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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION
GENETICS
P78 - Molecular characterization of Fusarium species
occurring on olive fruits in Apulia
S. Frisullo 1 , A. Susca 2 , G. Stea 2 , A. Villani 2 , L. Prudente 1 , M. Contursi 1 , P.
Ferrara 1 , A. Logrieco 2 , A. Moretti 2
1 Università di degli Studi di Foggia, Dipartimento di Scienze Agrarie, degli Alimenti e dell’Ambiente,
Foggia, Italy; 2 Institute of Sciences of Food Production, CNR, Bari, Italy
E-mail: antonio.moretti@ispa.cnr.it
Olive cultivation is one of the most important crop in Apulia, with 377,526 hectares
cultivated and 10,102,300 quintals of olive production. In a survey aimed to
evaluate the fungal colonization of olive fruits carried out in the whole Apulia
Region, 5 fields for each of the 92 localities selected were investigated. From the
survey, together with fungal strains belonging to Botriosphaeriae, Colletotrichum,
Diplodia, Neofusicoccum and Penicillium genera, several hundreds of strains
belonging to Fusarium genus have been isolated mainly from olive fruits and, at a
lesser extent, also from branches. The strains of Fusarium were identified at a
morphologically level, resulting species able to produce a wide range of
mycotoxins such as cyclohesadepsipeptides, moniliformin and trichothecenes.
However, since each Fusarium species can have a specific mycotoxin profile, the
toxicological risk related to their occurrence can be highly variable, according with
the main species colonizing the olive fruits and must be accurately assessed.
Confirmation of strain identification was carried out by using molecular approach.
One-hundred and forty-eight representative strains were analyzed by sequencing
a portion of calmodulin and β-tubulin genes, which have been proved to be
effective for distinguishing species in Fusarium. Data have shown, for the first
time, a wide genetic diversity within the population of Fusarium isolated from
olives. In particular, F. acuminatum, F. avenaceum, F. longipes, F. merismoides,
F. oxysporum, F. proliferatum, F. solani, and F. torulosum were identified.
However, many strains could not be assigned to any species and therefore may
represent new entities within the genus. The occurrence of some highly toxigenic
Fusarium species suggests that a toxicological risk can occur in olive fruits highly
contaminated by Fusarium and that such risk must be constantly monitored, also
in order to evaluate possible influence of climatic changes on the Fusarium
spread on this crop in Apulia.
Keywords: olive fruits, Fusarium acuminatum, calmodulin, β-tubulin
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