Figure 3.

Effects of varying concentrations of nitrate on nodule formation by lot1 and the wild type. Seedlings of 7 d after germination were transplanted into B & D medium on vermiculite containing the indicated concentrations of KNO₃, and, after 1 week, they were inoculated with M. loti Tono. The seedlings were grown for 3 weeks, and then the number of mature nodules was determined. The means and sds (n = 6) are presented. Different letters above the bars indicate significant differences at P < 0.01 according to the t test.