Mycelial discs (5 mm diameter) were inoculated in potato dextrose broth as above and incubated at 28+1°C for 7 days. The mycelial inoculum of M. phaseolina was centrifuged at 5000 rpm for 10 minutes. Supernatant was decanted and pellets were washed and re-suspended in sterile distilled water. At 15th days after sowing, the soil was inoculated in Set-II by drenching the soil near plant roots. On 8th day ten seedlings from three replicates were chosen randomly for measurements of shoot and root growth, fresh weight of the seedlings, disease incidence, and vigour index. Vigour index was calculated by using the following formula as described by Abdul Baki and Anderson (1973):
Vigour index = (Mean root length + Mean shoot length) × Germination (%)
Triggering of Induced Systemic Resistance
Leaf samples (1g) were collected from each treatment on zero …show more content…
The homogenate was centrifuged at 16,000 rpm for 15 min at 4°C (Karthikeyan et al., 2005). The supernatant served as source of enzyme for peroxidase assay. The reaction mixture consisted of 2.1 ml distilled water, 0.32 ml 100 mM potassium phosphate buffer (pH 6), 0.32 ml 5% freshly prepared pyrogallol solution, and 0.16 ml 0.5 % H2O2. Reaction mixture was mixed properly and incubated at room temperature for 10 minutes. Optical density of mixture duplicate was measured at 420 nm in a spectrophotometer (UV-Visible Spectrophotometer, Shimadzu, Japan). 100 µl of enzyme was added in the spectrophotometric cuvette and mixed properly. The change in OD was measured immediately at an interval of every 20 seconds till 2 minutes. Phosphate buffer (100 µl) added to reaction mixture acted as blank. The enzyme activity was expressed as changes in the absorbance/ min /mg of protein (Hammerschmidt et al., 1982). A value of 12 M-1 cm-1 was employed for the molar coefficient of
Vigour index = (Mean root length + Mean shoot length) × Germination (%)
Triggering of Induced Systemic Resistance
Leaf samples (1g) were collected from each treatment on zero …show more content…
The homogenate was centrifuged at 16,000 rpm for 15 min at 4°C (Karthikeyan et al., 2005). The supernatant served as source of enzyme for peroxidase assay. The reaction mixture consisted of 2.1 ml distilled water, 0.32 ml 100 mM potassium phosphate buffer (pH 6), 0.32 ml 5% freshly prepared pyrogallol solution, and 0.16 ml 0.5 % H2O2. Reaction mixture was mixed properly and incubated at room temperature for 10 minutes. Optical density of mixture duplicate was measured at 420 nm in a spectrophotometer (UV-Visible Spectrophotometer, Shimadzu, Japan). 100 µl of enzyme was added in the spectrophotometric cuvette and mixed properly. The change in OD was measured immediately at an interval of every 20 seconds till 2 minutes. Phosphate buffer (100 µl) added to reaction mixture acted as blank. The enzyme activity was expressed as changes in the absorbance/ min /mg of protein (Hammerschmidt et al., 1982). A value of 12 M-1 cm-1 was employed for the molar coefficient of