Submitted to: North American Conference on Symbiotic Nitrogen Fixation
Publication Type: Abstract Only
Publication Acceptance Date: 5/18/1998
Publication Date: N/A
Technical Abstract: In part, the mission of our Laboratory is to improve quality and reduce costs of soybean and alfalfa production by enhancing nodulation and the efficiency of symbiotic nitrogen fixation via the use of unique plant and microbial germplasm. The main focus of our program is the acquisition and genetic characterization of new and existing rhizobial germplasm for Medicago species and Glycine max. Medicago ruthenica and M. edgeworthii are native to China and have potential use in American agriculture. Seeds and rhizosphere samples were collected in their native habitat. Samples of M. ruthenica have yielded symbionts within the genus Rhizobium. Currently, our focus is the genetic analysis of rhizobial isolates of M. edgeworthii. Our objective with the soybean bradyrhizobia is to develop molecular methods for their identification. The nucleotide sequences of the spacer region between the two ribosomal genes distinguished groups more than those based upon 16S or 23S rRNA seqences alone. This observation may be useful since strains of B. japonicum and several Lotus species appeared to be closely related even though many fell into a separate DNA homology grouping.