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

Damm et al.
Table 1. (Continued).
Species Accession No. 1 Host/Substrate Country GenBank No.
ITS GAPDH CHS-1 HIS3 ACT TUB2
C. walleri CBS 125472, BMT(HL)19* Coffea sp., leaf tissue Vietnam JQ948275 JQ948605 JQ948936 JQ949266 JQ949596 JQ949926
Colletotrichum sp. CBS 129820, G5 Passiflora edulis, fruit, scab Colombia JQ948183 JQ948513 JQ948844 JQ949174 JQ949504 JQ949834
CBS 129821, G6 Passiflora edulis, fruit, scab Colombia JQ948182 JQ948512 JQ948843 JQ949173 JQ949503 JQ949833
CBS 129823, G8 Passiflora edulis, leaf, anthracnose Colombia JQ948192 JQ948522 JQ948853 JQ949183 JQ949513 JQ949843
IMI 384185, CPC 18937 Caryocar brasiliense Brazil JQ948191 JQ948521 JQ948852 JQ949182 JQ949512 JQ949842
CBS 101611 Fern Costa Rica JQ948196 JQ948526 JQ948857 JQ949187 JQ949517 JQ949847
CBS 129810, T.A.2 Solanum betaceum, fruit, anthracnose Colombia JQ948179 JQ948509 JQ948840 JQ949170 JQ949500 JQ949830
1 CBS: Culture collection of the Centraalbureau voor Schimmelcultures, Fungal Biodiversity Centre, Utrecht, The Netherlands; IMI: Culture collection of CABI Europe UK Centre, Egham, UK; MAFF: MAFF Genebank Project, Ministry of Agriculture, Forestry
and Fisheries, Tsukuba, Japan; BRIP: Plant Pathology Herbarium, Department of Employment, Economic, Development and Innovation, Queensland, Australia; ICMP: International Collection of Microorganisms from Plants, Auckland, New Zealand; STE-U:
Culture collection of the Department of Plant Pathology, University of Stellenbosch, South Africa; HKUCC: The University of Hong Kong Culture Collection, Hong Kong, China; PD: Plantenziektenkundige Dienst Wageningen, Nederland; * ex-holotype or
ex-epitype cultures.
3–8.5 µm diam. Setae very few, medium brown, basal cell pale,
smooth-walled, 1–2-septate, 45–85 µm long, base cylindrical,
3–4 µm diam, tip ± acute. Conidiophores hyaline to pale brown,
smooth-walled, septate, branched, to 30 µm long. Conidiogenous
cells hyaline, smooth-walled, cylindrical to ampulliform, 9–20 × 3.5–
5 µm, opening 1–1.5 µm diam, collarette 0.5–1 µm long, periclinal
thickening distinct. Conidia hyaline, smooth-walled, aseptate,
straight, cylindrical with one end round and one end slightly acute,
(12.5–)15–18.5(–20.5) × (4–)4.5–5 µm, mean ± SD = 16.8 ± 1.7 ×
4.7 ± 0.3 µm, L/W ratio = 3.6.
Culture characteristics: Colonies on SNA flat with entire margin,
hyaline to pale cinnamon, on filter paper, Anthriscus stem and
medium partly covered with short floccose-felty white aerial
mycelium and salmon, orange to olivaceous grey acervuli, reverse
same colours, growth rate 20–21.5 mm in 7 d (32–33 mm in 10 d).
Colonies on OA flat with entire margin; surface buff to honey, almost
entirely covered with floccose-felty white to pale olivaceous grey
aerial mycelium and olivaceous grey to salmon acervuli, reverse
buff, pale olivaceous grey, grey olivaceous to iron-grey, growth rate
17.5–20 mm in 7 d (27.5–30 mm in 10 d). Conidia in mass salmon
to orange.
Material examined: New Zealand, Nelson, from bitter rot on fruit of Malus domestica,
1 Aug. 1987, P.R. Johnston, (CBS H-20725 holotype, culture ex-type CBS 128530
= ICMP 12921 = PRJ 1199.3).
Notes: Bitter rot has been considered an economically signficant
disease of apple for many years (Schrenk & Spaulding 1903b), and
was initially ascribed to Gloeosporium fructigenum (Berkeley 1856).
However, Berkeley’s type was examined by Vinnere (2004) and
found to have falcate conidia, thus excluding it from the C. acutatum
species complex. Currently, bitter rot is known to be caused primarily
by fungi from the C. gloeosporioides species complex (González et al.
2006); that study focused on strains from the USA and Brazil, and we
do not know whether their C. acutatum s. lat. strains are conspecific
with C. acerbum. Those of Lee et al. (2007) from Korea are referable
to C. acutatum clades 2 (C. nymphaeae and related species) and
3 (C. fioriniae), so the host certainly appears susceptible to a wide
range of Colletotrichum pathogens.
The ex-type strain of C. acerbum is the only strain we included
in our study that represents C. acutatum group B as delineated by
Lardner et al. (1999). It may be common on Malus in New Zealand,
but Lardner et al. (1999) found that more strains from fruit rot of
apple, as well as from feijoa and fig, belonged to group C and had
similar RAPD banding patterns (Lardner et al. 1999). It is possible
that their group C includes more than one species. The GAPDH
sequence of strain PJ9 (= PRJ 819 in Lardner et al. 1999), which
was isolated from apple in New Zealand and was sequenced by
Guerber et al. (2003), is identical to that of CBS 128530, the extype
strain of C. acerbum.
Colletotrichum acerbum is distinguishable from C. rhombiforme
and all other species in all gene sequences analysed except for
CHS-1, and is most effectively distinguished with TUB2 and ITS.
In morphological terms its conidia are longer and the appressoria
are shorter and wider than those of C. rhombiforme. Based on
our studies and blastn searches in GenBank, it seems that C.
acerbum could be endemic to New Zealand. The closest match
based on TUB2 sequence that we could find (with 99 % identity, 5
bp differences) was AJ748624 from isolate PT250 (= CBS 129953),
derived from olive in Portugal (Talhinhas et al. 2005), which
we assign to C. rhombiforme. The closest matches for the ITS
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