Golovinomyces Glandulariae Fungal Planet Description Sheets 369

368 Persoonia – Volume 43, 2019

Golovinomyces glandulariae Fungal Planet description sheets 369

Fungal Planet 1015 – 18 December 2019 Golovinomyces glandulariae L. Kiss & Vaghefi, sp. nov.

Etymology. Name refers to the genus Glandularia, from which this obligate basal septa sometimes 2–3 µm displaced from the point of biotrophic fungus was isolated. branching, and smaller conidia. ITS sequences are not available Classiﬁcation — Erysiphaceae, Erysiphales, Leotiomycetes. in GenBank for G. verbenae, thus the phylogenetic relationship between these two species cannot be determined. Phylogeneti- Mycelium on stems, leaves, and sepals, amphigenous, produc- cally, G. glandulariae is sister to G. magnicellulatus, which is ing dense, white patches that can cover the aerial host plant morphologically similar, although its conidia are larger. As of surfaces. Hyphae hyaline, thin-walled, 3–6 µm wide, with sim- 26 July 2019, the ITS sequence of G. glandulariae is identi- ple, nipple-shaped hyphal appressoria. Conidiophores erect, cal to only two Golovinomyces specimens, KR-M-43410 and consisting of a foot-cell, 38–95 × 9–15 μm, basal septum at KR-M-43411, available in GenBank (acc. nos. LC076839 and the branching point or up to 2–3 µm displaced, increasing in LC076840, respectively). These were collected from Verbena width from base to top, followed by 1–4 shorter cells, forming in Germany and were recognised as representing a distinct catenescent conidia. Conidia ellipsoid-cylindrical or doliiform, lineage, without being identiﬁed at the species level (Scholler 20–36 × 11–17 µm. Germ tubes arising from an end, mostly et al. 2016). The next closest hits using the ITS sequence of shorter than the conidial length, and terminating in a simple, G. glandulariae are 10 G. magnicellulatus specimens with four often swollen appressorium. Sexual morph not seen. to six nucleotide position differences in the ITS2 sequences.

Typus. Australia, Queensland, Bunya Mountains, -26.8002, 151.5686, Most of the powdery mildew mycelium on Gl. aristigera con- alt. 969 m, on leaves, stems and sepals of Glandularia aristigera (Verbena sisted of hyphae, conidiophores and conidia of G. glandulariae, ceae), 4 July 2019, L. Kiss (holotype BRIP 70490, ITS and LSU sequences although small patches of Podosphaera xanthii were also found GenBank MN190239 and MN539541, MycoBank MB831976). on the aerial plant surfaces. Podosphaera xanthii has conidia Additional materials examined. Australia, Queensland, Bunya Mountains with fibrosin bodies, which distinguishes it from G. glandulariae. - Maclagan Road, close to the intersection with Bunya Mountains Road, The ITS sequence of P. xanthii was determined in each speci- -26.9708, 151.6133, alt. 555 m, on leaves, stems and sepals of Glandularia men (acc. nos. MN190026–MN190029 and MN190244), and aristigera, 10 June 2019, L. Kiss, BRIP 70491, ITS sequence GenBank MN190241; Bunya Mountains, -26.8799, 151.5975, alt. 967 m, on leaves, these were all identical to those available in GenBank for over stems and sepals of Glandularia aristigera,18 Feb. 2017, L. Kiss, BRIP 70492, 30 other specimens of P. xanthii collected from diverse host ITS sequence GenBank MN190240; Bunya Mountains, -26.8811, 151.5975, plant species in different parts of the world. This is the first alt. 963 m, on leaves, stems and sepals of Glandularia aristigera,10 Mar. report of P. xanthii on Gl. aristigera globally. It has long been 2018, L. Kiss, BRIP 68801, ITS sequence GenBank MN190242; Bunya known that the same plants, and even the same leaves may Mountains Road, -26.8002, 151.5686, alt. 686 m, 10 June 2019, on leaves, be infected by multiple powdery mildew species (Kiss et al. stems and sepals of Glandularia aristigera, L. Kiss, BRIP 70531, ITS sequence GenBank MN190243. 2008, Desprez-Loustau et al. 2018) as detected in this study. Notes — Golovinomyces contains approximately 60 species of powdery mildew (Braun & Cook 2012), including many common, widespread, plurivorous taxa (Braun et al. 2019). Amongst these, G. orontii s.lat., G. verbenae and G. spadiceus infect diverse host plant species in the Verbenaceae (Braun & Cook 2012, Braun et al. 2019). Glandularia aristigera is a 77/1.0 verbenaceous species native to South America that has been 98/1.0 naturalised in parts of Australia. Golovinomyces glandulariae is the first powdery mildew re- -/0.96 ported on Gl. aristigera globally, causing severe local epidemics 100/1.0 in 2017–2019 in Australia. One other species, G. verbenae, has been reported on Gl. phlogiflora (Braun & Cook 2012); other 100/1.0 Glandularia spp. are not known as hosts of powdery mildews. 100/1.0 Golovinomyces glandulariae differs from G. verbenae by having conidiophores with foot-cells followed by up to four shorter cells, 100/1.0

Maximum likelihood phylogram based on the internal transcribed spacer sequences of the nuclear ribosomal DNA and the intervening 5.8S region. The alignment was deposited in TreeBASE (acc. no. 24823). The analysis was performed using RAxML v. 8 (Stamatakis 2014) in Geneious Prime (Bio- matters Ltd.) based on the GTR substitution model with gamma-distribution rate variation. A second measure of branch support was estimated through Colour illustrations. A roadside population of Glandularia aristigera heavily Bayesian Inference of the same alignment using MrBayes v. 3.2.4 (Ronquist infected with powdery mildew in Bunya Mountains, Queensland, Australia. et al. 2012). The tree is rooted to Arthrocladiella mougeotii BRIP 66057. A close-up of an infected plant; conidiophores, non-germinating and germi- Maximum Likelihood bootstrap values > 80 % and Bayesian Posterior Proba nating conidia, and a hyphal appressorium of Golovinomyces glandulariae. bility values > 0.80 are shown above or below the branches. The scale bar Scale bars = 15 μm (conidiophores, conidia), 5 μm (hyphal appressorium). represents nucleotide substitutions per site.

Levente Kiss & Niloofar Vagheﬁ, Centre for Crop Health, University of Southern Queensland, Toowoomba 4350, Queensland, Australia; e-mail: [email protected] & [email protected] Márk Z. Németh, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest H-1022, Herman Otto út 15, Hungary; e-mail: [email protected]