Materials and Methods
For studying the antagonistic ability of
Trichoderma herzianum and some bacterial
antagonists against Fusarium oxysporum f. sp.
lycopersici the antagonistic fungus as well as the
bacterial isolates was isolated from rhizosphere
soil. Bacteria were isolated by dilution plate
method of Goszczynska and Serfontein (1998)
and colony was purified on NA plates. Similarly,
T.herzianum was isolated and purified on PDA
plates following a standard method
(Ashrafuzzaman, 1976). For the study F.
oxysporum f. sp. lycopersici was isolated from
seeds of tomato variety BARI tomato-2,
collected from Bangladesh Agricultural Research
Institute, Gazipur. Prevalence of other fungi on
the collected seeds was also studied by blotter
method (ISTA, 1996). The antagonistic ability of
the bacterial isolates was studied In-vitro
following a dual culture method described by
Azadeh et al. (2010). A 5 mm plug of the fungus
F. oxysporum f. sp. lycopersici at the centre of a
petri-dish containing 25 ml PDA, then the test
bacterial isolate was streaked 3 cm away from
the fungal plug both sides towards the edge of
the plate by a loop loaded with 48 hr old
bacterial culture. A control was maintained
without streaking of bacteria in the plate. The
test plates were then incubated at 280C for 7
days. Similarly, for testing the antagonism of T.
herzianum the dual culture technique described
by Sundar et al. (1995). Discs of 5mm diameter
of both the test fungi were cut with a sharp cork
borer from the growing edge of the culture plate.
A 5mm block (7 days old) of T. herzianum was
placed to PDA plate on one side and another
block of F. oxysporum f. sp. lycopersici was
placed at the other side. A plate only with the
disc of F. oxysporum f. sp. lycopersici at the
centre was used as control. The test plates were