The Mediterranean olive tree (Olea europaea var. europaea) is one of the first domesticated trees in human history, as manifested by first domestication evidence emerging from the Early Bronze Age (c. 6,000 years ago). Currently, the olive fruit 30 is of major agricultural importance in theMediterranean region and it is the source of the much appreciated olive oil. Roughly 3 million tons of olive oil is produced yearly in Mediterranean countries such as Spain, Italy, and Greece and exported worldwide. There are many different olive fruit varieties, each with particular size rangeand flavor, but the underlying molecular bases of phenotypic differences among domesticated cultivars or between domesticated olive trees and their wild relatives remain poorly understood. Both wild and cultivated olive trees have 46 chromosomes (2n).
A total of 543 gigabases (Gb) of raw DNA sequence from whole-genome sequencing shotgun and a fosmid library containing 155,000 clones of an over 1,000 year old olive tree were generated by Illumina sequencing using different combinations of mate-pair and pair-end libraries. They wereassembled to give a final genome with a scaffold N50 of 443 kb, and a total length of 1.31 Gb, which represents 95% of the estimated genome length (1.38G). In addition, the associated fungus Aureobasidium pullulans was partially sequenced. Genome annotation, assisted with RNA sequencing from leaf, root, and fruit tissues at various stages, resulted in 56,349 unique protein coding genes. The genome completeness, as estimated by the CEGMA pipeline, reached 98.79%.