Nodulation and molecular characterization of pure cultures isolated from root nodules ofCoriaria nepalensis

Four strains with typical morphology of actinomycete genus ofFrankia were isolated from root nodules ofCoriatia nepalensis. They were shown to nodulate the seedlings of host plant and hybridize withFrankia 16S rRNA targeted olionucleotide probes, indicating that they did belong to the genusFrankia. Furthermore, by nifHDK probe hybridizations, the homologous fragments of nifHDK genes were detected among the bacteria, and they were located in various sizes of restriction fragments of total DNA, showing diverse patterns of restriction fragment length polyrnorphisms of nifHDK gene (nifHDK-RFLPs). The PCR-based amplification and cloning of nifH gene throw light on the molecular phylogeny ofCoriaria -infectiveFrankia.