Morphology and phylogeny of Hyaloperonospora erophilae and H. praecox sp. nov., two downy mildew species co-occurring on Draba verna sensu lato

Abstract

Based on morphological and molecular data, it is shown that two distinct Hyaloperonospora species parasitize Draba (syn. Erophila) verna sensu lato. Hyaloperonospora praecox is described and illustrated as a new species, and detailed descriptions and illustrations including the diagnostic disease symptoms, haustoria and oogonia are provided for H. erophilae for the first time. Based on morphological and ITS sequence data, Peronospora drabae-majusculae is synonymised with H. erophilae. Hyaloperonospora praecox differs from H. erophilae by pyriform haustoria, by non-systemic infection combined with inconspicuous infection symptoms, and by slightly larger conidia. Both species were observed on Draba verna sensu stricto and Draba boerhaviae, and do not show a host preference. Molecular and morphological evidence is presented that H. erophilae and H. praecox can co-occur in the same host population.

Multi-locus tree and species tree approaches toward resolving a complex clade of downy mildews (Straminipila, Oomycota), including pathogens of beet and spinach

“…Additionally, this study revealed some previously unnoticed, host-specific lineages of Peronospora and that the type species of this genus is likely restricted to R. acetosella . These results support the view that a narrow species concept reflects the evolutionary history of downy mildews much better than a broad species concept, which is in line with recent studies for other species complexes, such as Bremia lactucae (Voglmayr et al, 2004; Choi et al, 2007b, 2011c), Hyaloperonospora parasitica (Choi et al, 2003, 2011b; Göker et al, 2004, 2009; Voglmayr and Göker, 2011; Voglmayr et al, 2014a), Peronospora arborescens (Voglmayr et al, 2014b), Peronospora lamii (Belbahri et al, 2005; Choi et al, 2009c; Thines et al, 2009b), and Plasmopara halstedii (Spring et al, 2003; Komjáti et al, 2007; Choi et al, 2009a).…”

Multigene phylogeny, taxonomy and reclassification of Hyaloperonospora on Cardamine

“…Recent molecular phylogenetic studies showed that the genus Hyaloperonospora , established by Constantinescu and Fatehi ( 2002 ) for Peronospora species infecting Brassicaceae , Capparaceae , Cistaceae , Limnanthaceae , Resedaceae and Zygophyllaceae , comprises a high biodiversity, its species usually being highly host specific (e.g. Riethmüller et al 2002 ; Choi et al 2003 ; Voglmayr 2003 ; Göker et al 2003 , 2004 , 2009a ; Choi et al 2011 ; Voglmayr and Göker 2011 ). Therefore, a narrow species circumscription as already advocated by Gäumann ( 1918 , 1923 ) has been confirmed, disproving the widely applied concept of Yerkes and Shaw ( 1959 ), who classified all accessions from Brassicaceae under a single species, H. parasitica (see review in Voglmayr 2008 ).…”

Plasmopara elegantissima sp. nov. (Oomycota, Peronosporales), a Downy Mildew Species Specialized to Impatiens textori (Balsaminaceae)

“…exhibits a high degree of differentiation according to the host species [14]. In addition, it adds evidence to the recently re-appraised view that a narrow species concept reflects the evolutionary history of downy mildews much better than a broad species concept, as exemplified on other species complexes, such as the ones around Bremia lactucae [35][36][37][38][39][40][41], Hyaloperonospora parasitica [42][43][44][45][46][47][48], Peronospora farinosa [7][8][9]49], Peronospora lamii [12,13,50], and Plasmopara halstedii [24,26,[51][52][53]. The downy mildew of I. textori is one of the most common downy mildew diseases throughout South Korea [21] and is common in China [54,55] and Japan [56] where the host plant is also widely distributed.…”