Stenocarpella
Syd. & P. Syd., Ann. Mycol. 15: 258. 1917. Fig. 53.
Fig. 53. Stenocarpella spp. A. Zea mays infected with Stenocarpella maydis. B–K. Asexual morphs. B. Conidiomata with exuding conidial mass on pine needle agar of Stenocarpella maydis (ex-epitype CBS 117559). C. Hyaline layer of conidiogenous cells giving rise to brown conidial mass of Stenocarpella macrospora (CPC 11863). D–F. Conidiogenous cells giving rise to conidia. D, E. Stenocarpella macrospora (CPC 11863). F. Stenocarpella maydis (ex-epitype CBS 117559). G–I. Conidia. G, H. Stenocarpella macrospora (CPC 11863). I. Stenocarpella maydis (ex-epitype CBS 117559). J. Conidiogenous cells giving rise to beta conidia of Stenocarpella macrospora (CPC 11863). K. Beta conidia of Stenocarpella macrospora (CPC 11863). Scale bars = 10 μm. All pictures except for A taken from Lamprecht et al. (2011).
Synonyms: Hendersoniopsis Woron., Fungal and Bacterial Diseases of Agricultural Plants: 255. 1922.
Phaeostagonosporopsis Woron., La Defense des Plantes, Leningrad 2: 333. 1925.
Classification: Sordariomycetes, Diaporthomycetidae, Diaporthales, Diaporthaceae.
Type species: Stenocarpella macrospora (Earle) B. Sutton, basionym: Diplodia macrospora Earle. Isotype: IMI 12790. Ex-epitype strain designated by Crous et al. (2006b): CBS 117560 = MRC 8615.
DNA barcodes (genus): LSU, ITS.
DNA barcodes (species): ITS, tef1. Table 19.
Table 19. DNA barcodes of accepted Stenocarpella spp.
| Species | Isolates1 | GenBank accession number2 | References | |
|---|---|---|---|---|
| ITS | tef1 | |||
| Stenocarpella macrospora | CBS 117560ET | FR748048 | MG934504 | Lamprecht et al. (2011), present study |
| S. maydis | CBS 117558ET | FR748051 | FR748080 | Lamprecht et al. (2011) |
- 1
-
CBS: Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands. ET indicates ex-epitype strains.
- 2
-
ITS: internal transcribed spacers and intervening 5.8S nrDNA; tef1: partial translation elongation factor 1-alpha gene.
Mycelium immersed, brown, branched, septate. Conidiomata pycnidial, solitary or sometimes confluent, globose or elongated, dark brown, subepidermal, unilocular; conidiomatal wall composed of dark brown, thick-walled cells of textura angularis; neck single, circular, papillate, protruding. Conidiophores usually reduced to conidiogenous cells. Conidiogenous cells enteroblastic, phialidic, determinate, discrete, rarely integrated on 1-septate conidiophores, cylindrical, collarette with minute channel, periclinal wall thickened, formed from inner cells of pycnidial wall. Conidia pale brown, 0−3-septate, continuous or constricted, cylindrical to fusiform, straight or curved, apex obtuse, base tapered and truncate, thick and smooth-walled, eguttulate. Beta conidia absent or present, hyaline, scolecosporous, curved. Sexual morph unknown (adapted from Sutton 1980).
Culture characteristics: Colonies flat, with abundant aerial mycelium giving a cottony appearance; under continuous near-ultraviolet light abundant sporulation in 1 wk. On OA surface white to rosy buff to vinaceous buff, centre isabelline; reverse vinaceous buff, centre isabelline.
Optimal media and cultivation conditions: OA and PNA at 25 °C under continuous near-ultraviolet light to promote sporulation.
Distribution: Africa, America, Asia and Europe.
Host: Zea mays (Poaceae).
Notes: The genus Stenocarpella was introduced by Sydow & Sydow (1917), with S. zeae designated as type species. Sutton (1977) synonymised S. zeae with Diplodia macrospora, transferring this latter species to Stenocarpella, recognising S. macrospora as the correct name for the type species. Two species are included in this genus i.e. S. macrospora and S. maydis, which cause Diplodia ear rot of maize (Crous et al. 2006b).
Stenocarpella was initially placed in the Botryosphaeriaceae (Botryosphaeriales) because of the similarity with Diplodia. In a phylogenetic study based on LSU sequences, Crous et al. (2006b) showed that Stenocarpella belongs to the Diaporthaceae (Diaporthales). Subsequently, Lamprecht et al. (2011) confirmed this placement based on ITS and tef1 sequences.
References: Sutton, 1977, Sutton, 1980 (morphology and pathogenicity); Crous et al. 2006b (morphology and phylogeny); Lamprecht et al. 2011 (morphology, pathogenicity and phylogeny).
Authors: Y. Marin-Felix & P.W. Crous