Urocystis magica Pass.

Synonyms

Tuburcinia allii (Schellenb.) Liro
Tuburcinia cepulae (Frost) Liro
Tuburcinia magica (Pass.) Liro
Tuburcinia oblonga Massenot
Urocystis allii Schellenb.
Urocystis cepulae Frost
Urocystis colchici f. allii-subhirsuti Beltrani
Urocystis oblonga (Massenot) Zogg

Description

Sori as pustules in leaves and bulbs, often confluent, initially covered by the epidermis which ruptures to expose the dusty blackish brown mass of spore balls.

Spore balls globose to ovoid, composed of 1 or 2 central spores and a continuous to discontinuous layer of peripheral sterile cells.

Spores globose, subglobose, ovoid to slightly irregular, 13–16 (–19) × 10.5–13.5 µm diam., medium to dark reddish brown.

Sterile cells globose, ovoid to irregular, 5–10 µm diam., light yellowish brown.

Spore germination resulting in a hemispherical or short-cylindrical aseptate basidium from which 4–8 septate branching hyphae arise.

Hosts
   
Host family: Alliaceae
   
Host species: Allium cepa L.
Allium sativum L.

Distribution

Eradicated from Australia

Comments

Local outbreaks of onion smut (U. magica) have occurred in Australia since it was first detected in 1950 in South Australia, until its most recent detection in 1985 in New South Wales (Walker, 2001). In all cases, measures were taken to eradicate the disease. Walker (2001) detailed the history of onion smut in Australia and the various names that have been applied to this pathogen. He preferred to use the name U. cepulae for onion smut to make it clear that only one of the complex of smuts recorded on Allium spp. overseas had been found in Australia. Until a critical revision of this group is available, we have followed Lindeberg (1959) and used the oldest available name, U. magica.