Photoperiodism and rhythmic flower induction: complete substitution of inductive darkness by light

1969 ◽  
Vol 47 (8) ◽  
pp. 1241-1250 ◽  
Author(s):  
Bruce G. Cumming
Keyword(s):  
White Light ◽  
High Intensity ◽  
Dark Period ◽  
Flower Induction ◽  
Flower Initiation ◽  
Response Type ◽  
Short Day ◽  
Long Day ◽  
Sufficient Energy ◽  
Promotive Effect

In a short-day response type of Chenopodium rubrum (ecotype 60°47′ N), light of a relatively low red/far-red ratio—but of sufficient energy to allow photosynthesis—can bring about induction of flowering when it completely replaces a single dark period interrupting continuous white light. When high-intensity white incandescent light was interrupted for less than a 24-hour period, a longer period of inductive light than darkness was required even for minimal induction. An inductive light interruption of at least 60 hours was required for 100% flower induction. The result of such forcing of the system by inductive light, as compared with the circadian rhythmic induction that occurred in darkness, was a change towards a more linear inductive response and there were indications (requiring confirmation) of oscillations of higher frequency.When seedlings were maintained continuously in optimal inductive light or in darkness, after an initial high intensity white light period, there was some flower initiation within 5 days in inductive light, but not until about 10 days in darkness, and then only when sucrose was supplied throughout darkness.There were suboptimal and (inhibitory) supraoptimal effects on induction when the R/FR ratio and (or) the energy of inductive light were decreased or increased, respectively. These results, in conjunction with the effects that were obtained when glucose and 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were applied in inductive light as compared with darkness, implicate both photosynthate and phytochrome-Pfr as having a positive (promotive) effect during normal inductive darkness.These findings emphasize that the important controls in photoperiodism and flowering may be quantitative rather than qualitative in character, because it can now be questioned whether there is any essential dark-requiring reaction in the induction not only of long-day but also of short-day plants.

scholarly journals Photocontrol of Flowering and Extension Growth in the Long-day Plant Pansy

2003 ◽  
Vol 128 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Erik S. Runkle ◽  
Royal D. Heins
Keyword(s):  
Flower Development ◽  
Red Light ◽  
Reproductive Development ◽  
Extension Growth ◽  
Separate Experiment ◽  
Flower Initiation ◽  
Minimal Extension ◽  
Short Day ◽  
Long Day ◽  
Light Duration

Plastics that selectively reduce the transmission of far-red light (FR, 700 to 800 nm) reduce extension growth of many floricultural crops. However, FR-deficient (FRd) environments delay flowering in some long-day plants (LDPs), including `Crystal Bowl Yellow' pansy (Viola ×wittrockiana Gams). Our objective was to determine if FR light could be added to an otherwise FRd environment to facilitate flowering with minimal extension growth. In one experiment, plants were grown under a 16-hour FRd photoperiod, and FR-rich light was added during portions of the day or night. For comparison, plants were also grown with a 9-hour photoperiod [short-day (SD) control] or under a neutral (N) filter with a 16-hour photoperiod (long day control). Flowering was promoted most (i.e., percent of plants that flowered increased and time to flower decreased) when FR-rich light was added during the entire 16-hour photoperiod, during the last 4 hours of the photoperiod, or during the first or second 4 hours after the end of the photoperiod. In a separate experiment, pansy was grown under an FRd or N filter with a 9-hour photoperiod plus 0, 0.5, 1, 2, or 4 hours of night interruption (NI) lighting that delivered a red (R, 600 to 700 nm) to FR ratio of 0.56 (low), 1.28 (moderate), or 7.29 (high). Under the N filter, the minimum NI duration that increased percent flowering was 2 hours with a moderate or low R:FR and 4 hours with a high R:FR. Under the FRd filter, 2 or 4 hours of NI lighting with a moderate or low R:FR, respectively, was required to increase percent flowering, but a 4-hour NI with a high R:FR failed to promote flowering. Pansy appears to be day-neutral with respect to flower initiation and a quantitative LDP with respect to flower development. The promotion of reproductive development was related linearly to the promotion of extension growth. Therefore, it appears that in LDPs such as pansy, light duration and quality concomitantly promote extension growth and flowering, and cannot readily be separated with lighting strategies.

scholarly journals Flowering and Morphogenesis of Kalanchoe in Response to Quality and Intensity of Night Interruption Light

Plants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 90
Author(s):  
Dong Kang ◽  
Hai Jeong ◽  
Yoo Park ◽  
Byoung Jeong
Keyword(s):  
Plant Height ◽  
White Light ◽  
Light Emitting ◽  
Short Day ◽  
Spad Value ◽  
Long Day ◽  
Closed Type ◽  
Significant Difference ◽  
Plant Factory ◽  
White Light Emitting Diodes

