Characterization of halotolerant rhizobia isolated from root nodules of Canavalia rosea from seaside areas

Twelve nodule isolates from Canavalia rosea. an indigenous leguminous halop hyte growing in the seaside areas of southern Taiwan, were effective symbio nts for the original host and able to grow at NaCl concentrations up to 3-3 .5% (w/v). The taxonomy of these isolates was investigated using a polyphas ic approach, including phenotypic characteristics, banding patterns of tota l proteins from sodium dodecyl sulfate-polyacrylamide gel electrophoresis ( SDS-PAGE), genomic fingerprint patterns from random amplified polymorphic D NA (RAPD) analysis, pulsed-field gel electrophoresis (PFGE) analysis, ampli fied 16S rDNA restriction analysis (ARDRA), 16S rRNA gene sequencing, and m ifH gene sequencing. Based on the SDS-PAGE, RAPD, PFGE and ARDRA results, t he 12 isolates are highly diverse. The 16S rRNA and nifH gene sequences wer e determined for isolates with distinct ARDRA patterns and compared with ot her members of the rhizobial species. We propose these isolates should be c lassified into the genus Sinorhizobium and distinguished from the current s pecies of this genus. (C) 2000 Federation of European Microbiological Socie ties. Published by Elsevier Science B.V. All rights reserved.