TABLE 2.
Symbiotic parameters from soybean plants inoculated with the B. diazoefficiens USDA 110 wild type or its rsh mutant derivative
| Parameter | Result fora: |
||
|---|---|---|---|
| Wild type | rsh mutant | Uninoculated control | |
| Nodules per plant | 31 ± 12 A | 30 ± 14 A | 0 B |
| Nodule dry wt (mg) | 1.9 ± 0.2 A | 1.2 ± 0.2 B | 0 C |
| Shoot dry wt (g) | 0.46 ± 0.04 A | 0.31 ± 0.04 B | 0.20 ± 0.04 C |
| Ureides (μmol g−1 leaf dry wt) | 23.7 ± 3.7 A | 17.8 ± 2.1 A | 13.1 ± 1.0 B |
| Nodule occupation in competition (%)b | 74 ± 15 A | 26 ± 12 B | 0 C |
a
Values are the average ± SE from three independent experiments. Statistical analysis was performed by ANOVA followed by Tukey’s test. Values followed by different letters in the same row are significantly different (P < 0.05).
b
Plants were coinoculated with equal numbers of cells of the wild type and the rsh mutant. Nodules were then recovered, and the percentage of occupation was recorded by antibiotic resistance. Nodules containing Kmr bacteria harbored the rsh mutant, but some of them might also contain the wild type (double occupation).