Abstract

In vitro root formation of Nothofagus could be obtained by culturing shoots in an auxin-based medium, and it could be improved by using different media on each successive rooting stage. The aims of this work were to study the peroxidase variation along the in vitro rooting phase of two broadleaved South-American Nothofagus species under two light conditions, and to determine the duration of the induction and expression stages. Significant differences in peroxidase activity were found during rooting for the two light conditions and species. Peroxidase levels were higher in light conditions and for N. nervosa. In N. nervosa the induction stage ended at 3rd and 5th day of rooting, and in N. antarctica at 5th and 7th day for complete darkness and normal photoperiod treatments respectively. The induction stages were shorter in darkness than those obtained in normal photoperiod, while N. antarctica showed longer phases than N. nervosa. Biochemical variations related to morphological aspects are discussed.