scholarly journals Shasta Daisy Cultivars Respond Differently to Photoperiod and Vernalization

2007 ◽  
Vol 25 (2) ◽  
pp. 100-104
Author(s):  
J.T. Coleman ◽  
J.R. Kessler ◽  
G.J. Keever ◽  
J.L. Sibley
Keyword(s):  
Growth Index ◽  
Plant Size ◽  
Height Growth ◽  
Practical Application ◽  
Shoot Height ◽  
Shoot Number ◽  
Quality Rating ◽  
Short Days

Abstract Inconsistencies have been reported in the role of vernalization and photoperiod on growth and flowering of Leucanthemum x superbum Bergmans ex J. Ingram cultivars. Five cultivars were used to determine the effects of vernalization and photoperiod on days to flower, shoot height, growth index, flower shoot number, and quality rating. Plants received 0, 3, 6, 9, or 12 weeks of vernalization time (VER) at 4.4C (40F) and afterward were placed under either natural short days (SD) or night-interrupted lighting (NIL) in a greenhouse. ‘Becky’ showed an obligate requirement for NIL to flower with 100% of plants flowering under NIL and 0% of plants flowering under SD regardless of VER. Vernalization for 6 weeks before NIL increased shoot height, growth index, flower shoot number, and quality rating but the fewest days to flower occurred after 12 weeks of VER. ‘Silver Princess’, ‘Snow Cap’, ‘Snow Lady’, and ‘Summer Snowball’ showed a facultative requirement for NIL to flower. Plants under NIL flowered earlier, were larger, had more flower shoots, and had a higher overall quality rating than plants under SD. Shoot height and growth index were highest under NIL after 3 and 6 weeks of VER, flower shoot number was highest after 3 to 9 weeks of VER, but days to flower was least after 12 weeks of VER. Therefore, NIL after 3 or 6 weeks of VER would maximize plant size and quality for practical application in the cultivars studied but result in more DTF when compared to 12 weeks of VER.

scholarly journals Application Timing of Daminizide and Flurprimidol after Shearing Affects Growth and Flowering of Coreopsis verticillata `Moonbeam'

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 603a-603
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Growth Index ◽  
Plant Size ◽  
Height Growth ◽  
Shoot Length ◽  
Growth Retardants ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Application Timing ◽  
Quality Rating ◽  
Response Surface Regression

Vegetative cuttings of Coreopsis verticillata `Moonbeam' were rooted under intermittent mist, pinched, and potted into 10-cm pots in a greenhouse. Plants were sheared to 6.5 cm above the pot rim 2 weeks after potting and given foliar sprays of daminozide at 0, 2550, 5100, or 7650 mg·L-1 or flurprimidol at 0, 50, 100, or 150 mg·L-1. Night-break lighting to provide long photoperiods was started the day of shearing. Growth retardants were applied at 0, 3, 6, 9, 12, or 15 days after shearing. Daminozide reduced shoot height, growth index, and lateral shoot length compared to the control by 69.3%, 69.2%, and 70.0%, respectively, while increasing quality rating by 67.3% and time to flower by 8 days at 5100 and 7650 mg·L-1. Response surface regression predicted that minimum plant size and maximum quality rating occurred when growth retardants were applied 5.7 to 8.3 days after shearing. Application timing had no effect on responses to flurprimidol. Shoot height, growth index, and lateral shoot length decreased quadratically with increasing rate while quality rating only improved compared to control. Flurprimidol did not cause a flowering delay.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Coreopsis verticillata ‘Moonbeam’

2007 ◽  
Vol 25 (4) ◽  
pp. 229-233
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Maleic Hydrazide ◽  
Growth Index ◽  
Height Growth ◽  
Growth Retardant ◽  
Shoot Length ◽  
Lateral Shoot ◽  
Shoot Height ◽  
Quality Ratings ◽  
Quality Rating

