Colletotrichum: complex species or species ... - CBS - KNAW

Damm et al.
Fig. 6. Colletotrichum chrysanthemi (from strain CBS 126518). A–B. Conidiomata. C–H. Conidiophores. I–N. Appressoria. O–P. Conidia. A, C–E, O. from Anthriscus stem. B,
F–N, P. from SNA. A–B. DM, C–P. DIC, Scale bars: A = 100 µm, C = 10 µm. Scale bar of A applies to A–B. Scale bar of C applies to C–P.
reverse same colours; growth rate 18–20 mm in 7 d (26–29 mm in
10 d). Colonies on OA flat with entire margin; surface buff, rosy buff
to pale saffron, covered with short white aerial mycelium, reverse
same colours; growth rate 17.5–18.5 mm in 7 d (27.5–28.5 mm in
10 d). Conidia in mass salmon.
Material examined: Australia, Queensland, Brisbane, Eight Mile Plains, from fruit
rot of Capsicum annuum, 14 Jul. 1955, J.H. Simmonds, (IMI 117622 holotype of C.
brisbanense (also paratype of C. acutatum), CBS H-20801 isotype, culture ex-type
CBS 292.67 = BRIP 4684).
Notes: The type and only confirmed strain of C. brisbanense was
cited as one of the paratype strains of C. acutatum by Simmonds
(1968), and assigned to C. simmondsii by Shivas & Tan (2009).
Conidia and appressoria of C. brisbanense are larger overall
than those of C. simmondsii as accepted in this treatment. The
two species are easily separable using all sequence data except
for ITS, and most effectively with TUB2 and GAPDH sequences.
There is only one bp difference in CHS-1 sequence between C.
brisbanense and C. indonesiense. There is a further species in
clade 2 associated with Capsicum annuum, C. scovillei, possibly
a species endemic to Southeast Asia. Colletotrichum brisbanense
can be separated easily from C. scovillei based on appressorium
measurements, as well as by most DNA data. See C. scovillei for
further information.
A blastn search with the TUB2 sequence of strain CBS 292.67
resulted in a 100 % match with GU183275, the sequence of the
same strain generated by Shivas & Tan (2009); next closest was
DQ454064 from isolate S6 from Fragaria in Thailand with 99 %
identity (four differences; Sang et al. 2011). With the GAPDH
sequence there was no match with more than 95 % identity. The ITS
sequence of strain CBS 292.67 matched 100 % with GU183315, a
sequence of the same isolate generated by Shivas & Tan (2009).
Colletotrichum chrysanthemi (Hori) Sawada, Rep. Govt
Res. Inst. Dep. Agric., Formosa 85: 81. 1943. Fig. 6.
≡ Gloeosporium chrysanthemi Hori, in Takimoto, Jour. Hort. Japan 36(9):
27. 1924.
Sexual morph not observed. Asexual morph on SNA (CBS 126518).
Vegetative hyphae 1.5–9 µm diam, hyaline, smooth-walled, septate,
branched. Chlamydospores not observed. Conidiomata absent,
conidiophores formed directly on hyphae. Setae not observed.
Conidiophores hyaline to pale brown, smooth-walled, septate and
branched, to 55 µm long. Conidiogenous cells hyaline, smoothwalled,
cylindrical to ampulliform, 7–15 × 3–4.5 µm, opening 1.5–2
µm diam, collarette distinct, 0.5–1 µm long, periclinal thickening
distinct. Conidia hyaline, smooth-walled, aseptate, straight,
broadly ellipsoidal to ovoid, with both ends acute, rarely clavate
to cylindrical with one round end one acute end, (6–)7–9.5(–12) ×
(3–)4–5.5(–6) µm, mean ± SD = 8.3 ± 1.3 × 4.8 ± 0.6 µm, L/W ratio
= 1.7, conidia from aerial mycelium shorter, measuring (3.5–)4.5–
9(–15) × 3–5(–6.5) µm, mean ± SD = 6.7 ± 2.3 × 4.1 ± 0.8 µm,
L/W ratio = 1.6. Appressoria single, medium brown, smooth-walled,
60