Spegazzinia affinis J. Mena & Cantillo, 2017

Mena-Portales, Julio, Cantillo-Pérez, Taimy & Minter, David W., 2017, A new species of the conidial fungal genus Spegazzinia (Pleosporales, Didymosphaeriaceae) collected on sugarcane in Cuba, Phytotaxa 331 (2), pp. 295-298 : 295-297

Spegazzinia affinis J. Mena & Cantillo sp. nov.

Diagnosis:—Differs from Spegazzinia species by its irregularly lobed, echinulate, with short and blunt spines type “b” conidia

Etimology: — Latin, affinis , referring to the similar characteristic shared by this specie with S. sundara , S. flabellate and S. tessarthra .

TYPE — CUBA, Camagüey, Km 14 from Camagüey to Vertientes, on dead leaves of Saccharum officinarum , 26 March 1989, J. Mena (Holotype HACM 8980).

MB 817855

Description:— Colonies on the natural substratum punctiform, dark blackish brown to black. Mycelium mostly immersed. Conidiophores mother cells lageniform or ampulliform, brown, 5–12 x (3.5–) 4–6 μm. Conidial secession schizolytic. Conidiophores secession basauxic, macronematous, mononematous, arising singly from mother cells, mostly flexuous, verrucose, pale brown to mid brown, of two types: conidiophores with “a” conidia up to 130 μm long, 2–3 μm thick, 3–5 μm at the apex; those with “b” conidia up to 25 (–35) μm long, 2–3.5 μm thick, 3.5–4.5 μm at the apex. Conidiogenous cells monoblastic, integrated, terminal, narrowly cylindrical. Conidia solitary, dry, acrogenous, of two kinds: “a” conidia divided into 4 subglobose cells, dark brown to blackish brown, 16–22 x 12–24 μm excluding spines which are up to 13 μm long and “b” conidia subsphaerical or broadly ellipsoidal, flattened, cruciately septate, brown to mid brown, irregularly lobed, echinulate, with short and blunt spines; 18–24 x 16–22 μm, 8–12 thick.

Other specimens examined: Spegazzinia flabellata :— BRAZIL, Bahia. On decaying fruit, 16 March 2008, S. M. Leão-Miranda ( HUEFS 136870, holotype). Spegazzinia sundara — CUBA: Camagüey, on dead petioles of Coccothrinax sp. , 21 May 1990, A. Hernández ( HACCM 67, 85); Artemisa, Biosphere Reserve Sierra del Rosario, near the sulphurous baths of San Juan River, on dead petioles of Coccothrinax sp. , 3 November 1995, V. Iacona & J. Mena ( HACM 9300). Spegazzinia tessarthra — CUBA: Artemisa, Sierra del Rosario Biosphere Reserve, near the sulphurous baths of San Juan River, on herbaceous stem of unidentified Gramineae, 3 September 1995, V. Iacona & J. Mena ( HACM 9430); Alquízar, on dead sheaths of Saccharum officinarum , March 1987, M. O. López & I. Sandoval ( INISAV 261); La Habana, Arroyo Naranjo, Instituto de Desarrollo de la Salud, on herbaceous stem of unidentified Gramineae, 11 July 1986, G. Delgado ( HACM 8237).

Notes:— Of those species with two types of conidia, the closest species to S. affinis in conidial morphology are S. flabellata S.M. Leão & Gusmão (2010: 4) and S. sundara Subram. (1956: 78) . However, in S. flabellata the type “b” conidia are finely spinulose and smaller (15–18 x 13–18 μm) ( Leão-Ferreira & Gusmão 2010) while in S. sundara the “b” conidia although are also irregularly lobed, doesn’t present short and blunt spines ( Ellis 1976). Spegazzinia sundara is neither rare in Cuba. It has been collected four times in Cuba, twice on dead petioles of Coccothrinax sp. in Camagüey Province (Hernández Gutíerrez & Mena Portales 1995) and other twice on the same host in Pinar del Río Province (Mercado-Sierra et al. 1997, Delgado-Rodríguez & Mena-Portales 2000).

Spegazzinia tessarthra (Berk & M.A. Curtis) Sacc. (1886: 758) is also similar to S. affinis in its general morphology and conidial size. However, the type “b” conidia of the latter are smaller (13–17 μm) and paler ( Ellis 1971), and although may have small spines, most specimens of S. tessarthra reported in the literature, however, have only smooth conidia (Nair & Tyagi 1961, Pavgi & Gupta 1967, Dennis 1970, Cole 1974, Cole & Samson 1979, Heredia Abarca

1994, Mercado-Sierra et al. 2000, Manoharachary & Kunwar 2010). Spegazzinia tessarthra is very common in Cuba; it has been collected on numerous host plants, including sugar cane ( Berkeley & Curtis 1869, Arnold 1985, López Mesa et al. 1999). In all specimens revised, only smooth “b” conidia were observed. Mercado-Sierra (1984) describes them, in a specimen collected on Andropogon bicornis L. in the Biosphere Reserve of Sierra del Rosario, as smooth or echinulate with sizes that reach 13–18 μm diam. Could not find this specimen in the Mycological Herbarium of Ecology and Systematic Institute of Havana, Cuba (HACM) to observe the ornamentation of type “b” conidia. Relevant features to differentiate currently recognized species of Spegazzinia are included in the following key.