Boesew., Canad. J. Bot. 60: 2289. 1982. Fig. 4.
Synonym: Nectricladiella Crous & C.L. Schoch, Stud. Mycol. 45: 54. 2000.
Classification: Sordariomycetes, Hypocreomycetidae, Hypocreales, Nectriaceae.
Type species: Cylindrocladiella parva (P.J. Anderson) Boesew., basionym: Cylindrocladium parvum P.J. Anderson. Representative strain: CBS 114524 = ATCC 28272.
DNA barcodes (genus): LSU, ITS.
DNA barcodes (species): his3, tef1, tub2. Table 3. Fig. 5.
CBS: Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands; IMI: International Mycological Institute, CABI-Bioscience, Egham, Bakeham Lane, U.K; IMUR: Institute of Mycology, University of Recife, Recife, Brazil; MAFF: Genetic Resources Centre, National Agriculture and Food Research Organization (NARO), NARO Genebank, Ibaraki, Japan. T indicates ex-type strains.
ITS: internal transcribed spacers and intervening 5.8S nrDNA; LSU: 28S large subunit nrDNA; his3: partial histone H3 gene; tef1: partial translation elongation factor 1-alpha gene; tub2: partial β-tubulin gene.
Ascomata perithecial, superficial, solitary, basal stroma absent, globose to obpyriform, collapsing laterally when dry, smooth, with minute, brown setae arising from ascomatal wall surface, red, changing colour in KOH, ostiole consisting of clavate cells, lined with inconspicuous periphyses. Asci unitunicate, 8-spored, cylindrical, sessile, thin-walled, with a flattened apex, and a refractive apical apparatus. Ascospores uniseriate, overlapping, hyaline, ellipsoid to fusoid with obtuse ends, smooth, 1-septate. Conidiophores monomorphic, penicillate, or dimorphic (penicillate and subverticillate), mononematous, hyaline. Penicillate conidiophores consist of a stipe, a penicillate arrangement of fertile branches, a stipe extension, and a terminal vesicle. Subverticillate conidiophores consist of a stipe, and one or two series of phialides. Stipe septate, hyaline, smooth. Stipe extensions aseptate, straight, thick-walled, with one basal septum, terminating in a thin-walled vesicle of characteristic shape. Conidiogenous apparatus with primary branches 0–1-septate, secondary branches aseptate, terminating in 2–4 phialides. Phialides cylindrical, straight or doliiform to reniform to cymbiform, hyaline, aseptate, apex with minute periclinal thickening and collarette. Conidia cylindrical, rounded at both ends, straight, (0–)1(–3)-septate, frequently slightly flattened at base, held in asymmetrical clusters by hyaline slime. Chlamydospores brown, thick-walled, more frequently arranged in chains than clusters (adapted from Boesewinkel 1982 and Lombard et al. 2012).
Culture characteristics: Colonies on MEA white to pale brick when young, becoming pale brick to dark sepia when mature, fluffy, cottony, effuse to convex with papillate surface, margin entire, undulate, lobate, or fimbriate, sometimes with abundant chlamydospores forming microsclerotia within medium.
Optimal media and cultivation conditions: CLA to induce sporulation of the asexual morph at 25 °C, while for the sexual morph sterile toothpicks placed on SNA is used at 20 °C.
Hosts: Soil-borne, weak pathogen of forestry, agricultural and horticultural crops (Crous, 2002, Lombard et al., 2012).
Disease symptoms: Leaf spots, cutting rot, stem cankers, damping-off and root rot.
Notes: Boesewinkel (1982) established the asexual genus Cylindrocladiella, based on C. parva, to accommodate several cylindrocladium-like species characterised by small (<20 μm long), 1-septate, cylindrical conidia and aseptate stipe extensions. Initially, Cylindrocladiella spp. were linked to the sexual genus Nectricladiella (Crous and Wingfield, 1993, Schoch et al., 2000). Following the implementation of the International Code of Nomenclature for algae, fungi and plants (ICN; McNeill et al. 2012), Rossman et al. (2013) proposed that the generic name Cylindrocladiella be retained over Nectricladiella. Recently, Lombard et al. (2015) showed that the genus Cylindrocladiella formed a monophyletic group in the Nectriaceae, closely related to the genera Aquanectria and Gliocladiopsis. To date, 36 species of Cylindrocladiella have been recognised (Crous and Wingfield, 1993, Van Coller et al., 2005, Inderbitzin et al., 2012, Lombard et al., 2012, Lombard et al., 2015, Lombard et al., 2017, Crous et al., 2017a), of which two are linked to nectricladiella-like sexual morphs (Schoch et al., 2000, Crous, 2002, Lombard et al., 2012, Lombard et al., 2015). These fungi are generally soil-borne and regarded as saprobes or weak pathogens of numerous plant hosts (Crous, 2002, Van Coller et al., 2005, Scattolin and Montecchio, 2007, Lombard et al., 2012). Disease symptoms associated with Cylindrocladiella infection include leaf spots and root, stem and cutting rots (Crous et al., 1991b, Peerally, 1991, Crous and Wingfield, 1993, Crous, 2002, Van Coller et al., 2005, Scattolin and Montecchio, 2007, Lombard et al., 2012).
