A new approach to species delimitation in Septoria - CBS - KNAW

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Verkley et al.Fig. 30. Septoria napelli. A–C. Colonies CBS 109104 (15 °C, nUV). A. On OA. B. On CHA. C. On MEA. D. Conidia and conidiogenous cells on OA (CBS 109104). E. Conidiain planta (CBS H-21153). Scale bars = 10 µm.Material examined: Austria, Ober Inntal, Samnaun Gruppe, Zanderstal near Spiss,alt. 1800 m., on living leaves of Aconitum napellus, 11 Aug. 2000, G. Verkley 1070,CBS H-21153, living cultures CBS 109104, 109105; same loc., host, date, G. Verkley1071, CBS H-21154, living culture CBS 109106. Romania, reg. Mureş-AutonomăMaghiară, on living leaves of A. degenii, 25 Aug. 1953, C. Sandu-Ville s.n., CBSH-18117, distributed in Herb. Mycol. Romanicum, fasc. 35, no. 1742.Notes: According to the brief original diagnosis, S. napelli ischaracterised by 120–130 µm wide hypophyllous pycnidia,and indistinctly septate conidia measuring 50–100 × 2–4 µm.Teterevnikova-Babayan (1987) reported up to 9-septate conidiameasuring 40–100 × 3–4 µm, and Shin & Sameva (2004)3–9-septate conidia, 40–105 × (2.5–)3–5 µm in Korean material.It is doubtful whether the description by Petrak (1957) of S. napelliwas based on correctly identified material. Pycnidia of that funguswere mostly hypophyllous, with 3–7, rarely 8–9-septate conidiameasuring 40–70 (rarely up to ca. 100) × 3–4 µm, arising fromseptate and branched conidiophores. The pycnidial wall wascomposed of globose to angular cells 5–8(–10) µm diam, withwalls thickened to an extent which would avoid any compression.Petrak (1957) also observed young fruitbodies of a sexual morphon dead leaves in between old and empty conidiomata. Althoughthis sexual morph was immature, in his opinion it was “undoubtedlyPleosporaceae, perhaps a species of Leptosphaeria, but certainlynot Mycosphaerella”. Certain similarities in the walls of the asexualand sexual morph, made him suspect that they were produced indifferent stages in the life-cycle of a single fungus. Because of thelarge size of the pycnidia of Petrak’s S. napelli, the structure ofthe pycnidial wall and conidial ontogeny, which were unlike typicalSeptoria, he proposed the combination Rhabdospora napelli.Petrak’s observations of S. napelli probably pertained to a differentseptoria-like fungus (Stagonospora?), probably with pleosporaleanaffinities, but of which the exact identity remains unclear.274
A new approach to species delimitation in SeptoriaThe fungus studied in the present study, which is a member ofthe Septoria clade, generally agrees with the original descriptionof S. napelli. It is unknown whether S. napelli has a sexual morph.Two Mycosphaerella names have been published from Aconitum,M. antonovii on Aconitum excelsum in Siberia, and M. aconitorum,on Aconitum sp. in Austria. Both names were introduced byPetrak, who did not observe associated asexual morphs for theseMycosphaerella spp. A comparison with S. lycoctoni, including themolecular results, is provide above in the notes on S. lycoctoni.CBS 128664 isolated from Aconitum pseudolaeve var. erectumin Korea, is genetically distinct from both Septoria spp. on Aconitumin Europe. The new name S. pseudonapelli is proposed for thisfungus by Quaedvlieg et al. (2013, this volume).Septoria obesa Syd., in Syd. & P. Syd., Annls mycol. 12:163. 1914.