Actinorhizal plants and Frankia in Japan.
The actinomycetal genus Frankia forms root nodules in some woody plants that fix atmospheric nitrogen. Such the plants are called as actinorhizal plants. Actinorhizal plants indigenous to Japan are the genus Alnus, Myrica, Elaeagnus and Coriaria as well as introduced species, Casuarina and Hippophaë. In this report, 12 species from six genus of actinorhizal plants were examined on the morphological characteristics of root nodules and of Frankia strains isolated. In addition, we described general procedures for isolating, culturing and inoculating Frankia.