Biology Reference
In-Depth Information
Anthracnose
The term “anthracnose” has been used for two
distinct types of disease, one characterized by
a typical necrotic spot, a lesion of dead tissue,
and the other by some hyperplastic symptom,
such as a raised border around a more or less
depressed center. The word was coined in France
for the latter type, to differentiate a grape disease
from a smut of cereals, both of which were called
charbon
. The new word was taken from the
Greek
Anthrax
(carbuncle) and
nosos
(disease),
and was first used for the grape disease, caused by
Sphaceloma ampelina
, the chief symptom of
which was a bird's-eye spot with a raised border.
A disease of brambles, raspberry and black-
berry, was then named anthracnose because it
looked like the grape disease. The fungus, how-
ever, instead of being correctly placed in the
genus
Sphaceloma
, was mistakenly named
Gloeosporium venetum
. The next disease enter-
ing the picture was a bean trouble, and, because
the fungus was identified as
Gloeosporium
(though later transferred to the genus
Colletotrichum
), this common bean disease with
typical necrotic symptoms was also called
anthracnose and came to typify diseases so
designated.
The term “spot anthracnose” has been given to
those diseases similar to the original hyperplastic
grape disease. Those with slight hyperplastic
symptoms are still commonly called anthracnose,
and those with pronounced overgrowth of tissue
are commonly called scab. Both types are caused
by
Sphaceloma
, and are treated, in this revised text,
as a separate group.
Spot Anthracnose
.
Anthracnose in the modern sense is a disease
characterized by distinctive limited lesions on
stem, leaf, or fruit, often accompanied by dieback
and usually caused by a
Gloeosporium
or
a
Colletotrichum
, anamorph fungi producing
slime spores oozing out of fruiting bodies
(acervuli) in wet, pinkish pustules. These spores
(conidia) on germinating form an appressorium
(organ of attachment) before entering the host
plant. The teleomorph state of the fungus, when
known, is
Gnomonia
or
Glomerella
(see
Fig. 1
).
▶
Apiognomonia
Apiognomonia errabunda (Anamorph,
Gloeosporium quercinum
).
Oak Anthracnose
.
See
Discula umbrinella
and
Fig. 2
.
Apiognomonia errabunda (formerly
Gnomonia quercina
).
Oak Anthracnose
. The
fungus is closely related to
Gnomonia platani
,
usually reported as
G. veneta
, but is now consid-
ered a separate species. The anthracnose appears
as brown areas adjacent to midribs and lateral
veins.
Apiognomonia tiliae (formerly
Gnomonia
tiliae
).
Linden Anthracnose
,
Leaf Spot
,
Leaf
Blotch
,
Scorch
on American and European lin-
den. Small, circular to irregular brown spots with
dark margins form blotches along main veins
in leaves,
▶
the
genus
Elsinoe¨
,
anamorph
state
leaf stalks, and young twigs, with
