PHOTOPERIODIC CONTROL OF DEVELOPMENT AND PHENOTYPE IN A SUBARCTIC POPULATION OF PIERIS OCCIDENTALIS (LEPIDOPTERA: PIERIDAE)

1975 ◽  
Vol 107 (7) ◽  
pp. 775-779 ◽  
Author(s):  
Arthur M. Shapiro
Keyword(s):  
Sierra Nevada ◽  
Continuous Light ◽  
Direct Development ◽  
Source Population ◽  
Photoperiodic Control ◽  
Temperature Regimes

AbstractPieris occidentalis nelsoni W. H. Edwards from Fairbanks, Alaska, was reared under a variety of photoperiod–temperature regimes. The source population is presumably univoltine and monophenic, with a phenotype resembling the vernal one produced by multivoltine, diphenic P. o. occidentalis Reakirt in Colorado and California. Photoperiods of 10 or 15 h produced 100% diapause pupae at 15 °C and circa 65% at 25 °C. Under continuous light 22% diapaused at 15 °C and < 1% at 25 °C. About 20% of non-diapause pupae produced adults resembling the estival phenotype of P. o. occidentalis, which is unknown in wild P. o. nelsoni. Although nelsoni is more likely to diapause than the nominate subspecies from the Sierra Nevada, its potential for direct development and polyphenism is interpreted as evidence that it is derived from a multivoltine ancestor.

scholarly journals EFFECT OF PHOTOPERIOD AND TEMPERATURE REGIMES ON YIELD OF SWEET POTATOES GROWN USING THE NUTRIENT FILM TECHNIQUE (NFT)

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 858g-858
Author(s):  
Desmond Mortley ◽  
Conrad Bonsi ◽  
Philip Loretan ◽  
Walter Hill ◽  
Edwin Martinez
Keyword(s):  
Sweet Potato ◽  
Constant Temperature ◽  
Continuous Light ◽  
Storage Root ◽  
Sweet Potatoes ◽  
Root Numbers ◽  
Temperature Regimes ◽  
Nutrient Film Technique ◽  
Growth Chambers ◽  
Hoagland Nutrient Solution

Hydroponic experiments using the nutrient film technique (NFT) were conducted in environmental growth chambers to evaluate the response of two sweet potato cultivars, `Georgia Jet' and `TI-155', to two photoperiod and temperature regimes. Vine cuttings of these cultivars were planted in growth channels supplied with modified half-Hoagland nutrient solution using NFT. Plants were subjected to a 24 h photoperiod or a 12:12 h light:dark photoperiod, a constant temperature of 28C or light:dark temperature of 28/22C. Plants were exposed to irradiance levels of 400 umol m-2 s-1 at canopy level and 70% RH. Storage root fresh and dry weights were increased for both cultivars under the 24 h photoperiod at the 28C constant temperature. `Georgia Jet' storage root numbers were not affected by any treatment while those for `TI-155' were reduced under continuous light for both temperature regimes. Foliage fresh and dry weights were not affected by any treatment.

Effect of temperature on the growth of wheat. II. "Grass-clump" dwarfs and dwarf varieties

1969 ◽  
Vol 47 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yun-te Yao ◽  
David T. Canvin
Keyword(s):  
Continuous Light ◽  
Normal Growth ◽  
Temperature Treatment ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Essentially Normal ◽  
Normal Varieties ◽  
Temperature Regimes ◽  
Temperature Requirements ◽  
Seed Yields

Six F1 "grass-clump" hybrids, two "grass-clump" selections, three normal varieties (Timstein, Redman, and Federation), and three dwarf varieties (Sonora 64, CB 151, and Norin 10) were grown in growth cabinets under 1200 ft-c of continuous light at various temperatures. The normal and dwarf varieties grew tallest at 16 °C and produced maximum shoot and seed yields at 16–19 °C.The Marquillo × Timstein "grass-clump" dwarf selection (F6) tillered extensively in temperature regimes that included 16 h of 16 °C in 24 h or 16 h of 21 °C and 8 h of 16 °C. Fertile tillers were produced in all temperature regimes except 16 °C. Growth at temperatures above 21 °C was essentially normal. The Redman × Federation "grass-clump" dwarf selection (F6) produced many tillers, but no fertile tillers when grown in a temperature regime that included 16 h of 16 °C. Fertile tillers were produced in all other temperature regimes, but extensive tillering was observed if the temperature treatment included 8 h of 16 °C. Completely normal growth was observed at temperatures above 26 °C.The six F1 "grass-clump" hybrids elongated and produced seed when grown at 30 °C.All "grass-clump" dwarf hybrids and dwarf selections investigated to date differ from normal varieties of wheat in that they are sterile dwarfs when grown at low temperature but grow essentially "normal" above a threshold temperature. Depending on the particular hybrid or selection the required temperature may be 21, 26, or 30 °C. In general, if the precise temperature requirements are not known, it appears probable that elongation and seed production by "grass-clump" dwarf can be induced by growing them under continuous light at 26 to 30 °C.

