The order Albuginales includes the causal agents of white blister rust disease, which affect a wide range of weedy plants, both cultivated and wild. The genus Pustula is one of the five major lineages of white blister rusts identified to date. It causes disease on asterids, the largest group of flowering plants. Pustula is represented by several phylogenetically distinct, host-specific lineages, many of which remain formally u...

The family Nectriaceae ( Hypocreales , Sordariomycetes ) includes saprobes, endophytes and numerous important pathogens, several of which are of high commercial interest. Presently there are numerous genera scattered throughout the Nectriaceae that have a fusarioid asexual morph ( i.e. , genera with fusarium-like macroconidia). Fusarioid fungi encompass diverse lifestyles, including plant, human, and animal pathogens or associ...

Phylogenetic inference is done regularly in many biological studies not focussed on the phylogeny itself, but which use phylogeny as a tool to infer hypotheses for the interpretation of laboratory experiments. However, phylogenetic inference is often performed at low standards in these studies, which can result in wrong interpretations. Using high-standard phylogenetic inference tools usually requires substantial methodologica...

Downy mildews are the most species-rich group of oomycetes, with more than 700 known species. The relationships within the main downy mildew lineages (i.e. the downy mildews with pyriform haustoria, the downy mildews with coloured conidia, and the brassicolous downy mildews) are increasingly well resolved, and 20 well-characterised monophyletic genera have been described. However, their relationships to each other, the various...

Peronospora belbahrii is one of the most destructive downy mildew diseases that has emerged throughout the past two decades. Due to the lack of quarantine regulations and its possible seed-borne nature, it has spread globally and is now present in most areas in which basil is produced. While most obligate biotrophic, plant parasitic oomycetes are highly host-specific, there are a few that have a wider host range, e.g. Albugo c...

Oomycetes infecting diatoms are biotrophic parasitoids and live in both marine and freshwater environments. They are ubiquitous, but the taxonomic affinity of many species remains unclear and the majority of them have not been studied for their molecular phylogeny. Only recently, the phylogenetic and taxonomic placement of some diatom-infecting, early-diverging oomycetes was resolved, including the genera Ectrogella , Miracula...

Summary Although protists occupy a vast range of habitats and are known to interact with plants among other things via disease suppression, competition or growth stimulation, their contributions to the ‘phytobiome’ are not well described. To contribute to a more comprehensive picture of the plant holobiont, we examined cercozoan and oomycete taxa living in association with the model plant Arabidopsis thaliana grown in two diff...

Summary Root endophytic fungi are found in a great variety of plants and ecosystems, but the ecological drivers of their biogeographic distribution are poorly understood. Here, we investigate the occurrence of root endophytes in the non‐mycorrhizal plant genus M icrothlaspi , and the effect of environmental factors and geographic distance in structuring their communities at a continental scale. We sampled 52 plant populations...