Evaluation of Salt Tolerance in Cultivated Potatoes (Solanum tuberosum L.) Based on Plant Growth and Tuber Yield

Salinization of soil and water under global warming is one of the main yield-limiting factors in potato production. To determine salt tolerance of cultivated potatoes is very useful for sustainable potato cultivation and production yield stability. Eighteen potato cultivars were grown under the soil and irrigation water of three salinity conditions (EC 1.0 dS∙m^-1 as control, 4 dS∙m^-1, and 8 dS∙m^-1). Relative aerial part weight (RAW; % control) and relative tuber yield (RTY; % control) were decreased in most cultivars according to salinity levels. Furthermore, the responses of RAW and RTY to salt stress were very different among cultivars. Although some cultivars (‘Daejima’, ‘Goun’, ‘Haryeong’, and ‘LT-8’) showed higher RAW than other cultivars under salinity condition, RTY of them was lower and moreover in the case of ‘LT-8’ there was no tuberization. On the other hand, ‘Superior’, ‘Kroda’, ‘Romana’, and ‘Duback’ showed higher RTY despite of their lower RAW. Negative correlation was observed between RAW and RTY, especially in the case of over 80% RAW at EC 8 dS∙m^-1. Increasing rate of proline content (IPC) was higher in the cultivars with high RAW than in the ones of high RTY. IPC showed a positive correlation with RAW at EC 8 dS∙m^-1, while a negative correlation with RTY. Hence, this study suggests that potato cultivar with high aerial part growth and high proline content under salt stress does not necessarily mean the high yielding cultivar to salt stress. In terms of yield stability, ‘Superior’, ‘Kroda’, ‘Romana’, and ‘Duback’ could be more useful as salt tolerant cultivars than the ones such as ‘Daejima’ or ‘LT-8’.