Nodulation competitiveness of Rhizobium leguminosarum bv. phaseoli and Rhizobium tropici strains measured by glucuronidase (gus) gene fusion

1992 ◽  
Vol 14 (2) ◽  
pp. 140-144 ◽  
Author(s):  
W. Streit ◽  
K. Kosch ◽  
D. Werner
Keyword(s):  
Gene Fusion ◽  
Rhizobium Leguminosarum ◽  
Gus Gene ◽  
Rhizobium Tropici ◽  
Nodulation Competitiveness

Increased metabolic potential of Rhizobium spp. is associated with bacterial competitiveness

2007 ◽  
Vol 53 (8) ◽  
pp. 957-967 ◽  
Author(s):  
Jerzy Wielbo ◽  
Monika Marek-Kozaczuk ◽  
Agnieszka Kubik-Komar ◽  
Anna Skorupska
Keyword(s):  
Rhizobium Leguminosarum ◽  
Growth Promotion ◽  
High Rate ◽  
Energy Sources ◽  
Metabolic Potential ◽  
Wide Range ◽  
Nodulation Competitiveness ◽  
Gusa Gene ◽  
Rhizobium Spp ◽  
Metabolic Properties

Of 105 rhizobial isolates obtained from nodules of commonly cultivated legumes, we selected 19 strains on the basis of a high rate of symbiotic plant growth promotion. Individual strains within the species Rhizobium leguminosarum bv. trifolii , R. leguminosarum bv. viciae , and Rhizobium etli displayed variation not only in plasmid sizes and numbers but also in the chromosomal 16S–23S internal transcribed spacer. The strains were tagged with gusA gene and their competitiveness was examined in relation to an indigenous population of rhizobia under greenhouse conditions. A group of 9 strains was thus isolated that were competitive in relation to native rhizobia in pot experiments. Nineteen selected competitive and uncompetitive strains were examined with respect to their ability to utilize various carbon and energy sources by means of commercial Biolog GN2 microplate test. The ability of the selected strains to metabolize a wide range of nutrients differed markedly and the competitive strains were able to utilize more carbon and energy sources than uncompetitive ones. A major difference concerned the utilization of amino and organic acids, which were metabolized by most of the competitive and only a few uncompetitive strains, whereas sugars and their derivatives were commonly utilized by both groups of strains. A statistically significant correlation between the ability to metabolize a broad range of substrates and nodulation competitiveness was found, indicating that metabolic properties may be an essential trait in determining the competitiveness of rhizobia.

Identification of soil bacteria expressing a symbiotic plasmid from Rhizobium leguminosarum bv. trofolii

1997 ◽  
Vol 43 (2) ◽  
pp. 164-177 ◽  
Author(s):  
S. Sivakumaran ◽  
B. D. W. Jarvis ◽  
P. J. Lockhart
Keyword(s):  
Dna Hybridization ◽  
Sinorhizobium Meliloti ◽  
Rhizobium Leguminosarum ◽  
Root Nodule ◽  
Sandy Loam ◽  
Rhizobium Tropici ◽  
Rhizobium Loti ◽  
Rrna Sequencing ◽  
Reference Strains ◽  
Good Agreement

A hundred strains of non-nodulating, Gram-negative, rod-shaped bacteria were isolated from clover–ryegrass pastures on three different soil types and from a sandy loam under lupins. When crossed with Escherichia coli PN200 containing the cointegrate plasmid pPN1, 11 transconjugants gained the ability to form nodules on the roots of white clover (Trifolium repens cv. Grasslands Huia). A nodA probe indicated that they had gained nodulation genes. The identities of these 11 strains and 4 others derived from earlier work on non-nodulating root nodule bacteria, were determined by ribotyping, DNA – DNA hybridization, and partial 16S rRNA sequencing. Good agreement was obtained between the three methods, and 11 of the strains were identified as Rhizobium leguminosarum (6), Rhizobium loti (2), Rhizobium etli (1), Rhizobium tropici (1), and Sinorhizobium meliloti (1). DNA –DNA hybridization indicated that the remaining four strains were related to the Rhizobium leguminosarum reference strains. The existence of several species of non-nodulating rhizobia in pasture soil, including species for which the normal host plant was absent, is discussed in relation to the fate of symbiotic plasmids from Rhizobium seed inoculants. It is also suggested that new species should be named for the geographical region from which they are first isolated rather than the host plant.Key words: Rhizobium, non-nodulating, nonsymbiotic, isolation, identification.

scholarly journals THE NODULATION COMPETITIVENESS OF TN5-MUTANTS RHIZOBIUM LEGUMINOSARUM BV. VICIAE

2008 ◽  
Vol 6 ◽  
pp. 18-28
Author(s):  
O.D. Krugova ◽  
N.M. Mandrovskaya
Keyword(s):  
Aboveground Biomass ◽  
Competitive Ability ◽  
Rhizobium Leguminosarum ◽  
High Nitrogen ◽  
Nodule Number ◽  
Industrial Strains ◽  
Nodulation Competitiveness ◽  
Tn5 Mutants ◽  
Wild Strains ◽  
Competition Ability

There has been studied the nodulation competitiveness of Tn5 mutants of pea rhizobia which were obtained from Rhizobium leguminosarum bv. viciae 263 б and which had high nitrogen fixing activity and promoted the increase of both nodule number and aboveground biomass in comparison with wild strains. It was shown that the competition ability of M1 and М68 mutants did not differ from the competitive ability of strains 263 б and Rhizobium leguminosarum bv. viciae 245 a of industrial strains.

scholarly journals Molecular Diversity of Rhizobia Occurring on Native Shrubby Legumes in Southeastern Australia

1998 ◽  
Vol 64 (10) ◽  
pp. 3989-3997 ◽  
Author(s):  
Bénédicte Lafay ◽  
Jeremy J. Burdon
Keyword(s):  
Rhizobium Leguminosarum ◽  
Phylogenetic Analyses ◽  
Acid Soils ◽  
Small Subunit ◽  
Rhizobium Tropici ◽  
Southeastern Australia ◽  
Eucalypt Forest ◽  
Genomic Species ◽  
Dna Pcr ◽  
Small Subunit Ribosomal Dna

ABSTRACT The structure of rhizobial communities nodulating native shrubby legumes in open eucalypt forest of southeastern Australia was investigated by a molecular approach. Twenty-one genomic species were characterized by small-subunit ribosomal DNA PCR-restriction fragment length polymorphism and phylogenetic analyses, among 745 rhizobial strains isolated from nodules sampled on 32 different legume host species at 12 sites. Among these rhizobial genomic species, 16 belonged to the Bradyrhizobium subgroup, 2 to theRhizobium leguminosarum subgroup, and 3 to the Mesorhizobium subgroup. Only one genomic species corresponded to a known species (Rhizobium tropici). The distribution of the various genomic species was highly unbalanced among the 745 isolates, legume hosts, and sites.Bradyrhizobium species were by far the most abundant, andRhizobium tropici dominated among the Rhizobiumand Mesorhizobium isolates in the generally acid soils where nodules were collected. Although a statistically significant association occurred between the eight most common genomic species and the 32 hosts, there was sufficient overlap in distributions that no clear specificity between rhizobial genomic species and legume taxa was observed. However, for three legume species, some preference for particular genomic species was suggested. Similarly, no geographical partitioning was found.

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