Woody ornamentals: a review of genetic resources in the Mediterranean area

The Mediterranean Basin is one of the world's major centers for plant diversity. The Mediterranean region harbors approximately 25,000 species, about half of which are endemic to the region. The native flora of different Mediterranean countries, often woody species, was recognized for its ornamental potential, also because the ornamental plant industry is characterized by great diversity and a continuous need for new genetic materials. The introduction of new and potential crops on the market could be considered as an efficient tool to meet the high consumer's demand for ornamentals. The shrubs, in particular, are a typology of plants very spread in the Mediterranean environment and constituent of 'Macchia' a typical vegetation of this ecosystem. The use of native shrubs for the realization of ornamental green areas has been recently analysed for their adaptability to both biotic and abiotic stress. Beyond the native species, it should be remembered that in the Mediterranean environment there are numerous exotic woody species, which have long been the subject of cultivation and for which there are many cultivars available. In some cases - for example the rose or the oleander - the use of genetic materials from different environments determined the presence of a very high number of cultivars, that are widely used for ornamental purposes. Shrubs, thanks to their plasticity, adaptability, and diverse ways of use, represent more than 40% of the nursery supply for ornamental garden plants. Thanks to their anatomical, morphological, physiological and biochemical traits, shrubs are suitable to tolerate abiotic stress; this aspect ensure particular interest in relation to climate change.