Abstract In the context of climate change, understanding fig trees physiology is very important, since the areas of fig production registered a large climate variability that severely affects fruit quality. The present study was conducted to evaluate the seasonal changes of physiological leaf behaviour of two Tunisian fig cultivars, Zidi and Bither Abiadh during two years. Plants were subjected to full irrigation to maintain the soil moisture around pot capacity through the experimental period. Leaf gas exchange characteristics (net photosynthetic rate (PN), stomatal conductance (gs), and transpiration rate (E)), chlorophyll content index, leaf temperature and the maximum photochemical efficiency of PSII (Fv/Fm) were measured. Results showed that the photosynthetic characteristics changed during the growing season. Changes of photosynthetic CO2 assimilation, stomatal conductance, and chlorophyll content were not significantly affected by cultivar, and their variation was attributed to year. Seasonal changes of PN and gs were similar suggesting that both processes are dependent. Indeed the best photosynthetic performance of fig occurred about 80-87 days after bud break (spring) of the second season of growth, being supported by a high stomatal aperture. The lowest values of PN, E and gs were recorded 156 days after bud break (summer) for 2017. The decrease of gas exchange rates and high temperatures were registered during the same dates. A little increase of the photosynthetic characteristics and chlorophyll content was noticed in the autumn period, about 180 days after bud break, until a definitive decrease at the end of the growing season with the occurrence of low winter temperature. These results revealed particular adaptive behaviour and could be used as preliminary criteria to predict the future impact of environmental abiotic stresses on ecophysiological fig tree behaviour.

中文翻译：

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无花果树（Ficus carica L.）生理特征的季节性变化揭示其适应性能

摘要 在气候变化的背景下，了解无花果树的生理学非常重要，因为无花果生产地区的气候变化很大，严重影响了果实质量。本研究旨在评估两个突尼斯无花果品种 Zidi 和 Bither Abiadh 在两年内生理叶片行为的季节性变化。在整个实验期间，对植物进行充分灌溉以保持盆栽容量附近的土壤水分。测量了叶片气体交换特性（净光合速率 (PN)、气孔导度 (gs) 和蒸腾速率 (E)）、叶绿素含量指数、叶片温度和 PSII 的最大光化学效率 (Fv/Fm)。结果表明，光合特性在生长季节发生了变化。光合CO2同化、气孔导度和叶绿素含量的变化不受品种的显着影响，其变化归因于年份。PN 和 gs 的季节性变化相似，表明这两个过程都是相关的。事实上，无花果的最佳光合性能发生在第二个生长季节的萌芽（春季）后约 80-87 天，由高气孔孔径支持。PN、E 和 gs 的最低值是在 2017 年萌芽后（夏季）156 天记录的。在同一日期记录了气体交换率的下降和高温。在秋季，芽破后约180天，光合特性和叶绿素含量略有增加，直到随着冬季低温的出现，在生长季节结束时出现明显的下降。这些结果揭示了特殊的适应性行为，可用作预测环境非生物胁迫对生态生理无花果树行为的未来影响的初步标准。