Hamidreza Roosta; Fatemeh Nili; Ali Pourkhaloee; Naser Askari
Abstract
Photosynthetic parameters and stem strength of Gerbera jamesonii ‘Bayadere’ plants were studied after foliar application with calcium chloride (0, 0.5, 1, and 1.5 g L-1) under natural light (NL), red light LEDs (R), blue light LEDs (B) and red + blue light LEDs (RB). Chlorophyll content increased ...
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Photosynthetic parameters and stem strength of Gerbera jamesonii ‘Bayadere’ plants were studied after foliar application with calcium chloride (0, 0.5, 1, and 1.5 g L-1) under natural light (NL), red light LEDs (R), blue light LEDs (B) and red + blue light LEDs (RB). Chlorophyll content increased under LED lights and foliar application with calcium chloride. The maximal quantum yield of PSII efficiency (Fv/Fm) and performance index (PI) reached the lowest value under NL conditions. The highest values of photosynthesis rate, stomatal conductance, and transpiration rate (E) were achieved by RB lighting. Under the RB light and calcium chloride spraying, the plants showed the lowest leaf nitrate content, compared to NL conditions. This resulted in the highest leaf nitrate content. The higher the nitrate content, the lower the stem strength. However, the leaf calcium content showed an opposite trend. Sprays of 1.5 g L-1 calcium chloride in combination with RB lighting significantly in creased the flower stem strength and reduced stem bending, compared to non-treated plants. In summary, the RB lighting and foliar application with calcium chloride enhanced the growth and flower stem firmness of cut gerbera.
Aida Shomali; Oksana Vladimirovna Lastochkina; Mohammad Mohammadian; Anshu Rastogi; Massimo Bosacchi; Tao li; Sasan Aliniaeifard
Abstract
Acclimation to the privileged lighting environment is an important step for the survival of newly developed horticultural plants such as transplants, tissue culture-generated plants, and mature plants when a change occurs in light intensity during the growth period or even during one full day. Capturing ...
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Acclimation to the privileged lighting environment is an important step for the survival of newly developed horticultural plants such as transplants, tissue culture-generated plants, and mature plants when a change occurs in light intensity during the growth period or even during one full day. Capturing excess light energy without an antecedent to acclimation imposes photooxidative cellular damage and photoinhibition in plants. Since carbon utilization may not keep pace with reductive energy production, it renders electron acceptors in the electron transfer chain oversaturated. However, plants are usually equipped with photoprotective mechanisms to attenuate the detrimental effects of excess light energy on the photosynthesis apparatus. In this review, we discussed how different controlled environment horticulture (CEH) systems are embedded with immense opportunities for improving yield and quality. Current understandings of the direct and indirect functional roles of light spectra are discussed in the context of photoinhibition, photoprotection, and their regulatory mechanisms.
Sasan Aliniaeifard; Mehdi Seif; Mostafa Arab; Mahboobeh Zare Mehrjerdi; Tao Li; Oksana Lastochkina
Abstract
Light is the driving force for plant photosynthesis. Different attributes of light (e.g. intensity, spectrum and duration) can influence plant growth and development. We studied growth and photosystem II performance ofEnglish marigold cut flowers under red (635-665 nm) and white (420-700 nm) LEDs. Although ...
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Light is the driving force for plant photosynthesis. Different attributes of light (e.g. intensity, spectrum and duration) can influence plant growth and development. We studied growth and photosystem II performance ofEnglish marigold cut flowers under red (635-665 nm) and white (420-700 nm) LEDs. Although growing plants under red light resulted in morphological deformation such as leaf epinasty, it led to an early flowering and improved growth compared with white light-grown plants. In plants that were grown under red light, flowers were emerged 45 days after germination. In the time of flowering, there were 30 leaves (sum of rosette and lateral leaves) on the red light-grown plants, while 20 leaves were observed on white light-grown plants without flowering on day 45. Fast induction of chlorophyll fluorescence showed that fluorescence intensities of O-J-I-P phases in a typical fluorescence transient exhibited after a 20 min dark-adapted leaves were increased in red light-grown plants. Maximum efficiency of photosystem II (Fv/Fm) and performance index per absorbed light were decreased by red light, while quantum yield of energy dissipation was increased by red light. Most of the energy absorbed by the photosystems in red light-grown plants was dissipated as heat. In conclusion, although red light improved growth and induced early flowering in Calendula officinalis, full light spectrum is required to prevent leaf deformation and electron transport disruption under monochromatic red light.