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

Verkley et al.wk (15–18 mm in 7 wk), as on MEA, but aerial mycelium denserwith longer hyphae; conidiomatal initials developing scarcely at thesurface, still sterile after 3 wk, but later on releasing dirty buff topale ochreous droplets of conidial slime. In older colonies on MEAand CHA a grey or greyish white, dense mat of aerial hyphae maycover small or larger sectors.Conidiomata as in vitro, pycnidial, often merged to complexstromata, first brownish, then black, glabrous or the surface coveredby short white hyphae; conidiogenous cells as in planta, but larger,7.5–20 × 3–5(–6) µm, holoblastic, proliferating sympodially, nopercurrent proliferation observed; conidia similar in shape as inplanta but mostly 3–7-septate, (45–)55–85(–105) × 4–5(–7) µm.Hosts: Clematis spp.Material examined: Austria, Tirol, Ötztal, Brunau, on living leaves of Clematisvitalba, 30 July 2000, G. Verkley 1025, epitype designated here CBS H-21182“MBT175353”, living cultures ex-epitype CBS 108983, 108984; same loc.,substr., date, G. Verkley 1026, CBS H-21183; same substr., S. Tirol, Eggenthal,Birchabruck, 23 July 1904, J. Kabát, distributed in Kabát & Bubák, Fungi imperfectiexsicc. 163, PC 0084599. France, Parc de Lébisey, 27 July 1848, Roberge (?), ‘Col.Desmazieres 1863, no. 8, 448’, isotype PC 0084593; same loc., substr., June 1848,Roberge, PC 0084596; same substr., Paris, Parc de St Cloud, Aug. 1908, Ludwig,PC 0084607; same substr., Fontainebleau forest, Aug. 1885, PC 0084604; samesubstr., Clères, 27 Aug. 1896 (herb. Mussat), PC 0084598; same substr., Seine-et-Oise, Meudon, 15 Nov. 1844, Roussel (Herb. Roussel), PC 0084594, PC 0084595.Romania, distr. Iaşi, Moldova, Bârnova, same substr., 30 Aug. 1934, T. Săvulescu& C. Sandhu, distributed in Săvulescu, Herb. Mycol. Romanicum 24, 1160, PC0084603, 0084608, 0084597.Notes: This is one of the large-spored species of Septoria fromthe genus Clematis. Teterevnikova-Babayan (1987), who studiedcollections from several species of Clematis observed, 4–6-septateconidia 60–90 × 3–5 µm. Vanev et al. (1997) reported conidiaas 39–100 × 2.5–4 µm. The type of S. clematidis in PC showed4-7-septate conidia 52–78 × 3–3.5 µm, in good agreement with theones observed in the Austrian material (CBS H-21182), which isdesignated above as epitype.The taxonomy of the 15 described species of Septoria onClematis is still unresolved (Shin & Sameva 2004), and wouldcertainly benefit from study of additional fresh material and cultureswhich could be compared with type material. Septoria clematidisRoberge is probably distinct from S. clematidis Pandotra & K.S.M.Sastry, a taxon described on Clematis grata in India that should berenamed because it is a later homonym. According to Muthumary(1999), the conidia in the type of S. clematidis Pan. & Sastry are1–3-septate, 38–66 × 2.5–3 µm, whereas in the original diagnosisthe conidia are described as “ septate”, 25.6–44.8 (av. 36.3) × 2.3–3.2 (av. 2.7). Two other large-spored species are S. jackmanii Ellis& Everh. 1892, which was described from Clematis jackmanii inGeneva, New York and, according to the diagnosis, has conidia 40–70 × 2.5–3 µm (number of septa not given), and also S. williamsiaePriest, based on material on C. aristata in Australia, which has(1–)3(–4)-septate conidia 20–45(–55) × (1.5–)2 µm (Priest 2006).Septoria convolvuli Desm., Annls Sci. Nat., sér. 2, Bot.17:108. 