Abstract Soil salinization is considered as one of the most important risks for agricultural soils. The objective of this experiment was to study the ecophysiological and the biochemical behaviour of two cultivars of Olea europaea L., 'Chemlali' and 'Koroneiki' under two salinity levels (100 and 200 mM NaCl) and the potential alleviation induced by gibberellic acid (GA3) foliar sprays. Salinity treatments significantly decreased photosynthetic assimilation rate and stomatal conductance compared to the control for both cultivars, but ‘Chemlali’ showed a higher resistance to increasing NaCl salinity compared to 'Koroneiki'. Leaf chlorophyll index also reduced gradually with increasing salinity concentration compared to the control. At the end of the experiment, a decrease in growth and dry matter accumulation was observed. Under high salinity stress, a significant decrease in root DW was recorded by 37% and 59% for ‘Chemlali’ and ‘Koroneiki’, respectively. High salinity stress decreased also shoot DW up to 51% for ‘Chemlali’. However, mannitol concentration increased under increasing salinity levels compared to control for ‘Chemlali’ cultivars. Interestingly, foliar application of GA3 alleviated the negative effects of salinity on ecophysiological parameters especially for ‘Koroneiki’. Indeed, GA3 improved photosynthetic assimilation up to 14% for ‘Chemlali’ and 36% for ‘Koroneiki’ compared to high salinity treatment. Both cultivars showed an increase in leaf chlorophyll index after applying GA3. Under high salinity combined with GA3, growth and dry weight were increased compared to salt stressed plants without GA3. The obtained results report that ‘Chemlali’ cultivar is more tolerant to salinity than ‘Koroneiki’ and suggest that GA3 plays an important role to reduce negative effects of NaCl salinity.

中文翻译：

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橄榄树（Olea europaea L.）对盐胁迫和赤霉酸诱导的缓解的生态生理和生化方面

摘要 土壤盐渍化被认为是农业土壤最重要的风险之一。本实验的目的是研究两种盐度水平（100 和 200 mM NaCl）下油橄榄的两个品种 'Chemlali' 和 'Koroneiki' 的生态生理和生化行为以及赤霉酸诱导的潜在缓解作用（ GA3) 叶面喷洒。与两个品种的对照相比，盐度处理显着降低了光合同化率和气孔导度，但与 'Koroneiki' 相比，'Chemlali' 对 NaCl 盐度的增加具有更高的抵抗力。与对照相比，叶片叶绿素指数也随着盐度浓度的增加而逐渐降低。在实验结束时，观察到生长和干物质积累减少。在高盐度胁迫下，“Chemlali”和“Koroneiki”的根系 DW 分别显着降低了 37% 和 59%。'Chemlali' 的高盐胁迫也使茎干干重降低了 51%。然而，与“Chemlali”品种的对照相比，在盐度增加的情况下，甘露醇浓度增加。有趣的是，叶面喷施 GA3 减轻了盐度对生态生理参数的负面影响，尤其是对“Koroneiki”。事实上，与高盐度处理相比，GA3 将 'Chemlali' 的光合同化提高了 14%，将 'Koroneiki' 的光合同化提高了 36%。两种栽培品种在施用 GA3 后均表现出叶片叶绿素指数的增加。在与 GA3 结合的高盐度下，与没有 GA3 的盐胁迫植物相比，生长和干重增加。