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Occurrence of privet anthracnose in Hungary
caused by Glomerella cingulata
L. Vajna1*, T. Bagyinka2
1 Plant Protection Institute of the Hungarian Academy
of Sciences, 1525 Budapest P. Box 102.
2 Plant Protection and Soil Conservation Service, 1519
Budapest P. Box 340.
*lvaj@nki.hu
Accepted for publication 29/01/02
In Hungary, privet (Ligustrum vulgare L.) and its cultivars
are widely planted and popular ornamental plants. Until 1999, there were
no records of any important diseases of privet in Hungary. In 1999, a
canker disease was observed in the south-eastern part of Hungary causing
severe losses of mother plants and rooted cuttings of some cultivars of L.
vulgare. Frequency of disease occurrence ranged between 30 - 40 % of
cv. 'Lodense', 10 - 20 % of 'Chlorocarpum', and 10 % of 'Pyramidale';
only slight symptoms developed on cv. 'Atrovirens'. Ten - 60 % of
infected mother plants of the different cultivars died. The highest loss
occurred among mother plants of cv. 'Lodense'.
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Fig. 1. Symptoms of anthracnose on privet twigs.
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Fig. 2. Colony of G. cingulata with ascocarps
on PDA medium.
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Fig. 3. Detail of acervuli of C. gloeosporioides
from stem of
infected privet.
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On infected stems and
twigs typical symptoms of anthracnose appeared: several sunken lesions
of 0.5 - 2.5 cm developed with pinkish, acervular type fruiting
structures. Affected bark on the cankers split, exposing the wood.
Plants died when twigs or stems were girdled. Dried-out leaves clung to
such stems and twigs. The cause of cankers was identified as Glomerella
cingulata (Stonem.) Spauld. et Schrenk, anamorph: Colletotrichum
gloeosporioides (Penz.) Penz. et Sacc. Development of both the
anamorph and teleomorph stage (acervuli and ascocarps) was common in
diseased, dead bark tissue. Conidia measured 15.7 x 5.1 μm (13.0 -
22.5 x 4.5 - 5.5 µm).
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Fig. 4. Conidia of C. gloeosporioides.
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Fig. 5. Phloem necrosis on cv. 'Lodense' (after artificial
inoculation with G. cingulata ).
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Pathogenicity of the fungus was confirmed
with a monoconidial culture on two-year-old potted privet plants of cvs.
'Lodense, 'Chlorocarpum', 'Pyramidale' and L. obtusifolium. Test
plants, propagated from cuttings, were obtained from a nursery and kept
during the test under greenhouse conditions at 15 - 28°C
and 80% relative humidity. Six plants of each cv. and L. obtusifolium
were inoculated with the fungus and three served as wounded uninoculated
controls. This test was run twice. Because of the small size of
test plants only one wound inoculation was made on each one, using
mycelial agar plugs. After 14 days, sunken necrotic lesions with a
brownish discoloration, similar to naturally occurring cankers,
developed on inoculated plants. The most intensive stem canker
development was observed on plants of cv. 'Lodense'. There was no
infection on L. obtusifolium. Glomerella cingulata was
successfully reisolated from the lesions of inoculated plants. After 6
weeks many stems died after cankers completely girdled them. No necrosis
developed around control wounds. This is the first report of the
occurrence of privet anthracnose in Hungary. This disease was reported
recently from Poland (Orlikowski & Wojdyla, 1991) and is recorded
from the Ukraine (Zerov, 1971) and several states in the US (Farr et
al., 1989).
Acknowledgements
Investigations were supported partly by the grant of OTKA T 032 104
References
Orlikowski LB, Wojdyla A, 1991. Occurrence, development and chemical
control of Colletotrichum gloeosporioides on privet (Ligustrum
vulgare L.). Prace Institutu Sadownictwa i Kwiaciarstwa w
Skierniewicach. Seria B: Rosliny - Ozdobne. 16, 151 - 156.
Farr DF, Bills GF, Chamuris GP, Rossman AY, eds, 1989. Fungi on
plants and plant products in the United States. St. Paul, Minnesota, US,
APS Press.
Zerov DK, ed, 1971. Viznatsnik Gribiv Ukraїni., Kiev,
Ukraine, Vidavnitzvo Naukova Dumka.
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