Diversity of Endophytic and Pathogenic Fungi of Saffron (Crocus sativus) Plants from Cultivation Sites in Italy

Crocus sativus is an important crop for the production of saffron and bioactive compounds.
Plant endophytic fungi are a source of secondary metabolites additional to those produced by the
plant itself. We analysed the biodiversity of endophytic fungi present in corms, stems, leaves, tepals,
and stigmas of C. sativus from ten Italian sites; furthermore, we isolated putative pathogenic fungi
from rotten plants. We used an in vitro isolation approach followed by molecular analysis of the
internal transcribed spacer (ITS rDNA) region. We obtained 165 strains belonging to 39 OTUs,
spreading over 26 genera and 29 species. Dark septate endophytes of the genus Cadophora and
the species Talaromyces pinophilus dominated in corms, while Alternaria alternata, Epicoccum spp.,
T. pinophilus, Mucor fragilis, and Stemphylium vesicarium dominated in other tissues. The most
frequently isolated pathogens were Fusarium oxysporum and Rhizopus oryzae. Endophytic communities
significantly differed among tissues and life stages, whereas differences among cultivation sites were
not statistically supported. Several endophytes were hypothesized to have changing trophic modes
and/or to be latent pathogens in C. sativus. All strains were conserved ex-situ for future bioactivity
tests and production of metabolites.