Genus Cercospora in Thailand: Taxonomy and Phylogeny (with a ...

diam., substomatal to intraepidermal, small,
composed of a few globose to subglobose,
brown cells. Conidiophores 52–129 × 2–3.5
μm, 6–8 in loose fascicles, 2–4-septate, arising
from stromata, straight to decumbent, smooth,
brown at the base, paler toward the apex,
unbranched, cylindrical, geniculate, mostly
near the apex. Conidiogenous cells integrated,
holoblastic, polyblastic, sometimes monoblastic,
sympodially proliferating. Conidiogenous
loci 1–2 μm, conspicuous, thickened and
darkened. Conidia 35–73 × 4–5 μm, solitary,
obclavate, slightly curved, hyaline, 3–11septate,
smooth, obconically truncate at the
base, with tapering toward a subacute apex,
hila 1–2.3 μm diam., thickened and darkened.
Specimen examined – THAILAND,
Chiang Mai Province, A. Mueang, Sri Pum,
Chiang Mai Public Garden, on leaves of
Impatiens walleriana Hook. f. (Balsaminaceae),
15 August 2008, Jamjan Meeboon (BBH
23582).
Hosts – Impatiens balsamina (Balsaminaceae)
(Yen & Lim 1980), Impatiens
walleriana (Meeboon 2009).
Distribution – Singapore, Thailand (Yen
& Lim 1980, Meeboon 2009).
Notes – The symptoms, stromata and
conidiophores of this specimen are close to C.
apii s. lat. fide Crous & Braun (2003), but the
conidia are obclavate with an obconically
truncate base. We decide to assign this
specimen to C. balsaminiana. The first report
of C. balsaminiana from Thailand was by
Meeboon (2009).
Literature – Yen & Lim (1980, p. 155).
Cercospora fukushiana (Matsuura) W.
Yamam., J. Soc. Trop. Agric. 6: 601 (1934).
≡ Cercospora fukushiana Matsuura, J.
Pl. Prot. 14: 699 (1927).
= Cercospora balsaminae Mend. Philipp.
J. Sci. 75: 166 (1941).
= Cercospora balsaminae Kellerm. &
Swingle, fide Chupp (1954).
(= C. apii s. lat.) Fig. 32
Leaf spots 15 – 30 mm diam., amphigenous,
circular or subcircular, at first pale
greenish to ochraceous, later brown to dark
brown, finally with greyish brown centre,
surrounded by a dark margin. Caespituli
Plant Pathology & Quarantine
Fig. 32 – Line drawings of Cercospora
fukushiana on Impatiens balsamina. a. Conidia.
b. Conidiophores and stromata. Bars: a = 100
µm, b = 40 µm. (Meeboon 2009).
amphigenous. Stromata 25-32 μm diam., small
to well-developed, composed of globose to
subglobose, brown to blackish brown cells.
Conidiophores 49–112 × 4–6.5 μm, 6–8 in
loose to dense fascicles, arising from stromata,
simple, straight, 1–4-septate, erect to decumbent,
smooth, subcylindrical, pale yellow to
pale brown, sometimes branched, geniculate to
sinuous. Conidiogenous cells integrated, terminal,
holoblastic, monoblastic or polyblastic,
sympodially proliferating. Conidiogenous loci
conspicuous, thickened, and darkened. Conidiogenous
loci 2–3 μm diam., conspicuous,
thickened, and darkened. Conidia 60–120 ×
2.5–5 μm, solitary, narrowly obclavate to
subacicular, 5–18-septate, straight, hyaline,
smooth, base truncate to obconically truncate,
with subacute apex, hila 1.5–2.5 μm diam.,
thickened and darkened.
Specimens examined – THAILAND,
Phetchabun Province, Nam Nao National Park,
on leaves of Impatiens balsamina L.
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