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The genus Peronospora is the largest genus of the oomycetes, fungus-like members of the kingdom Straminipila that also contains amoeboid (e.g., Leukarachnion) and plant-like (e.g., Laminaria) lifeforms. Peronospora species are obligate biotrophic plant pathogens, causing high economic losses in various crops and ornamentals, including Plantago species. Several species of Plantago are used as speciality crops and medicinal plants. In this study, Peronospora species parasitic on Plantago were investigated based on morphology and phylogenetic analyses using two nuclear (ITS, nrLSU) loci and one mitochondrial (cox2) locus. As a result of these investigations, 10 new species are added to the already known Peronospora species on Plantago. Interestingly, it was found that four independent species are parasitic to Plantago major, highlighting that the reliance on the host plant for pathogen determination can be misleading in Peronospora. Taking this into account, morphological and phylogenetic analyses should be conducted as a prerequisite for effective quarantine regulations and phytosanitary measures. [ABSTRACT FROM AUTHOR]

Plant pathogenic smut fungi in the broader sense can be divided into the Ustilaginomycetes, which cause classical smut symptoms with masses of blackish spores being produced in a variety of angiosperms, and the Exobasidiomycetes, which are often less conspicuous, as many do not shed large amounts of blackish spores. The leaf-spot causing members of the genus Entyloma (Entylomatales, Exobasidiomycetes) belong to the latter group. Currently, 172 species that all infect eudicots are included in the genus. Vánky (2012) recognised five Entyloma species on species of Ranunculus s.lat. Two have been reported only from Ficaria verna s.lat., while three, E. microsporum, E. ranunculi-repentis, E. verruculosum, have been reported to have a broad host range, encompassing 30, 26, and 5 species of Ranunculus, respectively. This broad host range is in contrast to the generally high host specificity assumed for species of Entyloma, indicating that they may represent complexes of specialised species. The aim of this study was to investigate Entyloma on Ranunculus s.lat. using multigene phylogenies and morphological comparisons. Phylogenetic analyses on the basis of up to four loci (ITS, atp2, ssc1, and map) showed a clustering of Entyloma specimens according to host species. For some of these Entyloma lineages, names not currently in use were available and reinstated. In addition, Entyloma microsporum s.str. is neotypified. Six novel species are described in this study, namely, Entyloma jolantae on Ranunculus oreophilus, E. klenkei on R. marginatus, E. kochmanii on R. lanuginosus, E. piepenbringiae on R. polyanthemos subsp. nemorosus (type host) and R. repens, E. savchenkoi on R. paludosus, and E. thielii on R. montanus. For all species diagnostic bases and morphological characteristics are provided. The results in this study once more highlight the importance of detailed re-investigation of broad host-range pathogens of otherwise specialised plant pathogen groups. [ABSTRACT FROM AUTHOR]

