Cystidial structure in two genera of the Russulales

Abstract

As a part of a broader study to determine whether the subcellular structure of cystidia can provide synapomorphies for clades of Agaricomycetes, cystidia of Auriscalpium vulgare Gray and Russula emetica (Schaeff.) Pers. were examined ultrastructurally, after freeze substitution. Vesicles with tubular invaginations occurred in immature hymenial cystidia of both species, and microbodies were also present. Gloeohyphae of A. vulgare also contained these organelles. The tubular invaginations disappeared from the vesicles in maturing cystidia of A. vulgare and were replaced by electron-dense deposits. These patterns of cellular organization may be synapomorphic for the Russulales. The data will be incorporated into the “Assembling the Fungal Tree of Life” (AFTOL) Structural and Biochemical Database to facilitate the use of morphological characters in phylogenetic analyses.