The effects of the quality and intensity of night interruption light (NIL) on the flowering and morphogenesis of kalanchoe (Kalanchoe blossfeldiana) ‘Lipstick’ and ‘Spain’ were investigated. Plants were raised in a closed-type plant factory under 250 μmol·m−2·s−1 PPFD white light emitting diodes (LEDs) with additional light treatments. These treatments were designated long day (LD, 16 h light, 8 h dark), short day (SD, 8 h light, 16 h dark), and SD with a 4 h night interruption (NI). The NIL was constructed from 10 μmol·m−2·s−1 or 20 μmol·m−2·s−1 PPFD blue (NI-B), red (NI-R), white (NI-W), or blue and white (NI-BW) LEDs. In ‘Spain’, the SPAD value, area and thickness of leaves and plant height increased in the NI treatment as compared to the SD treatment. In ‘Lipstick’, most morphogenetic characteristics in the NI treatment showed no significant difference to those in the SD treatment. For both cultivars, plants in SD were significantly shorter than those in other treatments. The flowering of Kalanchoe ‘Lipstick’ was not affected by the NIL quality, while Kalanchoe ‘Spain’ flowered when grown in SD and 10 μmol·m−2·s−1 PPFD NI-B. These results suggest that the NIL quality and intensity affect the morphogenesis and flowering of kalanchoe, and that different cultivars are affected differently. There is a need to further assess the effects of the NIL quality and intensity on the morphogenesis and flowering of short-day plants for practical NIL applications.

Variability in photoperiod and the inhibition of flowering in a high latitude population of Saxifraga rivularis

1981 ◽  
Vol 59 (3) ◽  
pp. 388-391 ◽  
Author(s):  
J. A. Teeri ◽  
S. J. Tonsor
Keyword(s):  
High Latitude ◽  
High Intensity ◽  
Dark Period ◽  
Controlled Environment ◽  
Photoperiodic Control ◽  
Incandescent Light ◽  
Devon Island ◽  
Low Intensity ◽  
Long Day ◽  
Long Day Plants

A population of Saxifraga rivularis L. collected at Truelove Lowland, Devon Island, N.W.T., Canada (75°41′ N) exhibits a photoperiodic control of flowering in controlled environment chambers. The plants respond in a manner typical of long-day plants with flowering inhibited by either a 6-h daily dark period, or by a 6-h daily low intensity irradiance regime of incandescent light. The inhibition of flowering by 6 h day−1 of incandescent light does not occur if the incandescent light is given in twelve 0.5-h doses, each followed by 1 h of red-rich high intensity irradiance.

scholarly journals Echinacea purpurea `Magnus': Is It an Intermediate-day or a Short-day/Long-day Plant?

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1100D-1100
Author(s):  
Ki Sun Kim ◽  
Art Cameron ◽  
Erik S. Runkle
Keyword(s):  
Developmental Stage ◽  
Continuous Light ◽  
Echinacea Purpurea ◽  
Flower Induction ◽  
Research Groups ◽  
Short Day ◽  
Purple Coneflower ◽  
Long Day ◽  
Primary Induction ◽  
Short Days

Echinacea purpurea Moench., or purple coneflower, has been classified both as an intermediate-day plant and a short-day/long-day plant by different research groups. We performed experiments to determine at what developmental stage Echinacea`Magnus' became sensitive to inductive photoperiods, and identified photoperiods that induced the most rapid flowering. Seedlings were raised under continuous light in 128-cell plug trays, then were transplanted into 11.4-cm plastic pots. Plants were transferred to 10-hour short days (sd) once seedlings developed 3, 4, 5, 6, 7, or 8 true leaves. After 4 or 6 weeks of sd treatment (primary induction), plants were moved to 16- or 24-hour photoperiods until flowering (secondary induction). Plants were also grown under continuous 10-, 14-, and 24-hour photoperiods to serve as controls. At least 4 leaves were required for flower induction; flowering was delayed and the percentage was low when plants had 3 leaves at the beginning of primary induction. Plants under continuous 14-hour photoperiods had the highest flower percentage (100%) and flowered earliest (87 days). Plants under continuous 10- and 24-hour photoperiods did not flower. Four weeks of sd followed by 16-hour photoperiods induced complete flowering and in an average of 95 days. However, 6 weeks sd was required for 100% flowering when the final photoperiod was 24 hours.

scholarly journals Transcriptomic analysis of flower induction for long-day pitaya by supplementary lighting in short-day winter season