Abstract This investigation was conducted to determine the plant growth retardant type, application method, and rate required to produce a marketable greenhouse pot plant of Coreopsis verticillata L. ‘Moonbeam’. Pruned plants in 10 cm (4 in) pots received growth retardant treatments in two experiments consisting of one application of ancymidol or paclobutrazol medium drenches at 0, 2, 4, or 6 ppm; daminozide spray at 0, 2550, 5100, or 7650 ppm; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 ppm; flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 ppm; or maleic hydrazide at 0, 360, 720, 1080, 1440, or 1800 ppm in the first experiment and sprays of daminozide at 0, 2550, 5100, or 7650 ppm; paclobutrazol at 0, 60, or 120 ppm; daminozide/paclobutrazol combinations at 0, 2550/16, 2550/32, 2550/48, or 2550/64 ppm, chloromequat at 0, 767, 1534, or 2301 ppm; or daminozide/chloromequat combinations at 0, 1275/1534, 2550/1534, 3825/1534, or 5100/1534 ppm in the second experiment. In the first experiment, there was a linear decrease in shoot height, growth index, and lateral shoot length with increasing rates of ancymidol and paclobutrazol drenches and flurprimidol sprays while daminozide decreased growth quadratically. There was a linear increase in shoot height and lateral shoot length with increasing rates of maleic hydrazide but no effect on growth index. Only daminozide and maleic hydrazide increased the number of days from treatment to flower with increasing rates. Quality ratings increased with increasing rates of ancymidol, daminozide, and flurprimidol with the highest ratings found at the two highest rates of daminozide and flurprimidol. Paclobutrazol spray did not affect the parameters measured. In the second experiment, chloromequat spray did not affect the parameters measured but when combined with increasing rates of daminozide, linearly decreased shoot height, growth index, and lateral shoot length while increasing the number of days to flower. Daminozide alone resulted in a quadratic change in growth index and lateral shoot length while linearly increasing the number of days to flower but with no effect on quality rating. The higher rates of paclobutrazol than were used in the first experiment decreased shoot height and lateral shoot length with no effect on growth index, the number of days to flower, or quality rating. Overall, the best quality ratings and the most compact plants resulted from spray applications of daminozide at 5100 ppm or 7650 ppm and flurprimidol at 150 ppm or 200 ppm, however flurprimidol is not currently registered for application to greenhouse crops but a newer product, Topflor, has the same active ingredient and greenhouse crop labeling.

Morphological variation among hemp dogbane (Apocynum cannabinum) populations

Weed Science ◽  
1998 ◽  
Vol 46 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Corey V. Ransom ◽  
James J. Kells ◽  
Loyd M. Wax ◽  
Michael S. Orfanedes
Keyword(s):  
Morphological Variation ◽  
Leaf Shape ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Degree Days ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Shoot Number ◽  
Emergence Date

Experiments were conducted to examine morphological variation among hemp dogbane populations. Rootstocks collected from 16 sites throughout Michigan and Illinois were used to establish nurseries in East Lansing, MI, and Champaign, IL. Growth, stem characteristics, and leaf characteristics were measured for each ecotype at both nurseries. Differences among ecotypes were observed for all measurements except emergence date and growing degree days to emergence. The number of shoots per plot produced by the ecotypes ranged from 5 to 54 and shoot height ranged from 69 to 126 cm. Ecotypes spread laterally at different rates, with the most aggressive covering 19 times more ground area than the least aggressive. Total shoot dry weight accumulation varied greatly among ecotypes. Some ecotypes could be identified from others by their unique leaf shape. Shoot number, shoot height, and ground area covered were greater for plants grown in Michigan than in Illinois. Differences in growth and morphological characteristics among ecotypes were not correlated with the geographical region where they were collected. Differences in measurements between the two nurseries illustrate the role of environment and genetics in the growth and morphology of this plant species.

scholarly journals Plant Growth Retardants Affect Growth and Flowering of Achillea × ‘Coronation Gold’

2008 ◽  
Vol 26 (1) ◽  
pp. 24-28 ◽  
Author(s):  
J.R. Kessler ◽  
G.J. Keever
Keyword(s):  
Plant Growth ◽  
Growth Index ◽  
Plant Size ◽  
Growth Retardant ◽  
Growth Retardants ◽  
Shoot Height ◽  
Stage Of Development ◽  
Quality Ratings ◽  
Plant Growth Retardants

