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.
Kianoush Hassanzadeh; Sasan Aliniaeifard; Mohammad Mehdi Farzinia; Madeh Ahmadi
Abstract
Rosemary (Rosmarinus officinalis L.) is an important medicinal plant that contained a wide range of secondary metabolites such as rosmarinic acid. In this study, essential oil content and composition and rosmarinc acid were determined at three phenological stages (before flowering, full flowering ...
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Rosemary (Rosmarinus officinalis L.) is an important medicinal plant that contained a wide range of secondary metabolites such as rosmarinic acid. In this study, essential oil content and composition and rosmarinc acid were determined at three phenological stages (before flowering, full flowering and fruit set stages). Hydro distillation method was used for essential oil extraction and GC and GC/MS was used for essential oil composition. On the basis of the obtained results rosemary plants in full flowering stage had higher amount of essential oil (1.99 ml/100 g dry weight) than in before flowering and fruit set stages (1.2 and 1.01 ml/100 per g dry weight, respectively). The extracted essential oil was contained 1,8-cineole, α-pinene, verbenone, camphor, geraniol, borneol acetae, camphene and linalool as major constituents. These constituents were affected by phenological stages. Before flowering, 1,8-cineole, α-pinene and verbenone (13.68%), in full flowering, 1,8-cineole (17.90%) and in fruit set α-pinene (21.77%) were the main constituents of the reosemary essential oil. Using HPLC analysis on leaf extract showed that the highest amount of rosmarinic acid (25.92mg/g DW) was observed in the fruit set stage. In conclusion, for essential oil content full flowering stage can be recommended for harvesting of Rosmarinus officinalis L. and for rosmarinic acid, fruit set stage can be the best time for harvesting of this medicinal plant.
