Cytological studies of Agaricus brasiliensis

Agaricus brasiliensis is a medicinal mushroom native to Brazil. It was first identified as Agaricus blazei and its scientific name continues to be debated. We examined the cytology of different Brazilian commercial strains of A. brasiliensis and the nuclear behavior of strain CS1 during basidiospore development using fluorescent microscopy. All strains have multinucleate hyphae and no significant differences in nuclei numbers were observed between them. Basidia from A. brasiliensis strain CS1 are typically tetrasporics and produce binucleate basidiospores, demonstrating that a postmeiotic mitosis occurs during basidiospore development. This result suggests that A. brasiliensis is primarily a heterothallic species.