Parallel variation in isoenzyme and nitrogen fixation markers in a Rhizobium population

Abstract

Twenty isolates of Rhizobium leguminosarum bv. viceae were isolated at random from one field and examined for symbiotic plasmid fragment length polymorphisms and for isoenzyme patterns. The latter are most probably chromosome markers. With one exception both methods separated the isolates into the same 13 different groups. The largest group was represented 7 times according to isoenzymes and 8 times according to RFLP. This fixed non-random association of plasmid and chromosomal genotypes is consistent with a clonal population structure; it indicates limited exchange of plasmids under natural conditions. Seventeen isolates of 11 groups were highly effective and 2 isolates in one group almost ineffective.

Compatibility of Rhizobial Genotypes within Natural Populations of Rhizobium leguminosarum Biovar viciae for Nodulation of Host Legumes

“…Correlations between chromosomal and Sym plasmid genotypes have been previously observed within pea R. leguminosarum bv. viciae populations (11,23,50,52). This suggests that both components of the rhizobial genome are involved in competitiveness for nodule formation with peas.…”

Characterization of variants of Bradyrhizobium elkanii and B. japonicum and symbiotic behaviour in soybeans

“…These results were also found by LEMOS (1994) who confirmed the four homology groups already defined. The enzymatic polymorphism tests might be an efficient way to characterize strains and establish the genetic structure of rhizobia populations (ENGVILD & NIELSEN, 1985;ENGVILD et al, 1990). The restricted differences found in this study (only between variants of strain 5019) might be related to the small number of enzymes tested.…”

Quantitative relationship between maximum growth rates and the intracellular pattern of α-esterase and β-esterase activity of leguminous infecting bacteria

“…Moreover, zymographic esterase patterns amplify the microbial characterization allowing the detection of differences at strain level (e.g. Figure 1; [14]). …”

“…Previously, the zymographic pattern of a-esterase and b-esterase isoenzymes was an approach to study the specificity of legume-Rhizobiales interactions as well as the biodiversity of legume infecting bacteria [14,15]. Moreover, zymographic esterase patterns amplify the microbial characterization allowing the detection of differences at strain level (e.g.…”