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1.
Abstract A study was made on the developmental rhythms of Ephestia kuehniella during different photoperiods: constant lighting (L/L), under conditions of 12 hours light per day (L/D) and in constant darkness (D/D). Observations were made every 2 hrs, for 3 successive 24‐hr periods, of the number of wandering larvae emerging from food, the number of pupations and of imaginai moults. Emergence of wandering larvae is rhythmic only under L/D conditions, and in addition this is also affected by the density of the larvae. Rhythm is least apparent with greatest density of the larvae. Pupation in E. kuehniella is a non‐rhythmic process with each of the photoperiods examined, whereas the imaginai moult is characterized by an endogenous (existing under D/D conditions) rhythm. Emergence of imagines is non‐rhythmic under L/L, and also when pupae under L/D fail to receive the final period of darkness. The rhythm of the imaginai moult is possibly controlled by the biological clock, which stops under conditions of constant light. 相似文献
2.
The flight activity of adults of a migrant skipper (Parnara guttata guttata) was measured on the day of emergence, and at 4 and 7 days after emergence by a flight mill and the activity was compared among the three seasonal forms which emerged under 12, 14 and 16 hr photoperiods. The flight activity of adults reared under 12 and 14 hrs was higher than that under 16 hr especially on the day of emergence. The flight activity of males under 12 and 14 hrs was higher on the day of emergence and decreased at 4 and 7 days. The activity of males under 16 hr was maintained at a low and constant level. The activity of females under 12 and 14 hrs increased or was constant on the days after the emergence, on the other hand, the activity of females under 16 hr was highest at 4 days after the emergence. The wing size did not affect the flight activity. The oviposition characteristics of females reared under the three photoperiods was compared. The female under 14 hr has a longer preoviposition period and lesser fecundity than that under 16 hr. The female under 12 hr has intermediate values of the former two. The size of eggs laid by females under 12 hr was also intermediate. 相似文献
3.
G. W. Ankersmit 《Entomologia Experimentalis et Applicata》1968,11(2):231-240
The photoperiodic responses were studied of Adoxophyes reticulana reared on a wheat-germ medium. Temperature had only a minor effect on the response. At photoperiods of 16 hrs or more hardly any diapause occurred. At photoperiods of 10 to 13 hrs a high incidence of diapause was observed. Light-interruptions during the dark period of an LD 13:11 cycle revealed a maximum sensitivity for light about 161/2 hrs after the beginning of the main light period. Light-interruptions of 2 min were effective. The effect of these short light-interruptions increased by lengthening of the main light period from 13 to 14 hrs. In field experiments with larvae on small apple-trees, 2-min light-breaks about 161/2 hrs after sunrise were effective in preventing diapause in about 80% of the population. The first half of the larval development period was the most sensitive phase for photoperiodic induction.
Zusammenfassung Die photoperiodische Reaktion von Adoxophyes reticulana wurde an einer Aufzucht mit Weizenkeimlings-Diät untersucht. Bei Tageslängen mit 16 oder mehr Stunden Licht je Tag traten kaum mehr Diapausen auf. Bei Photophasen von 10 bis 13 Stunden wurde starke Diapause-Induktion beobachtet. Die Temperatur hat nur geringen Einfluß auf die Reaktion. Störlichtphasen (Sekundärlicht) während der Dunkelphase eines LD 13:11-Zyklus enthüllte eine maximale Lichtempfindlichkeit etwa 161/2 Stunden nach Beginn der Hauptlichtphase. Dabei waren Belichtungszeiten von 2 Minuten wirksam. Die Wirkung dieser kurzen Unterbrechungen der Dunkelphase durch Licht verstärkte sich bei Verlängerung der Hauptlichtzeit von 13 auf 14 Stunden. Bei Feldversuchen mit Junglarven an kleinen Apfelbäumen verhinderte Störlicht von 2 Minuten Dauer etwa 161/2 Stunden nach Sonnenaufgang die Diapause bei etwa 80% der Population. Die erste Hälfte der Larvalentwicklung war für die photoperiodische Induktion am empfindlichsten.相似文献
4.
