Entyloma dahliae Syd. & P. Syd.

Synonyms

Entyloma calendulae f. dahliae (Syd. & P. Syd.) Viégas
Entyloma dahliae (Sternon) Cif.
Entyloma unamunoi Cif.
Entylomella dahliae Cif. ex Boerema & Hamers

Description

Sori in leaves as round or polygonal spots, at first pale blue-green, later dark brown and drying from the centre, 3–15 mm diam., or larger by fusion.

Spores solitary or often in small groups or chains, globose, ovoid to irregular, 9.5–17.0 (–20) × 8–16 µm, subhyaline to golden yellow; wall smooth, 2-layered, 1–4 µm thick; outer layer often unevenly thickened.

Spore germination resulting in aseptate basidia 60–80 × 5–8 µm. Basidiospores developing in 4s at the tips of basidia, acicular, 40–60 × 3–5 µm, sometimes producing uninucleate secondary sporidia or, after fusion, dikaryotic hyphae.

Anamorph may be present.

Hosts
   
Host family: Asteraceae
   
Host species: Dahlia sp.

Distribution

States & Territories: NSW, QLD, VIC

Comments

Entyloma dahliae causes dahlia leaf smut wherever cultivated Dahlia is grown. Conidia of the anamorphic stage (Entylomella dahliae) are produced on the surface of the leaf spots and contribute to the spread of the pathogen during the growing season. At the end of the growing season the teliospores fall to the ground with the senescing leaves where they survive and bring about infection in the following season. The smut fungus is not transmitted by seed or in tubers but may be spread by soil attached to tubers (Boerema & Hamers, 1990).