scholarly journals The Molecular identification of root nodule bacteria from edible crops of Fabaceae family, Kerala

2018 ◽  
Vol 10 (3) ◽  
pp. 1063-1065
Author(s):  
Darsha S. ◽  
Arivukarasu R. ◽  
Jayashankar M. ◽  
Mohammed Ali Saeed

The root nodule bacteria were isolated from three different leguminous plants belonging to the Fabaceae family such as Cajanus cajan, Lablab purpureus and Vigna unguiculata using YEMA medium and identified. The isolates were submitted to 16S rRNA and PCR–RFLP typing. A representative sample was further submitted to sequence analysis of 16S rRNA. Isolates were assigned to two genera and were related to Rhizobium spp. (75%) and Bacillus spp. (25%) respectively. This study opens the doors to researchers to do specific studies on this root nodule bacteria which are symbiotic with these legume plants in this area for their antibacterial activity, medicine and food application, and sustainable agriculture.  Rhizobium and other beneficial microbes may be used as biofertilizers as a substitute for chemical fertilizers.

1999 ◽  
Vol 65 (11) ◽  
pp. 4914-4920 ◽  
Author(s):  
Matthew A. Parker

ABSTRACT Multilocus enzyme electrophoresis, partial 23S rRNA sequences, and nearly full-length 16S rRNA sequences all indicated high genetic similarity among root-nodule bacteria associated with Apios americana, Desmodium glutinosum, andAmphicarpaea bracteata, three common herbaceous legumes whose native geographic ranges in eastern North America overlap extensively. A total of 19 distinct multilocus genotypes (electrophoretic types [ETs]) were found among the 35 A. americana and 33 D. glutinosum isolates analyzed. Twelve of these ETs (representing 78% of all isolates) were either identical to ETs previously observed in A. bracteatapopulations, or differed at only one locus. Within both 23S and 16S rRNA genes, several isolates from A. americana and D. glutinosum were either identical to A. bracteataisolates or showed only single nucleotide differences. Growth rates and nitrogenase activities of A. bracteata plants inoculated with isolates from D. glutinosum were equivalent to levels found with native A. bracteata bacterial isolates, but none of the three A. americana isolates tested had high symbiotic effectiveness on A. bracteata. Phylogenetic analysis of both 23S and 16S rRNA sequences indicated that bothA. americana and D. glutinosum harbored rare bacterial genotypes similar to Bradyrhizobium japonicumUSDA 110. However, the predominant root nodule bacteria on both legumes were closely related to Bradyrhizobium elkanii.


Microbiology ◽  
2021 ◽  
Vol 90 (4) ◽  
pp. 481-488
Author(s):  
A. A. Vladimirova ◽  
R. S. Gumenko ◽  
E. S. Akimova ◽  
Al. Kh. Baymiev ◽  
An. Kh. Baymiev

1999 ◽  
Vol 30 (3) ◽  
pp. 203-208 ◽  
Author(s):  
Luiz Antonio de Oliveira ◽  
Hélio Paracaima de Magalhães

Quantification of acidity tolerance in the laboratory may be the first step in rhizobial strain selection for the Amazon region. The present method evaluated rhizobia in Petri dishes with YMA medium at pH 6.5 (control) and 4.5, using scores of 1.0 (sensitive, "no visible" growth) to 4.0 (tolerant, maximum growth). Growth evaluations were done at 6, 9, 12, 15 and 18 day periods. This method permits preliminary selection of root nodule bacteria from Amazonian soils with statistical precision. Among the 31 rhizobia strains initially tested, the INPA strains 048, 078, and 671 presented scores of 4.0 at both pHs after 9 days of growth. Strain analyses using a less rigorous criterion (growth scores higher than 3.0) included in this highly tolerant group the INPA strains 511, 565, 576, 632, 649, and 658, which grew on the most diluted zone (zone 4) after 9 days. Tolerant strains still must be tested for nitrogen fixation effectiveness, competitiveness for nodule sites, and soil persistence before their recommendation as inoculants.


2001 ◽  
Vol 41 (3) ◽  
pp. 299 ◽  
Author(s):  
J. E. Thies ◽  
E. M. Holmes ◽  
A. Vachot

The symbiosis between legumes and their specific root-nodule bacteria, rhizobia, has been employed to improve agricultural productivity for most of the 20th century. During this time, great advances have been made in our knowledge of both plant and bacterial genomes, the biochemistry of the symbiosis, plant and bacterial signaling and the measurement of nitrogen fixation. However, knowledge of the ecology of the bacterial symbiont has lagged behind, largely due to a lack of practical techniques that can be used to monitor and assess the performance of these bacteria in the field. Most techniques developed in the last few decades have relied on somehow ‘marking’ individual strains to allow us to follow their fate in the field environment. Such techniques, while providing knowledge of the success or failure of specific strains in a range of environments, have not allowed insight into the nature of the pre-existing rhizobial populations in these sites, nor the interaction between marked strains and the background population. The advent of molecular techniques has revolutionised the study of Rhizobium ecology by allowing us to follow the flux of a variety of ecotypes within a particular site and to examine how introduced rhizobia interact with a genetically diverse background. In addition, molecular techniques have increased our understanding of how individual strains and populations of root-nodule bacteria respond to changes in the environment and how genetic diversity evolves in field sites over time. This review focuses on recently developed molecular techniques that hold promise for continuing to develop our understanding of Rhizobium ecology and how these can be used to address a range of applied problems to yield new insights into rhizobial life in soil and as legume symbionts.


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