References: Boesewinkel 1982 (morphology and pathogenicity); Crous & Wingfield 1993 (morphology); Schoch et al., 2000, Lombard et al., 2012, Lombard et al., 2017 (morphology and phylogeny); Crous 2002 (morphology, pathogenicity and monograph); van Coller et al. 2005 (morphology, pathogenicity and phylogeny).
L. Lombard & Crous, sp. nov. MycoBank MB824497.
Etymology: Name refers to Addis Ababa, Ethiopia, from where this fungus was collected.
Cultures sterile. Cylindrocladiella addiensis differs from its closest phylogenetic neighbours, C. elegans and C. noveazelandica, by unique fixed alleles in three loci based on the alignments deposited in TreeBASE (S22340): ITS position 92(T); tef1 positions 32(T), 80(C), 84(C), 154(indel), 155(A), 156(G), 157(indel), 199(A), 244(G), 261(G), 368(T), 398(T), 458(G/C), 466(G), 467(C), 475(T), 478(C), 483(T), 485(T), 487(T), 490(T) and 492(G); tub2 position 174(indel).
Culture characteristics: Colonies convex, cottony, with smooth margins, cream; reverse pale luteous; chlamydospores not seen; reaching 45–65 mm after 1 wk on MEA at 24 °C in ambient light.
Materials examined: Ethiopia, Addis Ababa, from soil, 2010, coll. P.W. Crous, isol. L. Lombard [holotype CBS 143794 (maintained as metabolically inactive culture), isotype cultures CBS 143793, CBS 143795 (also maintained as metabolically inactive cultures).
Note: None of the three isolates of C. addiensis could be induced to sporulate on MEA, PDA, OA, SNA or SNA amended with carnation leaf pieces.
Cylindrocladiella nauliensis L. Lombard & Crous, sp. nov. MycoBank MB824500. Fig. 6.
Etymology: Name refers to the area Aek Nauli, Indonesia, from where this fungus was collected.
Conidiophores 35–55 × 3–6 μm, dimorphic, penicillate and subverticillate, mononematous and hyaline, comprising a stipe, a penicillate arrangement of fertile branches, a stipe extension and a terminal vesicle; stipe septate, hyaline, smooth; stipe extension 100–135 μm long, 4–5 μm wide, aseptate, straight, thick-walled with one basal septum, terminating in thin-walled, broadly clavate to ellipsoidal vesicles sometimes with papillate apex. Penicillate conidiogenous apparatus 10–22 × 2–4 μm, with primary branches aseptate, secondary branches 8–15 × 2–4 μm, aseptate, each terminal branch producing 2–4 phialides; phialides 8–13 × 2–3 μm, elongate doliiform to reniform to cymbiform, hyaline, aseptate, apex with minute periclinal thickening and collarette. Subverticillate conidiophores abundant, comprised of a septate stipe and rarely primary branches terminating in 2–4 phialides; primary branches 25–45 × 2–4 μm, straight, hyaline, 0–1-septate; phialides 12–32 × 2–3 μm, cymbiform to cylindrical, hyaline, aseptate, apex with minute periclinal thickening and collarette. Conidia (10–)11–13(–14) × 2–3 μm (av. = 12 × 2 μm), cylindrical, rounded at both ends, straight, 1-septate, frequently slightly flattened at base, held in asymmetrical clusters by hyaline slime. Sexual morph unknown.
Culture characteristics: Colonies convex, cottony, with smooth margins, cream with pale luteous to brick centre; reverse pale luteous to honey with sepia centre; chlamydospores moderate throughout medium arranged in chains; reaching 60–70 mm after 1 wk on MEA at 24 °C in ambient light.
Materials examined: Indonesia, Sumatra Utara, Aek Nauli, from soil, May 2005, coll. M.J. Wingfield, isol. L. Lombard (holotype CBS H-23400, culture ex-type CBS 143792), isotype culture CBS 143791 (metabolically inactive).
Notes: Cylindrocladiella nauliensis is closely related to C. longistipitata. The stipe extensions of C. nauliensis (up to 135 μm long) are shorter than those of C. longistipitata (up to 216 μm long; Lombard et al. 2012). Additionally, the conidia of C. nauliensis are smaller [(10–)11–13(–14) × 2–3 μm (av. = 12 × 2 μm)] than those of C. longistipitata [(12–)14–16(–17) × 2–4 μm (av. = 15 × 3 μm); Lombard et al. 2012].
Authors: L. Lombard & P.W. Crous