Fig. 4

Comparison of the root nodulation properties. a Species of different lineages and groups that were tested for nodulation are listed in the simplified Bayesian phylogeny on the left. Root nodulation tests were performed using the DOA9, ORS285, ORS285∆nod and ORS278 strains. E, effective nodulation; e, partially effective nodulation; i, ineffective nodulation, −, no nodulation; blank, not tested. b Number of nodules per plant, c relative acetylene-reducing activity (ARA) and d aspect of the inoculated roots developing nodules or not (some nodules were cut to observe the leghemoglobin color inside) after inoculation with Bradyrhizobium DOA9, ORS285 and ORS278 on A. americana, A. patula, A. afraspera and A. evenia. Error bars in (b) and (c) represent s.d. (n = 6). Scale bar in (d): 1 mm