Phenotypic characteristics of Rhizobium sp. strains. (a) Growth kinetics. (b) Nodulation proficiency. Symbols in panel a: squares, wild-type NGR234; white circles, derivative of CFNX401; triangles, derivative of CFNX407; crosses, CFNX408; and black circles, CFNX416. Lanes in panel b: 1, wild-type NGR234; 2, CFNX401 derivative; 3, CFNX407 derivative; and 4, CFNX408. L, L. leucocephala; T, T. vogelii; and V, V. unguiculata. OD600, optical density at 600 nm.