Kinetics of nutrient utilization and photosynthetic enzyme activities during floral versus vegetative differentiation of Spathiphyllum in air-lift bioreactor cultures


The present study reports on the kinetics of nutrient utilization during in vitro flowering of Spathiphyllum in air-lift bioreactor cultures.Levels of electrical conductivity (EC), anions and cations, pH, ethylene, sugar content and photosynthetic enzymes were determined in bioreactor cultures of both flowering (FPs) and non-flowering (NFPs) plantlets over a growth period of 12 weeks.A decrease in ribulose 1,5-bisphosphate carboxylase/ oxygenase (Rubisco) activity with a corresponding increase in phosphoenolpyruvate carboxylase (PEPcase) activity occurred during floral induction of Spathiphyllum in vitro. Sucrose concentration decreased significantly in FPs, while no changes in glucose, fructose and total sugars were observed in both FPs and NFPs up to 8 weeks of culture. There were significant variations in mineral nutrient utilization between FP and NFP cultures.These results provide an insight to the physiological processes involved in inflorescence formation in Spathiphyllum.