Morphological and biochemical analysis along with gene expression dynamics in Lilium ‘Brunello’ under supplemented effect of blue and red light treatment in pin tray soil-less cultivation system

Abstract

The present research corroborates the influence of supplementation effect of blue light (BL), red light (RL), and the combination of both BL + RL on the morphological traits, biochemical, and expression of key flowering genes assessment in lilium cultivated in bulb forcing soil-less pin trays within a climate-controlled autonomous greenhouse system. The findings revealed profound effect of BL + RL treatment on increased plant height (79.59 cm), stem diameter (10.05 mm), bud length (93.73 mm), and bud diameter (29.87 mm), compared to individual BL and RL treatments and the white light (WL) control. The BL + RL treatment also resulted in shortening the flowering timeline. Maximum flower diameter (18.65 cm) and chlorophyll content index (48.60) were recorded under BL + RL treatment. BL + RL extended post-harvest longevity to 13.2 days, followed by RL (11.6 days). Total chlorophyll content highest at the color bud stage under BL + RL (499.87 μg g⁻¹), though RL treatment sustained the highest levels at the flower stage. Carotenoids content showed a contrasting trend, with RL promoting maximum accumulation during bud stages, while BL + RL enhanced carotenoid synthesis at the flower stage (166.88 μg g⁻¹). Phenol and flavonoid content also reached maximum levels under BL + RL at the color bud stage and anthocyanin content was highest under BL + RL at the flower stage. Additionally, antioxidant activity was significantly higher (86.75 %) in flowers grown under BL + RL. Similarly, up-regulation of flowering genes FT and CO9, particularly observed under the BL + RL treatment at the initial bud and color bud stages, while flowering repressor FLC was down-regulated under all light treatments, facilitating earlier floral induction. The combined BL + RL treatment enhances Lilium cultivation profitability by improving growth, accelerating flowering, increasing flower quality and shelf life, and enabling faster production cycles in controlled Soil-less systems.