Submitted to: Potato Association of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: January 26, 2001
Publication Date: N/A
Technical Abstract: Tuber skinning wounds result in costly disease, blemish defects and shrinkage in processing, seed and fresh market potatoes. We have conducted research and developed a body of information on the measurement of skin-set and the physiology of periderm maturation and resistance to skinning wounding. Measurement of the rate of skin-set development among diverse genotypes showed that resistance to skinning developed slowly and varied from year to year. Cultural conditions appeared to be as important as vine killing in affecting the rate of skin-set development. Contrary to anecdotal information, periderm maturation and the development of resistance to skinning wounds were not accompanied by skin thickening or large changes in skin tensile strength. Periderm maturation is characterized by a reduction in vapor conductance which is more pronounced in russeted than smooth skinned varieties. This water vapor loss may be important in skin-set development because our results show that the cellular damage incurred upon skinning is restricted to the turgor sensitive cells of the native periderm, i.e. the phellogen. The radial walls of active phellogen cells are thin, fragile, easily fractured and are the source of susceptibility to skinning. After growth ceases, the phellogen becomes inactive, the cell walls strengthen and thicken and are no longer easily broken; thus the skin is firmly held in place. Our current research is directed towards identifying the biochemical processes and regulatory mechanisms responsible for skin-set and related wound-healing.