J. Simmonds 《Biologia Plantarum》1985,27(4-5):318-324
Leaf expiants from vegetative plants of the short-day plantStreptocarpus nobilis (C. B. Clarke) developed flower budsin vitro when cultured in 8 h photoperiods. Tn non-inductive photoperiods only vegetative buds were formed.In vitro photoinduction was demonstrated by giving the expiants short-day (SD) cycles and then transferring them to non-inductive
photoperiods for expression of flowering. On medium containing 6-benzylaminopurine (BAP) organogenesis was initiated during
the photoinductive treatments. Photoinduction of leaf tissue without adventitious bud development was obtained on medium without
BAP. The photoinductive state of the leaf tissue was fairly stable, being expressed after 2–3 weeks in non-inductive photoperiods
when adventitious buds were formed. The quantitativein vitro flowering response to the endogenous floral stimuli, resulting from photoinduction, could provide the basis of a bioassay
for presumptive flower inducing chemicals. 相似文献
5.
The entrainment behaviour of the circadian rhythm of locomotor activity in the field mouse Mus booduga was studied in order to evaluate the role of the animals' free-running period (τ) and the duration of skeleton photoperiods in determining entrainment of animals with τ values beyond and close to the “limits of entrainment”. We predicted that animals with τ lesser than the lower “limit of entrainment” would entrain only to short skeleton photoperiods (≤ 6 h) and not to longer skeleton photoperiods. Experimental animals (n = 25) were entrained to light/dark (LD) 12:12 h schedule, and then subjected to various skeleton photoperiods in which the duration of one of the two intervals of darkness was successively reduced while holding the zeitgeber period (T) constant. Some animals (n = 9) entrained to long as well as short photoperiods, whereas others (n = 5) entrained only to extremely short skeleton photoperiods of 6 h or less. The mean τ of the animals entraining to all photoperiods (23.78 ± 0.22 h) was significantly greater than that of the animals that entrained only to very short skeleton photoperiods (22.43 ± 0.41 h) (t df 12 = 5.3, p < 0.001). We also selected a few animals (n = 11) with average τ value of 23.13 ± 0.38 h and studied them under several skeleton photoperiods. To our surprise the animals which were subjected to restricted dark intervals invariably underwent “phase-jump” assuming the longer dark interval as “subjective night”. We suggest that the observed variation in entrainment behaviour might be due to the variation seen among individual animals in τ and the shape of their PRC. These results support the view that the duration of the skeleton photoperiod and the τ of an individual animal interact to determine its entrainment, and underscore the relevance of inter-individual variation in circadian organisation to studies of circadian rhythms. 相似文献
6.
Klaus Hoffmann 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1982,148(4):529-534
Summary The effects of brief light pulses on photoperiodic reaction were examined in male Djungarian hamsters (Phodopus sungorus). Half of the animals came from long photoperiods and, accordingly, were in physiological summer state with large and functional testes. The other half had lived in short natural photoperiods before and was in physiological winter condition with involuted testes. These animals were exposed to long (LD 168) or to short (LD 816) photoperiods, or to short photoperiods in which the 16 h of darktime were interrupted by 1 min of light each night, either 4, 8 or 12 h after light off.Light pulses at midnight had the same effect as long photoperiods, they maintained gonadal size and activity or caused rapid recrudescence. If the light pulses were applied 4 or 12 h after light-off, however, a marked difference in effect ensued, depending on previous state and light regime. In animals coming from long photoperiods, these schedules induced regression, while in hamsters coming from short photoperiods the same schedules stimulated recrudescence, though significantly less than full long photoperiods or schedules with light-interruptions at midnight. Changes in body weight and pelage colour closely paralleled the changes in gonadal state. 相似文献
7.
