Figure 2

We found no evidence of partner choice. (a–c) show pea root systems with stained nodules following inoculation with different ratios of a fixing celB (blue) marked strain (3841 celB) and a non-fixing gusA (magenta) marked mutant strain (OPS0365): (a) 1:10 (fixing:non-fixing); (b) 1:1 (fixing:non-fixing); (c) 10:1 (fixing:non-fixing). (d) The percentage of nodules containing only the fixing strain exactly reflected the percentage of the fixing strain in the inoculum. The slope of the regression was 0.99 ± 0.02, 95% CI [0.95, 1.02] and this is not significantly different from one (t ₃₉ = −0.835, p = 0.41).