The microorganisms used in this work were B. trispora ATCC
14271, mating type (+) and B. trispora ATCC 14272, mating type
(). Both strains were obtained from the American Type Culture
Collection (ATCC) (Rockville, MD, USA). The strains were grown
on potato dextrose agar (PDA) Petri dishes at 26 C for 4 days for
sporulation. Eight ml of sterile distilled water was added to the
Petri dish and the spores were collected by scraping off the medium
surface. The spore suspension containing 1.5 106 and
4.0 105 spores/ml of the strains 14271 and 14272, respectively,
was used to inoculate the medium.