Abstract An experiment was conducted to determine the effects of several widely used plant growth retardants on plant size and flowering of Achillea × ‘Coronation Gold’. Plants in 10 cm (4 in) pots were grown in a greenhouse and treated with B-Nine at 0, 2550, 5100, or 7650 ppm; Cycocel at 0, 767, 1534, or 2301 ppm; B-Nine/Cycocel at 0, 1275/1534, 2550/1534, or 3825/1534 ppm; Sumagic at 0, 11, 22, 33, 44, or 55 ppm; Bonzi at 0, 32, 64, 96, 128, or 160 ppm; or Cutless at 0, 40, 80, or 120 ppm as a spray 1 week after vernalization. B-Nine, Cycocel, B-Nine/Cycocel, Sumagic, Bonzi, and Cutless reduced shoot height and growth index by 36 and 26%, 39 and 27%, 61 and 41%, 75 and 52%, 52 and 36%, and 75 and 51%, respectively, with the highest rate of each. B-Nine, Cycocel, B-Nine/Cycocel, and Sumagic, but not Bonzi or Cutless, increased the number of days to open inflorescence by 3-5 days with increasing rate. Sumagic, Bonzi, and Cutless reduced inflorescence diameter by up to 15, 18, and 14%, respectively but not B-Nine, Cycocel, or B-Nine/Cycocel. The highest quality ratings of 2.8 to 3.0 were found with B-Nine/Cycocel at 3825/1534 ppm, Sumagic at 22 and 33 ppm, and Bonzi at 64 ppm. Differences between the results in this study and earlier studies implicate the possible impact of differences in experimental environments, container size, or stage of development when the plant growth retardant treatments were applied.

Effects of Plant Growth Retardants and Application Timing after Shearing on Growth and Flowering of Coreopsis verticillata `Moonbeam'

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522a-522
Author(s):  
J. Raymond Kessler ◽  
Gary J. Keever
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Growth Index ◽  
Market Quality ◽  
Growth Retardants ◽  
Application Timing ◽  
Quality Rating ◽  
Plant Growth Retardants ◽  
Herbaceous Perennial ◽  
Short Days

Coreopsis verticillata `Moonbeam' is a herbaceous perennial that may grow too tall in small containers under greenhouse conditions for market acceptance, and therefore may benefit from plant growth retardants. Rooted terminal cuttings produced under short days were given a terminal pinch and transplanted to 10 cm pots. Cuttings were sheared to 6 cm above the pot rim 4 weeks later. Growth retardant treatments consisting of ancymidol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; paclobutrazol drench at 0, 0.125, 0.25, or 0.375 mg a.i./pot; daminozide spray at 0, 2550, 5100, or 7650 mg·L–1; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 mg·L–1; or flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 mg·L–1 were applied 10 days after shearing. Night-breaking lighting using incandescent bulbs was started the same day. The highest rate of ancymidol, paclobutrazol drench, daminozide, and flurprimidol decreased plant height compared to controls by 36, 30, 21, and 36%, respectively. Paclobutrazol sprays were not effective. A market quality rating of four or higher (good, salable) was given to plants treated with daminozide at 5100 or 7650 mg·L–1 or flurprimidol at 150 or 200 mg·L–1. A second experiment was conduced to determine application timing. A daminozide spray at 0, 2550, 5100, or 7650 mg·L–1 was applied 0, 3, 6, 9, 12, or 15 days after shearing. Plant height, growth index and lateral shoot length were least and market quality rating highest when 5100 or 7650 mg·L–1 of daminozide was applied between 6 and 9 days after shearing.

scholarly journals End-of-Day Lighting Effects on Herbaceous Perennials Grown Under Night Interrupted Lighting Outdoors in the Southern United States

2013 ◽  
Vol 31 (1) ◽  
pp. 1-6
Author(s):  
Gary J. Keever ◽  
J. Raymond Kessler ◽  
James C. Stephenson
Keyword(s):  
Stem Elongation ◽  
Growth Index ◽  
Height Growth ◽  
Shoot Length ◽  
Southern United States ◽  
Flower Number ◽  
Herbaceous Perennials ◽  
Natural Photoperiod ◽  
Quality Rating ◽  
Almost All

