Erysiphe heraclei

Erysiphe heraclei
Erysiphe heraclei on Heracleum sphondylium in the UK.
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Leotiomycetes
Order:	Helotiales
Family:	Erysiphaceae
Genus:	Erysiphe
Species:	E. heraclei
Binomial name
Erysiphe heraclei DC., 1815
Synonyms
List Alphitomorpha heraclei(DC.) Wallr., 1819 Alphitomorpha communis β umbelliferarumWallr., 1819 Erysiphe communis var. umbelliferarum(Wallr.) Link, 1824 Erysiphe communis i. umbelliferarum(Wallr.) Fr., 1829 Ischnochaeta heraclei(DC.) Sawada, 1951 Erysiphe pisi var. heraclei(DC.) Ialongo, 1992 Erysiphe scandicisDC., 1815 Erysiphe communis i. umbelliferarum(Wallr.) Fr., 1829 Erysiphe umbelliferarum f. scandicis(DC.) Jacz., 1927 Erysiphe pycnopusMart., 1817 Erysiphe umbelliferarumde Bary, 1870 Erysiphe martii f. pimpinellae-magnaeSacc., 1876 Erysiphe communis f. umbelliferarumJacz., 1896 Erysiphe umbelliferarum f. pastinaceaeHammarl., 1925 Erysiphe umbelliferarum f. siiHammarl., 1925 Erysiphe umbelliferarum f. torilidisHammarl., 1925 Erysiphe umbelliferarum f. aegopodiiJacz., 1927 Erysiphe umbelliferarum f. aethusaeJacz., 1927 Erysiphe umbelliferarum f. anethiJacz., 1927 Erysiphe umbelliferarum f. angelicaeJacz., 1927 Erysiphe umbelliferarum f. anthrisciJacz., 1927 Erysiphe umbelliferarum f. apiiJacz., 1927 Erysiphe umbelliferarum f. carviJacz., 1927 Erysiphe umbelliferarum f. caucalidisJacz., 1927 Erysiphe umbelliferarum f. chaerophyliiJacz., 1927 Erysiphe umbelliferarum f. cicutaeJacz., 1927 Erysiphe umbelliferarum f. coniiJacz., 1927 Erysiphe umbelliferarum f. dauciJacz., 1927 Erysiphe umbelliferarum f. eryngiiJacz., 1927 Erysiphe umbelliferarum f. falcariaeJacz., 1927 Erysiphe umbelliferarum f. gorlenkinianthesJacz., 1927 Erysiphe umbelliferarum f. hippomarathriJacz., 1927 Erysiphe umbelliferarum f. ligusticiJacz., 1927 Erysiphe umbelliferarum f. myrrhidisJacz., 1927 Erysiphe umbelliferarum f. orlayaeJacz., 1927 Erysiphe umbelliferarum f. peucedaniJacz., 1927 Erysiphe umbelliferarum f. phloidicarpiJacz., 1927 Erysiphe umbelliferarum f. physospremiJacz., 1927 Erysiphe umbelliferarum f. pimpinellaeJacz., 1927 Erysiphe umbelliferarum f. pleurospremiJacz., 1927 Erysiphe umbelliferarum f. seliniJacz., 1927 Erysiphe umbelliferarum f. seseliJacz., 1927 Erysiphe umbelliferarum f. silaeJacz., 1927 Erysiphe umbelliferarum f. silerisJacz., 1927 Erysiphe umbelliferarum f. smyrniiJacz., 1927 Erysiphe umbelliferarum f. thapsiaeJacz., 1927 Erysiphe umbelliferarum f. tordyliiJacz., 1927 Erysiphe umbelliferarum f. aulacospremiVasyagina, 1961 Erysiphe umbelliferarum f. cachrydisVasyagina, 1961 Erysiphe umbelliferarum f. ferulaeGolovin ex Vasyagina, 1961 Erysiphe umbelliferarum f. conioseliniShvarcman, 1961 Oidium erysiphoides f. umbelliferarumSacc., 1886 Oidium coriandriHosag., Vijay., Udaiyan & Manian, 1992

Erysipheheraclei is a species of powdery mildew in the family Erysiphaceae. It is found across the world, where it infects members of the family Apiaceae (umbellifers). It has also been recorded on Billardiera in Australia.

Description

Erysiphe heraclei infects various umbellifers, such as Anthriscus .

The fungus forms mycelium on both sides of the leaves of its hosts, as well as on stems and inflorescences. As with most Erysiphaceae, Erysiphe heraclei is fairly host-specific, infecting almost solely plants in the family Apiaceae (with the exception of one genus in the Pittosporaceae). However, it infects a comparatively large range of genera for a powdery mildew species, which could suggest that it is in fact a complex of multiple cryptic species. Erysiphe heraclei can be found in any habitats where its host species occur, both wild and in urban and suburban gardens and parks.

