EFS12- Book of abstracts - Contact

SESSION 2: SECONDARY METABOLITES – BIOCHEMISTRY,
BIOSYNTHESIS, FEED AND FOOD SAFETY
P34 - A survey on pre- and post-harvest garlic bulbs:
Fusarium proliferatum occurrence and fumonisins
(B1, B2) accumulation
S. Tonti 1 , M. Dal Prà 1 , S. Grandi 2 , P. Nipoti 2 , A. Prodi 2 , I. Alberti 1 , V. Cazzola 1
1 INRAN - Istituto Nazionale per la Ricerca degli Alimenti e la Nutrizione, Via Ca’ Nova Zampieri 37, S.
Giovanni Lupatoto (VR), Italy; 2 DipSA - Dipartimento di Scienze Agrarie, Alma Mater Studiorum,
Università degli Studi di Bologna, Viale Fanin 40, 40127 Bologna, Italy.
E-mail: i.alberti@ense.it
Fusarium proliferatum is considered worldwide as an emerging pathogen of garlic.
The presence of this fungus on plants during growing season it is hard to predict,
but symptoms of the disease become clear after the harvest, during the
conservation stage, when bulbs undergo a slow deterioration process. F.
proliferatum is know to produce Fumonisins B1 and B2 on different vegetable
matrices and Fumonisins contamination of garlic bulbs has been already reported
in Germany.
During year 2012, we performed a mycological screening in order to evaluate the
pre- and post-harvest occurrence of F. proliferatum on asymptomatic garlic plants
growing in the north-east of Italy. Fields were chosen for their different agronomic
conditions: crop rotation, irrigation level and fertilizer types. Field samples
consisted in whole plants eradicated with roots and bulbs at beginning of May.
Post harvest samples consisted in unprocessed garlic bulbs, sampled prior to be
cured. Fungal colonies morphologically resembling F. proliferatum were
recovered from all the bulbs. The morphological identification was confirmed by
Translation Elongation Factor 1-alpha (TEF) gene sequencing. All F. proliferatum
strains were tested for their toxigenic potential by conventional PCR. A primer pair
(FUM1P2-F and FUM1P2-R) designed on the sequence of FUM1 genes was
used in this experiment. The effective presence of Fumonisins B1 and B2 on postharvest
samples was evaluated by HPLC analysis.
F. proliferatum was recovered at high frequencies from all the fields tested,
suggesting that the presence of this fungus could be unrelated to the different
agronomic practices. PCR and preliminary HPLC data demonstrate that the
Fusarium dry rot population on garlic bulbs is potentially toxigenic and that
Fumonisins B1 and B2 are always present at low levels on infected bulbs.
Keywords: Fusarium proliferatum, garlic, mycotoxins detection
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