Hamidreza Roosta; Fatemeh Nili; Ali Pourkhaloee; Naser Askari
Abstract
Photosynthetic parameters and stem strength of Gerbera jamesonii ‘Bayadere’ plants were studied after foliar application of 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). Chlorophylls content was ...
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Photosynthetic parameters and stem strength of Gerbera jamesonii ‘Bayadere’ plants were studied after foliar application of 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). Chlorophylls content was increased under LED lights and foliar application of calcium chloride. The maximal quantum yield of PSII efficiency (Fv/Fm) and performance index (PI) reached the lowest value under NL conditions. Photosynthesis rate, stomatal conductance, and transpiration rate (E) showed the highest values using RB lighting. Plants grown under the RB light and sprayed with calcium chloride exhibited the lowest leaf nitrate compared to NL conditions which resulted in the highest leaf nitrate content. The higher the nitrate content, the lower the stem strength is expected. However, calcium content of leaves showed the opposite trend. Sprays of 1.5 g l-1 calcium chloride under RB lighting significantly increased flower stem strength and reduced stem bending compared to non-treated plants. In summary, RB lighting along with foliar application of calcium chloride enhanced growth and flower stem firmness of studied cut gerbera.
Aida Shomali; Oksana Vladimirovna Lastochkina; Mohammad Mohammadian; Anshu Rastogi; Massimo Bosacchi; Tao li; Sasan Aliniaeifard
Abstract
Acclimation to the privilege lighting environment is an important step for survival of newly developed horticultural plants such as for transplants, tissue culture-generated plants and for mature plants when there is a change in the light intensity during the growth period or even during the course of ...
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Acclimation to the privilege lighting environment is an important step for survival of newly developed horticultural plants such as for transplants, tissue culture-generated plants and for mature plants when there is a change in the light intensity during the growth period or even during the course of one day. Excess light energy capture without antecedent acclimation imposes photooxidative cellular damage and photoinhibition. Absorption of excess light beyond the capacity for photosynthetic electron transport is harmful to photosynthetic organisms. However, plants are equipped with photoprotective mechanisms to attenuate the detrimental effect of excess light energy on the photosynthesis apparatus. In this review, we discussed how different controlled environment horticulture (CEH) systems presented lots of opportunities for improving yield and quality, and the current understanding of the direct and indirect functional roles of light spectra in the regulation of photoinhibition and photoprotection are discussed.
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.
