Genotypic Characterization of Azotobacteria Isolated from Argentinean Soils and Plant-Growth-Promoting Traits of Selected Strains with Prospects for Biofertilizer Production
Table 1
Geographical origin and land use of soil samples from which Azotobacter isolates were obtained. Summary of fingerprinting and identification results of isolates and soil chemical characteristics.
Geographical origin*
Sampling site
Isolate
rep-PCR group
ARDRA cluster
Partial 16S rDNA sequence (accession number)
Species assignments
Soil chemical parameters**
OM (%)
pH
EC (mS cm−1)
P (ppm)
Buenos Aires (Azul)
Maize stubble
AT25
1
I
HQ623180
A. chroococcum
3.38
7.30
0.48
7.40
Buenos Aires (Balcarce)
Agricultural bare
AT22
1
nd
A. chroococcum
5.72
5.80
1.21
51.00
Buenos Aires (Mar Chiquita)
Lagoon bank 1
AT30
1
I
A. chroococcum
1.86
8.20
0.43
1.90
Buenos Aires (Mar Chiquita)
Lagoon bank 2
AT31
1
I
HQ623181
A. chroococcum
1.05
8.00
1.45
7.70
Buenos Aires (Santa Clara del Mar)
Urban land
AT4
1
I
A. chroococcum
0.98
8.45
0.48
8.50
AT5
1
nd
A. chroococcum
Buenos Aires (Santa Clara del Mar)
Side of road
AT9
1
I
A. chroococcum
5.72
7.83
0.80
8.50
Chubut (Esquel)
Natural pasture
AT24
1
nd
A. chroococcum
2.74
6.40
0.49
40.40
Chubut (Gaiman)
Natural pasture
AT28
1
I
A. chroococcum
3.15
8.30
0.66
45.80
Chubut (Trevelín)
River bank
AT43
1
I
A. chroococcum
1.02
6.60
1.58
8.10
Jujuy (Tilcara)
Side of routea
AT11
1
nd
A. chroococcum
0.19
8.77
0.28
4.80
AT13
1
nd
A. chroococcum
Jujuy (Tilcara)
Natural pasture
AT26
1
nd
A. chroococcum
0.17
8.60
0.20
4.50
AT27
1
I
A. chroococcum
Entre Ríos (Paraná)
Wheat crop
AT39
1
nd
A. chroococcum
4.47
7.00
0.93
13.50
Córdoba (Corral de Bustos)
Wheat crop 1
AT32
2
nd
A. armeniacus
3.12
6.13
0.69
10.10
Córdoba (Corral de Bustos)
Wheat crop 2
AT33
2
II
HQ623182
A. armeniacus
3.48
6.08
0.63
11.60
Córdoba (Corral de Bustos)
Wheat crop 3
AT36
2
nd
A. armeniacus
3.15
6.06
0.52
11.10
Salta (Embarcación)
Soybean crop
AT19
3
IV
HQ591467
A. salinestris
1.78
6.40
0.21
48.80
Salta (Joaquín V. González)
Natural pasture
AT14
3
IV
A. salinestris
1.64
7.80
2.24
3.30
Santiago del Estero (Quimilí)
Soybean crop 1
AT1
3
nd
A. salinestris
3.10
7.17
nd
127.80
AT2
3
nd
A. salinestris
AT16
3
nd
A. salinestris
Soybean crop 2
AT17
3
nd
A. salinestris
2.78
7.16
nd
104.20
AT18
3
IV
HQ541448
A. salinestris
Chubut (Puerto Madryn)
Natural pasture
AT42
4
IV
HQ623179
A. salinestris
1.09
7.50
0.48
7.40
Chubut (Villa Ameghino)
River bank
AT29
4
IV
A. salinestris
2.81
7.70
1.50
43.50
Jujuy (Tilcara)
Side of routea
AT12
5
IV
A. salinestris
0.19
8.77
0.28
4.80
Santa Fe (Videla)
Soybean crop 1
AT37
5
IV
HQ623178
A. salinestris
2.10
7.43
0.54
7.00
Santa Fe (Videla)
Soybean crop 2
AT38
5
IV
A. salinestris
1.00
8.28
0.94
3.00
Jujuy (Tilcara)
Side of routea
AT10
6
IV
A. salinestris
0.19
8.77
0.28
4.80
Buenos Aires, Córdoba, Entre Ríos, and Santa Fe are provinces of the Pampas region; Jujuy, Salta, and Santiago del Estero are provinces from the Northwest region, Chubut is a province from Patagonia region of Argentina.
aCorresponded to the same soil sample.
**OM: organic matter; EC: electrical conductivity; P: extractable phosphorus; nd: not determined.
