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.

scholarly journals Managing flowering time in Miscanthus and sugarcane to facilitate intra- and intergeneric crosses

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0240390
Author(s):  
Hongxu Dong ◽  
Lindsay V. Clark ◽  
Xiaoli Jin ◽  
Kossonou Anzoua ◽  
Larisa Bagmet ◽  
...  
Keyword(s):  
Flowering Time ◽  
High Latitude ◽  
Floral Induction ◽  
Day Treatment ◽  
Day Length ◽  
Close Relative ◽  
Short Day ◽  
Culm Length ◽  
Low Latitudes ◽  
Short Days

Miscanthus is a close relative of Saccharum and a potentially valuable genetic resource for improving sugarcane. Differences in flowering time within and between Miscanthus and Saccharum hinders intra- and interspecific hybridizations. A series of greenhouse experiments were conducted over three years to determine how to synchronize flowering time of Saccharum and Miscanthus genotypes. We found that day length was an important factor influencing when Miscanthus and Saccharum flowered. Sugarcane could be induced to flower in a central Illinois greenhouse using supplemental lighting to reduce the rate at which days shortened during the autumn and winter to 1 min d-1, which allowed us to synchronize the flowering of some sugarcane genotypes with Miscanthus genotypes primarily from low latitudes. In a complementary growth chamber experiment, we evaluated 33 Miscanthus genotypes, including 28 M. sinensis, 2 M. floridulus, and 3 M. ×giganteus collected from 20.9° S to 44.9° N for response to three day lengths (10 h, 12.5 h, and 15 h). High latitude-adapted M. sinensis flowered mainly under 15 h days, but unexpectedly, short days resulted in short, stocky plants that did not flower; in some cases, flag leaves developed under short days but heading did not occur. In contrast, for M. sinensis and M. floridulus from low latitudes, shorter day lengths typically resulted in earlier flowering, and for some low latitude genotypes, 15 h days resulted in no flowering. However, the highest ratio of reproductive shoots to total number of culms was typically observed for 12.5 h or 15 h days. Latitude of origin was significantly associated with culm length, and the shorter the days, the stronger the relationship. Nearly all entries achieved maximal culm length under the 15 h treatment, but the nearer to the equator an accession originated, the less of a difference in culm length between the short-day treatments and the 15 h day treatment. Under short days, short culms for high-latitude accessions was achieved by different physiological mechanisms for M. sinensis genetic groups from the mainland in comparison to those from Japan; for mainland accessions, the mechanism was reduced internode length, whereas for Japanese accessions the phyllochron under short days was greater than under long days. Thus, for M. sinensis, short days typically hastened floral induction, consistent with the expectations for a facultative short-day plant. However, for high latitude accessions of M. sinensis, days less than 12.5 h also signaled that plants should prepare for winter by producing many short culms with limited elongation and development; moreover, this response was also epistatic to flowering. Thus, to flower M. sinensis that originates from high latitudes synchronously with sugarcane, the former needs day lengths >12.5 h (perhaps as high as 15 h), whereas that the latter needs day lengths <12.5 h.

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.

scholarly journals Photoperiodic Response of Peanut Species1

1983 ◽  
Vol 10 (2) ◽  
pp. 59-62 ◽  
Author(s):  
H. T. Stalker ◽  
J. C. Wynne
Keyword(s):  
North Carolina ◽  
Day Treatment ◽  
Photoperiodic Response ◽  
Reproductive Capacity ◽  
Arachis Species ◽  
Short Day ◽  
The North ◽  
Long Day ◽  
Wild Peanut ◽  
Short Days

Abstract Many Arachis species collections do not produce pegs in North Carolina even though they flower profusely. To investigate reasons for the failure of fruiting, nine wild peanut species of section Arachis and three A. hypogaea cultivars representing spanish, valencia and virginia types were evaluated for response to short and long-day treatments in the North Carolina State Phytotron Unit of the Southeastern Environmental Laboratories. The objective of this investigation was to determine the flowering and fruiting responses of Arachis species to short and long-day photoperiods. Plant collections grown under a 9-hour short-day treatment were generally less vigorous, but produced more pegs than corresponding plants grown in long-day treatments which were produced by 9 hours of light plus a 3-hour interruption of the dark period. Annual species produced significantly more flowers and pegs than perennial species during both long and short days. The total number of flowers produced ranged from 0 during short days for A. correntina to more than 300 for A. cardenasii in long-day treatments. Only one plant of each species A. chacoense and A. villosa, and no plants of A. correntina, flowered in short days. Total numbers of pegs produced in short-day treatments were generally greater than in long-day treatments and the ratio of total number of pegs/total number of flowers was consistently greater during short-day treatments. A general trend was observed for more flowers produced in long-day treatments, but more pegs produced in short days. This study indicated that photoperiod can be manipulated to increase the seed set of some species and the success rate of obtaining certain interspecific hybrids. Furthermore, introgression from wild to cultivated species may possibly alter the reproductive capacity of A. hypogaea to photoperiod.

