The Permeability to Oxygen of the Periderm of the Potato Tuber

Abstract

The permeability to oxygen of the periderm of the potato tuber has been measured during its development and storage. When expressed as ml O2, diffusing through 1 cm2 periderm in 1 sec under an O2, pressure of 1 atm, the values for freshly harvested tubers ranged from a maximum of 2.4 × 10−4 in immature tubers, to less than 0.7 × 10−4 in tubers harvested mature some weeks after the death of the foliage. In every case, after storage for up to 10 weeks at 10° C, the permeabilities, as expressed above, were less than 0.7 × 10−4 (minimum values, c. 0.5 × 10−4 It was shown that the oxygen deficit under the periderm was unlikely to exceed 0.03 atm during development, and the oxygen status of the developing tuber should thus be adequate for the low oxygen-affinity oxidase system (if present) to function.