Abstract

As a yet thoroughly explored component of biodiversity, endophytic fungi are stimulating a huge research activity worldwide concerning their occurrence, biocenotic role, and opportunities for exploitation in biotechnologies. This paper presents the results of an investigation on fungal endophytes from 28 species of trees and shrubs thriving at the Astroni Nature Reserve near Naples, Italy. One hundred and eight isolates were recovered, a number of which represent new records of endophytic occurrence in the corresponding host plants. In a bioassay-driven procedure for the selection of strains possibly producing antitumor compounds based on their antifungal properties in vitro, about 35% of the isolates induced fungitoxic effects, and 10% were mycoparasitic, with the species Biscogniauxia mediterranea, Nemania serpens, Paraconiothyrium brasilienseand Phomopsis theicola reported for the first time for such an aptitude. Inhibition of mycelial growth was confirmed for about 60% of the culture extracts prepared from these bioactive strains, and was mostly correlated to an antiproliferative activity in human tumor cell cultures. Particularly, five strains were selected to be further investigated for the purification and the characterization of putative cytostatic compounds.

Key words: Endophytic fungi, antagonism, mycoparasitism, culture extracts, antiproliferative activity.

Abbreviation

PDA, Potato dextrose agar; CDB, Czapek-Dox broth; DMEM, Dulbecco’s modified Eagle’s medium; MTT, methyl thiazol tetrazolium