Physiological responses of olive cultivars to salinity stress

Abstract

The aim of this study was to evaluate the tolerance of seven promising olive cultivars for southern parts of Iran (‘Amigdalilolia’, ‘Dakal’, ‘Zard’, ‘Dezful’, ‘Tokhm-e-Kabki’, ‘Shiraz’, and ‘Conservalia’) against salinity stress. Biochemical and physiological responses of the cultivars irrigated with saline water application (control, 4, 8, and 12 dS m-1) were evaluated and the tolerant cultivars were identified. In contrast to the tolerant cultivars, the sensitive ones continue to grow with lower rate and died under salinity stress. In general, growth indices of olive cultivars were reduced with increasing salinity stress and the lowest growth indices were obtained under 12 dS m-1 treatment. Results indicated that the accumulation of higher levels of soluble carbohydrates and proline in the leaves of the tolerant cultivars helps them to deal with salinity stress. The results showed that saline waters up to 4 dS m-1 for irrigation can be used for olive cultivars, however, based on the result of this study, it is not recommended to use water sources with higher electric conductivities to irrigate sensitive olive cultivars. We concluded that the tolerant cultivars stopped growth and used their energy to defend against the salinity stress.