Table 2.
Plant growth-promoting potential and abiotic stress resistance of the microbial subcollection.
| genus | Nr. of isolates | Strain HC | PGP activities and tolerances to abioticstress (%) | ACCd | 4°C | 50°C | Average % survival after 14d of water stress | Average % survival after 14d of N- and C-starvation | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IAA | P Sol. | Sid. | Org. Acid | Acetoin | ||||||||
| Arthrobacter | 3 | 34;66;100 | 100 | 100 | 0 | 0 | 33 | 100 | 100 | 37.6 ± 1.13 | ||
| Bacillus | 2 | 26;45 | 50 | 100 | 0 | 100 | 0 | 100 | 100 | 50 | <5.0 ± 1.2 | 80.6 ± 3.2 |
| Burkholderia | 11 | 19;18;31;32;64;7 | 100 | 45 | 100 | 0 | 100 | 75 | 100 | 35.5 ± 2.4 | 74.5 ± 2.2 | |
| 9;106;114;122;12 9 | ||||||||||||
| 3;128 | ||||||||||||
| Methylobacterium | 1 | 91 | 100 | 0 | 0 | 100 | 0 | 100 | 0 | 100 | 42.2 | 52.2 |
| Mycobacterium | 1 | 96 | 100 | 0 | 0 | 100 | 0 | 100 | 0 | 100 | 47.6 | 57.6 |
| Pseud omonas | 4 | 1;88;94;131 | 75 | 50 | 100 | 100 | 0 | 100 | 50 | 50 | 62.2 ± 2.3 | 62.2 ± 1.3 |
| Ralstonia | 3 | 4;90;111 | 0 | 0 | 100 | 0 | 100 | 100 | 50 | 100 | 49.8 ± 1.2 | 69.8 ± 2.2 |
| Rhodanobacter | 2 | 50;52 | 100 | 100 | 0 | 0 | 0 | 0 | 100 | 100 | 82.5 ± 1.3 | 92.5 ± 1.2 |
| Sinomonas | 1 | 35 | 0 | 0 | 0 | 0 | 100 | 100 | 100 | 100 | 92.4 | 95.4 |
| Vario vorax | 1 | 92 | 100 | 100 | 100 | 100 | 0 | 100 | 100 | 100 | 87.5 | 89.5 |
| Viridibacillus | 1 | 16 | 0 | 100 | 0 | 0 | 0 | 100 | 0 | 0 | 81.6 | 72.7 |
| TOTAL (%) | 43.3 | 73.3 | 43.2 | 66.7 | 13.3 | 86.6 | 64.0 | 86.7 | ||||
The PGP activities are expressed in percentage of isolates within each genus that score positive for the test. In the last row, the total percentage of isolates scoring positive for PGP activities and tolerance to abiotic stress is shown. P Sol., inorganic phosphate solubilization; Sid., siderophores production; Org. Acid, organic acid production; AACd, ACC deaminase activity.