Roots of domestication: unveiling the dynamics of domestication through trait-based analysis of olive trees in northern Morocco.

Abstract

The domestication of crops, a transformative milestone in human history, has largely contributed to reshaping agricultural practices and plant characteristics. This study investigates the functional responses along the wild-cultivated continuum in olive trees in northern Morocco, focusing on leaf functional traits to elucidate domestication effects. We compared wild olive (Olea europaea subsp. europaea var. sylvestris) with traditional cultivated varieties (O. e. subsp. e. var. europaea). Our results reveal clear distinctions in leaf traits, including leaf area, specific leaf area and leaf dry matter content, indicating divergent resource-use strategies. Cultivated varieties displayed traits associated with thicker, denser leaves and higher stomatal density, suggesting adaptations to stress conditions such as water scarcity. Principal component analysis highlighted a leaf economic spectrum, which differentiated wild and cultivated forms and supported the functional trade-off between resource acquisition and conservation. Intraspecific trait variability was substantial, driven by both genetic factors and phenotypic plasticity in response to local environmental gradients. These findings underscore the significant impact of domestication on olive trees, providing insights into the adaptive mechanisms underlying crop resilience in traditional agroecosystems. Our research emphasizes the importance of conserving these traditional olive varieties, not only for their historical and cultural significance but also for the deep understanding they offer regarding the evolving relationship between humans and the plant world.This article is part of the theme issue 'Unravelling domestication: multi-disciplinary perspectives on human and non-human relationships in the past, present and future'.