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.

Environmental control of reproduction in Themeda australis

1969 ◽  
Vol 17 (3) ◽  
pp. 375 ◽  
Author(s):  
LT Evans ◽  
RB Knox
Keyword(s):  
Environmental Control ◽  
New Guinea ◽  
Reproductive Behaviour ◽  
Northern Territory ◽  
The Other ◽  
Day Length ◽  
Long Day ◽  
Flowering Behaviour ◽  
Ecological Races ◽  
Short Days

Seedlings and older plants of 30 ecological races of Themeda australis were grown under controlled conditions to determine the effect of day length and vernalization on their flowering and on the incidence of apomixis. The races ranged in origin from latitude 6°S. in New Guinea to latitude 43°S, in Tasmania. One race from New Guinea and several from the Northern Territory behaved as strict short-day plants. The more southerly races, on the other hand, and several from north Queensland were long-day plants. In some, long days were required for both initiation and development of the inflorescence, in others apparently only for initiation. Some races required long days as seedlings, but not as older plants. Races from drier inland areas tended to be indifferent to day length in their flowering behaviour. At least four races from the colder areas responded to vernalization. Both the sexual and the aposporous reproductive pathways are described. Two races were wholly sexual in their breeding system and two appeared to be almost entirely aposporous, but most were versatile, displaying both sexual and aposporous reproductive behaviour. In seven races there was some evidence that day length influenced the reproductive pathway, short days causing increased apospory in all cases, regardless of the day length requirements for flowering.

scholarly journals Frost hardening in white cedar container seedlings exposed to intermittent short days and cold temperatures

1991 ◽  
Vol 67 (5) ◽  
pp. 542-544 ◽  
Author(s):  
S. J. Colombo ◽  
E. M. Raitanen
Keyword(s):  
Day Treatment ◽  
Frost Hardiness ◽  
Day Length ◽  
Cold Temperatures ◽  
Thuja Occidentalis ◽  
Frost Hardening ◽  
White Cedar ◽  
Container Seedlings ◽  
Dark Green ◽  
Short Days

Shoot frost hardiness development in white cedar (Thuja occidentalis L.) container seedlings in response to intermittent short days (4 days per week) and warm (not less than 15 °C) or cool (10/5 °C, day/night) temperatures was assessed using the diffusate-electrical conductivity technique. A slight increase in frost hardiness was found within 2 weeks of the start of warm, short days. Frost hardiness increased linearly with time under warm, short days from week 7 to week 14, with seedlings being resistant to damage at −10 °C on week 14. Approximately one-quarter of the seedlings developed brown-green foliage colour after 5 weeks of warm, short day treatment. These seedlings were significantly more frost hardy than the remainder of the seedlings which had dark green foliage. Seedlings exposed to warm, intermittent short days for 13 weeks and then to cool continuous short days for a further 6 weeks became hardy to −20 °C, while seedlings exposed to warm, intermittent short days only for the full 19 week period did not harden to the −20 °C level. Key words: Thuja, day length, photoperiod

scholarly journals PHOTOPERIODIC CONTROL OF DEVELOPMENTAL GROWTH IN BEGONIA × TUBERHYBRIDA

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1144G-1144
Author(s):  
Meriam G. Karlsson ◽  
Jeffrey W. Werner
Keyword(s):  
Early Development ◽  
Plant Development ◽  
Root Development ◽  
Growth And Development ◽  
Average Rate ◽  
Day Length ◽  
Seedling Height ◽  
Long Day ◽  
Developmental Growth ◽  
Short Days

Plants of Begonia x tuberhybrida `NonStop Orange', `Clips Orange' and `Musical Orange' were exposed to 1, 2, 3 or 4 weeks of short days initiated at 4 stages of plant development (immediately upon germination, 5 weeks after germination, 10 weeks after germination and 15 weeks after germination). Prior to and succeeding short days, plants were exposed to a day length of 16 hours at 100 μmol·m-2s-1. Short days were 9 hours at an irradiance level of 180 μmol·m-2s-1 to give the same total daily irradiance (5.8 mol· m-2day-1) as long day conditions. The temperature was maintained at 21° ± 4°C during the day and 18° ± 2°C during night. The observed growth and development responses were similar among the studied cultivars. During the period of 4 to 8 weeks after germination, the seedling height increased at an average rate of 0.7 mm day-1 for plants grown under long days and 0.3 mm day-1 for short day plants. The photoperiodic conditions did not affect the number of emerging leaves. The root development was more proliferate on plants allowed to develop under long days compared to plants exposed to short days during early development.