scholarly journals Using simulated temperature regimes to test growth and development of an invasive forest insect under climate change

2021 ◽  
Author(s):  
Jonathan A. Walter ◽  
Lily M. Thompson ◽  
Sean D. Powers ◽  
Dylan Parry ◽  
Salvatore J. Agosta ◽  
...  
Keyword(s):  
Climate Change ◽  
Growth Rates ◽  
Larval Growth ◽  
Transplant Experiment ◽  
Native Forest ◽  
Source Population ◽  
Climate Change Scenarios ◽  
Temperature Regimes ◽  
Thermal Regimes ◽  
Environmental Chambers

AbstractTemperature and its impact on fitness are fundamental for understanding range shifts and population dynamics under climate change. Geographic climate heterogeneity, behavioural and physiological plasticity, and thermal adaptation to local climates makes predicting the responses of species to climate change complex. Using larvae from seven geographically distinct wild populations in the eastern United States of the non-native forest pest Lymantria dispar dispar (L.), we conducted a simulated reciprocal transplant experiment in environmental chambers using six custom temperature regimes representing contemporary conditions near the southern and northern extremes of the US invasion front and projections under two climate change scenarios for the year 2050. Larval growth rates increased with climate warming compared to current thermal regimes and responses differed by population. A significant population-by-treatment interaction indicated that growth rates increased more when a source population experienced the warming scenarios for their region, especially for southern populations. Our study demonstrates the utility of simulating thermal regimes under climate change in environmental chambers and emphasizes how the impacts from future increases in temperature can be heterogeneous due to geographic differences in climate-related performance among populations.

scholarly journals Effects of Air Temperature Regimes on Physiological Disorders and Floral Development of Tomato Seedlings Grown under Continuous Light

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1304-1306 ◽  
Author(s):  
Katsumi Ohyama ◽  
Yoshitaka Omura ◽  
Toyoki Kozai
Keyword(s):  
Air Temperature ◽  
Floral Development ◽  
Continuous Light ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Tomato Seedlings ◽  
Physiological Disorders ◽  
Air Temperatures ◽  
Temperature Regimes ◽  
Leaf Chlorosis

Providing continuous light (24-h photoperiod) at a relatively low photosynthetic photon flux (PPF) is one possible way to reduce both initial and operational costs for lighting and cooling during transplant production with an artificial light. However, physiological disorders (i.e., chlorosis and necrosis) are often observed in several species under continuous light with a constant temperature. The objective of this study was to find an effective air-temperature regime under the continuous light to avoid such physiological disorders, and simultaneously enhance floral development, using tomato [Lycopersicon esculentum Mill.] as a model. The seedlings with fully expanded cotyledons were grown for 15 d at a PPF of 150 μmol·m–2·s–1, a relative humidity of 70%, and a CO2 concentration of about 380 μmol·mol–1 (atmospheric standard). Leaf chlorosis was observed when the air temperature was constant regardless of average air temperature (16, 22,or 28 °C). Neither leaf chlorosis nor necrosis was observed when the air temperatures were alternated [periods of high (28 °C) and low (16 °C) air temperatures of 16/8, 12/12, and 8/16 h·d–1]. Faster floral development was observed in the seedlings grown at lower average air temperatures. These results indicated that physiological disorders of tomato seedlings grown under continuous light could be avoided, and at the same time floral development could be enhanced, by lowering the average air temperature through modification of the periods of high and low air temperatures.

scholarly journals Chytridiomycosis-induced mortality in a threatened anuran

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241119
Author(s):  
Andrea J. Adams ◽  
Allan Pessier ◽  
Peggy Cranston ◽  
Robert L. Grasso
Keyword(s):  
Sierra Nevada ◽  
Batrachochytrium Dendrobatidis ◽  
Disease Risk ◽  
Amphibian Declines ◽  
Ex Situ ◽  
Source Population ◽  
Sierra Nevada Mountains ◽  
Selection For ◽  
Source Populations ◽  
Two Populations

Effectively planning conservation introductions involves assessing the suitability of both donor and recipient populations, including the landscape of disease risk. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has caused extensive amphibian declines globally and may hamper reintroduction attempts. To determine Bd dynamics in potential source populations for conservation translocations of the threatened California red-legged frog (Rana draytonii) to Yosemite National Park, we conducted Bd sampling in two populations in the foothills of the Sierra Nevada Mountains, California, U.S.A. At one of two sites, we observed lethally high Bd loads in early post-metamorphic life stages and confirmed one chytridiomycosis-induced mortality, the first such report for this species. These results informed source population site selection for subsequent R. draytonii conservation translocations. Conservation efforts aimed at establishing new populations of R. draytonii in a landscape where Bd is ubiquitous can benefit from an improved understanding of risk through disease monitoring and ex situ infection studies.

