pernatant of VBK1 and VBC7 were used against A. alternata
VBAV007. The cell free supernatants of both the bacterial strains
were also found effective in controlling the radial growth of the
pathogen. 37.6 ± 1.66% and 88.4 ± 1.76% growth inhibitions of
VBAV007 were noticed in the presence of 1% and 10% cell free
supernatant of VBK1 respectively (Table 3). On the other hand
26.9 ± 2.2% and 75.6 ± 1.67% growth inhibitions were observed in
the presence of 1% and 10% cell free supernatant of VBC7 (Table 3).
Panwar et al. (2013) reported a maximum of 48.80% growth inhibition
of A. alternata by Trichoderma koningii.
The antifungal potentials of these two biocontrol strains against
A. alternata VBAV007 were also proved when prominent mycelial
degradations and damages were observed in scanning electron
micrographs of the fungal mycelia upon treatment with either
P. poae VBK1 (Fig. 5B) or B. cenocepacia VBC7 (Fig. 5C), as compared
to its untreated control (Fig. 5A), where intact mycelia structures
were observed. Such types of degradations were probably due to
production of some enzymes like chitinase or b-glucanase as
observed in other antagonistic organisms