A study was conducted in 2004 to determine if end-of-day lighting (EOD) alone or in combination with night-interrupted lighting (NIL) could be used to suppress stem elongation of ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’) when grown outdoors under nursery conditions in the southern U.S. without negating the benefits of earlier flowering from NIL. End-of-day lighting, NIL, and the combination of the two treatments accelerated time to flowering of all three cultivars compared to that of plants under a natural photoperiod (NP); however, rudbeckia flowered quicker when exposed to NIL or NIL + EOD than when grown under EOD only. Height of rudbeckia grown under EOD or NIL was greater than that of plants grown under NP, whereas ‘Moonbeam’ coreopsis exposed to EOD, NIL or EOD + NIL were similar in height and taller than plants grown under NP. Height of ‘Early Sunrise’ coreopsis was minimally affected by treatments, except that plants under EOD were shorter than those under EOD + NIL. Growth index, flower number, shoot length and quality rating were similar in almost all cases for plants of the three cultivars when grown under EOD lighting, NIL, or EOD + NIL. These results indicate EOD was ineffective in suppressing height growth and provided no benefit, either alone or in combination with NIL, over NIL alone in the accelerated production of these cultivars outdoors under nursery conditions.

scholarly journals The Role of Peptides in the Design of Electrochemical Biosensors for Clinical Diagnostics

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 246
Author(s):  
Patrick Severin Sfragano ◽  
Giulia Moro ◽  
Federico Polo ◽  
Ilaria Palchetti
Keyword(s):  
Functional Groups ◽  
Synthetic Peptides ◽  
Clinical Diagnostics ◽  
Electrochemical Biosensors ◽  
Practical Application ◽  
Design And Development ◽  
Electrode Surfaces ◽  
Electrochemical Transducers ◽  
Target Analyte

Peptides represent a promising class of biorecognition elements that can be coupled to electrochemical transducers. The benefits lie mainly in their stability and selectivity toward a target analyte. Furthermore, they can be synthesized rather easily and modified with specific functional groups, thus making them suitable for the development of novel architectures for biosensing platforms, as well as alternative labelling tools. Peptides have also been proposed as antibiofouling agents. Indeed, biofouling caused by the accumulation of biomolecules on electrode surfaces is one of the major issues and challenges to be addressed in the practical application of electrochemical biosensors. In this review, we summarise trends from the last three years in the design and development of electrochemical biosensors using synthetic peptides. The different roles of peptides in the design of electrochemical biosensors are described. The main procedures of selection and synthesis are discussed. Selected applications in clinical diagnostics are also described.

Pineal denervation by cervical sympathetic ganglionectomy suppresses the role of photoperiod on pregnancy or pseudopregnancy, body weight and moulting periods in the mink (Mustela vison)

1985 ◽  
Vol 107 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
Y. Chabi
Keyword(s):  
Body Weight ◽  
Environmental Factors ◽  
Prolactin Secretion ◽  
Corpora Lutea ◽  
Progesterone Secretion ◽  
Cervical Ganglion ◽  
Cervical Sympathetic ◽  
Implantation Period ◽  
Short Days

ABSTRACT In mink, termination of the delayed implantation period, following reactivation of the corpora lutea, and onset of the spring moult are associated with a rise in prolactin secretion triggered by increasing daylength, while decreasing daylength induces the autumn moult. To establish whether suppression of the function of the pineal rendered the mink unresponsive to daylength changes, the superior cervical ganglion was removed bilaterally 2–4 weeks before mating. Intact and operated females were then left outdoors or were put under a lighting regime of either 15 h light: 9 h darkness (15L: 9D) or 8L: 16D. In July, at the end of the spring moult, the 15L: 9D lighting regime was changed to one of 8L: 16D. Under artificial photoperiods ganglionectomy suppressed the stimulatory role of long days and the inhibitory role of short days on prolactin secretion, and consequently on progesterone secretion and spring moult. Neither was the autumn moult, induced early in intact females by the change to a short photoperiod, advanced in ganglionectomized females, showing that the latter were unresponsive to the artificial modification of the photoperiod. However, in animals kept outdoors, prolactin and progesterone secretion and spring moult were not changed by ganglionectomy. Increase in body weight and autumn moult were only slightly delayed by the operation suggesting that other environmental factors had replaced the synchronizing effect of the daylength changes. Alternatively the desynchronization between intact females responsive to photoperiodism and those rendered unresponsive may be too slow to be observed soon after ganglionectomy. J. Endocr. (1985) 107, 31–39

scholarly journals Complex interactions in legume/cereal intercropping system: role of root exudates in root-to-root communication