Photoperiodism and sexual activity in Merino ewes. I. The effect of continuous light on the development of sexual activity

1961 ◽  
Vol 12 (1) ◽  
pp. 139 ◽  
Author(s):  
HM Radford
Keyword(s):  
Sexual Activity ◽  
Continuous Light ◽  
First Year ◽  
Artificial Light ◽  
Light At Night ◽  
Constant Intensity ◽  
Photoperiodic Control ◽  
The Third ◽  
Second Year

Sixteen Merino ewes were subjected to continuous light made up of daylight during the day and artificial light at night for a period of 3 years from the time the ewes were 2–3 months old. Sexual activity in these exes was compared with that in 16 control ewes held in natural daylight. Criteria of sexual activity mere the occurrence of oestrus and ovulation. Oestrus was inferred from the presence of colour marks on the rumps of the ewes which were run with vasectomized rams painted on the brisket with sheep-branding fluid. Ovulation was inferred from the occurrence of characteristic changes in the vaginal contents. Compared with the activity exhibited by the control ewes, the occurrence of oestrus, but not of ovulation, was apparently partly suppressed by continuous light during the first year and was more variable during the second year of the experiment. There was little difference between the two groups in the third year. Despite the initial suppression of oestrus, most ewes under continuous light exhibited sexual activity which was seasonal in nature and little different from that exhibited by the control ewes. Subsequently the continuously lighted eves from the first experiment were subjected variously to continuous light of constant intensity alone or to continuous light of constant intensity on which daylight was superimposed, with and without exposure to rain and wind. Compared with the activity exhibited by control ewes, continuous light of constant intensity alone permitted, if anything, an increase in sexual activity. The results do not fit any existing hypothesis for photoperiodic control of sexual activity in Merino ewes, and several alternative suggestions are discussed.

Population, Temperature, and Substrate Influences on Common Milkweed (Asclepias syriaca) Seed Germination

Weed Science ◽  
1986 ◽  
Vol 34 (4) ◽  
pp. 525-528 ◽  
Author(s):  
Janis M. Farmer ◽  
Steven C. Price ◽  
C. Ritchie Bell
Keyword(s):  
Geographical Origin ◽  
Source Population ◽  
Strongly Correlated ◽  
Substrate Type ◽  
Asclepias Syriaca ◽  
Experimental Conditions ◽  
Germination Response ◽  
Temperature Regimes ◽  
Percent Germination ◽  
Different Populations

Seed from 21 common milkweed (Asclepias syriacaL. # ASCSY) populations from six states were germinated on six substrates (filter paper, sand, peat, clay, and mixtures) under three temperature regimes. The variation in germination response between populations and experimental conditions was analyzed. The greatest percent germination (59% average over all substrates) was obtained with an alternating 20 C (16 h), 30 C (8 h) temperature regime. At a constant temperature of 30 C, germination was lower (32% average) and much more variable among seeds from different populations. At 25 C, average percent germination dropped to 1.2% over all substrates. Germination appeared to be strongly correlated with seed source (population), temperature, and substrate type, and poorly correlated with seed size. No association was found between geographical origin and germination response.

Growth and phenology of 1-year-old maritime pine (Pinuspinaster) seedlings under continuous light: implications for early selection

1993 ◽  
Vol 23 (7) ◽  
pp. 1325-1336 ◽  
Author(s):  
Denis Martin Lascoux ◽  
Antoine Kremer ◽  
Ingegerd Dormling
Keyword(s):  
Continuous Light ◽  
Growth Period ◽  
Height Growth ◽  
Seedling Development ◽  
Maritime Pine ◽  
Controlled Environment ◽  
Temperature Regimes ◽  
Second Growth ◽  
Sib Families ◽  
Progeny Tests

