Cultivar Differences in Ethylene Production by Wounded Sweet Potato Roots1

Wounding freshly harvested or cured sweet potato [ Ipomoea batatas (L.) Lam.] roots by either breaking, or cutting them in half stimulated C 2 H 4 production in all 13 cultivars and selections examined. Ethylene production was stimulated within 1 day of wounding and generally continued to increase for 7 days before decreasing. At the peak of production, wounded freshly harvested roots produced about 22 times more C 2 H 4 than controls, while C 2 H 4 production from wounded cured roots of the same cultivar or selection increased about 86 times. Wounding stimulated CO 2 production by about 72% over the controls. There were marked cultivar differences in the maximum rate of wound-induced C 2 H 4 production.