A SURVEY OF FUSARIUM PROLIFERATUM INCIDENCE ON GARLIC PLANTS CULTIVATED IN THE NORTHEAST OF ITALY.

Fusarium proliferatum, a cosmopolitan saprophytic species, is also known to be a pathogen of garlic. Rot of stored bulbs is an emerging problem that affects Allium sativum L. cultivations worldwide. The presence of the pathogen on plants during the growing season is hard to predict, as infected plants only show yellowing and deterioration of leaves, that can be easily confused with the normal senescence phenomenon. After harvest, during the conservation stage, bulbs undergo a slow deterioration process, caused by the pathogen. Bulbs appear emptied and softened, under the sheath cloves present brown necrotic polygonal spots with a spongy centre, possibly evolving in black depressed lesions. During 2012, we performed a mycological screening in order to evaluate the presence of F. proliferatum on asymptomatic garlic plants growing in the north-east of Italy. Fields were chosen for their different agronomic conditions. Field samples consisted in whole plants eradicated with roots and bulbs. Fungal colonies morphologically resembling F. proliferatum were recovered from all the bulbs examined. The morphological identification was confirmed by Translation Elongation Factor 1-alpha (TEF) gene sequencing. The high frequency of recovery of F. proliferatum suggests a systemic infection before the harvesting stage. Moreover, the presence of this fungus is clearly not correlated to the different agronomic practices; this finding suggest a possible role of the reproduction material in the pathogen spread. [ABSTRACT FROM AUTHOR]