Effects of White and Blue-Red Light on Growth and Metabolism of Basil Grown under Microcosm Conditions

Indoor farming of basil (Ocimum basilicum L.) under artificial lighting to support year-roundproduce demand is an area of increasing interest. Literature data indicate that diverse light regimesdifferently affect downstream metabolic pathways which influence basil growth, development andmetabolism. In this study, basil was grown from seedlings to fully developed plants in a microcosm,an innovative device aimed at growing plants indoor as in natural conditions. Specifically, the effectsof white (W) and blue-red (BR) light under a photosynthetic photon flux density of 255 µmol m-2s-1on plant growth, photochemistry, soluble nutrient concentration and secondary metabolism wereinvestigated. Plants grew taller (41.8 ± 5.0 vs. 28.4 ± 2.5 cm) and produced greater biomass(150.3 ± 24.2/14.7 ± 2.0 g vs. 116.2 ± 28.3/12.3 ± 2.5 g fresh/dry biomass) under W light comparedto BR light. The two lighting conditions differently influenced the soluble nutrient concentration andthe translocation rate. No photosynthetic stress was observed under the two lighting regimes, butleaves grown under W light displayed higher levels of maximum quantum yield of PSII and electrontransport rate. Sharp differences in metabolic patterns under the two lighting regimes were detectedwith higher concentrations of phenolic compounds under the BR light.