Globisporangium coniferarum sp. nov., associated with conifers and Quercus spp

During a survey of gardens in Shiraz County, Iran, aimed at identifying oomycetes associated with roots of ornamental trees, a species of Globisporangium with distinctive morphological characters separating it from other known species in this genus was recovered from conifers and occasionally from a Quercus sp. Five isolates of this species were characterised. Phylogenetic analyses of nuclear (ITS and βtub) and mitochondrial (cox1 and cox2) loci using Bayesian inference and maximum likelihood analyses as well as their distinct morphological and cultural characteristics (e.g., abundant production of chlamydospores; globose, ellipsoid to ovoid sporangia; amorphous oogonia with a smooth wall; paragynous to rarely hypogynous antheridia and 1-5 antheridia per oogonium; mostly plerotic oospores) revealed that these isolates belong to a new Globisporangium species grouping in the phylogenetic clade G of Pythium sensu lato. This paper formally describes Globisporangium coniferarum sp. nov. as a new species and compares it with other phylogenetically related and already known Globisporangium species, including G. nagaii, G. violae, G. paddicum, G. okanoganense, G. iwayamae and G. canariense. Citation: Salmaninezhad F, Aloi F, Pane A, Mostowfizadeh-Ghalamfarsa R, Cacciola SO (2022). Globisporangium coniferarum sp. nov., associated with conifers and Quercus spp. Fungal Systematics and Evolution 10: 127-137. doi: 10.3114/fuse.2022.10.05.

Pythiogeton manoomin, a new species causing root and basal stalk rot of wild rice in the United States

A new species of Pythiogeton isolated from wild rice exhibiting rot and dieback of roots and stalks in California is described. Pythiogeton manoomin sp. nov. is characterized by coenocytic hyphae, club-like appressorium, and terminal or intercalary sporangia, which are often a short distance from the end of supporting hyphae. The protoplasm is discharged through a discharge tube into an elongate transient vesicle, which soon disappears, leaving the naked protoplasm to differentiate into reniform zoospores. Pythiogeton manoomin also produces thick-walled pigmented chlamydospores, not found in other Pythiogeton species. In greenhouse trials, Pg. manoomin did not infect economically important crops such as rice, bean, chard, corn, carrot, lettuce, oat, radish, sweet pepper, tomato, or wheat. Phylogenetic analysis based on ITS data supports the conclusion that this organism is a new species that is most closely related to Pg. ramosum. In this paper, we describe morphological characteristics, temperature–growth relationships, pathogenicity, and phylogenetic relationships that support the description of this taxon as a new species, Pythiogeton manoomin sp. nov.

urn:lsid:zoobank.org:pub:4C63AAA4-4D4A-4679-A344-79B75121A5C6

Molecular and morphological characterization of three new species of Pythium from Iran: P. ershadii, P. pyrioosporum, and P. urmianum

Three new species of Pythium: P. ershadii, P. pyrioosporum, and P. urmianum from soils of various regions in Iran are described and illustrated. These species are morphologically distinct from all other known species. Pythium ershadii is morphologically characterized by pyriform ornamented oogonia and rarely production of pyriform oospores. Pythium pyrioosporum differs from other species of the genus by the production of pyriform oospores and smooth walled oogonia, oospores with a tapering elongation toward a hypogynous antheridium and intercalary hypogynous antheridia. Pythium urmianum is distinguished by the presence of intercalary hypogynous antheridia, smooth walled oogonia formed laterally on hyphae or on short side branches and peanut-shaped oospores. Phylogenetic relationships of these new taxa with other Pythium species were investigated using internal transcribed spacers rDNA and partial coxI sequence data. The three species reside in clade E1 and are separated from closely related species.

Salisapiliaceae - a new family of oomycetes from marsh grass litter of southeastern North America

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.