Hossein Naderi Boldaji; Shirin Dianati Daylami; Sasan Aliniaeifard; Maryam Norouzi
Abstract
Light spectrum is one of the environmental cues that influence plant growth and development. Light is a stimulating factor for induction of somatic embryos during tissue culture practices. To accelerate the direct embryogenesis, six different light spectra including: white (W), red (R), blue (B), green ...
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Light spectrum is one of the environmental cues that influence plant growth and development. Light is a stimulating factor for induction of somatic embryos during tissue culture practices. To accelerate the direct embryogenesis, six different light spectra including: white (W), red (R), blue (B), green (G), red + blue (R+B) and red + far red (R+FR) together with dark condition (D), in combination with thidiazuron (TDZ) in four concentrations (0, 0.5, 1.5 and 3 mg L-1) were used. Inter-simple sequence repeat was used for identification and genetic stability analysis of somatic regenerated plantlets. Intact protocorm explants showed higher potential for direct somatic embryogenesis (DSE) than the other explants. The rate of DSE was highly dependent on the concentration of TDZ and its interaction with light spectra. R and R + FR spectra with 3 mg L-1 TDZ on intact protocorms and R+FR with 3 mg L-1 TDZ were efficient treatments to induce DSE without somaclonal variation. G light spectrum has also significant effects on DSE of protocorm explants. The amplified products showed 26 scorable bands and regenerates were completely identical to the mother plant. In conclusion, this protocol provides way to regenerate plants through embryogenesis, and is a reliable protocol to obtain proper development and genetic stable Phalaenopsis embryos.
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.
