Serological Distribution of Bradyrhizobium japonicum from U.S. Soybean Production Areas
- D. F. Weber ,
- H. H. Keyser and
- S. L. Uratsu
Bradyrhizobium japonicum strains are widely distributed throughout U.S. soybean [Glycine max (L.) Merr.] production areas. Many surveys of local or regional areas have been conducted, but none has covered all production states or related their distribution to strains previously used in commercial inoculants. A total of 767 isolates of root nodule bacteria, from 79 locations in 27 states of the major soybean production areas, were analyzed with 15 antisera to determine serological composition. Eight serogroups represented 63% of the isolates, 19% of the isolates had double reactions, and 15% did not react. The predominant serogroup was 123, which represented 24% of the isolates tested, followed by serogroup 31 with 14%. The other isolates were evenly distributed among serogroups. The relationship between the pattern of distribution of the isolates around the USA and strains used in commercial inoculants is discussed. Knowledge of isolates that constitute an indigenous Bradyrhizobium population should be helpful in selecting more effective strains for inoculants.
Copyright © . .