Olive breeding

The olive (Olea europaea L.) is, at the same time, one of the most ancient domesticated fruit trees and the most extensively cultivated fruit crop in the world, covering an area of about 7.5 million hectares. The recent diffusion of olive outside its traditional area of cultivation, the Mediterranean basin, together with a continu- ous trend in the modernisation of its industry, has greatly increased in recent years the demand for improved cultivars by olive growers. Hence, programmes of clonal selection and cross-breeding have been started in the main olive growing countries, aiming at selecting genotypes characterised by early bearing, resistance to pests and to abiotic stresses (such as frost and drought), limited alternate bearing, suitability to intensive culture and to mechanical harvesting, as well as high-quality productions, in terms of both organoleptic characteristics of fruits and oils, and high contents in substances useful for human health. This chapter reviews the recent advances in olive breeding, providing extended information on flower biology, main world cul- tivars, germplasm collection and preservation, propagation techniques, main char- acters for olive improvement and traditional breeding techniques (clonal selection, cross breeding and mutagenesis). In addition, information on the recent develop- ments of olive biotechnology for the improvement and the safeguard of genetic resources (tissue culture, synthetic seed technology, genetic transformation and cry- opreservation) is also reported.