽  
Light Intensities ◽  
Light Preference

Selection was carried out on a population of Drosophila pseudoobscura to obtain lines preferring high-light intensity or low-light intensity during oviposition. This species is generally characterized as preferring low-light intensities. It was possible to select for increased preference for high-light intensity, but not for low-light intensity during oviposition. However, additive genetic variability exists in preferences for both high- and low-light intensities. The original population was probably operating at a photonegative extreme for oviposition, yet maintained enough genetic variability to permit selection toward a photopositive preference.

scholarly journals Genetic and Environmental Factors Jointly Impact Leaf Phenolic Profiles of Iris variegata L.

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1599
Author(s):  
Uroš Živković ◽  
Stevan Avramov ◽  
Danijela Miljković ◽  
Nataša Barišić Klisarić ◽  
Ljiljana Tubić ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Secondary Metabolites ◽  
Light Intensity ◽  
Vegetation Period ◽  
High Light Intensity ◽  
High Irradiance ◽  
Natural Habitats ◽  
Low Light ◽  
Low Light Intensity ◽  
Phenolic Profiles

A plant’s main mechanism to diminish the effects caused by high free radical levels generated during high irradiance is the synthesis of various secondary metabolites. In addition to interspecies differences, their concentrations may be influenced by genetic, ontogenic, morphogenetic or environmental factors. We investigated the influence of genetic (genotypes from different natural habitats) and environmental (contrasting light regimes as well as successive parts of the vegetation period) variability on the accumulation of 10 selected phenolic compounds (phenolic acids, flavonoids, and xanthones) in Iris variegata genotypes. Genotypes originated from either sun-exposed or shaded natural habitats were transplanted to two experimental light treatments (high light intensity with a higher R/FR ratio and low light intensity with a lower R/FR ratio). Significant impacts of both genetic and environmental seasonal variability (spring, summer and fall during the vegetation period) on phenolic compound profiles were detected. Their highest amounts were detected in spring. The magnitude of difference between light treatments (high vs. low light intensity) and the direction of this change varied depending on the secondary compound class. Phenotypic correlations among the 10 analyzed secondary metabolites differed across the experimental light treatments and their number decreased from spring to fall.

High-Light-Intensity Damage to the Foliose Lichen Lobaria Pulmonaria within Natural Forest: The Applicability of Chlorophyll Fluorescence Methods

2000 ◽  
Vol 32 (3) ◽  
pp. 271-289 ◽  
Author(s):  
Yngvar Gauslaa ◽  
Knut Asbjørn Solhaug
Keyword(s):  
Light Intensity ◽  
Recovery Period ◽  
Substantial Reduction ◽  
High Light Intensity ◽  
Early Spring ◽  
High Light ◽  
Low Light ◽  
Ps Ii ◽  
Low Light Intensity ◽  
Significant Seasonal Variation

AbstractThe annual course of irradiance was recorded at two vertical and even-aged neighbouring Quercus stems, one rich in L. pulmonaria, one without. Irradiance never exceeded 610 μmol photons m−2 s−1 at the L. pulmonaria site, whereas the L. pulmonaria-deficient site could experience 2 h daily 2000 μmol photons m−2 s−1, and 6 h above 1000 μmol photons m−2 s−1 during a clear day in early spring. Thalli of L. pulmonaria were transplanted to these two stems. During the first 40 days (April–May), transplants at the L. pulmonaria-deficient site developed severe chlorophyll degradation, and a substantial reduction in maximal PS II efficiency (Fv/Fm) even when measured after a 48-h recovery period at low light intensity. Extensive bleaching was formed along light-exposed sides of the tiny ridges on the upper side. Subsequent to this damage, FV/FM gradually rose to nearly normal levels during the following year. This apparent recovery was probably mainly due to irreversible loss of damaged chlorophyll, but also to some level of acclimation. No damage was observed in control transplants on the L. pulmonariarich tree, which were the only transplants gaining sufficient growth for new attachment to the new substratum during the 397-day transplantation period. Nevertheless, a fine-scale, but highly significant seasonal variation in FV/FM of control transplants reflected variations of even low irradiance levels. FV/FM, as measured after a 48-h recovery period at low light intensity, is an efficient meth for recording permanent high light damages at and shortly after damage is formed. However, FV/FM is not a useful estimator of chronic long-term damage.

Effect of Climatic Conditions on Phytotoxicity of Terbutryn

Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 60-63 ◽  
Author(s):  
L. F. Figuerola ◽  
W. R. Furtick
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
High Light Intensity ◽  
Climatic Conditions ◽  
High Light ◽  
Controlled Environment ◽  
Low Light ◽  
Carbon Dioxide Uptake ◽  
Low Light Intensity ◽  
The Difference

Phytotoxicity of 2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine (terbutryn) on winter wheat (Triticum aestivum Vill. ‘Host’) was investigated in a controlled environment. Highly significant differences in foliage dry weight were caused by different light intensities and rates of terbutryn. Injury symptoms appeared much earlier in plants under high light intensity. Carbon dioxide uptake by wheat plants was reduced by terbutryn at high light intensity. At low light intensity the reduction was less severe and developed later. Respiration (CO2 evolved in the dark) was reduced only by the highest rates. Terbutryn was significantly less toxic to wheat than 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine). The difference was more noticeable at low rates under high light intensity. At low light intensity no injury was observed with terbutryn.

Adaptation of Melampsora medusae to increasing temperature and light intensities on a clone of Populus deltoides

1986 ◽  
Vol 64 (4) ◽  
pp. 834-841 ◽  
Author(s):  
C. S. Prakash ◽  
W. A. Heather
Keyword(s):  
Low Temperature ◽  
Light Intensity ◽  
Populus Deltoides ◽  
High Light Intensity ◽  
Disruptive Selection ◽  
Low Light ◽  
Environmental Selection ◽  
Melampsora Medusae ◽  
Low Light Intensity ◽  
Light Intensities

Race 4A of Melampsora medusae Thum. produces an incompatible reaction on Populus deltoides Marsh. cv. W-79/307 when incubated at high temperature and low light intensity (26 °C and 100 μE∙m−2∙s−1) or low temperature and high light intensity (17 °C and 700 μE∙m−1∙s−1), but a compatible one at low temperature and low light intensity 17 °C and 100 μE∙m−2∙s−1). When in separate studies, a population of this race was sequentially cultured on detached leaves, at increasing temperatures (17, 20, 23, or 26 °C) or light intensities (100, 300, 500, or 700 μE∙m−2∙s−1), isolates that were adpated to each of these regimes were selected. Such isolates, particularly those from low temperature and low light intensity, exhibited some specificity to their "own" environments, although isolates selected at 26 °C and 500 μE∙m−2∙s−1 were most aggressive at all temperatures and light intensity regimes, respectively. Such adaptation appeared to result from pathogen response to host-mediated environmental selection pressure. Isolate, incubating environment, and their interaction were significant contributors to the variation in aggressiveness traits (disease timing and intensity). This rust demonstrates considerable ability to adapt to varying environmental conditions. Thus physical environmental variables may be important selective forces in the regulation of this pathosystem, as spatial and temporal heterogeneity of the environment in nature may result in polymorphism of the pathogen by disruptive selection.

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