ACTIVITY VARIATION OF PEROXIDASE DURING IN-VITRO ROOTING OF NOTHOFAGUS-NERVOSA AND NOTHOFAGUS-ANTARCTICA

In vitro root formation of Nothofagus could be obtained by culturing s hoots in an auxin-based medium, and it could be improved by using diff erent media on each successive rooting stage. The aims of this work we re to study the peroxidase variation along the in vitro rooting phase of two broadleaved South-American Nothofagus species under two light c onditions, and to determine the duration of the induction and expressi on stages. Significant differences in peroxidase activity were found d uring rooting for the two light conditions and species. Peroxidase lev els were higher in light conditions and for N. nervosa. In N. nervosa the induction stage ended at 3(rd) and 5(th) day of rooting, and in N. antarctica at 5(th) and 7(th) day for complete darkness and normal ph otoperiod treatments respectively. The induction stages were shorter i n darkness than those obtained in normal photoperiod, while N. antarct ica showed longer phases than N. nervosa. Biochemical variations relat ed to morphological aspects are discussed.