The effects of day/night temperatures and photoperiod on the growth and dormancy of paper birch (Betula papyrifera) were studied in seedlings from different geographic origins. The response of Alaskan plants to temperature and photoperiod was distinctly different from other seed sources. Alaskan plants required very long days to prevent cessation of growth while plants from southern seed sources grew on photoperiods as short as 14 hr. Low night temperature (14 C) antagonized the promotive action of long photoperiods in Alaskan plants but had little effect in other seed sources. High day temperatures offset the inhibitory effect of the cool night to a lesser degree in Alaskan plants than in plants from other locations. Dormancy induced by short photoperiods was antagonized (relieved ?) to a lesser degree by high night temperatures in Alaskan birch than in other seed sources. Betula papyrifera var. humilis from Alaska may be an incipient species since its morphological traits are accompanied by adaptive physiological responses to its environment. These responses are as distinct as its morphological characteristics. 相似文献
8.
Lovegrove BG Raman J Perrin MR 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2001,171(1):11-21
Patterns of daily torpor were measured in response to photoperiod and food restriction at a constant temperature (18 °C)
in two species of elephant shrew (Macroscelidea), Elephantulus rozeti (from Morocco) and Elephantulus myurus (from southern Africa). Body temperature was monitored continuously for ca. 3 months using temperature-sensitive telemeters.
Under short photoperiods (8:16 L:D), both species entered spontaneous torpor on an ad libitum diet, but showed a higher frequency
of induced torpor when food was restricted. Under long photoperiods (16:8 L:D), E. myurus could be induced to enter daily `summer' torpor. A total of 378 torpor bouts were measured, none of which were longer in
duration than 18 h. Under short photoperiods, arousal from torpor was associated with the onset of the photoperiod, whereas
the time of entry was variable throughout the scotophase. However, E. myurus tended to phase shift torpor from the photophase to the scotophase under long photoperiods, despite displaying weak circadian
amplitudes of body temperature indicative of a photophase rest phase. Both species lacked well-defined circadian amplitudes
of body temperature, a pattern thought to be associated with polyphasic activity cycles characteristic of several Elephantulus species. It was concluded that these and other patterns of torpor shown by Elephantulus show similarities with other small Afrotropical insectivores inhabiting semi-arid habitats or unpredictable environments.
Accepted: 26 July 2000 相似文献
9.
H. Miliou 《Hydrobiologia》1992,232(3):201-209
The harpacticoid copepod Tisbe holothuriae Humes was reared for several generations under different photoperiods (white light) and spectral quality (continuous illumination).
The main life cycle parameters were measured and demographic variables were determined. Development time was retarded under
green wavelengths and at photoperiods different from LD 12:12, especially under continuous white light. Total body length
of females and males was shortest under LD 12:12 and longest under constant dark. Photoperiods different from LD 12:12 prolonged
the interval between broods of egg sacs. Short photoperiods caused higher abortion rate, while long photoperiods retarded
the maturation time of the egg sacs. Red wavelengths stimulated the abortion rate. Photoperiod LD 12:12 and blue wavelengths
increased the production of offspring and the life span of females. Highest intrinsic rates of natural increase were estimated
under LD 12:12 (rm =0.304) and blue wavelengths (rm = 0.254). These light conditions proved the most favourable for rearing Tisbe holothuriae. 相似文献
10.
Gibberellic acid (GA3) increases the height of Impatiens balsamina under both 8- and 24-h photoperiods. The height also increases with all guanosine monophosphates (GMPs) under 8-h photoperiods but only with 5′-GMP under 24-h photoperiods. GA3 as well as GMPs increase the number of leaves under 8-h but not under 24-h photoperiods. GA3 as well as GMPs induce floral buds under strictly non-inductive photoperiods and increase the number of floral buds under 8-h photoperiods. The floral bud initiation occurs earlier when cGMP is used in combination with 100 mg/l GA3. 相似文献
11.
