2.3. Dual culture assay to detect antifungal activities under metal
stress
The dual culture assay was performed by inoculating a 0.5 cm
diameter mycelial plug of WAA02 at an equidistance with mycelial
plug of Gb and the periphery of the plate. PDA plates used were
supplemented with metals as described in Section 2.2. The control
was established by inoculating agar plug instead of mycelial plugs
of endophytes. Incubation was performed using similar conditions
in Section 2.2, and the radial growth of Gb was measured at every
alternate day. The antifungal activity was expressed as Percentage
Inhibition of Radial Growth (PIRG, %) as follows:
PIRG ð%Þ ¼ ½ðR1 R2Þ=R1 100%
where R1 indicates the radial growth of Gb in control plates; R2 indicates
the radial growth of Gb co-paired with endophytes. The experiment
was performed in triplicates (for each metal concentration as
in Section 2.2) and repeated with other metals and isolates as in
Section 2.2.