Ustilago avenae (Persoon) Rostrup, 1890

loose smut of oats

on oat, etc.

Arrhenatherum elatius, Nieuwendam

detail

galled spikelet

same plant, somewhat less than a year later (the fungus is systemic): earlier stage of the infestation

Arrhenatherum elatius, Nieuwendam; whether the reduction of the awns is connected with the infection is not clear

all ovaries are black and swollen

the fungus erupts through the glumes

seen from the side

ten days later; the glumes are intact, within them the destruction is complete

spores

gall

The fungus primarily affects the ovaries, to a lesser degrees also the other parts of the spikelet. Spores c. 6 µm, olive brown when ripe; then also one can see that the spores are lighter at one side; wall spinulose. The infection begins at the seedlings.

host plants

Poaceae, oligophagous

Aegilops cylindrica, triuncialis; Arrhenatherum elatius; Avena barbata, fatua, nuda, sativa, sterilis & subsp. ludoviciana, strigosa; Dasypyrum villosum; Hordeum, murinum, vulgare & ? subsp. distichon.

synonyms

Ustilago arrhenatheri Schellenberg, 1915; U. aegiliopsidis Picbauer, 1932; U. decipiens (Wallroth) Liro, 1924; U. haynaldiae Becerescu, 1970; U. levis (Kellerman & Swingle) Magnus; U. nigra Tapke, 1932; U. perennans Rostrup, 1890; U. rostrupii Kutinen, 1922; U. segetum var. avenae (Persoon) Brunaud, 1878.
In her recent book, Kruse (2019a) treats Ustilago perennans as a valid species, parasitising Arrhenatherum elatius.

references

Ainsworth & Sampson (1950a), Almaraz (1998a), Beltran Tejera (1976a), Brandenburger (1985a: 779, 808), Buhr (1964b), Doppelbaur (1973a), Ellis & Ellis (1997a), Ivić, Sever, Scheuer & Lutz (2013a), Jage, Klenke, Kruse ao (2016a), Jage, Kruse, Kummer ao (2013a), Kabaktepe & Akata (2019a), Klenke & Scholler (2015a), Kozłowska, Mułenko & Heluta (2015a), Kruse (2019a), Llorens i Villagrasa (1984a), Losa España (1944a), Lutz & Vánky (2009a), Melgarejo Nárdiz, García-Jiménez, Jordá Gutiérrez ao (2010a), Navarro, Honrubia & Torres (1986a), Nielsen & Huang (1984a), Prillinger, Wuczkowski, Lopandic ao (2009a), Savchenko & Heluta (2012a), Scheuer & Bechter (2012a), Scholz & Scholz (2013a), Tomala-Bednarek (1977a), Tomasi (2014a), Unamuno (1941b, 1942a), Vanderweyen & Fraiture (2014a), Vánky (1994a, 2012a), Vánky & Abbasi (2013a), Woods, Chater, Smith ao (2018a), Zwetko (1993a).