Petrakia juniperi sp. nov., a new fungus on Juniperus sp.
Petrakia juniperi sp. nov., ein neuer Pilz an Juniperus sp.
Journal für Kulturpflanzen, 69 (5). S. 173–174, 2017, ISSN 1867-0911, DOI: 10.1399/JfK.2017.05.03, Verlag Eugen Ulmer KG, Stuttgart
Petrakia juniperi sp. nov., a new species collected on Juniperus sp. differs from other species of Petrakia in the size of conidia and shape of the appendages.
Key words: Petrakia juniperi sp. nov., Juniperus sp., symptoms, systematics, new species
Petrakia juniperi sp. nov., eine neue Art an Juniperus sp. unterscheidet sich von anderen Arten der Gattung Petrakia durch Größe der Konidien sowie Ausbildung der Fortsätze.
Stichwörter: Petrakia juniperi sp. nov., Juniperus sp., Symptome, Systematik, neue Art
Up to now we know four species of the genus Petrakia, namely P. echinata, P. deviata, P. irregularis, and P. paracochinensis. P. cochinensis was transferred to the genus Ernakulamia and P. kambakkamensis to the genus Pseudopetrakia.
For the determination of the fungus the usual mycological routine methods of light microscopy were adopted. Conidia of the fungus were stained with Wittmann’s Blue (Wittmann, 1970). They have been measured using the programme labSens by Olympus.
The conidia of the new species differ from other species of Petrakia in size and form of the appendages. P. echinata has 5–10 elongate, hyaline appendages, which are 16–22 μm long and 3–4 μm wide with rounded tips. P. deviata has often, but not always, a very small, subhyaline, papillate appendage, which measures 2.5 μm, or an elongated nearly thorn shaped up to 8 μm long and 2.5–3 μm wide appendage.
P. irregularis has 6–30 appendages, which are 20–50 μm long, almost hyaline, continuous or up to 4 septate with mostly a rounded, sometimes conspicuously club-shaped end. The base of the appendages is swollen (Van der Aa, 1968). P. paracochinensis has 3–5 biseptate appendages which measure 60–62 × 3–4 μm, tapering to a rounded apex (Wong et al., 2002) (Table 1).
Table 1. Species of the genus Petrakia in chronological order according to the original descriptions
Species | Current name | Host |
Petrakia echinata (Peglion) | On withering or dead leaves of | |
Petrakia deviata | On living leaves of | |
Petrakia cochinensis | Ernakulamia cochinensis (Subram.) | On dead spathe of |
Petrakia kambakkamensis | Pseudopetrakia kambakkamensis | On dead wood |
Petrakia irregularis | On dead branches of | |
Petrakia paracochinensis | On decaying culms of |
Index Fungorum IF 553181
Colonies darkbrown. The conidia are brown, oval to ellipsoid, muriform septate with up to three short appendages. The conidia are 15.75–21.59 μm long with an average of 18.25 μm and 10.99–13.49 μm wide with an average of 12.1 μm. The appendages arising from cells at both ends of the conidia, mostly two appendages at one end and only one appendage at the other end of the conidia. The appendages are simple, short, hyaline, narrowing above with a blunt rounded tip. They are 2.43–5.53 μm long with an average of 3.91 μm, 3.24–5.02 μm wide at the basis with an average of 3.97 μm and 1.24–2.03 μm wide at the tip with an average of 1.65 μm (Fig. 1).
Fig. 1. Conidium of Petrakia juniperi (stained with Wittmann\qs Blue).
On dead wood of Juniperus sp.
Type: Austria, Vienna. On dead wood of Juniperus sp., 12 August 2014, Weikendorf (district of Gänserndorf in Lower Austria) leg. et det. G. Bedlan (holotype, hb W).
The type specimen has been deposited at the department of Botany, Natural History Museum, Vienna (hb W).
Etymology: The new species found on Juniperus sp. is named after the host where it has been found.
Ellis, M.B., 1971: Dematiaceous Hyphomycetes. X. Mycological Papers 125, p.4.
Subramanian, C.V., 1957: Two new Species of Petrakia. Beiheft Sydowia 1, p. 14-15.
Subramanian, C.V., 1996 [1994/1995]: Hyphomycetes from South East Asia – Novelties from Singapore and Malaysia. Kavaka 22/23, 67.
Sydow, H., P. Sydow, 1913: Novae fungorum species – XI. Annales mycologici 11 (5), 407.
Van der Aa, H.A, 1968: Petrakia irregularis, a new fungus species. Acta Botanica Neerlandica 17 (3), 221.
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Wong, M.K.M., T.K. Goh, E.H.C. McKenzie, K.D. Hyde, 2002: Fungi on Grasses and Sedges: Paratetraploa exappendiculata gen. et sp. nov., Petrakia paracochinensis sp. nov. and Spadicoides versiseptatis sp. nov. (dematiaceous hyphomycetes). Cryptogamie/Mycologie 23 (2), p. 195-203 (p. 198).
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