This study examines the impact of drought, and by extension potential water scarcity, on the potential of sap conduction in the olive tree, the emblematic fruit tree of the Mediterranean Basin. To understand adaptation of sap conduction potential of varieties concerning drought, we focus on wood anatomical traits in trees cultivated in the conservatory orchard of the 'Conservatoire Botanique National Méditerranéen’ (Porquerolles, France) and others from their main cultivation area. Leveraging branch diameter as a key factor influencing anatomical traits, we model density of vessels (DVS) and lumen area of vessels in transverse section (LAV) variation based on branch diameter using regression analyses. Our results show that the pattern of increase in LAV cannot be considered to be dependent on the biogeography and evolutionary history of varieties. But, it is significantly linked to the aridity conditions of the main cultivation area of these varieties. In the perspective of a future drastic increase in aridity, results point to the potential incapacity of varieties from non-irrigated semi-arid zones, to produce vessels large enough to transport sap to the leafy parts of branches, and other varieties from the northern margins of olive distribution area, to modulate conduction in terms of efficiency – safety balance. While some varieties exhibit a robust or moderately plastic phenotype, showing negligible variations in conduction potential with changing aridity in growing conditions, these results concern about the sustainability and future viability of some varieties. More broadly, they raise questions about the olive cultivation sector's resilience in the face of intensifying water stress.

中文翻译：

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橄榄树中汁液传导的潜力与品种主要种植区的干旱条件有关，并允许揭示它们对持续气候变化的敏感性。


本研究考察了干旱以及潜在的水资源短缺对地中海盆地标志性果树橄榄树汁液传导潜力的影响。为了了解与干旱有关的品种对汁液传导潜力的适应，我们重点关注在“Conservatoire Botanique National Méditerranéen”（法国 Porquerolles）的温室果园中种植的树木的木材解剖特征以及来自其主要种植区的其他树木。利用分支直径作为影响解剖特征的关键因素，我们使用回归分析根据分支直径对血管密度 （DVS） 和横截面血管管腔面积 （LAV） 变化进行建模。我们的结果表明，不能认为 LAV 的增加模式取决于品种的生物地理学和进化历史。但是，它与这些品种主要种植区的干旱条件密切相关。从未来干旱急剧增加的角度来看，结果表明，来自非灌溉半干旱地区的品种可能无法生产足够大的容器以将汁液输送到树枝的叶子部分，以及来自橄榄分布区北部边缘的其他品种，以在效率 - 安全平衡方面调节传导。虽然一些品种表现出健壮或中等可塑性的表型，随着生长条件干旱度的变化，传导电位的变化可以忽略不计，但这些结果担心某些品种的可持续性和未来生存能力。更广泛地说，它们对橄榄种植部门在面对日益严重的水资源压力时的复原力提出了质疑。