2020 ◽  
Author(s):  
Rui Xiong ◽  
Chengli Liu ◽  
Min Xu ◽  
Shuang-Shuang Wei ◽  
Jia-quan Huang ◽  
...  
Keyword(s):  
Time Course ◽  
Floral Induction ◽  
Winter Season ◽  
Transcriptomic Analysis ◽  
Flower Induction ◽  
Pcr Analysis ◽  
Tropical Fruit ◽  
Short Day ◽  
Long Day ◽  
Supplementary Lighting

Abstract Background: Pitayas are currently attracting considerable interest as a tropical fruit with numerous health benefits. However, as a long-day plant, pitaya plants cannot flower in the winter season from November to April in Hainan, China. To harvest pitayas with high economic value in the winter season, it is necessary to provide supplementary lighting at night to induce flowering. To further explore the molecular regulating mechanisms of flower induction in pitaya plants exposed to supplementary lighting, we used de novo RNA sequencing-based transcriptomic analysis for four stages of pitaya plants subjected to light induction. Results: We assembled 68113 unigenes in total, comprising 29782 unigenes with functional annotations in the NR database, 20716 annotations in SwissProt, 18088 annotations in KOG, and 11059 annotations in KEGG. Comparisons between different samples revealed different numbers of significantly differentially expressed genes (DEGs). A number of DEGs involved in energy metabolism-related processes and plant hormone signaling were detected. Moreover, we identified many CONSTANS-LIKE, FLOWERING LOCUS T, and other DEGs involved in the direct regulation of flowering including CDF and TCP, which function as typical transcription factor genes in the flowering process. At the transcriptomic level, we verified 13 DEGs with different functions in the time-course response to light-induced flowering by quantitative reverse-transcription PCR analysis. Conclusions: The identified DEGs may include some key genes controlling the pitaya floral-induction network, the flower induction and development is very complicated, and it involves photoperiod perception and different phytohormone signaling. These findings will increase our understanding to the molecular mechanism of floral regulation of long-day pitaya plants in short-day winter season induced by supplementary lighting.

scholarly journals The level of phyA in Pharbitis nil Chois during the photoperiodic flower induction

2014 ◽  
Vol 69 (4) ◽  
pp. 269-272 ◽  
Author(s):  
Adriana Szmidt-Jaworska ◽  
Krzysztof Jaworski ◽  
Jan Kopcewicz
Keyword(s):  
Dark Period ◽  
Polyclonal Antibodies ◽  
Flower Induction ◽  
Pharbitis Nil ◽  
Light Illumination ◽  
Direct Control ◽  
Short Day ◽  
Rapid Destruction ◽  
Photoperiodic Flower Induction

The aim of this work was to determine if there is any relationship between an endogenous phyA level and photoperiodic flower induction. The level of phyA was characterised with polyclonal antibodies directed to phyA from pea. At first it was detected that phyA level is predominant in cotyledons, whereas in roots and stems the concentration of labile phytochrome is rather low. So cotyledons were used for later experiments. In these cotyledons exposed to light illumination a rapid destruction of phyA has been observed. The loss of extractable phyA chromoprotein occurs already after 60 min of irradiation. <em>Pharbitis nil</em> is a short-day plant and a single 16-hours-long dark period is fully inductive. We assessed that phyA level is extremely low during a long inductive night and an immunodetectable phytochrome appears only after 24 hours of darkness. The obtained results suggest that labile phytochrome is not taking part in the direct control of the photoperiodic flower induction.

scholarly journals Transcriptomic analysis of flower induction for long-day pitaya by supplementary lighting in short-day winter season

2019 ◽  
Author(s):  
Rui Xiong ◽  
Chengli Liu ◽  
Min Xu ◽  
Shuang-Shuang Wei ◽  
Jia-quan Huang ◽  
...  
Keyword(s):  
Time Course ◽  
Floral Induction ◽  
Winter Season ◽  
Transcriptomic Analysis ◽  
Flower Induction ◽  
Pcr Analysis ◽  
Tropical Fruit ◽  
Short Day ◽  
Long Day ◽  
Supplementary Lighting

