Net photosynthesis of selected foliage plants under low irradiation

Abstract

Net CO2 exchange, dark respiration, light compensation points, and light acclimation rates were determined for Brassaia actinophylla, Nephrolepis exaltata 'Bostoniensis,' and Scindapsis aureus under four irradiation levels. These three species exhibited increased rates of net CO2 uptake and decreased rates of dark respiration at the lowest irradiances, indicating an increase in photosynthetic efficiency. They demonstrated a 1.4 to 5.0 fold reduction in light compensation points over a seven week period of acclimation. Brassaia actinophylla reached its minimum light compensation point in 5 weeks, Scindapsis aureus in 3 weeks, and Nephrolepis exaltata 'Bostoniensis' never reached a minimum light compensation point. The plants were re-acclimated to lower irradiation levels for 3 weeks to determine if there was a change in photosynthetic activity. Brassaia actinophylla was capable of re-acclimating by showing increased photosynthetic efficiency at all irradiation levels within this period, Nephrolepis exaltata 'Bostoniensis' and Scindapsis aureus only approached the point of no net CO2 evolution.