scholarly journals TEMPERATURE DURING EARLY DEVELOPMENT AFFECTS PLANT MORPHOLOGY OF BEGONIA × HIEMALIS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1086f-1086
Author(s):  
M. G. Karlsson ◽  
J. W. Werner ◽  
H.C.H. McIntyre
Keyword(s):  
Early Development ◽  
Plant Morphology ◽  
Dry Weight ◽  
Day Length ◽  
Effect Of Temperature ◽  
Flower Number ◽  
Main Shoot ◽  
Long Day ◽  
The Mean ◽  
Short Days

The effect of temperature during the initial long day period on morphology and plant dry weight was determined for Begonia × hiemalis `Hilda'. Multistem cuttings were planted in 10 cm pots and grown at 13°, 16°, 19°, 22°, 25° or 28°C. The day length was 16 hours at an irradiance level of 280 ± 20 μmol·m-2s-1. After 21 days, the plants were moved to a greenhouse maintained at 20° ± 2°C and short days of 10 hours at 125 ± 20 μmol·m-2s-1. The plants were grown under short days for 14 days and then moved to a day length of 16 hours. At data collection 21 days later (56 days from planting), plant height averaged 185 mm for plants initially grown at 13°, 16°, 19° or 22°C while pants originally grown at 25° and 28°C were 40 and 78 mm shorter than plants started at lower temperatures. The mean number of shoots was 4 on plants exposed to 16°, 19°, 22° or 25°C during early development and decrease to 3 shoots for plants grown initially at 13° or 28°C. The average flower number on the main shoot was similar for plants first exposed to low and intermediate temperatures but decreased rapidly to 0 for plants with early exposure to 28°C. Plants in treatments with early temperatures of 19° or 22°C had the largest above ground dry weight at an average 460 mg.

Latitude affects photoperiod-induced changes in immune response in meadow voles (Microtus pennsylvanicus)

2005 ◽  
Vol 83 (10) ◽  
pp. 1271-1278 ◽  
Author(s):  
L M Pyter ◽  
Z M Weil ◽  
R J Nelson
Keyword(s):  
Immune Responses ◽  
Microtus Pennsylvanicus ◽  
Day Length ◽  
Delayed Type Hypersensitivity ◽  
Deer Mice ◽  
Meadow Voles ◽  
Short Day ◽  
Long Day ◽  
Induced Changes ◽  
Short Days

Animals use day length (photoperiod) to time seasonal adaptations to annual changes in their environment. Reproductive adjustments in deer mice (Peromyscus maniculatus (Wagner, 1845)) from high latitudes are more extensive in response to short days than in deer mice from low latitudes. These adjustments may permit individuals to survive the severe seasonal changes (e.g., temperature and food abundance) in high-latitude environments. Immune function is also affected by photoperiod. Short days were predicted to result in elevated immune and reproductive responses in meadow voles (Microtus pennsylvanicus (Ord, 1815)) from the Northwest Territories (NWT), Canada (~62°N), compared with voles from Ohio (OH), USA (~39°N). Male voles from both latitudes were maintained in long or short days for 10 weeks prior to a delayed-type hypersensitivity (DTH) immune challenge. Both populations displayed similar testicular regression and reduction of testosterone concentrations in short days. DTH immune responses, however, diverged between the two populations. DTH immune responses were enhanced in long-day NWT voles and short-day OH voles, but decreased in short-day NWT voles and long-day OH voles. Total and free corticosterone concentrations did not explain the latitudinal differences in immune responses. These results suggest that photoperiod affects reproductive and immune systems differently and that immune responses may reflect other environmental factors.

Effects of short-day treatment on long-term growth performance and maturation of farmed Arctic charr Salvelinus alpinus reared in brackish water

2014 ◽  
Vol 85 (4) ◽  
pp. 1211-1226 ◽  
Author(s):  
S. Gunnarsson ◽  
M. Johansson ◽  
A. Gústavsson ◽  
T. Árnason ◽  
J. Árnason ◽  
...  
Keyword(s):  
Growth Performance ◽  
Brackish Water ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Day Treatment ◽  
Short Day
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