A new series of pea symbiotic mutants induced in the line SGE

Abstract

Chemical mutagenesis of the pea laboratory line SGE with ethyl methane sulfonate was carried out. In the analysis of 425 families (2069 plants) of the M2 generation 45 putative symbiotic mutants were selected, including 30 mutants that form ineffective nodules (the Fix− phenotype), 13 mutants that are unable to form nodules (the Nod− phenotype) and two mutants that form occasional nodules (the Nod+/− phenotype). For one Nod− and five Fix− mutants monogenic inheritance and recessive phenotype manifestation were shown. For the Fix− mutant SGEFix−-9 the presence of an additional mutation that leads to the Nod+/− phenotype was shown. Complementation analysis showed that the mutant phenotype of the line SGEFix−-5 is determined by a mutation in the sym33 gene; of the line SGEFix−-6, in the sym40 gene; of the line SGEFix−-7, in the sym27 gene; and of the line SGEFix−-8, in the sym25 gene.