scholarly journals Effect of Stock Plant Photoperiod and Temperature on Cutting Production and Rooting of Herbaceous Perennials

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 501E-501
Author(s):  
Paul Koreman ◽  
Art Cameron ◽  
Royal Heins ◽  
William Carlson
Keyword(s):  
Stock Plant ◽  
Herbaceous Perennials ◽  
Long Day ◽  
Phlox Paniculata ◽  
Short Days ◽  
Cutting Production

Previous research has shown that the photoperiod under which stock plants are grown has a significant effect on cutting production and rooting of several species of herbaceous perennials. Long-day (LD) treatment of stock plants promoted cutting production of certain LD perennials but reduced rooting. Cuttings from plants grown under short days rooted readily but few were produced. Stock plants were exposed to alternating photoperiods to determine if this treatment would yield many cuttings with high rooting potential. Coreopsis verticillata `Moonbeam' and Phlox paniculata `Eva Cullum' stock plants were given 4 weeks of 4-h night interruption (NI), while Sedum `Autumn Joy' stock plants were grown under 14-h days. After 4 weeks plants were given 0, 2, or 4 weeks of 10-h days. Cuttings were harvested and propagated under mist and three different photoperiods (10-h, 14-h, NI) for 4 weeks, after which rooting percentage and the number and length of roots produced by each cutting were measured. The results will be presented.

scholarly journals The Effect of Short Days on Cold Acclimation in Gaura

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1115C-1115 ◽  
Author(s):  
Grace M. Pietsch ◽  
Paul H. Li ◽  
Neil O. Anderson
Keyword(s):  
Electrical Conductivity ◽  
Cold Acclimation ◽  
Cold Treatment ◽  
Woody Species ◽  
Environmental Cues ◽  
Herbaceous Perennials ◽  
Short Day ◽  
Long Day ◽  
Cornus Sericea ◽  
Short Days

Cold acclimation has been extensively studied in woody species such as Cornus sericea and Malu × domestica. These studies have shown that cold acclimation is initiated by short days and completed with the addition of a cold treatment. It is unknown whether herbaceous perennials respond in a similar manner to these environmental cues. Our research objective was to examine short day photoperiod effects on cold acclimation in herbaceous gaura populations collected at different latitudes. Gaura drummondii collected in Texas, and Gaura coccinea collected in Minnesota and Texas were clonally propagated, grown under a 16-hour long day photoperiod and 25/20 °C [day/night (D/N)] temperature for 8 weeks. Plants were then subjected to 0, 1, 2, 3, 4, or 5 weeks of 8-hour short days at 20/15 °C (D/N) temperatures. Cold acclimation was determined using electrolyte leakage (freezing stem pieces from –1 to –9 °C) and measuring electrical conductivity after treatment and tissue death. Mean separations showed two distinct statistical groupings of 0-2 weeks and 3–5 weeks of short days for Minnesota gaura, whereas Texas gaura overlapped for 0–5 weeks of short day treatments. It is unknown what environmental cue(s) initiate cold acclimation in Gaura native to southern latitudes such as Texas.

scholarly journals Influence of Stock Plant Photoperiod on Cutting Production and Rooting

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 597c-597
Author(s):  
Paul Koreman ◽  
Art Cameron ◽  
Royal Heins ◽  
William Carlson
Keyword(s):  
Cold Treatment ◽  
First Flush ◽  
Perennial Species ◽  
Stock Plant ◽  
Fresh Weight ◽  
Phlox Paniculata ◽  
Cutting Production ◽  
Total Fresh Weight

Five vegetatively propagated perennial species that received 0 or 15 weeks of cold treatment were placed under seven photoperiods (10-, 12-, 13-, 14-, 16-, 24-, and 4-hour night interruption). Cuttings were harvested every 3 weeks, and their number and total fresh weight were recorded. Cutting bases were dipped in a 1200 ppm IBA solution for 5 seconds, stuck in perlite, and placed under mist for 3 weeks. Results varied by species. Stock plants of Achillea `Moonshine' produced the most cuttings under a 12-hour photoperiod. Noncold treated Coreopsis verticillata `Moonbeam' only produced cuttings under photoperiods longer than or equal to 14 hours. Cold treated `Moonbeam' produced cuttings under all photoperiods in the first flush. Eighty percent of cuttings from the first flush of Phlox paniculata `Eva Cullum' rooted when taken from plants growing under the 10-hour photoperiod, but only 1.2 cuttings per plant were harvested; 2.5 cuttings per plant were taken from Phlox grown under the 24-h photoperiod, but only 20% rooted. Only stock plants of Sedum `Autumn Joy' receiving a 14-hour photoperiod produced significant numbers of vegetative shoots. Cutting production and rooting of Veronica `Sunny Border Blue' was not affected by photoperiod.

scholarly journals The Response of Long-day Herbaceous Perennials to a Night-interruption at Low Night Temperatures

