Isolation of Formosa strains
Undamaged pods were collected in 2001 harvest
from a single peanut field at Las Lomitas in Formosa
province. This was a experimental field, and it
represents the first report of a peanut field grown
in Formosa, Argentina.
The sample was processed immediately after harvest,
undamaged pods were selected and mixed uniformly.
They were first surface sterilized in 2%
NaOCl with 100 Al/l Tween 20 (1 min) followed by
a brief sterile water rinse and then hand shelled, 600
seeds from different pods were individually surface
sterilized in test tubes in the same manner followed by
three water rinses. Seeds were plated on Dichloran-
18% glycerol agar (DG18) and incubated 7 days at
25 jC.
Species of Aspergillus that developed from the
seeds were identified directly on the plates according
to Klich and Pitt (1988) and Pitt and Hocking
(1997). A. flavus isolates were transferred to slants
of Czapek-Dox agar (Cz) and incubated for 14 days
at 25 jC; S and L strains were included in this
study.