Affordable Access

Publisher Website

Peronospora kuewa, sp. nov., a new downy mildew species infecting the endangered Hawaiian plant Plantago princeps var. princeps.

  • Davis, William J1, 2
  • Ko, Mann3
  • Ocenar, Jordie R3
  • Romberg, Megan K1, 4
  • Thines, Marco5, 6
  • Crouch, Jo Anne1
  • 1 Mycology and Nematology Genetic Diversity and Biology Laboratory, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Avenue, Beltsville, Maryland 20705. , (United States)
  • 2 Agricultural Research Service Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830.
  • 3 Plant Pest Control Branch, State of Hawai'i Department of Agriculture, 1428 South King Street, Honolulu, Hawai'i 96814.
  • 4 National Identification Services, Plant Protection and Quarantine, Animal and Plant Health Inspection Service, United States Department of Agriculture, 10300 Baltimore Avenue, Beltsville, Maryland 20705. , (United States)
  • 5 Institute of Ecology, Evolution and Diversity, Department of Biological Sciences, Goethe University, Max-von-Laue-Str. 13, 60439 Frankfurt am Main, Germany. , (Germany)
  • 6 Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt am Main, Germany. , (Germany)
Published Article
Informa UK (Taylor & Francis)
Publication Date
Mar 18, 2021
DOI: 10.1080/00275514.2021.1872869
PMID: 33734033


Plantago princeps var. princeps is an endangered native Hawaiian plant, and part of the recovery plan includes repopulation using plants grown in a nursery. However, disease pressure from downy mildew is hindering repopulation efforts. The organism associated with the downy mildew was determined to be a Peronospora species with brown, ellipsoid conidia measuring 21 by 16 µm on average, which was morphologically different from validly described species of Peronospora that infect Plantago species, but it was morphologically similar to the invalidly published species Peronospora lanceolatae (Art. 40.1). Comparison of mitochondrial cytochrome oxidase subunit I (cox1), mitochondrial cytochrome oxidase subunit II (cox2), nuclear internal transcribed spacer (ITS), and nuclear 28S rRNA D1-D2 (28S) loci revealed the unknown Peronospora to be molecularly divergent from Peronospora alta and Peronsopora plantaginis, but very similar to Peronospora from Plantago lanceolata, the type host of P. lanceolatae. Phylogenetic trees inferred with maximum likelihood and Bayesian inference from a concatenated alignmaent and individual gene trees confirmed the divergence of the unknown Peronospora from P. alta and P. plantaginis and its similarity to P. lanceolatae. However, attempts to inoculate Plantago lanceolata with the strain from Plantago princeps var. princeps were unsuccessful, which, in conjunction with divergence in ITS, suggests that the unknown Peronospora is specific to Plantago princeps var. princeps. Herein, the Peronospora strain on Plantago princeps var. princeps is described as the new species Peronospora kuewa based on morphology, molecular phylogenetics, and host specificity. In addition, Peronospora gaponenkoae is described here to honor Nina Ivanova Gaponenko on the basis of her description of P. lanceolatae.

Report this publication


Seen <100 times