1842. Fig. 14.Description in planta: Symptoms leaf lesions circular, single orconfluent to form irregular extended lesions, pale to dark brown,showing one to several concentric lines and a dark brown,slightly raised line or zone delimiting the lesion, visible on bothsides of the leaf. Conidiomata pycnidial, epiphyllous, several ineach lesion, immersed, subglobose to globose, brown to black,(65–)90–120(–145) µm diam; ostiolum central, circular to irregular,initially 20–40 µm wide, later becoming more irregular and up to70 µm wide, surrounding cells somewhat darker; conidiomatalwall 10–15 µm thick, composed of a homogenous tissue ofhyaline, angular cells, 2.5–4.5 µm diam, the outermost cells palebrown with slightly thickened walls, the inner cells thin-walled.Conidiogenous cells hyaline, discrete, rarely integrated in 1-septateconidiophores, narrowly to broadly ampulliform, holoblastic,proliferating percurrently several times, with indistinct annellationson a relatively elongated neck, or sympodially, 6–10(–17) ×2.5–3.5(–4) µm. Conidia filiform to filiform-cylindrical, slightly tostrongly curved, often elegantly flexuous, attenuated in the uppercell to a narrowly rounded to pointed tip, narrowly truncate at thebase, 1–3(–4)-septate, not constricted around the septa, hyaline,contents minute oil-droplets and granular material in the rehydratedstate, (15–)23–42(–50) × 1.5–2 µm (rehydrated). Sexual morphunknown.Description in vitro: Colonies on OA 3–5 mm diam in 1 wk (16–20mm in 25 d; 40–48 mm in 33 d), with an even, glabrous margin,which is colourless, or faintly salmon due to a diffusable pigmentalready visible after 1 wk (but fading after 3 wk); colonies firstrestricted, conical to irregularly pustulate, but later spreading,immersed mycelium in the centre becoming first yellowish or citrine,then herbage green or darker olivaceous, surrounded by a morepalid, rosy-buff or pale salmon, later hazel outer zone; pycnidiaalready developing in clusters or radiating rows at the colonysurface, but they remain scarce, later releasing pale rosy-buff orwhitish droplets of conidial slime; aerial mycelium remaining scanty,but in the centre it may be well-developed, white, woolly; reversein the centre olivaceous-black to olivaceous-grey, surrounded bya first salmon or rosy-buff zone where the diffusable pigment isformed, but this becomes hazel. Colonies on CMA 3–5 mm diamin 1 wk [(15–)18–21 mm in 25 d; 38–40 mm in 33 d], as on OA, butsalmon pigment only faintly visible after 20 d, the margin becomingrosy-buff; centre much darker earlier on, entirely olivaceous-black,numerous black papillate to rostrate pycnidia developing after 21 d,releasing pale whitish to buff droplets of conidial slime. Colonies onMEA 2–5 mm diam in 1 wk [5–11 mm in 25 d; 16–18(– 23) mm in 33d], with a ruffled, mostly colourless margin already covered by whiteaerial hyphae after 1 wk; a halo of a diffusing pigment is visible after1 wk, which fades later on; colonies restricted, irregularly pustulateand up to 3 mm high after 1 wk, immersed mycelium dark, butmostly invisible from above due to well-developed, white to greyish,dense and short-felted aerial mycelium; black conidiomata alreadydeveloping after 1 wk, releasing large masses of buff conidialslime; reverse mostly sepia to isabelline. Some colonies may showa more spreading growth after 2 wk in sectors, that are glabrous,immersed mycelium almost black. Colonies on CHA 3–5 mm diamin 1 wk (18–30 mm in 25 d; 30–34 in 33 d), with an even, glabrous,colourless margin; colonies irregularly pustulate, up to 3 mm highafter 1 wk, immersed mycelium colourless to pale ochreous, but inthe centre the surface may be already almost black, while after 25d the entire colony attains that colour, the larger part covered bywell-developed, low, dense, pure white, later smoke-grey to greyolivaceous,felty to woolly-floccose, aerial mycelium; conidiomatalinitials developing mainly in the centre after 1 wk; reverse mostlyfawn, but later almost entirely brown-vinaceous.Conidiomata single, 60–150 µm diam, or merged to smallclusters of up to 350 µm diam, olivaceous to brown, formed mostlyon the agar surface; conidiogenous cells as in planta, 6–20 ×2.5–4(–5) µm; conidia as in planta, but often some conidia with250