Mineral nutrition in carnation tissue cultures under different ventilation conditions

Growth and propagation rates, hyperhydricity percentages, macronutrient absorption and pH evolution were evaluated in Dianthus caryophyllus CV Nelken cultured in vitro under different ventilation conditions. Culture in well ventilated conditions (HVC) i.e. low relative humidity, generated lower percentages of hyperhydric explants, with higher micropropagation coefficients and dry weight increments, than in less ventilated cultures (LVC). Macronutrient absorption was similar in both types of cultures, except for ammonium, nitrate, chloride and phosphate. In LVC, after 15 days of culture, carnation explants absorbed more nitrate than ammonium and chloride uptake was 5 times greater than in HVC. Phosphate uptake was more pronounced in LVC after 15 days of culture, reaching similar values in both types of culture vessels at the end of the experiment, and led to growth limiting conditions for more prolonged cultures. Medium pH decreased to acid values after 15 days of culture and even more at the end of the experiment; however, these acid conditions seem not be an obstacle for nutrient absorption.