Klaubauf, et al., Stud. Mycol. 79: 106. 2014. Fig. 27.
Classification: Sordariomycetes, Sordariomycetidae, Magnaporthales, Pyriculariaceae.
Type species: Macgarvieomyces borealis (de Hoog & Oorschot) Klaubauf, et al., basionym: Pyricularia borealis de Hoog & Oorschot. Holotype and ex-type strain: IMI 105288, CBS 461.65.
DNA barcodes (genus): LSU, ITS.
|Species||Isolates1||GenBank accession numbers2||References|
|Macgarvieomyces borealis||CBS 461.65T||KM484854||KM485170||KM485239||KM485070||Klaubauf et al. (2014)|
|Ma. juncicola||CBS 610.82||KM484855||KM485171||KM485240||KM485071||Klaubauf et al. (2014)|
|Ma. luzulae||CBS 143401ET||MG934440||MG934463||MG934519||MG934469||Present study|
|CPC 31555||MG934441||MG934464||MG934520||MG934470||Present study|
|CPC 31571||MG934442||MG934465||MG934521||MG934471||Present study|
CBS: Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands; CPC: Culture collection of Pedro Crous, housed at the Westerdijk Fungal Biodiversity Institute. T and ET indicate ex-type and ex-epitype strains.
ITS: internal transcribed spacers and intervening 5.8S nrDNA; act: partial actin gene; cal: partial calmodulin gene; rpb1: partial RNA polymerase II largest subunit gene.
Mycelium consisting of smooth, hyaline, branched, septate hyphae. Conidiophores solitary, erect, straight or curved, mostly unbranched, medium to dark brown, smooth or finely verruculose, septate. Conidiogenous cells integrated, terminal, rarely intercalary, medium to dark brown, smooth or finely verruculose, forming a rachis with protruding denticles, appearing flat-tipped. Conidia solitary, narrowly obclavate to narrowly pyriform, hyaline, often becoming pale brown with age, smooth, granular, guttulate, medianly 1-septate, apex obtusely rounded; hila somewhat thickened, refractive or not, not or slightly darkened. Chlamydospores brown, ellipsoid, arranged in chains (adapted from Klaubauf et al. 2014).
Culture characteristics: Colonies on MEA buff to rosy buff, isabelline or pale luteous, with pale olivaceous grey central mycelium, with entire, lobate or round and hairy edge, umbonate to conical or flat to slightly raised colony with somewhat velvety or wool-like texture; reverse iron grey, ochreous and buff towards edge or pale luteous. On CMA and OA transparent, pale luteous to olivaceous or grey olivaceous, flat, smooth and velutinous surface, undulate margin. Colonies on PDA pale luteous, white with buff centre or whitish to buff with honey centre, round, flat, fringed margin; reverse white with buff centre or whitish to buff with honey centre.
Optimal media and cultivation conditions: On OA at 25 °C under dark, or autoclaved barley seeds placed on SNA at 25 °C under near-ultraviolet light (12 h light, 12 h dark).
Distribution: Europe and New Zealand.
Disease symptoms: Leaf spots.
Notes: Macgarvieomyces was recently introduced to accommodate two species previously placed in Pyricularia. Phylogenetic analyses based on LSU, ITS, act, cal and rpb1 demonstrated that these taxa are not congeneric with Pyricularia s. str. (Klaubauf et al. 2014). Species in this genus were isolated from Juncaceae in Europe and associated with leaf spots. Species have also been reported on Cyperaceae and New Zealand (Farr & Rossman 2017); however, these host and distribution data have not been corroborated based on DNA sequence analyses.
Reference: Klaubauf et al. 2014 (morphology and phylogeny).
Basionym: Pyricularia luzulae Ondřej, Česká Mykol. 42: 81. 1988.
Leaf spots up to 17 mm long, ellipsoid to fusiform, grey to pale brown at middle, dark brown at margin. On SNA: Mycelium with hyaline, smooth, septate, branched, 2–3 μm diam hyphae. Conidiophores 60–120 × 4–7 μm, erect, dark brown, unbranched, subcylindrical, straight to flexuous, thick-walled, finely verruculose, 2–3-septate. Conidiogenous cells 30–50 × 4–6 μm, terminal and subcylindrical, finely verruculose, dark brown, tapering toward apex with numerous denticles pointing upwards, 1–4 × 1–1.5 μm; scars unthickened. Conidia (18–)20–22(–30) × (4–)5(–6) μm, solitary, narrowly pyriform, hyaline, becoming pale brown with age, guttulate, 1(–2)-septate, apex obtusely rounded, base truncate, 2 μm diam, slightly darkened, refractive.
Culture characteristics: Colonies flat, spreading, with sparse to moderate aerial mycelium and smooth, lobate margins, covering plate after 2 wk at 25 °C. On MEA, PDA and OA surface and reverse pale luteous.
Materials examined: Slovakia, on leaves of Luzula sylvatica (Juncaceae), Jul. 1984 (holotype of Pyricularia luzulae PRM 842743). Ukraine, on leaves of Luzula sp. (Juncaceae), 2016, A. Akulov (epitype of Pyricularia luzulae designated here MBT379806, CBS H-23355, culture ex-epitype CBS 143401 = CPC 32458); ibid., CWU (Myc) AS 5966 / 6437; Carpathian Biosphere reserve, on leaves of Luzula sylvatica (Juncaceae), Aug. 2016, A. Akulov, CPC 31555; ibid., CPC 31571.
Notes: Pyricularia luzulae was introduced for a fungus isolated on Luzula sylvatica from Slovakia (Ondřej 1988). In the original description PRM 842743 was designated as holotype, but no living culture was associated with this specimen. Therefore, a strain that closely fits the description of the protologue, and isolated from the same host in a close country to Slovakia, namely Ukraine, is designated here as epitype. The only difference observed was in the conidial size, since in the original description (in vivo) the conidia were larger and 1–2-septate (17.5–36 × 3.5–7.5 μm). However, the measurements of our isolate growing in vivo are 27.5–33 × 6.5–7.5 μm, and in vitro 18–30 × 4–6 μm, and conidia could become 2-septate with age.
The phylogenetic study of Py. luzulae revealed that it belongs to Macgarvieomyces. As noted above, the host of this genus is Juncus effusus in the same family as Luzula (Juncaceae).
Authors: Y. Marin-Felix, A. Akulov & P.W. Crous