Mutagenesis of faba bean (Vicia faba L.) and the identification of five different genes controlling no nodulation,ineffective nodulation or supernodulation

Summary Mutagenesis ofVicia faba L. using ethyl methanesulfonate has yielded three mutants (f13, f73, f245) with ineffective nodulation (Nod⁺Fix^–), one mutant (f48) unable to nodulate (Nod^–) and one supernodulating mutant (f32) having 3 to 5 times more nodules than the control in the absence of combined nitrogen, and expressing nitrate tolerant nodulation (Nod⁺⁺, Nts). All of the mutant phenotypes were controlled by single and distinct recessive genes designatedsyml tosym5, respectively. Grafting experiments showed that the (Nod⁺Fix^–) and (Nod^–) phenotypes were both under root genotype control and that the (Nod⁺⁺, Nts) phenotype was under shoot genotype control.