Phyllactinia guttata

Phyllactinia guttata
Various stages in the life cycle of Phyllactinia guttata. Fig 1. Natural size, on chestnut leaf. 2. Perithecium enlarged. 3. Two asci. 4.Three sporidia. 5.Conidia-bearing hyphae. 6.Conidium germinating.
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Leotiomycetes
Order:	Helotiales
Family:	Erysiphaceae
Genus:	Phyllactinia
Species:	P. guttata
Binomial name
Phyllactinia guttata (Wallr.) Lév. [1]
Synonyms [2]
List Alphitomorpha guttataWallr., Verh. Ges. nat. Freunde Berlin 1(1): 42 (1819) Erysibe coryli(DC.) Mussat, in Saccardo, Syll. fung. (Abellini) 15: 137 (1901) Erysibe guttata var. coryli(DC.) Link, Fl. lusit.: 484 (1833) Erysibe suffulta(Rebent.) Mussat, in Saccardo, Syll. fung. (Abellini) 15: 138 (1901) Erysiphe betulaeDC., Fl. franç., Edn 3 (Paris) 5/6: 107 (1815) Erysiphe coryliDC., in Lamarck & de Candolle, Fl. franç., Edn 3 (Paris) 2: 272 (1805) Erysiphe guttata(Wallr.) Link, in Willdenow, Sp. pl., Edn 4 6(1): 116 (1824) Erysiphe guttata f. corylea(DC.) Fr., Syst. mycol. (Lundae) 3(1): 246 (1829) Erysiphe guttata var. coryliLink, in Willdenow, Sp. pl., Edn 4 6(1): 116 (1824) Erysiphe suffultum(Rebent.) Nees, Syst. Pilze (Würzburg): 148, tab. 14, fig. 134 (1816) Erysiphe varium var. suffultum(Rebent.) Fr., Observ. mycol. (Havniae) 1: 206 (1815) Microsphaera betulae(DC.) Magnus, Ber. dt. bot. Ges. 16: 67 (1898) Phyllactinia betulae(DC.) Fuss, Archiv des Vereins für Siebenbürgische Landeskunde, Neue Folge 14(2): 463 (1878) Phyllactinia berberidisPalla, Ber. dt. bot. Ges. 17: 64 (1899) Phyllactinia corylea(Pers.) P. Karst., in Salmon, Monograph of Erysiphaceae (Berlin-Stuttgart): 224 (1900) Phyllactinia suffulta(Rebent.) Sacc., Michelia 2(no. 6): 50 (1880) Sclerotium erysiphe ß coryleaPers., Observ. mycol. (Lipsiae) 1: 13 (1796) Sclerotium suffultumRebent., Prodr. fl. neomarch. (Berolini): 360 (1804)

Phyllactinia guttata is a species of powdery mildew fungus in the family Erysiphaceae. A plant parasite, it infects the undersides of leaves of Corylus species (hazels).

Taxonomy

Originally named in 1801 as Sclerotium erysiphe by Christian Hendrik Persoon, the species went through a number of name changes in the 1800s. Salmon's 1900 monograph on the Erysiphaceae ^[3] established the name as Phyllactinia corylea for roughly half a century, until the starting date for the naming of fungi was moved, and the name was established as Phyllactinia guttata. ^[4]

Description

The mycelium may be abundant and persistent, or scant and short-lived (evanescent). ^[5] The cleistothecia can become large (216–245  μm), with soft wall tissue, and obscure cellular structure and cracks and wrinkles (reticulations).

Microscopic view of cleistothecium showing appendages with bulbous base

The cleistothecia typically develop 8–12 easily detachable hyaline appendages that vary in length from 191–290 μm long. The asci are 4 to 5 to 20 or more, ovate, supported by small stalk-like structures (pedicellate), with dimensions of 72–83 by 32–40 μm. There are typically 2 spores per ascus, sometimes 3 or 4, and they are 31–36 by 21–25 μm. ^[6]

The cells attached to the upper part of the ascomata that resemble hairs are known as penicillate cells; they are made of foots and filaments. The filaments can gelatinize by absorbing water and are thought to function in helping the ascomata adhere to the surface on which they grow, like the underside of leaves. ^[7] In P. guttata, the foots are cylindrical, irregular in width, 32–72 by 7.5–25 μm, and divided into 2–10 branchlets in the upper part. Each branchlet is short, bulbous, with filaments being 20–42 μm, somewhat shorter than the foots, which are 2–4 μm wide. The short, bulbous branchlets on the multi-branched upper part of the foots are unique among the Phyllactinia and are a distinguishing taxonomic characteristic of this species.

Habitat and distribution

Phyllactinia guttula is distributed throughout temperate regions of the world.

P. guttata is a host for the fungicolous hyphomycete Cladosporium uredinicola . ^[8]

References

1. (Wallr.) Lév., Annls Sci. Nat., Bot., sér. 3 15: 144 (1851)
2. "Species Fungorum - GSD Species". www.speciesfungorum.org. Retrieved 20 October 2023.
3. Salmon ES. (1907). "A monograph on the Erysiphaceae". Memoirs of the Torrey Botanical Club. 9: 1–292.
4. Cooke WB. (1952). "Nomenclatural notes on the Erysiphaceae". Mycologia . 44 (4): 570–74. doi:10.1080/00275514.1952.12024218. JSTOR   4547628.
5. Ellis JB, Everhart JM. (1892). North American Pyrenomycetes. New Jersey: Newfield. pp. 20–21.
6. Eslyn WE. (1960). "New Records of Forest Fungi in the Southwest". Mycologia. 52 (3). Mycologia, Vol. 52, No. 3: 381–387. doi:10.2307/3755953. JSTOR   3755953.
7. Yarwood CE. (1958). "Powdery mildews". Botanical Review. 23 (4): 235–301. doi:10.1007/bf02872581. S2CID   34913772.
8. Dugan F. (2006). "Phyllactinia guttata is a host for Cladosporium uredinicola in Washington state" . North American Fungi: 1–5. doi: 10.2509/pnwf.2006.001.001 (inactive 30 September 2025).^{[ dead link ]}