Pucciniomycetes

Pucciniomycetes (formerly known as Urediniomycetidae) is a diverse class of fungi in the subphylum Pucciniomycotina of phylum Basidiomycota.^[3] The class contains 5 orders, 21 families, 190 genera, and approximately 8,016 species.^[4] It has been estimated that this class contains about one third of all teleomorphic basidiomycetes. Pucciniomycetes contains many economically important plant pathogenic fungal rusts; the order Pucciniales (formerly Uredinales) is the largest clade in this class, representing approximately 7,000 species.^[5]

Pucciniomycetes
Aecia of Puccinia sessilis on Arum maculatum leaf
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Subdivision:	Pucciniomycotina
Class:	Pucciniomycetes R. Bauer, Begerow, J.P. Samp., M. Weiss & Oberw. (2006)[1]
Orders
Helicobasidiales Pachnocybales Platygloeales Pucciniales Septobasidiales
Synonyms[2]
Pucciniomycetes D.Hawksw., B.Sutton & Ainsw. (1983)

Pucciniomycetes are cosmopolitan and can be found in both terrestrial and aquatic environments, although aquatic species are poorly understood.^[5]

Characteristics

Species in the class Pucciniomycetes develop no basidiocarp, karyogamy occurs in a thick-walled resting spore (teliospore), and meiosis occurs upon germination of the teliospore. They have simple septal pores without membrane caps, and disc-like spindle pole bodies. Except for a few species, the basidia, when present, are transversely septate. Mannose is the major cell-wall carbohydrate; glucose, fucose, and rhamnose are the less prevalent neutral sugars; and xylose is not present.

Taxonomy

The class Pucciniomycetes was first defined as a monophyletic group in 1995. Pucciniomycetes contains rust fungi, the order Septobasidiales, teliospore-forming yeasts, and various species that were once classified as smut or jelly fungi.^[5]