Drought stress response in long-storage tomatoes: Physiological and biochemical traits

Long-storage tomato is traditionally cultivated under no water supply in Mediterranean area and could be considered for cultivation in arid and semi-arid countries. The aim of this work was to identify the main adaptive physiological and biochemical mechanisms of two long-storage tomato landraces (Pizzutello di Sciacca and Locale di Salina), grown under drought conditions with respect to a processing tomato cultivar (Brigade). Before flowering, control plants were irrigated daily, and drought stressed plants did not receive water until stomata conductance reached value near to zero. Recovery of plants was carried out by daily re-irrigation of pots. Pizzutello di Sciacca and Locale di Salina maintained higher values of the leaf photosynthetic rate with fewer reductions in stomatal conductance with respect to Brigade, and they showed a rapid and full recovery of all gas exchange parameters after re-watering, suggesting a good tolerance to water stress. The rates of change in stomatal conductance with abscissic acid were greater for Pizzutello di Sciacca and Locale di Salina compared to Brigade and caused the early stomatal closure, limiting further water loss and subsequent damages. Leaf water status of all genotypes was affected by drought; in particular, Brigade accumulated higher proline contents in the leaves. (C) 2015 Elsevier B.V. All rights reserved.