= S. artemisiae Unamuno, Assoc. españ. Progr. Cienc. Congr. Salamanca: 46.1923 [nom. illeg., later homonym, non Passerini, 1879].Descriptions in planta are provided by Punithalingam (1967c) andPriest (2006). Sexual morph unknown.Hosts: Artemisia lavandulaefolia and Chrysanthemum spp.Material examined: Germany, Weihenstephan, on Chrysanthemum indicum, R.Schneider Sep. 1957, living culture CBS 354.58 = BBA 8554 = IMI 091324. SouthKorea, Hongcheon, on Artemisia lavandulaefolia, H.D. Shin, 28 June 2006, livingculture SMKC 21934 = KACC 42453 = CBS 128588; Bonghwa, on Chr. indicum,H.D. Shin, 18 Oct. 2007, living culture SMKC 23048 = KACC 43193 = CBS 128623;Jeju, on Chr. morifolium, 5 July 2008, living culture KACC 43858 = CBS 128759.Notes: Jørstad (1965) regarded S. obesa as a synonym of S.leucanthemi, as both have similar conidial morphologies andoccur on several Chrysanthemum spp. Punithalingam (1967b, c),however, recognised S. obesa and S. leucanthemi as separatespecies, noting that the conidia of S. obesa are consistently widerthan those of S. leucanthemi. Verkley & Starink-Willemse (2004)found additional, molecular support for the treatment.as separatespecies in eight polymorphisms found on the ITS sequencesof strains representing these species. Further evidence is nowprovided here based on sequences of six other loci. The hostranges of the two species are also different: S. leucanthemiis capable of infecting various species of a wide range plantgenera, viz. Chrysanthemum, Tagetes, Achillea, Centaurea andHelianthus (Waddell & Weber 1963, Punithalingam 1967b).Septoria obesa seems to mainly infect Chrysanthemum spp.,but it does also infect Artemisia lavendulaefolia, as could bedemonstrated in this study with CBS 128588, a strain originallyidentified as S. artemisiae. The strain is genetically very close tothe other strains of S. obesa studied here and therefore regardedas conspecific. The conidia produced by CBS 128588 are in goodagreement with S. obesa as well, being much larger than in S.artemisiae (30–33 × 1.5 µm, according to the original diagnosisof S. artemisiae Passerini). The later homonym S. artemisiaedescribed by Unamuno based on material on Artemisia vulgarisin Spain with 4-septate conidia 35.5–52.5 × 2.5–3 µm, is placedhere in the synonymy of S. obesa.The conidia of the sunflower pathogen S. helianthi (50–85 ×2–3 μm) are similar to those of S. obesa (50–90 × 2.5–3.5 μm, cf.Priest 2006), but they can be distinguished by the number of septaformed, viz., seldom more than 5 in S. helianthi and 5–11 septa inS. obesa. Verkley & Starink already showed that ITS sequences ofthese species differ by more than 20 base positions, which is alsosupported by the results found in the present study for other genes(Fig. 2).Septoria paridis Pass., Atti Soc. crittog. ital. 2: 41. 1879. Fig.31.Description in planta: Symptoms leaf spots single, scarce, circular toirregular, white to pale ochreous, surrounded by a vague orange toreddish brown zone, visible on both sides of the leaf, decaying to shotholes.Conidiomata pycnidial, epiphyllous, one to a few in each leafspot, globose, black, immersed, 60–100 µm diam; ostiolum central,circular and 35–40 µm wide, surrounding cells concolorous to slightlydarker; conidiomatal wall up to 15 µm thick, composed throughout ofhyaline, angular cells, 2.5–5 µm diam, the outermost cells brown withsomewhat thickened walls, the inner cells hyaline and thin-walled.Conidiogenous cells hyaline, discrete, globose, doliiform, or broadlyampulliform, holoblastic, proliferating percurrently several times withdistinct annellations thus forming a relatively narrow neck, rarelyalso sympodially, 5–8(–11) × 2.5–5 µm. Conidia filiform, straight, orslightly curved, attenuated gradually to a narrowly pointed apex anda narrowly truncate base, 0–3-septate (septa very thin and easilyoverlooked), not constricted around the septa, contents with severalminute oil-droplets and granular material in each cell in the livingstate, with minute oil-droplets and granular contents in the rehydratedstate, (18–)20–28.5(–34) × 