FORMATION OF THE LIGNO-SUBERIZED BARRIER ZONE AND WOUND PERIDERM IN 4SPECIES OF EUROPEAN BROAD-LEAVED TREES

The development of wound periderm after mechanical wounding was examin ed in the barks of Acer pseudoplatanus, Betula pendula, Fagus sylvatic a and Sorbus aucuparia. Following the initial necrosis of cells immedi ately surrounding the wounds, development of the ligno-suberized barri er zone was detected within 7 days. Suberin deposition was observed in this tissue in A. pseudoplatanus, S. aucuparia and B. pendula 7 days after wounding, but not in F. sylvatica until day 14. By 28 days after wounding, extensive thickening of the walls of these cells had occurr ed. Differentiation of the wound periderm was detected immediately abu tting the ligno-suberized barrier-zone tissues in all species, with ex tensive development by 28 days. Fifty-six days after mounding, the wou nd periderm was fully formed and completely confluent with the origina l periderm. Development of the wound response was similar in all speci es, with differences only in the timing of first detection of suberin.