TaphrinaFries (1832)

This chapter studies the genus Taphrina. In the determination of the asexual reproduction it is seen that yeast states grow in culture. Budding cells are present, and budding is frequently unipolar or bipolar. Cells are globose, ovoid, ellipsoidal, or cylindrical. Giant cells with thickened cell walls may be present in old cultures. Pseudohyphae may be formed. Cell walls are two-layered. Budding has been considered either holoblastic or enteroblastic; percurrent or sympodial elongation may occur, giving rise to distinct protrusions reminiscent of those found commonly in basidiomycetous yeasts. Colonies are cream, yellowish, or pinkish-cream but may become more intensely pink, orange, or tan upon aging. In sexual reproduction it is found that the filamentous states only form on host plants and give rise to asci that are primarily clavate to cylindrical and occur in a subcuticular palisade layer or are formed as terminal cells of the septate intercellular or subcuticular dikaryotic hyphae. In some species asci arise from more or less thick-walled ascogenous cells. In those cases a septum may form across the basal portion of the developing ascogenous cell, giving rise to the so-called stalk cell at the base of the ascus. Eight spherical, ovoid, ellipsoidal, or fusiform ascospores are formed and often bud inside the ascus, which becomes filled with smaller blastospores. Rupturing of the unitunicate ascus wall at the apex forcibly ejects ascospores and the entire content of the ascus is discharged as a single projectile. The chapter also discusses physiology/biochemistry and phylogenetic placement of the genus. The type species taken is Taphrina populina. © 2011