TABLE 2.
Root colonization frequencies (%) of the auxins, polyamines and the 1-aminocyclopropane-1-carboxylic acid deaminase producing actinobacterial isolates in root segments (R) of Salicornia bigelovii and population densities (PD) (Mean log10 cfu g–1 dry soil) of the actinobacterial isolates in rhizosphere soil of S. bigelovii at 3 weeks post-sowing (wps) treated seeds in the non-sterile soil tube rhizosphere competence assay.
| Distance from seed (cm)a | Isolate | |||||||||||||||||||
| #2 |
#4 |
#6 |
#7b |
#11b |
#18 |
#21b |
#25 |
#27 |
#32 |
|||||||||||
| R | PD | R | PD | R | PD | R | PD | R | PD | R | PD | R | PD | R | PD | R | PD | R | PD | |
| 0–2 | 100 a | 5.02 a | 100 a | 4.41 a | 100 a | 3.91 a | 100 a | 5.55 a | 100 a | 6.35 a | 100 a | 3.65 a | 100 a | 5.33 a | 100 a | 4.42 a | 100 a | 4.83 a | 100 a | 4.11 a |
| 2–4 | 100 a | 4.39 b | 100 a | 3.65 b | 100 a | 3.33 b | 100 a | 5.42 a | 100 a | 5.72 b | 100 a | 2.97 b | 100 a | 4.85 b | 90 a | 3.72 b | 100 a | 4.22 b | 100 a | 4.05 a |
| 4–6 | 100 a | 3.78 c | 70 b | 3.02 c | 100 a | 3.21 b | 100 a | 4.72 b | 100 a | 5.61 b | 100 a | 2.45 c | 100 a | 4.43 c | 70 b | 3.11 c | 100 a | 4.05 b | 80 b | 3.25 b |
| 6–8 | 100 a | 3.15 d | 50 c | 2.45 d | 80 b | 2.55 c | 100 a | 4.65 b | 100 a | 4.86 c | 100 a | 2.57 c | 100 a | 4.31 c | 60 b | 2.55 d | 100 a | 3.66 c | 65 c | 2.66 c |
| 8–10 | 80 b | 2.45 e | 40 c | 1.56 e | 60 c | 2.45 c | 100 a | 4.18 c | 100 a | 4.74 c | 70 b | 1.94 d | 100 a | 3.89 d | 40 c | 1.82 e | 100 a | 3.41 c | 60 c | 2.05 d |
| 10–12 | 60 c | 1.88 f | 20 d | 1.47 e | 30 d | 1.58 d | 100 a | 4.25 c | 100 a | 4.93 c | 50 c | 1.25 e | 100 a | 3.72 d | 35 c | 1.22 f | 100 a | 3.55 c | 30 d | 1.52 e |
aS. bigelovii seeds were coated with each isolate and grown in non-sterile field sandy soils in plastic tubes in polystyrene boxes containing soil, in an evaporative-cooled greenhouse maintained at 25 ± 2°C. Seedlings were harvested 3 wps the seeds. bIsolates #7, #11, and #21 represent Streptomyces tritolerans RAK1, S. rochei RAMS1, and S. chartreusis UAE1, respectively. Values are means of 16 independent replicates for each treatment from two independent experiments. Values with the same letter within a column are not significantly (P > 0.05) different according to Fisher’s Protected LSD Test. Percentage data were arc-sine transformed before analysis.