Its reported host range includes Aegopodium , Aethusa , Ammi , Anethum , Angelica , Anthriscus , Apium , Arracacia , Astrodaucus , Athamantha , Aulacospermum , Berula , Bifora , Bowlesia , Bunium , Bupleurum , Cachrys , Carum , Caucalis , Centella , Chaerophyllum , Chaetosciadium , Cicuta , Cnidium , Conioselinum , Conium , Coriandrum , Cuminum , Daucus , Drusa , Dystaenia , Eryngium , Falcaria , Ferula , Foeniculum , Heracleum , Laser , Laserpitium , Levisticum , Ligusticum , Myrrhis , Oenanthe , Orlaya , Ostericum , Osmorhiza , Pastinaca , Petroselinum , Peucedanum , Phlojodicarpus , Physospermum , Pimpinella , Pleurospermum , Peucedanum , Rhabdosciadium , Ridolfia , Saposhnikovia , Scaligeria , Scandix , Schrenkia , Selinum , Seseli , Silaum , Siler , Sium , Smyrnium , Sphallerocarpus , Thapsia , Todaroa , Tordylium , Torilis , Trachymene , Trinia , Turgenia and Zizia in the Apiaceae and Billardiera in the Pittosporaceae. Some of these species also host other species of powdery mildew. ^[1]

Taxonomy

Erysiphe heraclei was formally described by de Candolle in 1815. The lectotype specimen was collected on Heracleum sphondylium . The specific epithet derives from the type host genus. Bradshaw et al. (2024) suggested that Erysiphe betae may be synonymous with Erysiphe heraclei. ^[2]

Pathology

Erysiphe heraclei affects carrots, a widely-grown vegetable, ^[3] and consequently research has been conducted into preventing or reducing the severity of infection on this host. ^[4] Currently, most conventional treatments involve the application of fungicides. The most successful fungicides are said to be sulphur and azoxystrobin. ^[5] Work has also been conducted to investigate creating and breeding infection-resistant cultivars of carrots.

Micromorphology

Description

The mycelium is hypophyllous (found on leaf undersides) and sometimes covers the entire surface. The hyphal appressoria are lobed and occur both solitarily and in opposite pairs. Conidophores arise from the top of their mother cell. They have cylindrical, straight foot cells. The conidiophores produce single conidia. Conidia are cylindrical; germ tubes arise an end and are variable in length. Conidia appressoria are vary variable and can have up to nine lobes. The chasmothecia (fruiting bodies) have a variable number of appendages in the lower half, which are myceloid and simple or irregularly branched. Appendages are said to often be interwoven with the mycelium. Appendages are pigmented yellowish-brown when mature. The peridium of the chasmothecia has inconspicuous cells of irregular shape. Erysiphe heraclei typically has three to five spores per ascus which are large, ellipsoid-ovoid and colourless. The asci are typically clavate or saccate and are sessile or short-stalked.

Measurements

Hyphal cells measure 40–90 × (2.5–)4–6(–10) μm. Conidiophores are up to 160 μm long, with foot cells that measure 20–70(–90) × 8–10(–12) μm. Conidia are 25–45(–55) × 12–20(–23) μm. The chasmothecia are 80–140(–170) μm in diameter with peridium cells 8–20(–25) μm in diameter. Appendages are (0.25–)0.5–1.5(–2)× the diameter of the chasmothecia and (3–)4–8(–10) μm wide. Asci number (2–)3–7(–10) and are 40–85(–90) × 30–45(–65) μm with ascospores measuring (16–)18–30(–34) × 10–18(–22) μm.

References

1. Braun, Uwe; Cook, Roger T. A. (2012). Taxonomic manual of the Erysiphales (powdery mildews). CBS biodiversity series. Utrecht: CBS-KNAW fungal biodiversity centre. ISBN   978-90-70351-89-2.
2. 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.
3. Boiteux, L. S.; Reis, A.; Fonseca, M. E. N.; Lourenço, V.; Costa, A. F.; Melo, A. G.; Borges, R. C. F. (2017). "Powdery Mildew Caused by Erysiphe heraclei: A Novel Field Disease of Carrot (Daucus carota) in Brazil". Plant Disease. 101 (8): 1544–1544. doi:10.1094/PDIS-01-17-0145-PDN. ISSN   0191-2917.
4. Takaichi, Miyuki; Oeda, Kenji (2000-04-25). "Transgenic carrots with enhanced resistance against two major pathogens, Erysiphe heraclei and Alternaria dauci". Plant Science. 153 (2): 135–144. doi:10.1016/S0168-9452(99)00254-X. ISSN   0168-9452.
5. Tülek, Senem; Canpolat, Sirel (2016-12-28). "Effects of some fungicides against powdery mildew (Erysiphe heraclei D.C.) of carrot". Plant Protection Bulletin. 56 (4): 349–358. ISSN   0406-3597.