*The Oleaster*

8 Olive Germplasm – The Olive Cultivation, Table Olive and Olive Oil Industry in Italy

the oleaster in the east and in the west.

in Spain [31] (Figure 2).

them to define zones where the *Olea* has probably thrive.

Its current dispersal depends upon the wild olive trees that survived after the last ice age in refugee populations. However, its spread during the middle-Pleniglacial (Late Pleistocene) before the ice age is based upon wood charcoal and pollen sequences [17, 29, 35, 36] and it was present both in the Levant and in Spain. Based on this evidence, the oleaster is also genuine in the west. During the Holocene it is noticeable that it spread quickly and became abundant or dominant [35]. From a botanical point of view, there is no difference between

Moreover, [35] analyzed botanical data to clearly identify the oleaster's associated with other thermophilous trees (*Ceratonia, Lentiscus, Phillyrea, Rhamnus*…) in the Mediterranean climate zone in comparison to those of the Atlantic formation (*Pinus, Betula* ), which enabled

However, the olive tree expanded widely outside the oleaster's limits and the famous French writer Georges [37] Duhamel has said " Là où l'olivier renonce, finit la Méditerranée "or 'There the olive has given up, the Mediterranean finishes', that means the olive tree is an excellent indicator of the Mediterranean climate. There is little knowledge on the spread of the olive, it was probably slow following the human colonization of harsh territories by populations seeking shelter to escape wars, and they were patient to adapt their cultivar set to the harsh environments. The spread of the olive follows the trade and settlement patterns of the Phoenicians from the Levant westward – to North Africa and Spain especially. Olive oil as both a trade good and utilitarian household item would have been a premier crop for any colonizer. The present diversity of the olive - probably around 2,000 cultivars - is a witness of this permanent fight between peoples and Nature [38]. The distribution of the olive tree around the Mediterranean basin goes in latitude northern and southern [39,40] and in elevation higher than the distribution of the oleaster tree (max 500m

The olive tree was introduced into the New World in South America by the Spanish (explorers and monks) at the beginning of the 1500's (Colombia, Peru, but later on the west coast of the USA). The common perception is that historic olive trees in California are dominated by the 'Mission' cultivar originally introduced by Spanish missionaries to the present day Caribbean and central Mexico in the early 1500's [41, 42]. Thomas Jefferson wrote to James Ronaldson on January 13, 1813, "it is now twenty-five years since I sent them (southern planters) two shipments of about 500 plants of the olive tree of Aix (Aix-en-Provence, France), the finest olive trees in the world." [43]. Olive seeds are believed to have been brought to California in 1769 to grow into trees hardy to 12 degrees Fahrenheit. Those olive trees were cultivated in the Franciscan Spanish monasteries. It was the Spanish who spread the olive to America. Catholic missionaries spread the olive to Mexico and later to California, as well as to South America. The late Earnest Mortensen of the Texas Agricultural Experiment Station brought olive trees to the Winter Garden area in the 1930's. It was introduced in South Africa after the Boer colonization and there it coexists with the subspecies *cuspidata.* In Australia the olive has been introduced by 1812 [21] and later cultivars were introduced in China, Japan, Argentina and Chili and in all countries with a Due to oleaster wood being used as biofuel during the prehistoric age, abundant evidence exists to assess its presence from the pleniglacial to the Middle Holocene (for review see [35]). These authors stated that these kinds of remains constituted safe indicators for the presence of *Olea*, although endocarps and pollen grains may have accumulated due to human and wind transport them over undetermined distances.

The first record of olive wood is by [44] who found a fireplace dating to around 790,000 years ago containing (wild) olive wood charcoals. Wood-charcoal analyses carried out at prehistoric sites would reflect the local flora and therefore the frequency of *Olea* wood indicates its presence. Wood charcoals may be due to natural fires or from fireplaces in prehistoric sites depending on the sites and other remains in the site.

As reported by [35] the oldest site where *Olea europaea* thrived in Klissouva cave 1 (Southern Greece) which is dated to 61,140 – 55,230 Cal. Yr. BP. At Higueral de Valleja *Olea europaea* has been dated to 42,630 –41,390 Cal. Yr. BP. *Olea europaea* has been present on both sides of the Mediterranean Basin, but obviously, such sites are scarcely distributed and do not allow us to draw an accurate map for the presence of *Olea europaea*.

Pollen sequences that contain Oleaceae family pollen may include pollen from *Phillyrea*, Jasmine (*Jasminum fruticans*), and Mediterranean ash tree (*Fraxinus angustifolia*) which thrives along rivers. The pollen is frequently transported long distances and accumulation sites (ponds, swamps, peat-lands) are often far from forests where the oleaster thrives. Thus some bias in pollen data may exist. However, pollen sequences are accurate for dating sites.

However, some of the oldest remains have been dated about to around one million years (wood charcoals from Israel [44] and leaf fragments from Tuff conglomerate [45]. Tuff does not give accurate aging of the site. These remains cannot attest to the presence of the actual oleaster, they belong to an *Olea europaea*, but the sub-species cannot be given. Moreover, such remains have been conserved due to exceptional favorable conditions and are too scarce to infer any model of distribution from them.