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 484D-484
Author(s):  
Alison Frane ◽  
Royal Heins ◽  
Art Cameron ◽  
William Carlson
Keyword(s):  
Low Temperature ◽  
Early Spring ◽  
Perennial Species ◽  
Treatment Results ◽  
Flower Bud ◽  
Herbaceous Perennials ◽  
Long Day ◽  
Node Count ◽  
Herbaceous Perennial ◽  
Short Days

A 4-hr night interruption (NI) is an effective way to promote flowering in many long-day herbaceous perennials. Some perennials are grown outdoors in the early spring and often are exposed to low night temperatures. Long days delivered by NI lighting ineffectively promote flowering under low-temperature conditions in some long-day species. The objective of this experiment was to determine the effectiveness of NI long-day lighting treatments delivered at different night temperatures in promoting flowering of several herbaceous perennials. Ten herbaceous perennial species were grown under natural short days augmented with a 4-hr NI. Night temperatures were 2.5, 5, 10, 15, 20, and 25°C with day temperature of 25°C for all treatments. Plants were transferred to 9-hr days at a constant 20°C after 7 weeks of treatment. Results on flowering percentage, date of visible bud and flowering, node count, flower bud count, and plant height at flowering will be presented.

scholarly journals Effects of Ethephon on Stock Plant Management of Coreopsis verticillata, Dianthus caryophyllus, and Veronica longifolia

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1616-1621 ◽  
Author(s):  
Janelle E. Glady ◽  
N. Suzanne Lang ◽  
Erik S. Runkle
Keyword(s):  
Dianthus Caryophyllus ◽  
Plant Management ◽  
Internode Elongation ◽  
Perennial Species ◽  
Stock Plant ◽  
Long Day ◽  
Leaf Necrosis ◽  
Vegetative Cuttings ◽  
Herbaceous Perennial ◽  
Short Days

Some day-neutral herbaceous perennial species can be difficult to manage as vegetative stock plants because they initiate floral buds under most environmental conditions. Although flowering of many long-day plants can be inhibited by maintaining plants under short days, extension growth is often suppressed, which makes cuttings difficult to harvest. Ethephon (2-chloroethylphosphonic acid) is an ethylene-releasing chemical used to abort flowers, inhibit internode elongation, and promote branching of floriculture crops. The objective of this research was to determine whether ethephon is effective at maintaining vegetative growth and increasing the number of cuttings harvested for three popular perennial species that are difficult to maintain as vegetative plants. Spray applications of ethephon were applied for 10 weeks biweekly (every 2 weeks) or weekly at 0, 400, 600, or 800 mg·L−1. Biweekly applications at 600 mg·L−1 or weekly applications at 400 mg·L−1 increased branching and the number of vegetative cuttings in Coreopsis verticillata L. ‘Moonbeam’ and Veronica longifolia L. ‘Sunny Border Blue’, respectively. Ethephon application increased branching in Dianthus caryophyllus L. ‘Cinnamon Red Hots’, inhibited leaf expansion and stem extension, but did not abort flowers, and induced marginal leaf necrosis at all concentrations tested. Therefore, ethephon application has potential to maintain vegetative stock plants of C. verticillata ‘Moonbeam’ and V. longifolia ‘Sunny Border Blue’ but not D. caryophyllus ‘Cinnamon Red Hots’.

scholarly journals FLORAL INITIATION IN THE LONG-DAY PLANT Rudbeckia hirta

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 719A-719
Author(s):  
Richard L. Harkess ◽  
Robert E. Lyons
Keyword(s):  
Methyl Green ◽  
Floral Initiation ◽  
Serial Sections ◽  
Sodium Cacodylate ◽  
Rudbeckia Hirta ◽  
Long Day ◽  
Cacodylate Buffer ◽  
Ethanol Series ◽  
Inductive Photoperiod ◽  
Short Days

A study was undertaken to determine the rate of floral initiation in Rudbeckia hirta. R. hirta plants were grown to maturity, 14-16 leaves, under short days (SD). Paired controls were established by placing half of the plants under long days (LD) with the remainder left under SD. Beginning at the start of LD (day 0), five plants were harvested daily from each photoperiod group for twenty days. Harvested meristems were fixed in 2% paraformaldehyde - 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.0) for 24 hrs, dehydrated in an ethanol series, embedded in paraffin and sectioned at 8 μm. Serial sections were stained with Methyl-green Pyronin, with adjacent sections treated with RNase for nucleic acid comparison. All events of floral initiation were identified, The results of limited inductive photoperiod indicate that 16-18 LD were required for flowering.

