Response of Potato Landraces (Solanum tuberosum L.) to Water Stress by Drought

In order to evaluate the response to water stress by drought in seven potato landraces, we assessed the enzymatic activity of catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (POX). The results showed that the Imilla lunku, Pinta boca and Waychu qoyllu landraces were resistant and/or tolerant to drought and showed higher values in the enzymatic activity of CAT, APX and POX, that their own controls. This confirmed that these cultivars were resistant to drought. In contrast, Waych'a, Candelero and Sakampaya cultivars were susceptible and showed lower values of these enzyme activities than their controls. However, Sakampaya cultivar with 20 days of drought contrary to what was expected, showed high levels of APX enzyme activity compared to control. This suggested that this cultivar probably had other mechanisms of resistance and/or tolerance to drought that allowed more dramatic reaction to drought stress. Finally, the cuticle permeability showed that the Waychu qoyllu and Pinta boca cultivars, high chlorophyll content compared to other cultivars. This indicated that the resistant and/or tolerant cultivars for drought had higher chlorophyll content than susceptible cultivars.