Occurrence and Bioassay Responses of G A Plant Growth Regulator in Eucalyptus and Other Myrtaceae

A growth regulator (G) occurs at high concentrations in adult leaves of E. grandis Maiden. Low concentrations of G are present in juvenile leaves of this species and also in adult leaves of some other Myrtaceae. Low concentrations of G (5×10−6 and 10−5 M) promote rooting in mung-bean cuttings and elongation in Avena coleoptile sections; high concentrations (5×10−4 M) inhibit. These and other bioassay results indicate that G may have auxin-like activity.