Analysis of diversity in the fruit tree genetic resources from a Mediterranean island

A large number of genotypes of different fruit tree species have been described in Sardinia, where the plant
species have evolved by adaptation to the Mediterranean environment. In this work results are summarized
of a long-term survey carried out in the island by the authors since the early 1980s. Ten fruit tree species have
been surveyed and collections of the traditional varieties were established. Some are major staple crops such
as olive and grape, others such as almond, cherry, plum, fig, apple and pear are nowadays less cultivated, and
still others have been more recently introduced like apricot and cactus pear. Data on the level of inter and
intra-species diversity are given, as illustrated by representative morphological traits. The results of isozymes
and RAPD-PCR analysis on the species Ficus carica genotypes are included, to assess genetic relationship
among accessions. Observations on composition, as well as on state of conservation of selected traditional
varieties are reported, and the main causes of genetic erosion are listed.