What is the response of cucumber seedlings to supplementary LED lights?

In order to inhibit the growth of cucumber seedlings under low radiation and improve its quality, under extremely low irradiance (ELI), supplementary light-emitting diode (LED) lights on the morphological and physiological characteristics of cucumber seedlings at different growth stages are investigated .

In experiment one, the single-color, two-color and three-color LED lights on cucumber seedlings were supplemented, and in experiment two, the combination ratio and intensity of blue light and red light (RB) were supplemented Led Street lamps.

As early as the single-leaf seedling stage, under ELI conditions, supplementation of single-color red light or two-color red light (RB and RG) can effectively promote the morphological and physiological parameters of cucumber seedlings, which can be achieved by inhibiting the hypocotyl and first Length of internodes, increase the stem to prove. Diameter and biomass, higher net photosynthetic rate (Pn) and soluble sugar content. Under ELI, single color or extra green light is not good for cucumber seedlings. RB SL is as early as the single-leaf seedling stage, the length of the stem and hypocotyl decreases, and the stem diameter and leaf area increase.

Increasing the ratio of blue light (1R1B / 1R2B) can effectively promote the root activity, root to shoot ratio, catalase (CAT) and peroxidase (POD) activities and Mucha sponge ratio of cucumber seedling leaves. Increasing light intensity (50/75) can enhance the accumulation of soluble sugar in leaves. The RB ratio and light intensity have a synergistic effect on increasing the vertical cross-section stem diameter, leaf area, seedling index and decreasing the hypocotyl cell area. In summary, 1R2B-75 may be the best SL to inhibit the spiny growth of cucumber seedlings under ELI conditions.