Erysiphe alliariicola

Erysiphe alliariicola
Erysiphe alliariicola on Alliaria petiolata
Scientific classification Edit this classification
Kingdom: Fungi
Division: Ascomycota
Class: Leotiomycetes
Order: Helotiales
Family: Erysiphaceae
Genus: Erysiphe
Species:
E. alliariicola
Binomial name
Erysiphe alliariicola
M. Bradshaw & U. Braun, 2024

Erysiphe alliariicola is a species of powdery mildew in the family Erysiphaceae. It is found on plants in the genus Alliaria in Eurasia and North America (where A. petiolata is an invasive species)[1] as well as occasionally on Thlaspi.

Description

The fungus forms thin, white irregular patches on the leaves of its host. Erysiphe alliariicola, like most Erysiphaceae, is highly host-specific and only infects two genera. It is the only species to infect Alliaria,[2] and has been theorised to be applicable as a way to reduce the severity of the impact of this genus where it is invasive.[3] It has also been reported as infecting Thlaspi in North America.[4]

Taxonomy

The fungus was formally described in 2024 by Michael Bradshaw and Uwe Braun. The species epithet refers to the host genus, Alliaria. The type specimen was collected in Germany.[5] E. alliariicola was formerly considered conspecific with Erysiphe cruciferarum but was split from this species on the basis of genetic analysis.[2]

Micromorphology

Description

The mycelium is white or greyish, commonly found on both sides of the leaf, and regularly on stems or even pods. The hyphal appressoria are nipple-shaped to moderately lobed, and occur solitarily. Conidophores arise from the upper surface of their mother cell. They are erect with cylindrical foot cells that are straight or curved. The conidiophores produce single conidia. The conidia are ellipsoid to barrel-shaped, with some cylindrical long conidia. The chasmothecia (fruiting bodies) have not been described.

Measurements

Hyphal cells measure 2–7 μm in diameter. Hyphal appressoria are 2–7 μm in diameter. Conidiophores are up to 110 μm long, with foot cells that measure 15–40 × 6–10 μm. Conidia are 25–45 × 10–20 μm.

References

  1. ↑ Welk, Erik; Schubert, Konstanze; Hoffmann, Matthias H. (2002). "Present and potential distribution of invasive garlic mustard (Alliaria petiolata) in North America". Diversity and Distributions. 8 (4): 219–233. doi:10.1046/j.1472-4642.2002.00144.x. ISSN 1472-4642.
  2. 1 2 Braun, Uwe (2024-05-06). "Contributions to the knowledge of the phylogeny and taxonomy of the Erysiphaceae (powdery mildews) – part 2". Sydowia. 76: 113–145. doi:10.12905/0380.sydowia76-2024-0113. ISSN 0082-0598.
  3. ↑ Cipollini, Don; Enright, Stephanie (2009). "A Powdery Mildew Fungus Levels the Playing Field for Garlic Mustard ( Alliaria petiolata ) and a North American Native Plant". Invasive Plant Science and Management. 2 (3): 253–259. doi:10.1614/IPSM-08-144.1. ISSN 1939-7291.
  4. ↑ Zhang, Julia X.; Greatens, Nicholas; Arenz, Brett; Flynn, Jennifer; Anderson, James A. (2025-06-23). "First Report of Powdery Mildew Caused by Erysiphe alliariicola on Pennycress (Thlaspi arvense) in North America". Plant Disease: PDIS–10–24-2055-PDN. doi:10.1094/PDIS-10-24-2055-PDN. ISSN 0191-2917.
  5. ↑ Bradshaw, Michael; Braun, Uwe; Mitchell, James K.; Crouch, Uma; LaGreca, Scott; Pfister, Donald H. (2025-01-02). "Phylogeny and taxonomy of the genera of Erysiphaceae, part 6: Erysiphe (the "Microsphaera lineage" part 2)". Mycologia. 117 (1): 110–165. doi:10.1080/00275514.2024.2386230. ISSN 0027-5514. PMID 39495585.