Aflatoxin Formation on Sixteen Soybean Varieties

Sixteen commercial varieties of soybeans were each inoculated with 5 isolates of fungi from the Aspergillus flavus series to determine varietal differences in supporting aflatoxin production. The isolates were 2 strains of A. parasiticus (NRRL 2999 and NRRL 3145), 2 strains of A. flavus (NRRL 3357 and NRRL 3353), and 1 strain from a new variant of A. flavus (NRRL 3251). Levels of aflatoxin formed were dependent both on the isolate and on the variety of soybeans. Amsoy-71, Calland, Harosoy, and Pamona varieties were the poorest substrates for aflatoxin production in the laboratory fermentation, so they may be resistant to mold invasion and /or toxin formation.