Chemotaxonomic observations on zearalenone and trichotecenes production byGibberella zeae from cereals in Southern Italy

Abstract

Fusarium graminearum Schwabe, the imperfect stage of Gibberella zeae (Schw.) Petch, is a toxigenic fungus often associated with feed refusal and emesis in animals fed with infected grains (3, 16, 17). Detailed studies on natural outbreaks ofF. graminearum toxicosis led to the identification of various mycotoxins, including zearalenones and trichothecenes (9). Based on the production of the different trichothecenes, Ichinoe et al. (5) reported the occurrence of two chemotypes of isolates of G. zeae from rice in Japan. The 'NIV-type' produces nivalenol (NIV) and fusarenone-X (FUS) while the 'DON-type' produces deoxynivalenol (DON) and 3-acetyldeoxynivalenol (3-ADON). A chemotype is defined by Pitt and Hawksworth (13) as a chemically characterized strain of morphologically indistinguishable fungi. It appears that there are geographical differences in the natural distribution of the toxigenic isolates as well as of their corresponding trichothecenes. Deoxynivalenol is found worldwide in cereals infected by Fusarium graminearum, often together with its monoacetates 15-ADON or 3-ADON (8, 10, 19). The occurrence of NIV has been reported in Japan, Korea, France, Austria and the U.K. (1, 6, 7, 15, 20), and FUS together with NIV only in Japan and in Austria (1, 20). This paper reports some preliminary data on the occurrence of both chemotypes of G. zeae on cereals in southern Italy.