Polyphyly and two emerging lineages in the rust genera Puccinia and Uromyces

Abstract

The phylogenetic validity of Puccinia and Uromyces, Pucciniaceae, and closely related genera was evaluated using nucLSU rDNA sequences. Using a wide range of rust species with different life cycles and with different host specificities, Puccinia and Uromyces were shown to be highly polyphyletic and to also include representatives of the genera Aecidium, Cumminsiella, Dietelia, Endophyllum, Miyagia, and Uredo. Furthermore, the structure of the phylogenetic data did not reflect previous sub-generic delimitations based on teliospore pedicel structure, but rather suggests that at least two major lineages have evolved within Puccinia/Uromyces: Rusts with telial states on Poaceae were exclusively found in one of these groupings and those with telial states on Cyperaceae resided in the other lineage. This might suggest that the two lineages evolved in close association with these host groups in different biomes.

Phylogenetic relationships of sugarcane rust fungi

“…Species infecting Cyperaceae or Juncaceae in their uredinial or telial state are found in a highly supported monophyletic group (group 1) among other angiosperm rusts. In contrast, species infecting Poaceae in their uredinial and telial stages are found in various unsupported clades outside group 1 and are referred to as group 2 (Aime 2006; Maier et al 2007). This study found that, although the sugarcaneinfecting Puccinia species are not closely related to each other, they both fall outside the highly supported group 1 rust clade, further maintaining the separation of rust species infecting Poaceae from Cyperaceae-and Juncaceae-infecting rusts and their evolutionary derivatives.…”

One stop shop: backbones trees for important phytopathogenic genera: I (2014)

“…Large-scale systematic studies of rust fungi have focused mainly on the SSU and LSU regions of rDNA (Aime 2006;Beenken et al 2012;Dixon et al 2010;Maier et al 2003Maier et al , 2007Minnis et al 2012;Wingfield et al 2004;Yun et al 2011) (Table 21). Protein coding genes such as beta-tubulin ; Van der Merwe et al 2007 and elongation factor (TEF) (Seier et al 2009; Van der Merwe et al 2007) were successfully used at the family, genus and species level in rust fungi, although beta-tubulin required cloning rather than direct sequencing of PCR product.…”

“…Uromyces with one-celled teliospores is typically differentiated from Puccinia, although some species of Puccinia have both onecelled (mesospores) and two-celled teliospores, e.g., P. lagenophorae. Teliospore morphology is homoplasious, and Puccinia and Uromyces were polyphyletic in systematic studies based on the LSU and SSU regions of nuclear ribosomal DNA (Maier et al 2007;Aime 2006), and the two nuclear genes: elongation factor and β-tubulin ( Van der Merwe et al 2007). Some rust fungi have teliospores morphologically similar to Puccinia, but are not closely related or have an uncertain systematic position.…”

The Uredinales: Cytology, Biochemistry, and Molecular Biology

“…While these two genera form a strongly supported group together with two more genera, the analysis by Maier and coworkers (2003) also suggests that these two genera are polyphyletic. This pioneering work on molecular phylogeny of rust fungi has lately been substantiated by two further molecular studies (Maier et al 2007;van der Merwe et al 2007). Findings from these studies indicate that some of the morphological characteristics, i.e.…”

“…In terms of number of species the Pucciniaceae are by far the largest among all rust families (Maier et al 2007). Within this family, the genus Puccinia, with about 4000 species, and the genus Uromyces, with about 600 species, together represent almost two-thirds of all known rust species (Cummins and Hiratsuka 2003).…”