Tagesperiodische antagonistische Schwankungen der Blauviolett- und Gelbrot-Empfindlichkeit als Grundlage der photoperiodischen Diapause-Induktion bei Pieris brassicae

1960 ◽  
Vol 15 (4) ◽  
pp. 205-213 ◽  
Author(s):  
Erwin Bünning ◽  
Gabriele Joerrens
Keyword(s):  
Dark Period ◽  
Red Light ◽  
Pieris Brassicae ◽  
Light Period ◽  
Measuring Process ◽  
The Third ◽  
Long Day ◽  
Critical Daylength ◽  
Qualitative Responses ◽  
Short Days

In Pieris brassicae, diapause is inhibited if long-day conditions are imposed during and immediately after the third molting. The critical daylength is approximately 14 hours. Under short-day conditions with a main light period of 6 or 12 hours’ duration, supplementary light given in the period from 14 to 16 hours after the beginning of the main light period will inhibit diapause. In contrast to this effect of late exposures to light, light given from 1 to 12 hours after the beginning of the main light period promotes diapause. Experiments with extremely long light periods (10—35 hours), but always with a dark period of 10 hours, show that these diurnal fluctuations in quantitative and qualitative responses to light can continue endogenously for several days. Thus, this time-measuring process operates through the mechanism of endogenous diurnal oscillations in just the same way as do photoperiodic reactions in plants.The inhibition of diapause by light in the second half of the diurnal oscillation (under long days or by light interruptions in the dark period) and the promotion by light in the first half (under short days) occur only with light of short wavelengths: ultraviolet, violet, and blue up to about 550 mμ. Yellow and red light act in the opposite fashion, giving diapause inhibition in the first half of the cycle and promotion in the second half. In white light the violet reaction predominates, so that diapause is promoted by short days and inhibited by long days.

Red and far-red light influence carbon partitioning, growth and flowering of bahia grass (Paspalum notatum)

1995 ◽  
Vol 125 (3) ◽  
pp. 355-359 ◽  
Author(s):  
F. J. Marousky ◽  
F. Blondon
Keyword(s):  
Light Quality ◽  
Dark Period ◽  
Leaf Growth ◽  
Red Light ◽  
Dry Weight ◽  
Paspalum Notatum ◽  
Starch Accumulation ◽  
Long Day ◽  
Bahia Grass ◽  
Short Days

SUMMARYBahia grass (Paspalum notatum Flugge) plants were grown in growth chambers at Gif, France, and at Gainesville in Florida, demonstrating that the species is a long-day plant and greatly influenced by light quality during the photosynthetic period. Flowering occurred in all instances when the middle of the dark period was interrupted with red or red + far-red light. With nightly interruptions of farred light, flowering occurred only when a sufficient quantity of far-red was present during the photosynthetic period. Plants grown under short days with nightly interruptions of red, far-red or red + far-red light had less starch accumulation and greater leaf growth and dry weight than plants grown without nightly light interruptions, whatever the light quality during the photosynthetic period. The treatments did not affect the partitioning of assimilates and flowering in the same way.

CO2 and H2O exchanges in response to alteration of photoperiod in Anagallis arvensis, a long-day flowering plant

1984 ◽  
Vol 62 (9) ◽  
pp. 1880-1883
Author(s):  
Marianne Mousseau
Keyword(s):  
Water Saturation ◽  
Red Light ◽  
Light Period ◽  
Flowering Plant ◽  
Water Saturation Deficit ◽  
Rooted Cuttings ◽  
Long Day ◽  
Entire Plant ◽  
Stomatal Movements ◽  
Short Days

Rooted cuttings of Anagallis arvensis grown in short days (SD) were given 1 to 4 long days (LD) consisting of nights interrupted by red light. Just after LD treatment, young upper leaves showed a lower net photosynthetic rate than leaves of SD control plants, measured at various light intensities and CO2 concentrations. Respiratory CO2 output decreased during the first interrupted night and remained lower for one or two SD after treatment. Net CO2 uptake during the light period decreased similarly, so that the total CO2 balance of the entire plant was the same as for SD plants during and immediately after the treatment. After one interrupted night, the transpiration rate was lower, especially in the morning. The water saturation deficit similarly decreased in young upper leaves after the LD treatment, but leaf water potential did not change. The observed changes in CO2 and H2O exchanges with alteration of photoperiod were associated with, and may be explained in terms of, stomatal movements.

