The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

The spectrum of light significantly influences the growth plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white (W, 170 ?mol m?2 s?1) and addition red (W + R) or blue B) (230 s?1). until they reached seedling phase (30 days). Each cultivar reacted differently to applied. red-leaved exhibited strongest plasticity response spectrum. stimulated surface all plants. negatively influenced length leaves cultivars, but it positively affected their number dark-green lettuce. It also increased relative chlorophyll content fresh weight gain containing anthocyanins. When light, had longer higher value shape index. light-green a greater weight. Both cultivar. enhanced positive influence on most parameters analysis butter cultivars. These characterised by highest absorbance light.