POSTMEIOTIC NUCLEAR BEHAVIOR IN LENTINUS, PANUS, AND NEOLENTINUS

We investigated nuclear behavior during basidiosporogenesis in Lentinu s, Panus, and Neolentinus in an attempt to discover characters for tax onomic segregation of lentinoid-pleurotoid fungi. In Lentinus tigrinus and Panus lecomtei somatic hyphae are binucleate. Karyogamy and meios is occur in the basidia, meiotic products migrate into spores and post meiotic mitosis occurs; this is followed by back-migration of one nucl eus from each spore into the basidium. Mature spores are consequently uninucleate and discharged basidia are quadrinucleate. In Neolentinus lepideus many somatic cells are multinucleate. Karyogamy, meiosis, and postmeiotic mitosis occur as in L. tigrinus and P. lecomtei, but ther e is no back-migration, mature spores are binucleate, and discharged b asidia are anucleate. The patterns of nuclear behavior in L. tigrinus and P. lecomtei correspond to type C nuclear behavior as defined by Du ncan and Galbraith, whereas that of Neolentinus corresponds to type D nuclear behavior. Lentinus and Panus cannot be distinguished on the ba sis of postmeiotic nuclear behavior, but both can be distinguished fro m Pleurotus which has been reported to have type A nuclear behavior se nsu Duncan and Galbraith.