title: A unique species in Phytophthora clade 10,Phytophthora intercalarissp. nov., recovered from stream and irrigation water in the eastern USA.
abstract: A novel species of the genusPhytophthorawas recovered during surveys of stream and nursery irrigation water in Maryland, Massachusetts, North Carolina, Virginia and West Virginia in the USA. The novel species is heterothallic, and all examined isolates were A1mating type. It produced rare ornamented oogonia and amphigynous antheridia when paired with A2mating type testers ofPhytophthora cinnamomiandPhytophthora cryptogea. Sporangia of this novel species were non-papillate and non-caducous. Thin-walled intercalary chlamydospores were abundant in hemp seed agar and carrot agar, while they were produced only rarely in aged cultures grown in clarified V8 juice agar. Phylogenetic analyses based on sequences of the internal transcribed spacer region and the β-tubulin and mitochondrial cytochrome-coxidase 1 (cox1) genes indicated that the novel species is phylogenetically close toPhytophthora gallicain Phytophthora clade 10. The novel species has morphological and molecular features that are distinct from those of other species in Phytophthora clade 10. It is formally described here asPhytophthora intercalarissp. nov. Description of this unique clade-10 species is important for understanding the phylogeny and evolution of Phytophthora clade 10.
authors.affiliation: Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, VA, USA.
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Plant Sciences and Landscape Architecture, University of Maryland, College Park, MD, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Balci
authors.affiliation: UMass Extension, Center for Food, Agriculture and the Environment, University of Massachusetts, Amherst, MA, USA.
authors.forename: N J
authors.initials: NJ
authors.lastname: Brazee
authors.affiliation: Department of Plant Pathology, North Carolina State University, Raleigh, NC, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Loyd
authors.affiliation: Hampton Roads Agricultural Research and Extension Center, Virginia Tech, Virginia Beach, VA, USA.
authors.forename: C X
authors.initials: CX
authors.lastname: Hong