Melanoxa, a new genus in the Urocystidales (Ustilaginomycotina)

Abstract

A smut fungus, Melanotaenium oxalidis, forming dark-coloured spores in the leaves of Oxalis oregana (Oxalidaceae) was collected a few times in the USA. A similar smut fungus on Oxalis acetosella was recently collected in Slovenia. Teliospores, hyphal septations, cellular interactions and ITS and LSU rDNA sequences of these two smuts on Oxalis were examined and the results obtained were compared with each other and with findings in other members of the Ustilaginomycotina. The data show that the specimen from Slovenia is very close to Melanotaenium oxalidis, but represents a new species, and that the two Melanotaenium species occurring on Oxalis are members of the Urocystidaceae. Among the Urocystidaceae, they are morphologically very similar to Flamingomyces, Melanustilospora and Vankya species, but differ from them, and from all other Urocystidaceae, by their multilamellate teliospore walls. In addition, molecular phylogenetic analyses indicated good separation of the Melanotaenium species from Flamingomyces, Melanustilospora and Vankya. Accordingly, a new genus, Melanoxa, and a new species, M. oxalidiellae, are described, and a new combination, Melanoxa oxalidis, is proposed for Melanotaenium oxalidis.

Exobasidium darwinii, a new Hawaiian species infecting endemic Vaccinium reticulatum in Haleakala National Park

“…We encourage to employ a similar approach in future molecular studies on the genus Exobasidium. This is in line with similar observation of Lutz et al (2011) on urocystidalean species.…”

Expanding evolutionary diversity in the Ustilaginomycotina: Fereydouniaceae fam. nov. and Fereydounia gen. nov., the first urocystidalean yeast lineage

“…with five species on Araliaceae, Urocystis Rabenh. ex Fuckel with 166 species on different monocot and dicot families, Ustacystis Zundel with one species on Rosaceae, and Vankya Ershad with three species on Liliaceae (Denchev 2003;Bauer et al 2007;Denchev and Kakishima 2007;Vánky 2009aVánky , 2009bVánky and Abbasi 2011;Lutz et al 2012a). …”

Shivasia gen. nov. for the Australasian smut Ustilago solida that historically shifted through five different genera

“…However, molecular phylogenetic analyses proved to be useful in the Ustilaginales . Indeed, molecular phylogenetic analysis has been crucial in the generic placement of several ustilaginalean species with ambiguous morphological characteristics (Piepenbring et al 1999, Cunnington et al 2005, Vánky et al 2006, Bauer et al 2007, González et al 2007) and has also helped to elucidate the generic placement for several smuts from other orders (Vánky et al 1998, Bauer et al 1999, 2001a, 2005, Castlebury et al 2005, Bauer et al 2007, 2008, Chandra & Huff 2008, Vánky et al 2008a, b, Lutz et al 2012). …”