Sporisorium elegantis Vánky (1997: 62)

Piątek, Marcin, Piątek, Jolanta & Yorou, Nourou S., 2014, Emended description and geographical distribution of Sporisorium elegantis (Ustilaginaceae), a species shared between West Africa and India, Phytotaxa 175 (3), pp. 148-154 : 149

Sporisorium elegantis Vánky (1997: 62) Figs 1–4

Sori destroying the whole inflorescences, forming long cylindrical bodies, up to 40 mm long and 3 mm wide, initially enclosed by a dirty white peridium and partly concealed by leaf sheaths; later the peridium easily ruptures in several places disclosing the blackish brown powdery mass of spores and sterile cells surrounding 1–3 (mostly 2) columellae of the sorus length; columellae stout, narrowing and dividing into short apical branches. Peridial cells in more or less well-developed chains or pseudoparenchymatous, single cells subhyaline or hyaline, very variable in shape and size, globose, subglobose to broadly ellipsoidal or long cylindrical to elongated, sometimes inflated, 6.0–25.0 × 6.0–15.0 µm, with 1–3 spherical bodies (?lipid bodies) in the cytoplasm; wall even, about 0.8 µm thick, smooth. Spore balls present, easily disintegrating into single spores under gentle pressure. Spores yellowish brown or brown, globose or subglobose, rarely broadly ellipsoid, often somewhat irregular or collapsed, 9.0–13.0 × 8.0–12.0 µm [av. ± SD, 10.7 ± 1.0 × 9.9 ± 0.9 µm, n = 50/1]; wall even, 0.8–1.0 µm thick, surface finely punctate in LM, finely, densely verrucose in SEM, spore profile smooth or very finely serrulate. Sterile cells in irregular groups or chains, usually composed of several cells, subhyaline or hyaline, subglobose or broadly ellipsoidal, usually more or less flattened at the sides of contact due to mutual pressure, 6.5–13.0 × 5.5–12.0 µm; wall even, 0.5–0.8 µm thick, smooth.

Specimens examined: — BENIN, Atakora Department: between Tanguiéta and Tanougou , ca. 40 km N of Natitingou, 10°39´34˝N, 01°17´45˝E, elev. 218 m a.s.l., on Thelepogon elegans , 26 Oct. 2011, M . Piątek & N. S . Yorou ( KRAM F-56853!, hb. M. Piątek!) . INDIA, Madhya Pradesh: Ujjain , on Thelepogon sp. , 1966, S. K . Chauhan (paratype K ( M) 154774!) . NIGERIA, Zaria Province: Bomo , on Thelepogon elegans , 30 Sept. 1959, E . Harris 537 (paratype K ( M) 154794!) .

Literature report: — INDIA, Maharashtra State: 36 km NW of Pune, near National Defence Academy , alt. 610 m, on Thelepogon elegans , 28 Oct. 1992, C. Vánky & K. Vánky (holotype H. U. V. 17656, Vánky 1997, 2012) .

Location, habitat and population size: — In Benin, the infected plants were found on the northern slopes of the Atakora Mts, in a locally wet and semi-shaded place within the northern Sudanian savanna (with Sahelian element), close to a small natural water pond ( Fig. 1A ). The level of infection of available plant specimens was small (less than 10% specimens were infected). None of the grasses occurring in the proximity of diseased Thelepogon elegans were infected. The ecological details of populations from India and Nigeria are unknown.

Sporulating time: — India: March, October; Nigeria: September; Benin: October.

Figures

FIGURE 1. Sporisorium elegantis on Thelepogon elegans. A. Habitat in Benin (phot. M. Piątek). B. Healthy inflorescence of Thelepogon elegans (phot. M. Piątek). C. Macroscopic symptoms of infection: to the left—two infected plants with sori with disappeared peridia and two columellae (a columella indicated by arrow divides into short apical branches), and to the right—enlarged sori with disappearing peridia and with disappeared peridium, respectively, showing a columella dividing into short apical branches (del. J. Piątek). Bar = 1 cm.

FIGURE 2. Sporisorium elegantis on Thelepogon elegans seen by light microscopy (KRAM F-56853). A–C. Peridial cells. D. Disintegrating spore ball. E–F. Spores, median and superficial views. G–H. Sterile cells. Bars = 10 µm.

FIGURE 3. Sporisorium elegantis on Thelepogon elegans seen by scanning electron microscopy (KRAM F-56853). A. Spore balls. B–C. Spores. D. Spore ornamentation. E. Spores and chains of sterile cells. F. Group of sterile cells. Bars: A = 50 µm, E = 30 µm, B, F = 10 µm, C = 5 µm, D = 3 µm.

FIGURE 4. The geographical distribution of Sporisorium elegantis.