Evaluation of Pistacia lentiscus L. genetic resources to select ecotypes having high efficiency in the colonisation of marginal lands

Pistacia lentiscus L. is a bush that plays a particularly important role in the ecosystem of the Mediterranean maquis. This is a rustic, drought resistant evergreen species with a good capacity to resprout after cutting or fire, and with a horizontal growth assuring good protection against soil erosion. In mountains or in hilly lands of warm Mediterranean areas the cover by Pistacia lentiscus may be more or less total and uniform, particularly in areas with a desertification risk. Although the protective role played by lentisk in the maquis is well known, little information is available about its potential capacity to colonise new soils, since the knowledge of spreading mechanisms of the species is scanty. Spontaneous populations appear to be characterised by a natural variability in seed germination ability, as a consequence of the more or less high incidence of partenocarpy and ovary abortion. The availability of selected ecotypes having high seed germination for possible use in sustainable forestry or anti-desertification programs is therefore important. For this purpose, a study of spontaneous populations of lentisk was carried out in Sardinia to define the variability of characters related to fruit production, seed dispersion and germination. Herein are presented the characteristics of 33 female ecotypes, with biometric data for the following parameters: length of the two-year-old branches; bunch and fruit number per internode; fruit and seed size; seed germination rate. Fruit number per branch ranged from 7 to 100; percentage of seed germination was between 0 and 56%; and germination time varied between 7 and 33 days. Good correlation between seed germination rate and fruit number per branch was observed in some promising ecotypes.