Table 3.
In vitro inhibition of R. solanacearum and production of antagonistic compounds and plant growth promoting substances by XRB.
| Strain | Haplotype | Inhibition of R. solanacearum | Volatile and diffusible inhibitory compounds | Plant growth promoting substances | |||||
|---|---|---|---|---|---|---|---|---|---|
| Radius in mm | HCN | Ammonia | Acetoin | Siderophore | Phosphate solubilisation | ACC deaminasea | IAAb μg/mL | ||
| XB1 | M80-7 | 2.83 ± 0.29 | − | − | − | − | − | +++ | 105.00 ± 7.07 |
| XB7 | M80-27 | 3.33 ± 0.58 | + | − | − | + | + | − | 47.73 ± 3.21 |
| XB8 | M80-20 | 3.33 ± 0.29 | − | − | − | − | + | − | 19.09 ± 1.29 |
| XB20 | M80-20 | 3.27 ± 0.40 | − | − | − | − | + | − | 25.45 ± 1.71 |
| XB27 | M80-20 | 1.83 ± 0.29 | − | − | − | − | + | − | 15.91 ± 1.07 |
| XB62 | M80-31 | 8.17 ± 0.76 | + | − | − | − | + | ++++ | 73.18 ± 4.93 |
| XB70 | M80-15 | 3.83 ± 0.58 | − | − | − | − | − | − | 171.82 ± 11.57 |
| XB86 | M80-7 | 2.33 ± 0.76 | − | − | − | − | − | +++ | 66.82 ± 4.50 |
| XB93 | M80-6 | 3.17 ± 0.29 | + | − | + | − | + | − | 57.27 ± 3.86 |
| XB99 | M80-9 | 6.83 ± 0.58 | − | + | + | − | + | − | 321.36 ± 21.64 |
| XB100 | M80-9 | 4.50 ± 0.50 | − | + | + | − | + | − | 238.64 ± 16.07 |
| XB114 | M80-31 | 6.50 ± 0.50 | − | − | − | + | + | − | 89.09 ± 6.00 |
| XB122 | M80-28 | 4.33 ± 0.58 | + | − | − | + | + | − | 66.82 ± 4.50 |
| XB123 | M80-31 | 3.00 ± 0.87 | − | + | + | − | + | − | 416.82 ± 28.07 |
| XB126 | M80-27 | 2.83 ± 0.29 | − | − | + | − | + | − | 60.45 ± 4.07 |
| XB134 | M80-37 | 1.57 ± 0.12 | − | + | + | − | + | − | 645.91 ± 43.50 |
| XB140 | M80-5 | 3.67 ± 0.76 | − | + | − | + | + | ++++ | 50.91 ± 3.43 |
| XB153 | M80-6 | 3.17 ± 0.29 | − | − | + | − | + | − | 155.91 ± 10.50 |
| XB157 | M80-6 | 2.50 ± 1.00 | − | − | + | − | + | − | 184.55 ± 12.43 |
| XB165 | M80-29 | 1.57 ± 0.12 | − | − | − | − | − | + | 190.91 ± 12.86 |
| XB169 | M80-6 | 1.53 ± 0.06 | − | − | − | − | − | − | 15.91 ± 1.07 |
| XB170 | M80-6 | 3.51 ± 0.02 | + | − | − | − | + | − | 28.64 ± 1.93 |
| XB177 | M80-6 | 1.99 ± 0.49 | − | − | − | − | − | − | 76.36 ± 5.14 |
| XB196 | M80-10 | 3.93 ± 0.12 | − | − | − | − | − | − | 35.00 ± 2.36 |
| XB197 | M80-38 | 4.33 ± 0.29 | − | − | + | − | − | − | 41.36 ± 2.79 |
| XB200 | M80-36 | 1.87 ± 0.23 | − | − | − | − | − | ++ | 168.64 ± 11.36 |
| XB202 | M80-31 | 4.67 ± 0.21 | − | − | − | − | + | +++ | 82.73 ± 5.57 |
| XB203 | M80-31 | 3.67 ± 0.29 | − | − | − | − | − | − | 70.00 ± 4.71 |
Inhibition zones are mean of three replications and showing standard deviation. Inhibition zone was measured as radius from the outer edge of well. All the experiments were conducted at 28 ± 2°C. + indicates presence of trait; − indicates absence of trait in plate based assays. aLevels of ACC deaminase activities based on growth on plate based assay denoted as + for less growth, +++ for moderate growth, +++ for luxuriant growth, and ++++ for highly luxuriant growth; bIAA was estimated in culture filtrate and expressed as μg/mL using analytical grade IAA as standard; values indicate mean and standard deviation.