Low levels of benzyl adenine (BAP), low water potential of the growth medium and low humidity due to cotton covers, inhibited vitrification of carnation (Dianthus caryophyllus L.) in vitro. However, under these conditions, a low development of plants and a decrease in the multiplication ratio, were observed. High levels of amonium nitrate enhanced vitrification with an increase in the total soluble protein content. An inverse correlation was observed in the presence of high levels of calcium chloride. The latter was correlated to an increase in peroxidase activity. The results allowed the establishment of a protocol to control vitrification during carnation meristein growth, as follows: "Gelrite", 4 g/1; naphtalene acetic acid, 0.5 mg/l; BAP, 0.05 mg/l; normal dosis of MS salts; cotton covers. For in vitro multiplication the protocol should be altered to BAP, 0.5 mg/1; amoniuin nitrate 10.3 mM; calcium chloride 12.0 mM.
Dianthus caryophyllus; meristem; vitrification; carnation; micropropagation