Ascochyta silphii sp. nov. – a new Ascochyta species on Silphium perfoliatum
Ascochyta silphii sp. nov. – eine neue Ascochyta-Art an Silphium perfoliatum
Journal für Kulturpflanzen, 66 (8). S. 281–283, 2014, ISSN 1867-0911, DOI: 10.5073/JfK.2014.08.03, Verlag Eugen Ulmer KG, Stuttgart
Ascochyta silphii sp. nov., a new species collected on Silphium perfoliatum L., differs from other species of Ascochyta on this host in length, width of the conidia and diameter of the pycnidia.
Key words: Ascochyta silphii sp. nov., Silphium perfoliatum L., symptoms, systematics, new species
Ascochyta silphii sp. nov., eine neue Art an Silphium perfoliatum L., unterscheidet sich von anderen Arten der Gattung Ascochyta auf diesem Wirt in Länge und Breite der Konidien als auch im Durchmesser der Pyknidien.
Stichwörter: Ascochyta silphii sp. nov., Silphium perfoliatum L., Symptome, Systematik, neue Art
On Silphium spp. we know two different species of Ascochyta, namely A. treleasei Berl. & Vogl. and A. compositarum Davis (see Tab. 1).
Table 1. Ascochyta species on Silphium spp. (in chronological order) according to the original descriptions
Species | Host plant | Diameters of the pycnidia in μm | Length of conidia in μm | Width of conidia in μm | Characteristics of the conidia |
Ascochyta treleasei Berl. & Vogl. | Silphium integrifolium | 100–1201) | 7–141) | 3–51) | Hyaline, ovate, oblong or reniform, often compressed in the median part, with 2–4 guttules, later 1-septate. |
Ascochyta compositarum | Eupatorium urticaefolium, Helianthus strumosus, Aster drummondii | about 100 2) | 14–24 2) | 4–6 2) | Hyaline, cylindrical, sometimes almost foot-shaped, sometimes with an eccentric septum, slightly constricted, 4-guttulated. |
Ascochyta silphii sp. nov. | Silphium perfoliatum | 40.57–100.37 | 3.74–10.02 | 1.09–3.37 | Hyaline, oblong-cylindrical, rounded at the ends with 1 septum in the midth. At the septum sometimes constricted, some slightly flexuose. |
1) according to Trelease (1881–1883) and Berlese and Voglino (1886) | |||||
On leaves of Silphium perfoliatum originating from a field at Strem near Güssing (Burgenland, Austria) an Ascochyta species was identified which differs in the diameter of the pycnidia, length and width of conidia to the well-known species on Silphium spp.
For the determination of the fungus the usual mycological routine methods of light microscopy were adopted. Pycnidia and conidia of the fungus were stained with Wittmann’s Blue (Wittmann, 1970). Both have been measured using the programme labSense by Olympus.
The main difference between the above mentioned two species and the new one are the diameters of the pycnidia, the length and width of the conidia (Tab. 1).
The diameters of the pycnidia of the new species is 40.57–100.37 μm with an average of 65.6 μm. The conidia are 3.74–10.02 μm long with an average of 6 μm and 1.09–3.37 μm wide with an average of 1.95 μm and are two celled with 1 septum in the midth of the conidia.
Ascochyta silphii Bedlan sp. nov.
Index Fungorum IF550685
On leaves brown roundish or irregular shaped spots with dark-brown margins or large indefinite greyish, dark grey or brown areas (s. Fig. 1 and 2). Conidiomata (pycnidia) on the upper side of the leaf spots (s. Fig. 3). Pycnidia semi-immersed, dark brown, globose, 40.57–100.37 μm diameter (average 65.6 μm). The ostioles measure 7.48–21.28 μm (average 14.1 μm). The conidia are 3.74–10.02 μm long with an average of 6 μm and 1.09–3.37 μm wide with an average of 1.95 μm, hyaline, oblong-cylindrical, rounded at the ends with 1 septum in the midth. At the septum sometimes constricted, few conidia are slightly flexuose (Fig. 4).
Fig. 1. Symptoms on upper side of leaf (more or less roundish leaf spot).
Fig. 2. Symptoms on upper side of leaf (large indefinite brown areas).
Fig. 3. Pycnidia (stained with Wittmann’s Blue).
Fig. 4. Conidia (stained with Wittmann’s Blue).
On living leaves of Silphium perfoliatum L.
Type: Austria, Strem (near the district capital Güssing)/Burgenland, Austria. On living leaves of Silphium perfoliatum L., 03 October 2012, G. Bedlan (holotype, hb W).
The type specimen has been deposited at the Department of Botany, Natural History Museum, Vienna (hb W).
This publication is part of the project “Increasing biomass production by Silphium perfoliatum L. for energy recovery in Austria”, financed by the Austrian Climate and Energy Fund (KLI.EN) and carried out in the context of the program “NEUE ENERGIEN 2020”.
Berlese, A.N., P. Voglino, 1886: Sylloge Fungorum. Additamenta ad Volumina I-IV: i-iv, 1-484, p. 332.
Davis, J.J., 1919a: North American Ascochytae. Transactions of the Wisconsin Academy of Sciences, Arts and Letters, Vol. XIX, Part II, p. 655-670.
Davis, J.J., 1919b: Notes on parasitic fungi in Wisconsin – V. Transactions of the Wisconsin Academy of Sciences, Arts and Letters, Vol. XIX, Part II, p. 690-704.
Saccardo, P.A., 1931: Sylloge Fungorum XXV, p. 324.
Trelease, W., 1881–1883: Preliminary list of Wisconsin parasitic fungi. Transactions of the Wisconsin Academy of Sciences, Arts and Letters, Vol. VI (1881–1883), pp. 106-144 (p. 121).
Wittmann, W., 1970: Ein neues Rezept zur Herstellung mykologischer Präparate. PflSchber., Bd. 41, Heft 5/6/7, 91-94.
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