TABLE 3.

Colonization of alfalfa root by S. meliloti strainsa

Strain mixtureMixture ratio (WT/MU)Total cells per root (103)bRm1021 cells per root (103)Mutant cells per root (103)WT/MU (% ratio)c
ExpectedObserved
Rm1021 + Sm70191:044.8 ± 8.0 BNANA
0:135.6 ± 8.3 BNANA
1:129.8 ± 5.1 B20.9 ± 4.57.8 ± 1.650:5068:32*
Rm1021 + Rm96281:038.6 ± 2.2 BNANA
0:164.4 ± 5.6 CNANA
1:170.0 ± 9.8 C43.8 ± 7.526.2 ± 3.350:5060:40*
Rm1021 + Sm70251:023.6 ± 2.0 ANANA
0:122.3 ± 3.5 ANANA
1:136.1 ± 6.2 B28.1 ± 4.77.7 ± 2.050:5084:16*
  • a WT, wild-type Rm1021; MU, mutant strain; NA, not applicable.

  • b Treatments followed by the same letter were not statistically significant at the 95% confidence level. Data are means ± standard errors.

  • c Chi-square test performed with Minitab statistical software;

  • * P = <0.001.