Table 3.

Influence of P. putida strains differing in pyoverdine production on population size of P. putida N1R Pvd (pvd-inaZ) in the rhizosphere of cucumber

Coinoculated strainaRhizosphere population size of N1R Pvd(pvd-inaZ)b(log10 [CFU/root system] ± SEM) for coinoculated strain initially at:
ca. 106 CFU/root systemca. 104 CFU/root system
Day 1Day 6Day 1Day 6
None6.42 ± 0.207.33 ± 0.065.66 ± 0.217.04 ± 0.07
WCS3585.09 ± 0.296.11 ± 0.185.52 ± 0.256.80 ± 0.13
WCS358 Pvd 5.11 ± 0.066.19 ± 0.115.57 ± 0.256.88 ± 0.07
N1R4.78 ± 0.095.49 ± 0.095.86 ± 0.196.70 ± 0.13
  • a Root systems were dipped in aqueous suspensions of N1R Pvd (pvd-inaZ) alone or in combination with a coinoculated strain (WCS358, WCS358 Pvd, or N1R) before planting in sterilized soil. Coinoculated strains applied at ca. 106 CFU/root system established rhizosphere populations of 6.5 to 7.0 log10(CFU/root system) at day 1 and 7.5 to 7.6 log10 (CFU/root system) at day 6. Coinoculated strains applied at ca. 104CFU/root system established populations of 5.9 to 6.4 log10(CFU/root system) at day 1 and 6.9 to 7.0 log10 (CFU/root system) at day 6.

  • b Initial populations of N1R Pvd(pvd-inaZ) were approximately 104CFU/root system. Mean rhizosphere population sizes were estimated at 1 or 6 days after root systems were inoculated with bacterial strains.