Peronospora radii

Peronospora radii
Grey conidiophores of Peronospora radii on an inflorescence of Tripleurospermum maritimum.
Scientific classification
Domain: Eukaryota
Clade: Sar
Clade: Stramenopiles
Phylum: Oomycota
Class: Peronosporomycetes
Order: Peronosporales
Family: Peronosporaceae
Genus: Peronospora
Species:
P. radii
Binomial name
Peronospora radii
de Bary, 1864
Synonyms[1]

Peronospora danica Gäumann, 1923

Peronospora radii is a floricolous downy mildew which infects plants in the Asteraceae.[2] It disfigures the inflorescence, mainly causing symptoms in the ray florets, but can also be visible on the leaves. It forms greyish-violet conidia. It has been reported from hosts in the genera Achillea, Anthemis, Argyranthemum, Chrysanthemum, Coleostephus, Cota, Glebionis, Leucanthemum, Matricaria, and Tripleurospermum.[1]

Symptoms

When Peronospora radii infects chamomile it causes more inflorescences to be produced by the plant, and the inflorescences to be larger and malformed. In some plants it causes more severe malformations like the absence of disc florets, and indeterminate growth resulting in a branched inflorescence.[3]

Economic impact

Since appearing in northern Serbia in 2004, Peronospora radii has become a threat to chamomile cultivation there.[3]

References

  1. ^ a b Ellis, WN (2025). "Peronospora radii". bladmineerders.nl. Retrieved 1 December 2025.
  2. ^ Thines, M, Kummer, V (1 May 2013). "Diversity and species boundaries in floricolous downy mildews". Mycological Progress. 12 (2): 321–329. Bibcode:2013MycPr..12..321T. doi:10.1007/s11557-012-0837-7. ISSN 1861-8952.
  3. ^ a b Duduk, B, Duduk, N, Vico, I, Stepanović, J, Marković, T, Rekanović, E, Kube, M, Radanović, D (November 2019). "Chamomile Floricolous Downy Mildew Caused by Peronospora radii". Phytopathology. 109 (11): 1900–1907. Bibcode:2019PhPat.109.1900D. doi:10.1094/PHYTO-04-19-0138-R. ISSN 0031-949X. PMID 31369362.