BEYOND THE YIELD: LIGHT SPECTRUM AS A DRIVER OF PHENOTYPIC REORGANIZATION IN GREENHOUSE TOMATO PRODUCTION

Abstract

Supplemental lighting is a key environmental driver of greenhouse tomato productivity in high-latitude regions; however, its role extends beyond yield enhancement toward reorganization of whole-plant phenotypic coordination. Here, we applied an integrated multivariate analytical framework to disentangle how spectrally differentiated LED lighting reshapes the joint structure of growth, photosynthetic, metabolic, yield, and fruit quality traits under identical photon flux density. Multivariate trait integration revealed divergent phenotypic strategies between LED spectra. The red-dominant spectrum (KSDO2) was associated with a yield-oriented phenotype characterized by maximal assimilative surface expansion, enhanced nitrogen assimilation, and a pronounced reduction in fruit nitrate concentration (−26.7%). In contrast, the balanced spectrum (KSDO1) promoted a more metabolically balanced phenotype, marked by increased fruit titratable acidity (+18.7%) and stable pigment investment. Correlation analyses demonstrated strong coupling between canopy architecture, yield formation, pigment metabolism, and nitrogen accumulation, with clear trade-offs between antioxidant-related traits and nitrate storage. These findings highlight the value of multivariate, phenotype-centered approaches for designing goal-oriented LED lighting strategies in controlled-environment tomato production.