Optimal LED Light Ratio for Growth and Coloration of Tissue-Cultured Sedum rubrotinctum
This study investigated the effects of different LED light quality combinations on the growth and leaf colour of *Sedum rubrotinctum* plantlets derived from tissue culture. Six light treatments-monochromatic red (R), monochromatic blue (B), white (W), and mixed red/blue ratios 4R1B, 3R1B, and 2R4B-were applied for 90 days. Growth parameters, pigment contents, leaf chroma, and comprehensive quality were measured and analysed.
Results showed that light quality significantly affected plant morphology and leaf colouration. Monochromatic R light promoted stem elongation but led to the lowest biomass, leaf size, and root development. Monochromatic B light favoured biomass accumulation and leaf and root growth better than R light but was less effective than R/B combinations. Compared with monochromatic R, B, and W light, R/B mixed light significantly increased shoot and root fresh weight, stem diameter, crown width, total root length, root surface area, and root volume.
For pigments, R/B combinations enhanced chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid contents. Anthocyanin accumulation and leaf redness (a* value) were notably higher under 3R1B, 4R1B, and 2R4B, resulting in attractive red leaves, while leaves under R and B light remained green. Light quality had little effect on the b* value.
Principal component analysis (PCA) based on multiple indicators yielded a comprehensive ranking: 4R1B > 2R4B > 3R1B > W > B > R. The 4R1B treatment performed best in overall growth, biomass, root system development, and ornamental leaf colour. Correlation analysis confirmed strong positive relationships between biomass traits, chlorophyll contents, and anthocyanin with a* value.
In conclusion, red–blue LED combinations are superior to monochromatic and white light for *Sedum rubrotinctum* tissue-cultured plantlets. The 4R1B light regime is recommended for commercial production to promote robust growth and vivid leaf colour, providing a practical light-management strategy for succulent cultivation.
https://www.benweilight.com/lighting-tube-bulb/grow-lights-for-houseplants.html
