To improve the in vitro rooting of selected clones of wild cherry (Prunus avium), the search for a physiological marker for rhizogenesis was initiated. Peroxidase activity is considered as a good rooting marker for other Prunus species. Peroxidase activity was thus assayed by spectrophotometric measurement, and cationic and anionic isoperoxidases were separated by polyacrylamide gel electrophoresis. The measurement of peroxidase activity was made during the first 8 days of subculture on rooting medium with and without auxin (β-indolylbutyric acid). From a first set of experiments, there was no relationship between peroxidase activity and the rooting process. In a second series of experiments, before subculturing on the rooting medium with and without auxin, the explants were divided into three classes according to their lignification level: less, moderately, and more lignified cuttings. Level and changes in peroxidase activity were found to be correlated with the lignification level of the explants. However, there was no effect on final rooting rate. In each class of shoots, the relationship between peroxidase activity and rooting rate, with or without auxin, was highly variable.
Polyamines and ethylene during in vitro rooting of Prunus avium L