Novel species of fungi described in this study include those from various countries as follows: Argentina , Neocamarosporium halophilum in leaf spots of Atriplex undulata . Australia , Aschersonia merianiae on scale insect ( Coccoidea ), Curvularia huamulaniae isolated from air, Hevansia mainiae on dead spider, Ophiocordyceps poecilometigena on Poecilometis sp. Bolivia , Lecanora menthoides on sandstone, in open semi-desert montane areas, Sticta monlueckiorum corticolous in a forest, Trichonectria epimegalosporae on apothecia of corticolous Megalospora sulphurata var. sulphurata , Trichonectria puncteliae on the thallus of Punctelia borreri . Brazil , Catenomargarita pseudocercosporicola (incl. Catenomargarita gen. nov.) hyperparasitic on Pseudocercospora fijiensis on leaves of Musa acuminata , Tulasnella restingae on protocorms and roots of Epidendrum fulgens . Bulgaria , Anthracoidea umbrosae on Carex spp. Croatia , Hymenoscyphus radicis from surface-sterilised, asymptomatic roots of Microthlaspi erraticum , Orbilia multiserpentina on wood of decorticated branches of Quercus pubescens . France , Calosporella punctatispora on dead corticated twigs of Aceropalus . French West Indies (Martinique) , Eutypella lechatii on dead corticated palm stem. Germany , Arrhenia alcalinophila on loamy soil. Iceland , Cistella blauvikensis on dead grass ( Poaceae ). India , Fulvifomes maritimus on living Peltophorum pterocarpum , Fulvifomes natarajanii on dead wood of Prosopis juliflora , Fulvifomes subazonatus on trunk of Azadirachta indica , Macrolepiota bharadwajii on moist soil near the forest, Narcissea delicata on decaying elephant dung, Paramyrothecium indicum on living leaves of Hibiscus hispidissimus , Trichoglossum syamviswanathii on moist soil near the base of a bamboo plantation. Iran , Vacuiphoma astragalicola from stem canker of Astragalus sarcocolla . Malaysia , Neoeriomycopsis fissistigmae (incl. Neoeriomycopsidaceae fam. nov.) on leaf spots on flower Fissistigma sp. Namibia , Exophiala lichenicola lichenicolous on Acarospora cf. luederitzensis . Netherlands , Entoloma occultatum on soil, Extremus caricis on dead leaves of Carex sp., Inocybe pseudomytiliodora on loamy soil. Norway , Inocybe guldeniae on calcareous soil, Inocybe rupestroides on gravelly soil. Pakistan , Hymenagaricus brunneodiscus on soil. Philippines , Ophiocordyceps philippinensis parasitic on Asilus sp. Poland , Hawksworthiomyces ciconiae isolated from Ciconia ciconia nest, Plectosphaerella vigrensis from leaf spots on Impatiens noli-tangere , Xenoramularia epitaxicola from sooty mould community on Taxus baccata . Portugal , Inocybe dagamae on clay soil. Saudi Arabia , Diaporthe jazanensis on branches of Coffea arabica . South Africa , Alternaria moraeae on dead leaves of Moraea sp., Bonitomyces buffels-kloofinus (incl. Bonitomyces gen. nov.) on dead twigs of unknown tree, Constrictochalara koukolii on living leaves of Itea rhamnoides colonised by a Meliola sp., Cylindromonium lichenophilum on Parmelina tiliacea , Gamszarella buffelskloofina (incl. Gamszarella gen. nov.) on dead insect, Isthmosporiella africana (incl. Isthmosporiella gen. nov.) on dead twigs of unknown tree, Nothoeucasphaeria buffelskloofina (incl. Nothoeucasphaeria gen. nov.), on dead twigs of unknown tree, Nothomicrothyrium beaucarneae (incl. Nothomicrothyrium gen. nov.) on dead leaves of Beaucarnea stricta , Paramycosphaerella proteae on living leaves of Protea caffra , Querciphoma foliicola on leaf litter, Rachicladosporium conostomii on dead twigs of Conostomium natalense var. glabrum , Rhamphoriopsis synnematosa on dead twig of unknown tree, Waltergamsia mpumalanga on dead leaves of unknown tree. Spain , Amanita fulvogrisea on limestone soil, in mixed forest, Amanita herculis in open Quercus forest, Vuilleminia beltraniae on Cistus symphytifolius . Sweden , Pachyella pulchella on decaying wood on sand-silt riverbank. Thailand , Deniquelata cassiae on dead stem of Cassia fistula , Stomiopeltis thailandica on dead twigs of Magnolia champaca . Ukraine , Circinaria podoliana on natural limestone outcrops, Neonematogonum carpinicola (incl. Neonematogonum gen. nov.) on dead branches of Carpinus betulus . USA , Exophiala wilsonii water from cooling tower, Hygrophorus aesculeticola on soil in mixed forest, and Neocelosporium aereum from air in a house attic. Morphological and culture characteristics are supported by DNA barcodes. Citation : Crous PW, Costa MM, Kandemir H, et al. 2023. Fungal Planet description sheets: 1550-1613. Persoonia 51: 280-417. doi: 10.3767/persoonia.2023.51.08., (© 2023 Naturalis Biodiversity Center & Westerdijk Fungal Biodiversity Institute.)

Several filamentous oomycete species of the genus Halophytophthora have recently been described from marine environments, mostly from subtropical and tropical ecosystems. During a survey of oomycetes from leaf litter of Spartina alterniflora in salt marshes of southeastern Georgia, isolates of four taxa were recovered that bore similarity to some members of Halophytophthora but were highly divergent from isolates of Halophytophthora s.str. based on a combined sequence analysis of two nuclear loci. In phylogenetic analyses, these isolates were placed basal to a monophyletic group comprised of Pythium of the Pythiaceae and the Peronosporaceae. Sequence and morphology of these taxa diverged from the type species Halophytophthora vesicula, which was placed within the Peronosporaceae with maximum support. As a consequence a new family, the Salisapiliaceae, and a new genus, Salisapilia, are described to accommodate the newly discovered species, along with one species previously classified within Halophytophthora. Morphological features that separate these taxa from Halophytophthora are a smaller hyphal diameter, oospore production, lack of vesicle formation during sporulation, and a plug of hyaline material at the sporangial apex that is displaced during zoospore release. Our findings offer a first glance at the presumably much higher diversity of oomycetes in estuarine environments, of which ecological significance requires further exploration.

The obligate biotrophic lineages of the white blister rusts (Albuginales, Oomycota) are of ancient origin compared to the rather recently evolved downy mildews, and sophisticated mechanisms of biotrophy and a high degree of adaptation diversity are to be expected in these organisms. Speciation in the biotrophic Oomycetes is usually thought to be the consequence of host adaptation or geographic isolation. Here we report the presence of two distinct species of Albugo on the model plant Arabidopsis thaliana, Albugo candida and Albugo laibachii, the latter being formally described in this manuscript. Both species may occupy the same host within the same environment, but are nevertheless phylogenetically distinct, as inferred from analyses of both mitochondrial and nuclear DNA sequences. Different ways of adapting to their host physiology might constitute an important factor of their different niches. Evidence for this can be gained from the completely different host range of the two pathogens. While Albugo candida is a generalist species, consisting of several physiological varieties, which is able to parasitize a great variety of Brassicaceae, Albugo laibachii has not been found on any host other than Arabidopsis thaliana. Therefore, Albugo laibachii belongs to a group of highly specialised species, like the other known specialist species in Albugo s.s., Albugo koreana, Albugo lepidii and Albugo voglmayrii. The comparative investigation of the effector genes and host targets in the generalist and the specialist species may constitute a model system for elucidating the fundamental processes involved in plant pathogen co-adaptation and speciation.