Impact of end-of-day red and far-red light on plant morphology and hormone physiology of poinsettia

The response of `Bright Golden Anne' and `Spears' chrysanthemum plants to EOD-R or FR light was evaluated to determine the involvement of phytochrome in regulation of plant morphology under CuSO4 filters. Light transmitted through the CuSO4 filter significantly reduced height, internode length and stem dry weight of `BGA' and `Spears' chrysanthemum plants. However, the degree of response varied with the cultivar. Exposure to EOD-FR reversed the reduction of plant height, internode length and the stem dry weight caused by the light transmitted through CuSO4 filters to a level comparable with control plants. Exposure to EOD-FR did not significantly alter height and stem dry weight under control filter Exposure to EOD-R light reduced the height and stem dry weight of `BGA' plants grown under control filter but EOD-R had no effect under CuSO4 filters. In `Spears' plants, EOD-R caused stem dry weight reduction under control filters, but did not reduce stem or internode elongation. The results suggest phytochrome may be involved in controlling plant response under CuSO4 filters. However, there are evidence to indicate that an additional mechanism may be acting on stem/internode elongation.

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The Effect of Light Spectrum on the Morphology and Cannabinoid Content of Cannabis sativa L.

Medical Cannabis and Cannabinoids ◽

10.1159/000489030 ◽

2018 ◽

Vol 1 (1) ◽

pp. 19-27 ◽

Cited By ~ 12

Author(s):

Gianmaria Magagnini ◽

Gianpaolo Grassi ◽

Stiina Kotiranta

Keyword(s):

Light Intensity ◽

Cannabis Sativa ◽

Red Light ◽

Total Yield ◽

Plant Morphology ◽

Dry Weight ◽

Light Sources ◽

Light Spectrum ◽

Light Spectra ◽

Generative Phase

Cannabis sativa L. flowers are the main source of Δ-9-tetrahydrocannabinol (THC) used in medicine. One of the most important growth factors in cannabis cultivation is light; light quality, light intensity, and photoperiod play a big role in a successful growth protocol. The aim of the present study was to examine the effect of 3 different light sources on morphology and cannabinoid production. Cannabis clones were grown under 3 different light spectra, namely high-pressure sodium (HPS), AP673L (LED), and NS1 (LED). Light intensity was set to ∼450 µmol/m2/s measured from the canopy top. The photoperiod was 18L: 6D/21 days during the vegetative phase and 12L: 12D/46 days during the generative phase, respectively. At the end of the experiment, plant dry weight partition, plant height, and cannabinoid content (THC, cannabidiol [CBD], tetrahydrocannabivarin [THCV], cannabigerol [CBG]) were measured under different light treatments. The experiment was repeated twice. The 3 light treatments (HPS, NS1, AP673L) resulted in differences in cannabis plant morphology and in cannabinoid content, but not in total yield of cannabinoids. Plants under HPS treatment were taller and had more flower dry weight than those under treatments AP673L and NS1. Treatment NS1 had the highest CBG content. Treatments NS1 and AP673L had higher CBD and THC concentrations than the HPS treatment. Results were similar between experiments 1 and 2. Our results show that the plant morphology can be manipulated with the light spectrum. Furthermore, it is possible to affect the accumulation of different cannabinoids to increase the potential of medicinal grade cannabis. In conclusion, an optimized light spectrum improves the value and quality of cannabis. Current LED technology showed significant differences in growth habit and cannabinoid profile compared to the traditional HPS light source. Finally, no difference of flowering time was observed under different R:FR (i.e., the ratio between red and far-red light).