C. Louskas et Y. Laudého 《Entomologia Experimentalis et Applicata》1977,22(3):243-250
Résume
Eupelmus urozonus, parasite de Dacus oleae présente en Grèce un arrêt de développement hivernal pendant le 5ème stade de son évolution larvaire. Sous une exposition à une photophase courte (20°-8 h d'éclairement), plus de 99% de la population du parasite a un arrêt de développement alors que soumis à 16 h d'éclairement, les insectes peuvent évoluer sans diapause. Presque immédiatement après l'exposition du stade sensible à la photopériode courte, l'insecte arrête son développement morphogénétique et il peut être conservé dans cet état pendant plusieurs mois. La reprise du développement a pour principal agent le retour à une photophase longue. L'arrêt de développement étudié présente de nombreuses caractéristiques d'une oligopause.
Summary Eupelmus urozonus, a parasite of Dacus oleae, in Greece hibernates in the fifth-larval stage during winter. A preliminary study of this has been made in the laboratory. Under the conditions 20° and 8 hrs light, more than 99% of parasites cease development; but with 16 hrs light, the insects develop directly without any break in morphogenisis. Exposure to a range of intermediate photoperiods confirmed that photoperiod was the most important determinent of the type of developmental cycle. Development of sensitive larvae ceases immediately on exposure to the short photoperiod and they may then be kept in this state for several months. Reactivation occurs under long photoperiods. This arrest of development presents many characteristics of an oligopause.相似文献
12.
Summary To assess the role of the hypothalamic neurosecretory system in the mechanism of photoperiodic control of testicular growth in Spizella arborea, we have examined the effect of (1) photostimulation on the density of paraldehyde-fuchsin-stainable (PAF+) material in the neurovascular zone of the median eminence, and (2) interruption of the hypothalamo-hypophysial (neurosecretory) tract on the photoperiodic testicular response. Birds were captured during midwinter and retained on 8-hr daily photoperiods several months prior to the experiment. Interruption of the neurosecretory tract was effected by a small knife fashioned from stainless steel wire; radiography was employed to facilitate stereotaxic placement of the knife assembly.Extending the daily photoperiod from 8 to 20 hrs induced rapid testicular growth in photosensitive Spizella arborea, but had no consistent effect on the density of PAF+ material in the palisade layer of the anterior median eminence. Whereas some terminal controls showed moderate depletion after 21 days' exposure to 20-hr daily photoperiods, others retained as much or more stainable material than initial controls in which testicular growth was not induced. Moreover, testicular growth was induced at essentially identical rates whether the PAF+ innervation of the anterior median eminence was intact or eliminated to varying degrees. The finding that the rate of photoperiodically induced testicular growth is independent of the density or pattern of accumulation of PAF+material in the neurovascular zone of the median eminence, coupled with the inconstant effect of photostimulation on the density of stainable material therein, strongly suggests that the eminential component of the hypothalamic neurosecretory system is not a part of the mechanism that controls photoperiodic testicular growth in S. arborea.Contribution No. 980, Division of Biology, Kansas Agricultural Experiment Station, Manhattan 66502. This investigation was supported in part by the Undergraduate Research Participation Program (GY-771) of the National Science Foundation. We are grateful to French's Pet Bird Laboratory, Rochester, N.Y., for the parakeet foods, to Richard S. Donham, Michael D. Ruff, Thomas G. Shane, and Philip G. Watt for assisting with field operations, to Mr. Gary R. Dierking for preparing the drawing, and to Mr. Don Pihlaja for assisting with the photomicrography. 相似文献
13.
Gibberellins A3 and A13 cause floral induction inImpatiens balsamina, a qualitative short day plant, under non-inductive 24-h photoperiods (continuous illumination). However, the influence of
the two inductive factors,i.e. gibberellins and short days (8-h photoperiods) on the peroxidase enzyme system is different. The total peroxidase activity
decreases under both inductive and non-inductive photoperiods, with or without gibberellin treatment. The electrophoretic
pattern of isoperoxidases changes only in response to gibberellin treatment. Under 24-h photoperiods, treatment with gibberellins
A3 and A13 causes the appearance in the stem of three additional isoenzymes of peroxidase (Rm 0.50, 0.71 and 0.76). These bands do not
appear in the leaves, which are non-essential for gibberellin-caused floral induction in this plant. Under 8-h photoperiods
also, gibberellins induce the appearance of new isoenzyme bandsi.e. two in the stem (Rm 0.50 and 0.76) and one in the leaves (Rm 0.05). These may be correlated with the synergistic increase
in the number of floral buds in these plants in response to simultaneous exposure to two inductive factors. 相似文献
14.