Experiments were conducted in the Stockholm Phytotron to test continuous light as a method to hasten the development of seedlings. Two sets of maritime pine (Pinuspinaster Ait.) families were grown under growth-accelerating conditions in a controlled environment. The first set comprised 18 open-pollinated families that were exposed to continuous light and 16-h photoperiod during the first growth period. The second set comprised nine half-sib families that were exposed to two continuous light treatments differing in their temperature regimes. In both cases seedlings were exposed to a 16-h photoperiod during the second growth period. All families were chosen according to their breeding values for height growth and polycyclism estimated in the oldest progeny tests of the maritime pine program. In both experiments, traits were found that correctly ranked the families for either growth or polycyclism during the second growth period. During the first growth period, better results were obtained under the most growth accelerating treatments. Yet, in the second experiment, consistency between phytotron and field rankings was already achieved for both treatments in the first growth period. It is suggested that more attention should be paid to the seedling development over the first years and that future retrospective tests should be conducted in a similar way in order to end controversies.

scholarly journals Temperature and Developmental Stage Influence Diurnal Rhythms of Stem Elongation in Snapdragon and Zinnia

1997 ◽  
Vol 122 (6) ◽  
pp. 778-783 ◽  
Author(s):  
Will G. Neily ◽  
Peter R. Hicklenton ◽  
David N. Kristie
Keyword(s):  
Developmental Stages ◽  
Stem Elongation ◽  
Continuous Light ◽  
Early Morning ◽  
Progressive Increase ◽  
Diurnal Rhythms ◽  
Growth Stages ◽  
Night Temperature ◽  
Temperature Regimes ◽  
Large Peak

Stem elongation rates (SERs) of `Giant Tetra' snapdragon (Antirrhinum majus L.) and `Pompon' zinnia (Zinnia violacea Cav.) were determined in three temperature regimes in which differentials had been established between day and night temperature. The differentials [expressed as day temperature - night temperature (DIF)] were +5 DIF, 21 °C day/16 °C night; 0 DIF, 18.7 °C constant; and -5 DIF, 16.5 °C day/21.5 °C night; daily average 18.7 °C. In each regimes SERs were determined for three developmental stages—vegetative, visible bud, and preanthesis. SER was measured in controlled-environment chambers under 13-hour day/11-hour night photoperiods using linear voltage displacement transducers. Snapdragon and zinnia displayed rhythmic patterns of growth with strikingly different characteristics. SER for snapdragon consisted of a large peak in growth at the day/night (D/N) transition followed by a minimum in SER at the night/day (N/D) transition. The pattern did not change through development. In contrast the SER pattern changed significantly in zinnia. At the vegetative stage, diurnal SER was dominated by a large peak after the N/D transition [an early morning peak (EMP)]. At the later growth stages, the EMP remained visible, but the proportion of growth occurring at night increased. SER was rhythmic in both species for a limited period in continuous light and constant temperature. Zinnia displayed a stronger endogenous rhythm of SER than snapdragon. In both species, only day period growth was affected by DIF. The size of EMPs in both species increased under positive DIF and decreased under negative DIF, resulting in the overall DIF effect on plant height (a progressive increase in total diurnal elongation as DIF increased from -5 to +5). Internode lengths for snapdragon and zinnia were similar for plants grown to full flower at constant 17, 20, or 23 °C (0 DIF), indicating that DIF—not average daily, night, or day temperature—is a major determinant of extension growth.

The influence of temperature on flowering in species of Lolium and in Poa pratensis

1960 ◽  
Vol 54 (3) ◽  
pp. 410-416 ◽  
Author(s):  
L. T. Evans
Keyword(s):  
Poa Pratensis ◽  
Cold Treatment ◽  
Continuous Light ◽  
Response Curves ◽  
Short Rotation ◽  
Rate Limiting Step ◽  
Temperature Regimes ◽  
Influence Of Temperature On ◽  
Night And Day ◽  
Short Days

The influence of various night- and day-temperature regimes on inflorescence initiation and earing in vernalized and unvernalized Lolium temulentum, L. multiflorum, short-rotation ryegrass, and two varieties of L. perenne, and also in the Athabasca strain of Poa pratensis, is described.Vernalization response curves for the ryegrasses, when grown under controlled conditions, are presented, and are consonant with the operation of a first-order reaction as the rate-limiting step in the vernalization ofLolium perenne. Velocity coefficients for the rate of vernalization in various conditions are deduced, and are shown to be higher in seedlings than in seeds, and higher in short days at 10° C. than at 4° C. The Q 10 for the velocity of vernalization over this range is about 2·7.Low-temperature vernalization in L. perenne can occur when low night temperatures are combined with moderately high day temperatures, and it can take place during abundant vegetative growth. In short days and in continuous light mean temperatures up to 10° C, at least, are fully effective, but in 16 hr. photoperiods even 7° C. was not a fully effective vernalizing temperature. The requirement of perennial ryegrass plants for cold treatment may be replaced by short-day induction if light intensities are low and if the plants are continually divided.

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