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Effects of low and high red to far-red light ratio on tomato plant morphology and performance of four arthropod herbivores

Scientia Horticulturae ◽

10.1016/j.scienta.2021.110645 ◽

2022 ◽

Vol 292 ◽

pp. 110645

Author(s):

Davy Meijer ◽

Mara Meisenburg ◽

Joop J.A. van Loon ◽

Marcel Dicke

Keyword(s):

Tomato Plant ◽

Red Light ◽

Plant Morphology ◽

And Performance

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(402) Effect of Light Quality on Growth and Essential Oil Composition in Rosemary

HortScience ◽

10.21273/hortsci.40.4.1062c ◽

2005 ◽

Vol 40 (4) ◽

pp. 1062C-1062

Author(s):

Giuliana Mulas ◽

Lyle E. Craker

Keyword(s):

Essential Oil ◽

Light Quality ◽

Biomass Yield ◽

Red Light ◽

Plant Morphology ◽

Essential Oil Composition ◽

Light Conditions ◽

Oil Composition ◽

Number Of Leaves ◽

Effect Of Light

Variation in light quality is known to modify plant morphology, growth, and chemical constituency in plants. In the present study, the effect of light quality on growth and essential oil composition in rosemary (Rosmarinus officinalis L.) was investigated by comparing plants receiving supplemental red (660 nm) and far-red (730 nm) with each other and with control plants not receiving supplemental light. Except for the supplemental light treatments, all plants were grown under natural light conditions in a greenhouse and received full daylight, averaging 9.23 h/day during the study. The red and far-red light treatments, given as day extensions, started daily 15 min before sunset and continued for 4 h each evening for 4 weeks. No significant differences were observed in biomass yield from the different light treatments, but far-red light caused elongation of internodes and a reduction in the number of leaves in comparison with control and red-light treated plants. Essential oil production was highest in plants grown under far-red light treatments.

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A facilitative effect of red light on dark adaptation. (Proj. No. NM 001 059.28.01).

PsycEXTRA Dataset ◽

10.1037/e416402004-001 ◽

1952 ◽

Author(s):

Samuel C. McLaughlin

Keyword(s):

Dark Adaptation ◽

Red Light ◽

Facilitative Effect

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Adaptation of vision at night through use of red light and red spectacles. (FIAT, 1946; Publ. Bd., No. 16875.).

PsycEXTRA Dataset ◽

10.1037/e475022004-001 ◽

1946 ◽

Author(s):

H. Schober

Keyword(s):

Red Light

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Quinacridinium Ion as a Versatile Organic Photoredox Catalyst for Red-Light-Mediated Reactions

Synfacts ◽

10.1055/s-0040-1707377 ◽

2020 ◽

Vol 16 (10) ◽

pp. 1217

Keyword(s):

Red Light

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Postnatal growth rate and gonadal development in circadian tau mutant hamsters reared in constant dim red light

Reproduction ◽

10.1530/reprod/118.2.327 ◽

2000 ◽

pp. 327-330 ◽

Cited By ~ 7

Author(s):

RJ Lucas ◽

JA Stirland ◽

YN Mohammad ◽

AS Loudon

Keyword(s):

Time Course ◽

Red Light ◽

Somatic Growth ◽

Postnatal Growth ◽

Gonadal Development ◽

Testicular Development ◽

Wild Type ◽

Similar Time ◽

Syrian Hamsters ◽

Body Weights

The role of the circadian clock in the reproductive development of Syrian hamsters (Mesocricetus auratus was examined in wild type and circadian tau mutant hamsters reared from birth to 26 weeks of age under constant dim red light. Testis diameter and body weights were determined at weekly intervals in male hamsters from 4 weeks of age. In both genotypes, testicular development, subsequent regression and recrudescence exhibited a similar time course. The age at which animals displayed reproductive photosensitivity, as exhibited by testicular regression, was unrelated to circadian genotype (mean +/- SEM: 54 +/- 3 days for wild type and 59 +/- 5 days for tau mutants). In contrast, our studies revealed a significant impact of the mutation on somatic growth, such that tau mutants weighed 18% less than wild types at the end of the experiment. Our study reveals that the juvenile onset of reproductive photoperiodism in Syrian hamsters is not timed by the circadian system.

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