Dwiroopa ramya Subram. & Muthumary, Proc.

Sánchez, Romina M. & Bianchinotti, M. Virginia, 2023, New records of mitosporic ascomycetes on Nothofagaceae from Patagonia, Argentina, Boletin de la Sociedad Argentina de Botanica 58 (4), pp. 491-503 : 495

3. Dwiroopa ramya Subram. & Muthumary, Proc. Indian Acad. Sci., Pl. Sci. 96: 196. 1986. Fig. 2 A-D.

Conidiomata stromatic immersed, erumpent through the bark, gelatinous and dark brown when wet, carbonaceous and black when dry, 3-9 × 3-7 mm ( M = 6.1 × 4.3); plurilocular, locules oval to pyriform, separated by cells in textura porrecta, cylindrical, smooth, hyaline, 5-18 × 2-8 μm ( M = 11.2 × 5.6). Conidiogenous cells of two types: a) holoblastic, discrete, cylindrical, smooth, hyaline; those producing macroconidia measure 5-17 × 2-7 μm ( M = 10.3 × 3.6), while mesoconidia producing cells are 12-26 × 2-4 μm ( M = 16.7 × 2.4); b) enteroblastic phialidic, cylindrical, smooth, hyaline, 4-15 × 1-3 μm ( M = 9.7 × 2), these cells are integrated on cylindrical, branched, smooth, hyaline conidiophores, ca. 27- 39 × 2 μm. Macroconidia unicellular, ellipsoidal, dark brown, 1-2 longitudinal germ slits, smooth with SEM, 11-29 × 8-12 μm ( M = 19.6 × 9.7; n = 51). Macroconidia germinates through the slits to produce a septate, hyaline mycelium. Mesoconidia unicellular, ellipsoidal, smooth, hyaline to pale brown, 6-15 × 2-8 μm ( M = 11.2 × 5.1; n = 28). Microconidia unicellular, ellipsoidal, apical end rounded, base truncate, smooth, hyaline, 2-10 × 1-3 μm ( M = 6.4 × 2.5; n = 31) .

Distribution and habitat. Growing on bark of fallen branches and logs of N. pumilio in Argentina and on an indeterminate host in India ( Subramanian & Muthumary, 1986).

Comments. The material on Nothofagus fully agrees with the original description of the species. Besides the species reported here, the genus contains two other ones: D. lythri (D.F. Farr & Rossman) D.F. Farr & Rossman on leaves of Lythrum salicaria L. from the USA and D. punica K.V. Xavier, A.N. Kc, J.Z. Groenew., Vallad & Crous which is pathogenic to Punica granatum L. in the USA. The macroconidia of D. ramya are the longest in the genus (up to 30 μm), in D. lythri they are subglobose to ellipsoidal (up to 19 μm) and in D. punica broadly ellipsoid (up to 20 μm) ( Subramanian & Muthumary, 1986).

Material examined: ARGENTINA. Chubut: Parque Nacional Los Alerces, Huemules forest (42º 47’ 27.7” S, 71º 28’ 15.5” W), 1137 m alt., on fallen branches of N. pumilio , 20-XI-2003, Rajchenberg 12131 (BBB); Esquel, Aserradero Pelech Hnos., 8-V-2006; on logs of N. pumilio (from Parque Nacional Los Alerces, Huemules forest), Bianchinotti 67, 68 (BBB).

Figures

Fig. 2. Dwiroopa ramya. A: Stromatic conidioma on decorticated wood. B: Two microconidia surrounded by macroconidia. C: View of the longitudinal germ slits of macroconidia. D: Conidium germinating through the longitudinal slit. Gilmaniella multiporosa. E: Sporodochial conidioma on substrate. F: Conidiophore. G: Conidiogenous cell. H: Conidia in chains. I: Terminal conidia showing multiple scars. Monodictys paradoxa. J: Conidioma on substrate. K: Conidium detached from the conidiogenous cell which narrows towards the apex. L: Conidium showing the lighter basal cells and a rest of the conidiogenous cell. M: Germinating conidium and formation of a new one. N: Different shapes and sizes of conidia. Pycnopeziza quisquiliaris. O: Vertical section of a conidioma. P: Chain of two conidia (phloxine stain). Q: Conidia attached to conidiogenous cells (phloxine stain). R: Conidiophore.Abbreviations= cg: conidiogenous cell; cp: conidiophore; mc: microconidia; s: scars; sl: germ slits. Scale bars= A: 1 mm; B–I, L–N, P: 15 µm; K, Q–R: 10 µm; O: 50 µm.