1–1.5(–2) µm (living; rehydrated, 1 µmwide). Sexual morph unknown.Description in vitro: Colonies on OA 8–11 mm diam in 10 d (30–35mm in 3 wk; more than 75 mm in 7 wk), with an even, glabrous,colourless margin; immersed mycelium mostly homogeneouslypale coral to pale red, some pigment diffusing beyond the colonymargin, olivaceous to greenish hyphal radial strands also weaklyor more strongly developing in some sectors or entire colonies(especially after 7 wk, when most of the red pigment is no longervisible); in the centre olivaceous-black and slightly elevated dueto superficial and immersed pycnidia, surrounded by an area withmore scattered pycnidia, releasing pale whitish droplets of conidialslime; aerial mycelium very scanty, few minute white tufts; reverseolivaceous-black to greenish grey, surrounded by coral to siennaareas. Colonies on CMA 7–10 mm diam in 10 d (28–33 mm in 3wk; more than 75 mm in 7 wk), as on OA, but the colonies soonerpigmented, dark green, dark blueish green or olivaceous, and ared pigment tardily formed, but more persistent and still well visibleafter 7 wk. Sporulation as on OA. Colonies on MEA 6–11 mmdiam in 10 d (23–30 mm in 3 wk; 64–75 mm in 7 wk), the margineven, glabrous, buff; colonies spreading, but the centre elevated,irregularly pustulate, up to 2 mm high, the surface dark greyishbrown, later black, covered by short felty white aerial mycelium,or higher tufts; reverse of the colony brown-vinaceous or sepia,paler towards the margin. Pycnidia mostly superficial, in densegroups. Colonies on CHA 5–8 mm diam in 10 d (28–35 mm in 3 wk;45–55 mm in 7 wk), with an even to ruffled, glabrous, colourless tobuff margin; immersed mycelium in areas where first sporulationoccurs becoming dark, greenish grey to dark slate blue, latermore throughout colony, covered by well-developed, tufty whitishgrey aerial mycelium that later shows a reddish haze; reverseolivaceous-black to sepia, but margin paler; in the central part ofthe colony numerous pycnidia develop; in older colonies the centrebecomes up to 3 mm high.Conidiomata (OA) as in planta, immersed or developing onthe agar surface, single or merged into complexes 100–220 µmwww.studiesinmycology.org275
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Page 18 and 19: Verkley et al.CaryophyllaceaeRutace
Page 20 and 21: Verkley et al.CaryophyllaceaeRutace
Page 22 and 23: Verkley et al.Fig. 3. Caryophyllose
Page 38 and 39: Verkley et al.wk (15-18 mm in 7 wk)
Page 40 and 41: Verkley et al.Conidiomata simple or
Page 42 and 43: Verkley et al.Fig. 16. Septoria cuc
Page 44 and 45: Verkley et al.Fig. 17. Septoria dig
Page 46 and 47: Verkley et al.Baarnsche bos, ex lea
Page 48 and 49: Verkley et al.Septoria galeopsidis
Page 50 and 51: Verkley et al.already considered th
Page 52 and 53: Verkley et al.Fig. 23. Septoria lac
Page 54 and 55: Verkley et al.much more profound di
Page 56 and 57: Verkley et al.Fig. 26. Septoria lyc
Page 58 and 59: Verkley et al.Fig. 27. Septoria lys
Page 60 and 61: Verkley et al.to very dark dull gre
Page 64 and 65: Verkley et al.Fig. 31. Septoria par
Page 66 and 67: Verkley et al.Fig. 32. Septoria pet
Page 68 and 69: Verkley et al.Fig. 34. Septoria pol
Page 70 and 71: Verkley et al.CBS 179.77; same area
Page 72 and 73: Verkley et al.0(-9-11?)-septate con
Page 74 and 75: Verkley et al.to 60 µm diam, lacki
Page 76 and 77: Verkley et al.Fig. 38. Septoria sis
Page 78 and 79: Verkley et al.on OA, but olivaceous
Page 80 and 81: Verkley et al.Fig. 41. Septoria urt
Page 82 and 83: Verkley et al.ampulliform to almost
Page 84 and 85: Verkley et al.diam; Conidiogenous c
Page 86: Verkley et al.Notes: The type mater
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