Abstract
Leguminous plants form root nodules in association with soil bacteria Rhizobia leading to symbiotic nitrogen fixation. Molecular genetic studies using the model legumes such as Lotus japonicus and Medicago truncatula indicated that more than 100 plant genes are involved in the symbiotic interaction and/or nodule formation. However, most of those genes have not been isolated. Generation of symbiotic mutants is still required. It has been well described that the plants regenerated from cultured cells have mutations frequently. To get novel mutants, regenerated plants were developed from the calli or the cultured cells of Lotus japonicus. Total 889 lines were derived from Gifu and 446 lines from Miyakojima. The next generation of the plants was screened to find the symbiotic mutants. Genetic analyses showed 12 mutant lines carrying single recessive genes. More detailed characterization of these mutants and genetic analyses of the other putative mutant lines are currently under way.
