Fumonisin production by, and mating populations of, Fusarium section Liseola isolates from maize in Argentina

The relation between the pattern of fumonisin production and the mating population and mating type of Fusarium isolates from maize in Argentina at different maturity stages has been evaluated. Fifty-one isolates of Fusarium species belonging to the Liseola section were identi®ed to mating population and tested for their ability to produce fumonisins (FB", FB# and FB$). Only mating populations associated with maize, A (Fusarium moniliforme, 23 isolates), D (F. proliferatum, 24 isolates) and E (F. subglutinans, 4 isolates) were found. All but two isolates of populations A and D produced, when grown on maize substrate, high levels of fumonisins ranging from 0±01 to 3±99 mg g-" (mean 2±00 mg g-" and 1±69 mg g-", respectively), whereas isolates of population E yielded less than 0±02 mg g-" (mean 0±01 mg g-"). Five isolates of F. proliferatum, all belonging to mating type D-, produced more FB#, than FB", which is consistent with ®nding a relatively large amount of FB# (0±01 mg g-"; FB#}FB"¯2±27) in one of the maize samples from which these isolates were obtained. Amounts of FB$ were similar to FB# in cultures of mating population A (mean FB$}FB#¯0±89), but much lower than FB# in cultures of mating population D (mean FB$}FB#¯0±21).