Tilletia vankyi L.M.Carris & L.A.Castlebury

Description

Sori in ovaries, enclosed by a pericarp, partially hidden by floral envelopes; spore mass foetid, dark reddish brown, powdery.

Spores globose, subglobose to ovoid or broadly ellipsoidal, 18–26 × 16–22 µm, yellowish to medium dark olivaceous brown, reticulate, 5–9 meshes per spore diameter; muri 1.5–2.5 µm high, blunt or subacute, 22–33 on the equatorial circumference.

Sterile cells globose, subglobose, ellipsoidal, occasionally irregular, 10.5–19.0 × 9.5–17.0 µm, subhyaline to pale yellowish brown; wall 0.5–1.5 µm thick, smooth.

Spore germination (on WA at 5° and 15°C; 14 days) resulting in simple or branched basidia up to 400 µm long, with 14–34 nuclei, producing apically 20–40 non-conjugating uninucleate hyaline filiform basidiospores measuring 53–74 × 1.5–3.5 µm. Sporidia (secondary basidiospores) uninucleate, of two types: allantoid, 13.2–20.2 × 3.1–4.5 µm; and filiform, 35–57 × 1.8–2.6 µm. Allantoid sporidia forcibly discharged, produced asymmetrically from subulate sporogenous cells 2.6–7.0 × 1.3–1.8 µm, formed from hyphae, primary basidiospores and sporidia. Filiform sporidia passively released from cylindrical sporogenous cells, formed on hyphae.

Hosts
   
Host family: Poaceae
   
Host species: Lolium perenne L.

Distribution

States & Territories: NSW, SA, VIC, WA

Comments

No map provided: Carris et al. (2007) recorded it from 28 unspecified locations in Australia.

Tilletia vankyi was discovered in seedlots of perennial ryegrass (Lolium perenne) originating from commercial production fields in W.A., S.A., N.S.W. and Vic. and from other unknown locations (Carris et al., 2007). Carris et al. (2007) also reported it as occurring in Oregon, U.S.A. on Festuca rubra. Tilletia vankyi (BRIP 27634) was also intercepted in a seedlot of bulk fescue (Festuca rubra) imported from the U.S.A. in 2000.

This fungus differs from the more common T. lolii Auersw. ex G.Winter (known on several Lolium species in Europe, Asia and New Zealand, but not reported from Australia) in having slightly larger spores, with several often incomplete meshes per spore diameter and shorter muri, less numerous on the equatorial circumference. The spores of T. lolii are 17.5–24.0 × 17.5–22.0 µm, the meshes are rarely incomplete, (5–) 6–8 per spore diameter and the muri are 1.5–3.0 µm high, with 25–31 on the equatorial circumference.