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

ABSTRACT

Biggs, A. R.  1984.  Boundary Zone Formation in Peach Bark in Response to Wounds and Cytospora leucostoma Infection. Can. J. Bot. 62:2814-2821.

Seedlings of peach (Prunus persica (L.) Batsch cv. Halford) were mechanically wounded or inoculated with mycelium of  Cytospora leucostoma (Pers.)Fr.  Bark samples for histological study were taken from margins of visibly affected areas at varying times after treatment.  Histological examination revealed that host responses to wounding and pathogen colonization were basically similar, differing only in timing and extent of the responses examined.  Nonspecific host responses included gum production, changes in cell wall polysaccharides, cell wall lignification, and formation of suberized impervious tissue as part of the process of necrophylactic periderm formation.  The presence of the fungus was associated with inhibited differentiation of living tissues; and, as a result, host processes responsible for impervious tissue and necrophylactic periderm formation were affected adversely.