Effects of LED Light-Quality Ratios on Growth, Rooting, and Hydroponic Acclimatization of Spathiphyllum floribundum ‘Tianjiao’

Light quality plays a critical role in regulating plant growth during both in vitro culture and hydroponic stages, attracting increasing research attention. However, comprehensive studies incorporating far-red LED light throughout the entire growth cycle of Spathiphyllum floribundum (Linden & André) N.E.Br. ‘Tianjiao’ remain limited. To investigate the effects of red, blue, and far-red light ratios on proliferation, rooting, and hydroponic acclimatization, six LED treatments were established with red: blue ratios of 80:20, 70:30, and 60:40, each with or without far-red light supplementation. Fluorescent light was used as the control. At each stage, morphological traits, photosynthetic pigments, osmotic compounds, antioxidant enzyme activities, and photosynthetic parameters were measured. The results identified distinct optimal light combinations for each growth phase. The optimal treatment for proliferation was 80%R + 20%B + Fr, which produced significant proliferation coefficients and enhanced chlorophyll b and soluble protein content. For rooting, 60%R + 40%B + Fr was most effective, resulting in the highest total chlorophyll content (0.109 mg·g−1) and improved carotenoid accumulation and CAT activity. During hydroponic acclimatization, 60%R + 40%B without far-red light yielded the best performance, achieving the highest plant height (15.28 cm) and net photosynthetic rate (4.77 μmol·m−2·s−1), along with improved water-use efficiency. These results provide potential LED light strategies for the complete process from tissue culture to hydroponics, offering a theoretical basis for designing specialized LED lighting systems for plant tissue culture and hydroponic production.