INTERACTIONS BETWEEN Fusarium verticillioides (Sacc.) Nirenberg, Aspergillus flavus Link AND Talaromyces funiculosus Thom IN HERMETIC ENVIRONMENTS
Claudia C. Castellari1*, Facundo J. Marcos Valle1, y Ana M. Pacin2
Corn is naturally infected by mycotoxigenic fungal species such as F. verticillioides, A. flavus and T. funiculosus. Interactions between the species and survival strategies under hermetic conditions are unknown. The objective of this study was to determine the effect of the hermetic environment on the interactions between F. verticillioides, A. flavus and T. funiculosus. F. verticillioides, A. flavus and T. funiculosus were evaluated in vitro. The species grew in pairs in Petri dishes without O2 restriction and in microcultures in hermetic environments with two initial concentrations of O2 and CO2. Growth inhibition and colonization strategies of each species were determined using stereoscopic and light microscopy. The hermetic environment reduced growth and altered the morphology of somatic and reproductive structures of the mycotoxigenic species. T. funiculosus inhibited the growth of both mycotoxigenic species and caused hyphal parasitism. Mutual intermingling of the hyphae was observed between the mycotoxigenic species. The levels of O2 and CO2 in the hermetic environments varied according to the pair of species that grew up in each of them. The study of fungal interactions in hermetic environments provided information to understand the colonization and permanence of mycotoxin producing species associated with grain during their storage in hermetic systems, such as the bag.
Key words: micotoxigenic mycobiota, maize, Zea mays, hermetic environment, bag silo.
1 Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, Ruta Nacional 226 Km 73,5 (B7620) Balcarce, Buenos Aires, Argentina.
2 Fundación de Investigaciones Científicas Teresa Benedicta de la Cruz, M. Dorronzoro 141, Luján (B6700FTA), Argentina.