Photoperiodic control of development in the pitcher-plant mosquito, Wyeomyia smithii

1972 ◽  
Vol 50 (6) ◽  
pp. 713-719 ◽  
Author(s):  
William E. Bradshaw ◽  
L. Philip Lounibos
Keyword(s):  
Larval Instar ◽  
Pitcher Plant ◽  
Photoperiodic Control ◽  
Wyeomyia Smithii ◽  
Diapause Termination ◽  
Environmental Consequences ◽  
The Third ◽  
Short Day ◽  
Critical Daylength ◽  
Short Days

Wyeomyia smithii diapause in the third larval instar. Long days avert or terminate and short days promote or maintain diapause. Diapause occurs early in the third instar and may be terminated by photoperiodic stimuli without the intervention of chilling or other factors. Fifty percent termination of diapause requires about 3 long days and another [Formula: see text] days are consumed in the third instar for postdiapause development. The critical daylength is identical for both the initiation and termination of diapause, 14.75 h of light per day. But, the photoperiodic clock monitoring diapause decisions is several times as accurate during initiation as in termination, reflecting the more drastic environmental consequences of development misdirection in the fall than in the spring. This accuracy is further enhanced by a prolongation of the second instar under short-day conditions. The doubling in the duration of the second instar exhibits the same critical daylength properties as diapause determination.The third instar is divisible into four distinct developmental periods: prediapause, diapause, termination of diapause, and postdiapause. Methods for quantifying these periods are presented. Similar manipulations could be employed for other diapausing arthropods, regardless of the stage at which dormancy occurs or the cues used in its regulation.

scholarly journals Inflorescence Initiation in Lolium Temulentum l. II. Evidence for Inhibitory and Promotive Photoperiodic Processes Involving Transmissible Products

1960 ◽  
Vol 13 (4) ◽  
pp. 429 ◽  
Author(s):  
LT Evans
Keyword(s):  
Leaf Blade ◽  
Light Period ◽  
Continuous Illumination ◽  
Rate Of Development ◽  
Lolium Temulentum ◽  
Short Day ◽  
Long Day ◽  
Inductive Treatment ◽  
Short Days

Plants of Lolium temulentum, raised in short days, were given an inductive treatment by exposure of one leaf blade to a 32-hr period of continuous illumination. Then either the leaf exposed to this one long light period or varying areas of lower leaves which were simultaneously in short-day conditions were removed at intervals after the long-day exposure. The longer the long-day leaves remained on the plants, the greater was the proportion of plants which initiated inflorescences and the greater the rate of development of their inflorescences. This was so even when short-day leaves were present above the long-day ones. The longer the short-day leaves remained, and the greater their area, the lower was the proportion of plants which initiated inflorescences.

Inflorescence Initiation in Lolium temulentum L. XIV. The Role of Phytochrome in Long Day Induction

1976 ◽  
Vol 3 (2) ◽  
pp. 207 ◽  
Author(s):  
LT Evans
Keyword(s):  
Initial Period ◽  
Red Light ◽  
Pharbitis Nil ◽  
Initial Exposure ◽  
Continuous Irradiation ◽  
Long Day ◽  
Optimum Proportion ◽  
Subsequent Exposure ◽  
Short Days

Plants of L. temulentum grown in short days were exposed at various times during one night to mixtures of red (R) and far red (FR) light or to prolonged irradiation on a spectrograph. Irradiation with red light through the latter half of the 16-h night was inductive of flowering, its effect being enhanced by exposure to FR during the first 6 h after the period in daylight. Brief exposure to FR during this initial period was as effective as continuous irradiation with FR, and its effect was reversible by brief subsequent exposure to R, implicating the pigment phytochrome. Brief exposures to mixtures of R + FR at various times during the first 6 h in darkness were used to chart apparent changes in the two forms of phytochrome. To judge from the R + FR mixtures giving null responses, phytochrome reverted from the Pfr to the Pr form progressively over the first 5 h of darkness. There was no evidence of inverse reversion after an initial exposure to FR. Optimum flowering response required most of the phytochrome to be present in the Pfr form in the initial hours after daylight, followed by a rise in the proportion of the Pfr form to that set by R. Reflecting this shift during the night in the optimum proportion of Pfr, the spectrograph experiments indicated peak effectiveness in the far red region of the spectrum for irradiation at the end of the period in daylight, and in the red region (~670 nm) for irradiation during the latter part of the night. Flower induction in this long day plant is optimal when phytochrome is mostly in the Pr form early in the night, and in the Pfr form later, a sequence opposite to that required by short day plants such as Pharbitis nil and Chenopodium rubrum.

scholarly journals 631 Photocontrol of Flowering and Stem Extension of the Intermediate-day Plant Echinacea purpurea Moench.

