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|Comparative data regarding the growth of spruce (Picea abies l) and black locust (Robinia pseudoacacia l) plantlets and their content in assimilating pigments in the 40st day of in situ or in vitro seed germination exposed to diferent wavelenght led ligh
|Cachiţa D., Burescu L., Craciun C.
|1University of Oradea, Faculty of Sciences; 2„V. Goldiş” University from Arad, Faculty of Sciences, Engeniering and Informatics; 3„Babeş-Bolyai” University from Cluj-Napoca, Electron Microscopy Center;
|The cultivation of plants in rooms isolated from the natural environment involves the set-up of automated lighting systems that will not overly increase the production costs. In this case using Light Emitting Diodes (LED) especially in plant biotechnology has become a useful and efficient lighting method. Whishing to compare the reaction of the plantlets grown in a septic or aseptic medium to LED lighting, the influence upon the germination and growth of the spruce (Picea abies L) and black locust (Robinia pseudoacacia L) in the 40st day from placing the seeds for germination, of the different color LED light (red, yellow, green and blue) compared with the white light that was used as reference, was studied. The lighting of the spruce or black locust seeds and plantlets using monochromatic ultrabright LED light (mainly white but also yellow and green and to a lesser extent blue or red light) can sustain the growth of the plantlets for 40 days both in septic or aseptic regime. The white light provided an optimum development conditions both for the plantlets organs growth and for the accumulation, mainly in the cotyledons, of green or carotenoid assimilating pigments. In the case of spruce, the germinated seeds and the plantlets grown in containers or in vitro cultivated under green ultrabright LED light – compared with the ones exposed to white light – a stimulation by 7-8% of the growth of the plantlets was noticed, of the stemlets by 15% whereas the red and blue light have inhibited by 3,7% the growth of their organs. In the case of the black spruce plants the maximum beneficial effects were recorded under yellow LED light and to a lesser extent under green light. Thus, at the batches germinated in a septic medium, in containers, the yellow light has stimulated the growth of the plantlets stemlets by 51% whereas the red light has strongly inhibated – by 40% – the growth of the embryonary rootlets and by 52% of the size of the stemlets. This effect was less intense in the batches grown in a aseptic medium. From the obtained data result the importance of the light composition to which the seeds under germination or the plantlets growning in different culture conditions are exposed, and this composition has a strong influence not only on the development of their organs but also on the cellular metabolism ie. the sysnthesis of secondary metabolites. Plant responses to light composition was species-dependent.
|spruce, black locust, vitro germination, LED lighting
|Constantin Craciun, Babeş-Bolyai” University from Cluj-Napoca, Electron Microscopy Center; email@example.com