TY - JOUR A1 - Thines, Marco A1 - Kummer, Volker T1 - Diversity and species boundaries in floricolous downy mildews JF - Mycological progress : international journal of the German Mycological Society N2 - Floricolous downy mildews are a monophyletic group of members of the genus Peronospora (Oomycota, Peronosporales). These downy mildews can be found on a variety of families of the Asteridae, including Asteraceae, Campanulaceae, Dipsacaceae, Lamiaceae, and Orobanchaceae. With the exception of Peronospora radii, which can also cause economically relevant losses, sporulation usually takes place only on floral parts of their hosts. However, only very few specimens of these mostly inconspicuous downy mildews have so far been included in molecular phylogenies. Focusing on Lamiaceae, we have investigated multiple specimens of floricolous downy mildews for elucidating species boundaries and host specificity in this group. Based on both mitochondrial and nuclear loci, it became apparent that phylogenetic lineages in the Lamiaceae seem to be host genus specific and significant sequence diversity could be found between lineages. Based on distinctiveness in both phylogenetic reconstructions and morphology, the downy mildew on flowers of Stachys palustris is introduced as a new species, Peronospora jagei sp. nov., which can be morphologically distinguished from Peronospora stigmaticola by broader and shorter conidiospores. The diversity of the floricolous down mildews might be higher than previously assumed, although specimens from a much broader set of samples will be needed to confirm this view. KW - cox2 KW - Internal transcribed spacer KW - Peronosporaceae KW - Phylogeny Y1 - 2013 U6 - https://doi.org/10.1007/s11557-012-0837-7 SN - 1617-416X VL - 12 IS - 2 SP - 321 EP - 329 PB - Springer CY - Heidelberg ER -