M. Menezes et Rt. Hanlin, APPRESSORIA OF BRAZILIAN ISOLATES OF COLLETOTRICHUM-GLOEOSPORIOIDES (PENZ) SACC CAUSAL AGENT OF ANTHRACNOSES DISEASES, Revista de Microbiologia, 27(4), 1996, pp. 247-251
Morphological and functional aspects of appressoria of Colletotrichum
gloeosporioides from different sources and localities in the Northeast
ern Brazil were studied. From leaves of avocado (Persea gratissima L.)
, cashew (Anacardium occidentale L.), citrus (Citrus sp.), guava (Psid
ium guajava L.), Anona muricata L., and mango (Mangifera indica L.) sh
owing typical anthracnose symptoms twelve isolates were selected. From
each isolate, fifteen monoconidial cultures were made, and the microc
ulture technique was used for studies of appressorial morphology. All
isolates produced appressoria, but variation in size, amount, and shap
e were observed among isolates. The same isolate showed unlobed or sli
ghtly lobed appressoria, which varied in color from dark to light brow
n, occasionally one septate showing a germ pore in each cell. In some
cases, appressoria germinated and formed secondary appressoria in chai
n or isolated. Sometimes they formed germtube that produced conidia in
phialidic way. These results suggest that appressoria play an importa
nt role in the nature, not only in the direct penetration of a host, b
ut also in the ability to propagate species by production of conidia.