A. R. Biggs, West Virginia University, University Experiment Farm. P. O. Box 609, Kearneysville, WV 25430

ABSTRACT (Copyright © American Phytopathological Society)

Biggs, A. R. 1985. Suberized boundary zones and the chronology of wound response in tree bark. Phytopathology 75:1191-1195.

Wound response in mechanically injured outer bark of thirteen species of woody dicotyledonous angiosperms was assessed quantitatively by using microscopic photometry/fluorometry and new histochemical techniques. In all species, a morphologically distinct boundary zone formed prior to initiation of new phellogen. The boundary zone tissue, formed from cells present at the time of wounding, was comprised initially of cells with lignified walls. These cells with time developed intracellular suberin linings that imparted an impervious quality to the boundary zone. New phellogen and its derivatives formed immediately internal to this impervious tissue. Based on these findings, a revised wound response chronology for tree bark is proposed.