An overview of the higher level classification of Pucciniomycotina based on combined analyses of nuclear large and small subunit rDNA sequences

Abstract

In this study we provide a phylogenetically based introduction to the classes and orders of Pucciniomycotina (5Urediniomycetes), one of three subphyla of Basidiomycota. More than 8000 species of Pucciniomycotina have been described including putative saprotrophs and parasites of plants, animals and fungi. The overwhelming majority of these (,90%) belong to a single order of obligate plant pathogens, the Pucciniales (5Uredinales), or rust fungi. We have assembled a dataset of previously published and newly generated sequence data from two nuclear rDNA genes (large subunit and small subunit) including exemplars from all known major groups in order to test hypotheses about evolutionary relationships among the Pucciniomycotina. The utility of combining nuc-lsu sequences spanning the entire D1-D3 region with complete nuc-ssu sequences for resolution and support of nodes is discussed. Our study confirms Pucciniomycotina as a monophyletic group of Basidiomycota. In total our results support eight major clades ranked as classes (Agaricostilbomycetes, Atractiellomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Microbotryomycetes, Mixiomycetes and Pucciniomycetes) and 18 orders.

A higher-level phylogenetic classification of the Fungi

“…Equivalent to Urediniomycetes Swann & Taylor 1995;. The classification of Pucciniomycotina employed here parallels that of and Aime et al (2007). fig.…”

Evolution of Mating Systems in Basidiomycetes and the Genetic Architecture Underlying Mating-Type Determination in the YeastLeucosporidium scottii

“…This species belongs to the order Leucosporidiales, which is phylogenetically related to both Sporidiobolales (red yeasts) and Microbotryales (anther-smuts) (Sampaio et al 2003;Aime et al 2006). Early studies by Fell and co-workers aimed at characterizing the mating system of this species had already suggested the presence of a multiallelic tetrapolar system, with at least five and three mating specificities, respectively, for the inferred MAT A and MAT B loci (Fell and Statzell-Tallman 1982).…”

“…This last scenario was shown to be at the basis of extant bipolar species belonging to two of the three major Basidiomycota lineages, namely Cryptococcus neoformans (subphylum Agaricomycotina) Findley et al 2012) and Ustilago hordei (subphylum Ustilaginomycotina) (Bakkeren et al 2006). In these cases, the MAT locus has expanded into a large, nonrecombining region of a chromosome that is usually highly rearranged between the two mating types and rich in repetitive elements Bakkeren et al 2006).The third and earliest-branching lineage of basidiomycetes (subphylum Pucciniomycotina) comprises species with diverse cellular forms and lifestyles (Aime et al 2006). Pioneering studies addressing the molecular basis of mating behavior in this lineage were conducted in Microbotryum lychnidis-dioicae (order Microbotryales), an anther-smut fungus in which heteromorphic mating-type chromosomes were first described (Hood 2002;Hood et al 2013).…”

“…The third and earliest-branching lineage of basidiomycetes (subphylum Pucciniomycotina) comprises species with diverse cellular forms and lifestyles (Aime et al 2006). Pioneering studies addressing the molecular basis of mating behavior in this lineage were conducted in Microbotryum lychnidis-dioicae (order Microbotryales), an anther-smut fungus in which heteromorphic mating-type chromosomes were first described (Hood 2002;Hood et al 2013).…”

Pycnopulvinus aurantiacus gen. et sp. nov., a new sporocarp-forming member of Pucciniomycotina

“…Colacogloea, on the other hand, has been demonstrated several times to form a separate clade of Microbotryomycetes, distant from Heterogastridiales (e.g. Aime et al 2006;Kurtzman et al 2011). Thus, at present, only Heterogastridium and its sole species, H. pycnidioideum, can be confidently assigned to Heterogastridiales with molecular data.…”