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

Verkley et al.Fig. 32. Septoria petroselini. A, B. Colonies CBS 109521 (15 °C, nUV). A. On OA. B. On MEA. C, D. Conidia on OA (CBS 109521). E. Conidia and conidiogenous cells in planta(CBS H-21166). F. Conidia on OA (CBS 182.44). G. Conidia on OA (CBS 109521). Scale bars = 10 µm.Hosts: Petroselinum crispum (syn. Apium petroselinum), otherPetroselinum spp. and Coriandrum sativum (Priest 2006).Material examined: Netherlands, Prov. Utrecht, Baarn, garden Eemnesserweg 90,on living leaves of Petroselinum crispum, 29 Mar. 2001, H.A. van der Aa 12642,CBS H-21166, living culture CBS 109521; Laren, on living leaves of P. sativum, June1944, S. Dudok de Wit s.n., living culture CBS 182.44 = IMI 100279, dried specimenof culture on CMA, CBS H-18128.Notes: CBS 182.44, isolated from Petroselinum sativum, producesconidia 29–49 × 1–2 µm, and this range of sizes agrees withthose given for S. petroselini by most authors [26–45(–52) ×(1–)1.5–2 µm cf. Priest 2006; 16–46 × 1–2 mm cf. Jørstad 1965on Petroselinum]. In contrast, the conidia in the collection on P.crispum (CBS H-21166), as well as in the isolate CBS 109521derived from it, were up to 80 µm long and 2.5 µm wide, and thepycnidia were also larger than described for S. petroselini, for whichthis material was initially identified as S. apiicola, but the moleculardata provide evidence that it also belongs to S. petroselini. Thematerial is 100 % homologous on ITS, Act, RPB2 and EF, and99.7 % on Cal with CBS 182.44. The range of conidial sizes for S.petroselini is therefore expanded here, although it should be notedthat the conidia formed in vitro are not over 65 µm in length in thematerial available. The ITS sequence of S. anthrisci is distinct fromthat of S. apiicola, but identical to that of S. petroselini and otherspecies. Septoria anthrisci can be distinguished from S. petroseliniby the Act, EF and RPB2 sequences.Septoria phlogis Sacc. & Speg., in Sacc., Michelia 1: 184.1878 [as “phlocis”; non Ellis & Everh., in G. Martin, J. Mycol.3: 85. 1887; nec P. Syd., Mycoth. March., Cent. 18, no 1757;Cent. 23, no 2278. 1887; later homonyms]. Fig. 33.Description in planta: Symptoms leaf lesions developing in areasof the leaf lamina that first turn yellow, indefinite or delimited bydarkening veinlets, hologenous, pale to dark brown. Conidiomatapycnidial, epiphyllous, numerous, semi-immersed to immersed,subglobose to globose, dark brown to black, 100–160 µmdiam; ostiolum central, circular, initially 25–35 µm wide, laterbecoming more irregular and up to 70 µm wide, surrounding cellsconcolourous; conidiomatal wall 15–28 µm thick, composed of anouter layer of isodiametric to irregular cells mostly 5–9 µm diamwith pale brown cell walls up to 2 μm thick, and an inner layer ofhyphal to isodiametric cells 3–5 μm diam with thin, hyaline walls.Conidiogenous cells hyaline, discrete or integrated in 1–2-septateconidiophores up to 22 µm long, cylindrical, or narrowly to broadlyampulliform, holoblastic, often proliferating percurrently withindistinct annellations as well as sympodially, 5–7.5(–8) × 2.5–4(–5) µm. Conidia cylindrical, filiform, straight to slightly curved,278