Change in Electrophoretic Pattern of Ribonuclease during Dormancy and Growth of Bird-cherry Buds

A morphactin formulation containing methyl-2-chloro-9-hydroxyfluorene-9-carboxylate as the major component caused abnormal stem growth in Pinus radiata D. Don seedlings when applied as a bark band. The banded region swelled due to increased cell division in the periderm and cambium. The abnormal stem development in treated trees did not cause a localized girdling effect. The morphactin treatment inhibited shoot elongation and root growth. Treated trees exposed to ¹⁴CO₂ translocated significantly less assimilate to the roots than did control trees although fixation of ¹⁴CO₂ by the shoots was not reduced. Label from a bark band of ¹⁴C-morphactin was rapidly translocated to the roots indicating that direct inhibition of root growth by the inhibitor probably occurred.