Fungal and bacterial endophytes in Olea europaea.

Abstract

The composition of the endophytic community in leaves and twigs of the olive-tree (Olea europaea L.) was studied in Sicily (Italy). Two sampling areas were selected: one in San Cipirello (PA) and the other one in Racalmuto (AG). The olive-yards were similar for plant age, cultivar and agricultural management. Isolation assays were made from samples collected from each locality in spring, summer and autumn during 2007 and 2008. Quantities of fungal and bacterial isolates were different in relation to the sampled sites. The prevailing fungal genera in almost all samplings were Alternaria, Cladosporium, Diplodia, Phoma, Septoria, Stemphylium and its teleomorph Pleospora. Regarding bacterial genera, Bacillus and Pseudomonas were also detected. The colonization frequencies were dependent on the sampling site. Our preliminary results showed a potentially constant composition of endophytic community of O. europaea in Sicily, the degree of endophytic infection depending on season, and both, geographical and environmental factors. Further studies will be carried out in order to complete fungal and bacterial identification at species level and to investigate the interaction between endophytic microorganisms, host and environment.