2017 ◽  
Author(s):  
Yinshan Jiao ◽  
Entao Wang ◽  
Wenfeng Chen ◽  
Donald L. Smith
Keyword(s):  
Nitrogen Fixation ◽  
Root Exudates ◽  
Faba Bean ◽  
The Novel ◽  
Practical Application ◽  
Corn Root ◽  
Complex Interactions ◽  
Root Interactions ◽  
Ecological Principles

Dear Editor,Legume/cereal intercropping systems have been regarded as the practical application of basic ecological principles such as diversity, competition and facilitation. In a recent PNAS paper, Li et al. (1) describe the novel finding that maize exudates promote faba bean nodulation and nitrogen fixation by upregulating genes involved in (iso)flavonoids synthesis (chalcone–flavanone isomerase) within faba bean, resulting in production of more genistein, a legume-to-rhizobia signal during establishment of the faba bean N2–fixing symbiosis. Although we salute the authors’ methodological efforts, there is another mechanism that could be responsible for the effect of corn root exudates on faba been nitrogen fixation observed in this article (1). The authors may misunderstand their data and the signalling role of maize exudates, thus got a defective model for the root interactions between faba bean and maize.

Regulation of the photoperiod-induced cycle in the peripheral blood concentrations of β-endorphin and prolactin in the ram: role of dopamine and endogenous opioids

1990 ◽  
Vol 127 (3) ◽  
pp. 461-469 ◽  
Author(s):  
E. Ssewannyana ◽  
G. A. Lincoln
Keyword(s):  
Plasma Concentrations ◽  
Prolactin Secretion ◽  
Endogenous Opioids ◽  
Fold Change ◽  
Opioid Antagonist ◽  
Light Cycle ◽  
Blood Concentrations ◽  
The Mean ◽  
Short Days

ABSTRACT In a group of adult Soay rams housed indoors under an artificial light cycle of alternating 16-week periods of long and short days, there was a conspicuous longterm cycle in the peripheral plasma concentrations of β-endorphin and prolactin. The levels of β-endorphin were highest under short days and lowest under long days (15-fold change), and inversely related to the changes in the plasma levels of prolactin (120-fold change). The role of dopamine in the control of β-endorphin and prolactin was investigated in a series of experiments, conducted under both long and short days, in which rams were treated with dopamine receptor agonists (dopamine and bromocriptine) and antagonists (pimozide and sulpiride). Naloxone (opioid antagonist) was also administered to assess the additional involvement of endogenous opioids. Dopamine injected i.v. (6·6 mg/kg every 10 min) did not significantly affect the mean plasma concentrations of β-endorphin and prolactin under either long or short days. Pimozide (0·08 mg/kg i.m. every 2 h) caused a large increase in the mean plasma concentrations of β-endorphin and prolactin under long days but not short days. Naloxone (1·6 mg/kg, i.v.), administered alone or in combination with dopamine or pimozide, had no effect on the mean plasma concentrations of β-endorphin and prolactin, except under short days when, combined with pimozide, it induced an increase in the plasma concentrations of the two polypeptides. Bromocriptine (0·06 mg/kg, s.c.) caused a significant decrease in the plasma concentrations of both β-endorphin and prolactin; this effect was most marked at the times of increased secretion (under short days for β-endorphin and under long days for prolactin). Sulpiride (0·59 mg/kg, s.c.) produced the converse effect and caused an increase in the plasma concentrations of β-endorphin and prolactin with the amplitude and duration of the effect varying with the stage of the photoperiod-induced cycle. From these results in the Soay ram, we conclude that dopamine inhibits β-endorphin and prolactin secretion by way of D2 receptors under both long and short days. Endogenous opioids interact with dopamine, augmenting this inhibition under short days. Differences in the acute responses in the secretion of β-endorphin and prolactin, and the inverse relationship between β-endorphin and prolactin during the cycle, indicate that different regulatory systems involving dopamine influence the two pituitary polypeptides. Journal of Endocrinology (1990) 127, 461–469

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