Abstract Background: Pitayas are currently attracting considerable interest as a tropical fruit with numerous health benefits. However, as a long-day plant, pitaya plants cannot flower in the winter season from November to April in Hainan, China. To harvest pitayas with high economic value in the winter season, it is necessary to provide supplementary lighting at night to induce flowering. To further explore the molecular regulating mechanisms of flower induction in pitaya plants exposed to supplementary lighting, we used de novo RNA sequencing-based transcriptomic analysis for four stages of pitaya plants subjected to light induction. Results: We assembled 68113 unigenes in total, comprising 29782 unigenes with functional annotations in the NR database, 20716 annotations in SwissProt, 18088 annotations in KOG, and 11059 annotations in KEGG. Comparisons between different samples revealed different numbers of significantly differentially expressed genes (DEGs). A number of DEGs involved in energy metabolism-related processes and plant hormone signaling were detected. Moreover, we identified many CONSTANS-LIKE, FLOWERING LOCUS T, and other DEGs involved in the direct regulation of flowering including CDF and TCP, which function as typical transcription factor genes in the flowering process. At the transcriptomic level, we verified 13 DEGs with different functions in the time-course response to light-induced flowering by quantitative reverse-transcription PCR analysis. Conclusions: The identified DEGs may include some key genes controlling the pitaya floral-induction network, the flower induction and development is very complicated, and it involves photoperiod perception and different phytohormone signaling. These findings will increase our understanding to the molecular mechanism of floral regulation of long-day pitaya plants in short-day winter season induced by supplementary lighting.

scholarly journals Photons from NIR LEDs can delay flowering in short-day soybean and Cannabis: Implications for phytochrome activity

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255232
Author(s):  
Paul Kusuma ◽  
F. Mitchell Westmoreland ◽  
Shuyang Zhen ◽  
Bruce Bugbee
Keyword(s):  
Glycine Max ◽  
Plant Development ◽  
High Intensity ◽  
Near Infrared ◽  
Cannabis Sativa ◽  
Dark Period ◽  
Sensitive Species ◽  
Long Wavelength ◽  
Short Day

Photons during the dark period delay flowering in short-day plants (SDP). Red photons applied at night convert phytochromes to the active far-red absorbing form (Pfr), leading to inhibition of flowering. Far-red photons (greater than 700 nm) re-induce flowering when applied after a pulse of red photons during the dark period. However, far-red photons at sufficiently high intensity and duration delay flowering in sensitive species. Mechanistically, this response occurs because phytochrome-red (Pr) absorbance is not zero beyond 700 nm. We applied nighttime photons from near infrared (NIR) LEDs (peak 850 nm) over a 12 h dark period. Flowering was delayed in Glycine max and Cannabis sativa (two photosensitive species) by 3 and 12 days, respectively, as the flux of photons from NIR LEDs was increased up to 83 and 116 μmol m-2 s-1. This suggests that long wavelength photons from NIR LEDs can activate phytochromes (convert Pr to Pfr) and thus alter plant development.

scholarly journals Transcriptomic analysis of flower induction for long-day pitaya by supplementary lighting in short-day winter season

2020 ◽  
Author(s):  
Rui Xiong ◽  
Chengli Liu ◽  
Min Xu ◽  
Shuang-Shuang Wei ◽  
Jia-quan Huang ◽  
...  
Keyword(s):  
Time Course ◽  
Floral Induction ◽  
Winter Season ◽  
Transcriptomic Analysis ◽  
Flower Induction ◽  
Pcr Analysis ◽  
Tropical Fruit ◽  
Short Day ◽  
Long Day ◽  
Supplementary Lighting

Abstract Background: Pitayas are currently attracting considerable interest as a tropical fruit with numerous health benefits. However, as a long-day plant, pitaya plants cannot flower in the winter season from November to April in Hainan, China. To harvest pitayas with high economic value in the winter season, it is necessary to provide supplementary lighting at night to induce flowering. To further explore the molecular regulating mechanisms of flower induction in pitaya plants exposed to supplementary lighting, we used de novo RNA sequencing-based transcriptomic analysis for four stages of pitaya plants subjected to light induction. Results: We assembled 68113 unigenes in total, comprising 29782 unigenes with functional annotations in the NR database, 20716 annotations in SwissProt, 18088 annotations in KOG, and 11059 annotations in KEGG. Comparisons between different samples revealed different numbers of significantly differentially expressed genes (DEGs). A number of DEGs involved in energy metabolism-related processes and plant hormone signaling were detected. Moreover, we identified many CONSTANS-LIKE , FLOWERING LOCUS T , and other DEGs involved in the direct regulation of flowering including CDF and TCP , which function as typical transcription factor genes in the flowering process. At the transcriptomic level, we verified 13 DEGs with different functions in the time-course response to light-induced flowering by quantitative reverse-transcription PCR analysis. Conclusions: The identified DEGs may include some key genes controlling the pitaya floral-induction network, the flower induction and development is very complicated, and it involves photoperiod perception and different phytohormone signaling. These findings will increase our understanding to the molecular mechanism of floral regulation of long-day pitaya plants in short-day winter season induced by supplementary lighting.

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