Cercospora beticola (Sacc.) is an etiologic agent of cercospora leaf spot on beet, which is characterized as the main disease of beet crop. Laboratory assignments require a purified organism with expressive sporulation. After the monosporic isolation of C. Beticola, a disc with micelles (9 mm) was replicated in a tomato extract growth medium (200g of tomato extract 3 g of CaCO3, 20g of agar and 1000 ml of distillate water). The mycelium growth needed more than 20 days to cover the entire dish Petri (80 x 12 mm) in incubation at 25ºC and with a photoperiod of 12 hours. From the mycelium growth there was removed a piece of approximately 2 x 2 cm using a scalpel. Then the fragment of mycelium cut was scrubbed on the tomato extract growth medium by using a histological needle (Figure 1A). The same mycelium cut was scrubbed over the entire Petri dish. Residues of mycelium or fragment of growth medium were removed from the surface by using a scalpel. The growth medium was incubated at 25ºC and with a photoperiod of 12 hours. The growth medium produced in average 1x104 spores ml-1placa-1. The sporulation started after the fourth day. The mycelium growth was maintained and evaluated after seven days of incubation (Figure 1B), reducing the sporulation after this period. This methodology has been used to conduct research with C. beticola in the laboratory of Phytopathology at the Federal Institute Catarinense/Campus Rio do Sul. This technique can be evaluated for induction of sporulation in other species of Cercospora.
Publication Dates
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Publication in this collection
Jan-Mar 2015
History
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Received
16 Oct 2014 -
Accepted
19 Dec 2014
