Reproductive Development, Seed Yield and Seed Quality of Gloxinia (Sinningia speciosa) in a Closed Plant Production System as Influenced by LED Light Quality and Intensity

Abstract

The flower seed industry is facing a variety of issues related to ongoing climate change. The closed plant production system (CPPS) may be a solution to these issues as the environment inside the system can be fully controlled to allow seed production from many plant species. In this study, the influence of an artificial light condition, one of the key factors influencing plant growth and development in CPPS, on gloxinia (Sinningia speciosa) seed production was investigated. Three types of lights: warm white (3200 K), daylight (6500 K), and red and blue lights (RB) at a photosynthetic photon flux density of either 150 or 200 μmol·m⁻²·s⁻¹ were applied to gloxinia plants. The highest vegetative growth was found in plants grown under 3200 K at 200 μmol·m⁻²·s⁻¹ light but this did not correlate with seed yield. Plants grown under RB light exhibited the most compact canopy. Day to anthesis, flower diameter and percentage of pod set were not significantly different among the light treatments. Gloxinia plants grown under RB light at 150 μmol·m⁻²·s⁻¹ had the highest seed yield, which is attributed to higher pollen elongation and flower number. The effect of light quality on seed yield is strongly dependent on light intensity. Moreover, treatment with RB light resulted in longer pollen grains and seeds than the other light quality treatments. Gloxinia seeds from all light treatment exhibited more than 80% germination and similar seed vigor. The results from this study suggest that CPPS, with suitable light conditions, may be used for commercial gloxinia seed production.