Maitra SK Dey M Dey R Bhattacharya S Sengupta A 《Indian journal of experimental biology》2000,38(11):1111-1116
Effects of daily (one hour prior to onset of darkness) injection of melatonin (25 micrograms/100 g body wt. for 30 days) on concentrations of blood glucose and adrenal catecholamines were studied in adult male roseringed parakeets, P. krameri under both natural (NP; about 12L:12D) and artificial long (LP; 16L:8D; lights were available in between 0600 and 2200 hrs) or short (SP; 8L:16D; lights were available between 0600 and 1400 hrs) photoperiodic conditions. The results indicate that neither LP, nor SP as such exerts any significant effect on blood glucose titre of control (vehicle of hormone administered) birds. Treatment with melatonin, however, induced hyperglycemia in both NP and LP bird groups, but hypoglycemia in SP birds. Unlike glycemic levels, amount of epinephrine (E) and norepinephrine (NE) in adrenals of control birds exhibited significant changes under altered photoperiods. A decrease in E and an increase in NE were noted in adrenals of both LP and SP birds. Exogenous melatonin in NP birds also caused a decrease in E and concomittant rise in NE levels. On the other hand, treatment of melatonin in both LP and SP bird groups resulted in an increase in the quantity of both E and NE compared to respective values in adrenals of melatonin injected NP birds. However, relative to the amount of E and NE in adrenals of placebo treated LP and SP birds, significant effect of melatonin treatment was observed only in SP birds. The results suggest that influences of exogenous melatonin on the levels of both blood glucose and adrenal catecholamines are largely modulated by short rather than long photoperiods. 相似文献
15.
Stanley D. Beck 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1976,105(3):267-277
Summary The Dual System Theory of photoperiodic determination was found to be consistent with experimental data on diapause induction in response to skeleton photoperiods. Symmetrical and asymmetrical skeleton photoperiods of both diel and nondiel durations were investigated. The theoretical model was shown to predict accurately the incidence of diapause among larvae of the European corn borer,Ostrinia nubilalis, that had been reared under the different photoperiodic regimes.Research supported by the College of Agricultural and Life Sciences, University of Wisconsin, and by a research grant (GM 07557) from the National Institutes of Health. 相似文献
16.
Diatom growth responses to photoperiod and light are predictable from diel reductant generation
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Light drives phytoplankton productivity, so phytoplankton must exploit variable intensities and durations of light exposure, depending upon season, latitude, and depth. We analyzed the growth, photophysiology and composition of small, Thalassiosira pseudonana, and large, Thalassiosira punctigera, centric diatoms from temperate, coastal marine habitats, responding to a matrix of photoperiods and growth light intensities. T. pseudonana showed fastest growth rates under long photoperiods and low to moderate light intensities, while the larger T. punctigera showed fastest growth rates under short photoperiods and higher light intensities. Photosystem II function and content responded primarily to instantaneous growth light intensities during the photoperiod, while diel carbon fixation and RUBISCO content responded more to photoperiod duration than to instantaneous light intensity. Changing photoperiods caused species‐specific changes in the responses of photochemical yield (e?/photon) to growth light intensity. These photophysiological variables showed complex responses to photoperiod and to growth light intensity. Growth rate also showed complex responses to photoperiod and growth light intensity. But these complex responses resolved into a close relation between growth rate and the cumulative daily generation of reductant, across the matrix of photoperiods and light intensities. 相似文献
17.
