Ustilago hordei (Pers.) Lagerh.

Synonyms

Erysibe vera α hordei (Pers.) Wallr.
Reticularia segetum Bull.
Uredo carbo α hordei (Pers.) DC.
Uredo segetum (Bull.) Pers.
Uredo segetum α hordei Pers
Uredo segetum α Uredo hordei Pers.
Ustilago arrhenatheri Schellenb.
Ustilago avenae var. levis Kellerm. & Swingle
Ustilago dura Appel & Gassner
Ustilago kolleri Wille
Ustilago levis (Kellerm. & Swingle) Magnus
Ustilago rostrupii Kitunen
Ustilago segetum (Bull.) Roussel
Ustilago segetum var. hordei (Pers.) Brunaud
Ustilago segetum var. hordei (Pers.) Rabenh.
Ustilago segetum var. hordei f. tecta Rostr. & J.L. Jensen (as "Hordii")

Description

Sori in spikelets, as a blackish brown coherent spore mass, at first covered by a membrane of host tissue origin (covered smut), later exposed to verying degrees depending on the extent of destruction of the spikelet parts.

Spores globose, subglobose to ovoid, 5–9 (–10) µm diam., paler on one side, smooth.

Spore germination: 4-celled basidia (often of the 3 + 1 pattern) producing basidiospores on artificial media; dikaryons formed between either compatible basidial cells or basidiospores, infecting seedlings.

Hosts
   
Host family: Poaceae
   
Host species: Arrhenatherum elatius (L.) P.Beauv. ex J. Presl & C. Presl
Avena sativa L.
Hordeum vulgare L.

Distribution

States & Territories: NSW, QLD, SA, TAS, VIC

Comments

Ustilago hordei occurs worldwide and causes covered smut of cultivated barley and oats. The smut spores are spread during harvest and other seed handling operations. The spores are carried externally on the seed, and when it is sown the spores germinate in the soil along with the seed and penetrate the shoots of seedlings just before they emerge from the soil. Covered smut can be controlled by sowing disease-free seed, chemical seed treatment and resistant cultivars.