ORIGINAL ARTICLE

Grouping of Some Potato Cultivars by Water Deficiency Tolerance Based on Their Agro-physiological Characteristics

A 2-year field experiment was conducted to evaluate the response of potato plants to water deficit. Treatments included 10 potato cultivars were evaluated at the presence of different moisture conditions (30-40 and 60-70% depletion of available soil water). Water deficit increased the activities of peroxidase (POX), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), ion leakage and proline content while decreased chlorophyll pigments, plant dry mass (PDM) and tuber yield (TY) in all cultivars. The extents percent of increases in SOD, POX and CAT activity were greater in tolerant cultivars. The biplot analysis results also showed SOD and POX closely correlated with biomass production of the tolerant cultivars. The highest tuber yields were obtained in Santé under control irrigation and in Spirit under water deficit. The reductions in TY ranged from 55.08 (Born) to 83.42% (Agria). Based on both STI index and biplot analysis Spirit and Agria were respectively identified as the most tolerant and sensitive cultivars to water deficit.