PvLHY and Lhcb expression has been studied in primary bean leaves after exposure of etiolated leaves to two or three white light-pulses
and under different photoperiods. Under the tested photoperiods, the steady-state mRNA levels exhibit diurnal oscillations
with zenith in the morning between ZT21 and 4 for PvLHY and between ZT4 and 6 for Lhcb. Nadir is in the evening between ZT12 and 18 for PvLHY and ZT18 and 24 for Lhcb. Light-pulses to etiolated seedlings induce a differentiated acute response that is reciprocally correlated with the amplitude
of the following circadian cycle. In addition, the clock modulates the duration of the acute response (descending part of
the curve included), which according to the phase of the rhythm at light application extends from 7 to 18 h. This constitutes
the response dynamics of the Phaseolus clock to light. Similarly, the waveform of PvLHY and Lhcb expression during the day of different photoperiods resembles in induction capability (accomplishment of peak after lights-on)
and duration (from lights-on phase to trough) the phase-dependent progression of acute response in etiolated seedlings. Consequently,
the peak of Lhcb (all tested photoperiods) and PvLHY (in LD 18:6) attained in the photophase corresponds to the acute response peak, while the peak of PvLHY during the scotophase (in LD 12:12 and 6:18) corresponds to the circadian peak. Thus, the effect of the response dynamics
in the photoperiod determines the coincidence of the peak with the photo- or scotophase, respectively. This represents a new
model mechanism for the adaptation of the Phaseolus clock to light. 相似文献
18.
Apterous exules of Rhopalosiphum padi which experienced short photoperiods only during the first half of their nymphal life all produced gynoparae which made up 57% of the offspring produced in the first 7 days of the mother's reproductive life. Short photoperiods during the second half of a mother's nymphal life did not induce the production of gynoparae. However, when short photoperiods were experienced throughout a mother's nymphal life significantly more gynoparae (82%) were produced. Ten per cent of the offspring of mothers that experienced short photoperiods only during their adult life developed into gynoparae. Of the offspring reared in short photoperiods, but born to mothers reared and kept in long photoperiods, 30% developed into gynoparae. When mothers were exposed to short photoperiods in their adult life and their offspring so treated, then 90% of the offspring developed into gynoparae. Males only occurred amongst the last offspring of mothers that experienced short photoperiods in either the first or the second half of their nymphal life. 相似文献
19.
Piringer , A. A., and H. A. Borthwick . (U.S.D.A., Beltsville, Md.) Effects of photoperiod and kind of supplemental light on growth, flowering and stem fasciation of Celosia. Amer. Jour. Bot. 48(7): 588–592. Illus. 1961.—Four cultivars of Celosia argentea L. var. cristata were grown on photoperiods ranging from 8 hr to continuous light. Supplemental low-intensity incandescent light was used to extend 8 hr of natural light and provide the given photoperiod. In all cultivars, short main stems occurred on photoperiods of 12 or fewer hours and long main stems, due to more nodes, on photoperiods of 16 or more hours. Flowering was a nonobligate short-day response in all cultivars. Plants of certain cultivars tended to have shorter stems and flower later when 8 hr of fluorescent instead of incandescent light was used to provide the 16-hr photoperiod. In 3 of the cultivars studied, photoperiods of 16 or more hours induced marked stem fasciation. 相似文献
20.
Abstract The bruchid beetle Bruchidius dorsalis Fahraeus (Coleoptera: Bruchidae) has been known to undergo larval diapause during the final instar under short photoperiods ( Kurota & Shimada, 2001 ). This species has a multivoltine life cycle and the overwintering stages show a geographical variation across Japan ( Kurota & Shimada, 2002 ). In cooler areas, overwintering occurs during the final instar, whereas in warmer climates overwintering can occur during several developmental stages: non‐diapausing young instars, diapausing instars, and adults. In this study, we investigated the adult reproductive diapause in three populations from different geographical regions to clarify the role of geographical variation on overwintering strategies. We found that: (1) B. dorsalis entered reproductive diapause in addition to larval diapause under short photoperiods, (2) diapause propensity was higher and the critical photoperiod was longer in populations from cooler regions, and (3) the sensitive photoperiod range was the first 5 days after emergence. Predictions of the overwintering stage, derived from critical photoperiods, were consistent with actual overwintering stages observed in each population. The geographical variation in diapause induction is likely to reflect the adaptive overwintering strategy in each local environment. 相似文献