Filobasidium Olive (1968)

Publisher Summary This chapter discusses the genus Filobasidium. It provides a systematic discussion of the species and concludes with comments on the genus. The diagnosis of the genus is done on the basis of asexual, sexual, physiology and biochemistry, and phylogenetic placement. In asexual reproduction reproduction occurs by budding. Cells are globose, ovoid, ellipsoid, or elongated. Pseudohyphae and true hyphae may be produced. Colonies are white, grayish-white, cream colored, or slightly pinkish and usually mucoid. In sexual reproduction hyphae with lateral or terminal holobasidia are produced following mating in heterothallic species such as F.floriforme, F.capsuligenum, and F.uniguttulatum. Although sexual patterns have not been defined in the remaining species of Filobasidium, general sexual features are similar to heterothallic species of the genus. Basidiocarps are absent. Sessile basidiospores are produced terminally on the apex of the holobasidiumina petal-like whorl, giving the basidium a flower-like appearance from an apical view. Clamp connections are present at septa, which contain dolipores with or without parenthesomes. Physiologically, F.capsuligenum differs from the other members of the genus by the ability to ferment glucose and maltose. Ultrastructurally, F.capsuligenum differs from F.floriforme by having cone-shaped vesicular parenthesomes, while the latter species seems to lack this typical parenthesome structure but has poorly preserved vesicles present near the dolipore.