The inhibition of exogenous ethylene generated by solid ethylene-releasing agents on sprouting of potato tubers in relation to carbohydrate metabolism

Abstract

The effects of exogenous ethylene generated by solid ethylene-releasing agents on carbohydrate metabolism and sprouting in potato tubers at 15 °C were investigated in this study. Potato tubers were randomly divided into 4 groups, and treated with 0, 1, 2, and 3 bags of solid ethylene-releasing agents. The initial time of potato tuber sprouting and sprouting index were recorded. The rate of respiration, total sugar, total reducing sugar, starch, fructose, glucose, and sucrose content during the sprouting were determined. Our result indicated that exogenous ethylene inhibited the sprouting of potato tubers (sprout index from 0.583 to 1.125), whereas little effect on the initial time of sprouting was observed. Moreover, exogenous ethylene enhanced respiration slightly (less than 8.2%), elevated the total sugar (from 17.73 to 32.58 mg/g) and reduced sugar levels (from 0.23 to 4.43 mg/g). Nevertheless, the starch, glucose, and fructose content varied minimally. The sucrose content was decreased significantly by exogenous ethylene. Therefore, exogenous ethylene treatment could inhibit the potato sprouting process, and a dose-dependent relationship was observed between exogenous ethylene and sprouting index. The inhibitory effect of sprouting was related to carbohydrate metabolism, including changes in the total sugar, total reducing sugar, and sucrose content, to some extent.