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 506C-506
Author(s):  
Erik S. Runkle ◽  
Royal D. Heins ◽  
Arthur C. Cameron ◽  
William H. Carlson
Keyword(s):  
Red Light ◽  
Echinacea Purpurea ◽  
Physiological Age ◽  
Stem Length ◽  
Low Intensity ◽  
Stem Extension ◽  
Long Day ◽  
Short Days

Intermediate-day plants (IDP) flower most rapidly and completely under intermediate photoperiods (e.g., 12 to 14 h of light), but few species have been identified and their flowering responses are not well understood. A variety of experiments was conducted to determine how light controls flowering and stem extension of Echinacea purpurea `Bravado' and `Magnus'. Both cultivars flowered most completely (79%) and rapidly and at the youngest physiological age under intermediate photoperiods of 13 to 15 h. Few (14%) plants flowered under 10- or 24-h photoperiods, indicating E. purpurea is a qualitative IDP. Plants were also induced to flower when 15-h dark periods were interrupted with as few as 7.5 min of low-intensity lighting (night interruption, NI). Flowering was progressively earlier as the NI increased to 1 h, but was delayed when the NI was extended to 4 h. Stem length increased by 230% as the photoperiod or NI duration increased, until plants received a saturating duration (at 14 h or 1 h, respectively). At macroscopic visible bud, transferring plants from long days to short days reduced stem extension by up to 30%. Flowering was inhibited when the entire photoperiod was deficient in blue or red light and was promoted in a far-red deficient environment, suggesting that phytochrome and cryptochrome control flowering of E. purpurea. Because of our results, we propose the flowering behavior of IDP such as E. purpurea is composed of two mechanisms: a dark-dependent response in which flowering is promoted by a short night, and a light-dependent response in which flowering is inhibited by a long day.

scholarly journals Far-red Light Alters Primocane Morphology of Red Raspberry

HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 973-974 ◽  
Author(s):  
Adam Dale ◽  
Theo J. Blom
Keyword(s):  
Dark Period ◽  
Red Light ◽  
Internode Length ◽  
Red Raspberry ◽  
Short Days

The objectives of the study were to determine whether raspberries responded to decreased red to far-red ratio and whether it was more effective at the beginning or end of the dark period. Increased proportions of far-red light increased the internode length when at the beginning of the dark period on the three raspberry cultivars `Lauren',`Reveille', and `Titan'. Cultivars varied in that internode length also increased in ambient daylength compared to short days in `Lauren' and `Reveille', but not in `Titan'. They also responded differently to photoperiod: `Titan' and `Lauren' grew under short days, whereas `Reveille' ceased growth.

Egg production in Arctic charr (Salvelinus alpinus L.) broodstock: effects of photoperiod on the timing of ovulation and egg quality

1994 ◽  
Vol 72 (2) ◽  
pp. 334-338 ◽  
Author(s):  
C. Gillet
Keyword(s):  
Egg Production ◽  
Egg Quality ◽  
Cold Water ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Day Treatment ◽  
Light Period ◽  
Day Length ◽  
Long Day ◽  
Short Days

Arctic charr were subjected to different photoperiod manipulations applied at several stages of the reproductive cycle to advance or delay ovulation. Spawning was delayed by 6 weeks when the fish were subjected to long days (17 h light: 7 h dark) from midsummer. Ovulations were spread over a period of 2.5 months if fish were maintained under a long-day regime until spawning. When the long-day treatment was stopped in December, ovulations were synchronized to within 1 month. Long days early in the year followed by short days at the beginning of summer advanced spawning by 3 months. Immature, 20-monfh-old fish maintained in constant long days from 1 October started to spawn at the beginning of the following summer, i.e., 6 months before fish kept in a natural light period. The eggs produced in January by females with delayed ovulation were of better quality than those of fish kept in a natural day length in December. This improvement was probably due to a decrease in water temperature from 8 to 6 °C between December and January, since overripening of the ova was reduced when the temperature was decreased. It seems possible that by manipulating the photoperiod, viable eggs can be obtained from Arctic charr broodstock all year round provided the cold-water requirement of spawners is taken into account.

Immunocytochemical studies on the behavior of RuBisCO and LHCP II during the cell cycle of synchronized Euglena gracilis

1990 ◽  
Vol 48 (3) ◽  
pp. 662-663
Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff
Keyword(s):  
Cell Cycle ◽  
Immunoelectron Microscopy ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Dark Period ◽  
Light Period ◽  
Carboxylase Activity ◽  
Immunocytochemical Studies ◽  
Lhcp Ii

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.

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