Two
leaves and two segments of roots from each
collected plant were used. Samples were sterilized
according to FISHER et al. (1992) with
modiifications (PEREIRA et al.,1993; 1999).
They were washed in water following surface
sterilization with ethanol 70% for 30 seconds and
then treated with sodium hypochloride (3%-5%
available chlorine) for 3 minutes. Samples were
exaustively rinsed with sterile water. Sterility
checks and reconstruction experiments showed
that most or all epiphytic microorganisms were
eliminated during this treatment. Each root was
divided into pieces of ca. 1 cm and each leaf was
divided into fragments of about 1 cm
2
. Root and
leaf fragments were assepticaly transferred to petri
dishes containing starch-casein-agar medium
(Kuster & Williams, 1964) and 2.5% water-agar
medium. Nystatin and cycloheximide (50µg/ml of
each) were added to both media to suppress fungal
growth (Williams & Davies, 1965).Plates were
incubated at 280 C for a maximum of three weeks.
Actinomycetes growing on the media