The experiment was carried out to investigate the growth behavior in-vitro plant tissue culture of Potato plantlets under different light spectra. The 3 rd generation in vitro plantlets of potato was used. The experiment included 5 treatments were conducted as factorial based on completely randomized design (CRD) with five replications and each replication included five jars with 3 plants per each one. The adventitious shoots of S. tuberosum (0.5-1 cm in length) were exposed in jars containing approximately 30 ml of the Murashige and Skoog (MS) salt medium. The cultures were kept under each light LEDs (W, Y, G, B and R) separately, for 15 days (subculture period). Results of 3 subcultures indicated a significant increase of multiplication rate under all light conditions, which recorded the highest mean value with green light followed by blue then red. Also, an increase in shoot length due to the optical spectrum lights and the highest value recorded with the blue light followed by red one. Number of leaves scored the highest value with the blue light. As for the fresh weight of plant found that the highest mean values recorded with blue light followed with the red one. While the lowest mean values for all parameters recorded with the yellow light. The highest quantities of glucose, fructose, sucrose, soluble carbohydrates, amino acid and tocopherol recorded the highest values under blue light, while soluble protein and anthocyanin scored the highest values under red light.

This study was conducted to explore the growth behavior of plants tissue culture in vitro using an optical spectrum system exchange. In this investigation, the 3 rd generation in vitro plantlets of potato cv. "Diamond" were employed. The experiment included 5 treatments. The adventitious shoots of S. tuberosum (0.5-1 cm in length) were exposed in jars containing approximately 30 ml of the Murashige and Skoog (MS ) salt medium. The cultures were kept under following LED lights: White, Yellow, Green, Red and Blue respectively for 4 days switch within every light, compared to continuous white light for the same period (20 days). Comparing to the white light every 20 days found that the third subculture was significantly higher than the second and the first, in most optimal spectrum LED treatment color, also most averages of growth treatment was higher under red and blue LED light. the contents of amino acids and proteins exhibited accumulation trend with variant degree depend on type of light used. Generally, the combined light had the highest accumulation of amino acids and proteins compared to monochromatic light. For monochromatic light, the blue light recorded the most accumulation of amino acids and proteins compared to other lights. Also, plantlets exposed to red and blue light had the maximum levels of pigments. High accumulation of α─tocopherol content in the order, blue>red>green>yellow>white. Blue light and plants subjected to multiple light cycles were found to have the most accumulation in anthocyanin.