Flowering of Stylosanthes guianensis in controlled temperatures under natural photoperiod

1984 ◽  
Vol 35 (2) ◽  
pp. 219 ◽  
Author(s):  
RL Ison ◽  
LR Humphreys
Keyword(s):  
Floral Initiation ◽  
Minimum Duration ◽  
Stylosanthes Guianensis ◽  
Short Day ◽  
Long Day ◽  
Natural Photoperiod ◽  
Low Levels ◽  
Short Days

Seedlings of Stylosanthes guianensis var. guianensis cv. Cook and cv. Endeavour were grown in naturally lit glasshouses at Brisbane (lat. 27� 30' S.) at 35/30, 30/25 and 25/20�C (day/night), and were sown so as to emerge at 18-day intervals from 18 January to 11 June. Cook behaved as a long day-short day plant, with seedlings emerging after 5 February flowering incompletely or remaining vegetative until the experiment was terminated in mid-October. In the 25/20�C regimen flowering was incomplete in Cook; in Endeavour flowering was delayed but a conventional short-day response was observed. At 35/30�C Endeavour flowering was inhibited in the shortest days of mid-winter, suggesting a stenophotoperiodic response, but short days were confounded with low levels of irradiance. Minimum duration of the phase from emergence to floral initiation was c. 66-70 days in Cook and c. 40-45 days in Endeavour; the duration of the phase floral initiation to flower appearance was linearly and negatively related to temperature.

Photoperiod modulates the effects of norepinephrine on lymphocyte proliferation in Siberian hamsters

2003 ◽  
Vol 285 (4) ◽  
pp. R873-R879 ◽  
Author(s):  
Gregory E. Demas ◽  
Timothy J. Bartness ◽  
Randy J. Nelson ◽  
Deborah L. Drazen
Keyword(s):  
Lymphocyte Proliferation ◽  
Splenic Tissue ◽  
Splenocyte Proliferation ◽  
Short Day ◽  
Siberian Hamsters ◽  
Long Day ◽  
Β Adrenergic Receptors ◽  
Short Days

Siberian hamsters ( Phodopus sungorus) rely on photoperiod to coordinate seasonally appropriate changes in physiology, including immune function. Immunity is regulated, in part, by the sympathetic nervous system (SNS), although the precise role of the SNS in regulating photoperiodic changes in immunity remains unspecified. The goal of the present study was to examine the contributions of norepinephrine (NE), the predominant neurotransmitter of the SNS, to photoperiodic changes in lymphocyte proliferation. In experiment 1, animals were maintained in long [16:8-h light-dark cycle (16:8 LD)] or short days (8:16 LD) for 10 wk, and splenic NE content was determined. In experiment 2, in vitro splenocyte proliferation in response to mitogenic stimulation (concanavalin A) was assessed in spleen cell suspensions taken from long- or short-day hamsters in which varying concentrations of NE were added to the cultures. In experiment 3, splenocyte proliferation was examined in the presence of NE and selective α- and β-noradrenergic receptor antagonists (phenoxybenzamine and propranolol, respectively) in vitro. Short-day animals had increased splenic NE content compared with long-day animals. Long-day animals had higher proliferation compared with short-day animals independent of NE. NE (1 μM) further suppressed splenocyte proliferation in short but not long days. Last, NE-induced suppression of proliferation in short-day hamsters was blocked by propranolol but not phenoxybenzamine. The present results suggest that NE plays a role in photoperiodic changes in lymphocyte proliferation. Additionally, the data suggest that the effects of NE on proliferation are specific to activation of β-adrenergic receptors located on splenic tissue. Collectively, these results provide further support that photoperiodic changes in immunity are influenced by changes in SNS activity.

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 Temperature and Photoperiod Influence Flowering and Morphology of Four Petunia spp.

HortScience ◽  
2010 ◽  
Vol 45 (3) ◽  
pp. 365-368 ◽  
Author(s):  
Ryan M. Warner
Keyword(s):  
Base Temperature ◽  
Optimal Temperature ◽  
Flower Bud ◽  
Breeding Programs ◽  
Node Number ◽  
Daily Light Integral ◽  
Long Day ◽  
Light Integral ◽  
Short Days ◽  
Petunia Axillaris

Flowering and morphology of four Petunia Juss. spp. [P. axillaris (Lam.) Britton et al., P. exserta Stehmann, P. integrifolia (Hook.) Schinz & Thell., and P. ×hybrida Vilm.] were evaluated in response to photoperiod and temperature. Photoperiod responses were evaluated under 9-h short days (SD), 9-h photoperiod plus 4-h night-interruption lighting (NI), or a 16-h photoperiod supplemented with high-pressure sodium lamps (16-h HPS). All species flowered earlier under NI than SD and were classified as facultative (quantitative) long-day plants. Increasing the daily light integral within long-day treatments increased flower bud number for P. axillaris only. In a second experiment, crop timing and quality were evaluated in the temperature range of 14 to 26 °C under 16-h HPS. The rate of progress toward flowering for each species increased as temperature increased from 14 to 26 °C, suggesting the optimal temperature for development is at least 26 °C. The calculated base temperature for progress to flowering varied from 0.1 °C for P. exserta to 5.3 °C for P. integrifolia. Flowering of P. axillaris and P. integrifolia was delayed developmentally (i.e., increased node number below the first flower) at 14 °C and 17 °C or less, respectively, compared with higher temperatures. Petunia axillaris and P. integrifolia flower bud numbers decreased as temperature increased, whereas P. ×hybrida flower bud number was similar at all temperatures. The differences in crop timing and quality traits observed for these species suggest that they may be useful sources of variability for petunia breeding programs.

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