Within the Archaeological Area of Fiesole - among the Temple, the Roman Theatre, and the Baths - numerous olive trees have long been present. Some of these trees are featured in this interpretive trail, forming a natural frame around the Roman ruins, including the Temple, which was most likely dedicated to the goddess Minerva.
Minerva, known as Athena to the Greeks, was the goddess of wisdom and was symbolically associated with the olive tree, considered her sacred plant. According to myth, it was she who gifted humanity the first olive tree, so that it might be cultivated in harmony and its fruits used for the benefit of all.
For this reason, olive trees have long symbolized peace and humanity’s capacity to cultivate the land for the collective good.
THE INITIATIVE TO ENHANCE THE NATIVE PHENOTYPES OF THE FIESOLE TERRITORY
Safeguarding biodiversity and promoting a product of local excellence: this is the dual objective of the project led by the Institute of BioEconomy of the National Research Council (CNR-IBE) in Florence, carried out as part of the FIESOIL Project, funded by the European Agricultural Fund for Rural Development (EAFRD) under the 2014–2020 Rural Development Programme of the Tuscany Region.
The project, which covered the entire rural territory of Fiesole including the Roman Theatre area, began in 2019 with a comprehensive census of the olive trees in the region. These trees were then selected based on phenotypic, morphological, and qualitative characteristics.
With the collaboration of several farms belonging to the local Organic District, researchers were able to identify around thirty native olive phenotypes - unique and typical of Fiesole - ncluding some found within the archaeological site itself. These phenotypes display distinctive traits: most are highly rustic and resistant compared to more commonly cultivated Tuscan olive varieties. Some also exhibit high productivity and the potential to produce extra-virgin olive oil of outstanding quality.
To explore this potential, in-depth analyses were conducted to assess the chemical properties of the olives, yielding highly promising and scientifically significant results.
Each distinctive olive tree (phenotype) identified was given a name inspired by the specific place in which it was found, reinforcing the connection between plant and territory. This interpretive trail will guide you through the discovery of some of these unique trees located within the Roman Theatre of Fiesole.
What is a “phenotype”?
The phenotype refers to the set of observable characteristics of a living organism. It results from the expression of the organism’s genotype (the complete set of genes contained in its DNA) as influenced by environmental factors.
A phenotype encompasses distinct features such as morphology (form and structure), development, biochemical properties (chemical and biological compounds produced or present in the plant that determine its physiological and ecological functions), and physiological traits (vital functions and biological processes enabling the plant to grow, reproduce, and respond to its environment).
Practical Examples Applied to the Olive Tree (Olea europaea)
🧬 Genotype (the plant’s genetic heritage) determines inherited traits, such as:
- Disease resistance: Some cultivars (e.g., Leccino) show greater resistance to olive knot (Pseudomonas savastanoi) or Xylella fastidiosa compared to others.
- Type and quantity of oil produced: For instance, the cultivar Leccio del Corno produces an oil rich in polyphenols, with a notably bitter and pungent taste. Moraiolo is known for its high oil yield.
- Ripening time: Some cultivars ripen early (e.g., Leccino), while others are late-ripening (e.g., Leccio del Corno).
🌦️ Environmental factors (climate, soil, agronomic practices, etc.) significantly influence olive growth and yield. For example:
L’ambiente condiziona fortemente lo sviluppo e la resa dell’olivo. Alcuni esempi:
- Temperature: Late frosts can damage flower buds and reduce yields, even in genetically high-yielding varieties.
- Soil type: Heavy, poorly drained clay soils can cause root asphyxiation, negatively impacting plant health.
- Agronomic management: Good cultivation practices can enhance productivity even in less naturally productive cultivars.
- Sun exposure: Influences photosynthesis and therefore oil yield and polyphenol content.
🌿 Phenotype (observable traits resulting from the interaction of genotype and environment) can influence, for instance:
- Leaf shape and size: A plant of a specific cultivar may have smaller or larger leaves depending on climate, soil properties (physical and chemical), sun exposure, and management practices, even though the genotype sets the baseline.
- Tree structure and canopy shape: Tree vigor, growth habit, and canopy architecture may vary from expected norms due to environmental conditions and cultivation practices, despite a common genetic background.
- Actual olive yield: While genetic potential plays a key role, environmental stresses (especially climatic ones) and farming techniques significantly affect productivity.
- Fruit color at ripening: Although genetically determined, it may vary slightly based on soil and climatic conditions during the maturation period.