Pathogenic characterization of epiphytic fungi of apple cv. 'Golden Delicious'

Associations between plants and microorganisms may be beneficial, neutral or detrimental. Fungi are well known to be the main biotic agents causing plant diseases. Apple is a crop that may be affected by plant pathogenic fungi, causing important economic losses. Apple variety ‘Golden Delicious’ is susceptible to phytopathogenic fungi and is one of the most consumed in the world. In this study, fungal populations obtained from the surface of ‘Golden Delicious’ apple cultivated in Queretaro were identified using taxonomic keys, and their possible pathogenic activity was evaluated inoculating them into apple fruit. Eleven fungi morphotypes were obtained, from which 90% was possible to identify at genus level. Main genera identified were Alternaria, Aspergillus, Cladosporium and Penicillium. Assays in fruit showed that all fungal morphotypes had some phytopathogenic activity. Morphotypes identified as Penicillium were the most harmful (>59% decay). Results show there exist associated fungi during pre-harvest apple grow that may damage fruit in post-harvest phase.