FIG 4.

Symbiosis and competition for root-nodule colonization. Soybean, cowpea, siratro, and mungbean seedlings were coinoculated into 3 plants at a ratio of 10:90 B. japonicum wild-type (wt) to Δfrc-oxc cells. Percentages of wild-type and mutant strains recovered from plant nodules at different inoculum ratios were compared. The tested host plants are shown along the x axis. The y axis represents mean values ± standard deviations of percentages of bacteroids recovered from crushed nodules. Experimental data were assessed for statistical significance by means of the Student t test. Statistical analyses were performed using SPSS 17.0 software. Recovered percentages were significantly different between the wild type and mutant (P < 0.05).