scholarly journals Isolation and Enumeration of Bradyrhizobium Species Dwelling In the Root Nodules of Soybean Plant

2020 ◽  
pp. 17-25
Author(s):  
Ishaq Z. ◽  
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Root Nodule ◽  
Low Cost ◽  
Root Nodules ◽  
Selective Medium ◽  
Soybean Plant ◽  
Plant Infection ◽  
Soybean Plants ◽  
Biological Nitrogen

Biological Nitrogen fixation is one of the important aspects of organic agriculture gaining considerable attention globally. Information about the number of viable indigenous Bradyrhizobia in soils planted with legumes and their capacity to nodulate is a valuable tool in developing strategies to improve biological nitrogen fixation. Such strategies could potentially lead to increased soybean yields at low cost. This study was conducted to isolate and enumerate Bradyrizobium species dwelling in the root nodule of soybean plant using Bradyrhizobium japonicum selective medium (BJSM). Twenty (20) strains of Bradyrizobium species were isolated from the root nodules of soybean plants harvested from Ahmadu Bello University farm site, located at Bomo district of Sabongari local government area, Kaduna State, Nigeria. This was achieved using the streak method of isolation on BJSM. Ninety percent (18) of these isolates were confirmed as Bradyrizobium species using the plant infection test as they were able to nodulate the roots of soybean plants. The enumeration of the indigenous Bradyrizobium species gave a count ranging from 2.07x105 - 4.0x106 CFU/mL. Thus, the number of Bradyrhizobia obtained in the soil of this study is sufficient to achieve satisfactory results on nodulation and nitrogen fixation. Key words: Soybean, Bradyrhizobium species, Nodulation, Nitrogen fixation

Biological Nitrogen Fixation and Root-Nodule Bacteria (Rhizobium Sp. and Bradyrhizobium Sp.) In Two Rehabilitating Sand Dune Areas Planted With Acacia Spp

1985 ◽  
Vol 33 (5) ◽  
pp. 595 ◽  
Author(s):  
YM Barnet ◽  
PC Catt ◽  
DH Hearne
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Sand Dune ◽  
Root Nodule ◽  
Nodule Bacteria ◽  
Root Nodule Bacteria ◽  
Bradyrhizobium Sp ◽  
Biological Nitrogen ◽  
Slow Growing ◽  
Rhizobium Sp

This paper reports a study of biological nitrogen fixation in two sand dune regions of New South Wales where planted Acacia spp. had been used in revegetation programmes. At one location (Bridge Hill Ridge), natural regrowth had produced a complex plant community, and native legumes in addition to the planted acacias were present. The other area (Wanda Beach) was a grossly disturbed site which contained only the planted species. Symbiotic fixation in association with Australian legumes occurred at both locations at rates within the range reported by other authors. Distinct seasonal changes were apparent, with higher activities in the cooler months. The legume association seemed the only source of biologically fixed nitrogen at Bridge Hill Ridge, but at Wanda Beach cyanobacteria in an algal mat also made a contribution. Fast and slow-growing bacterial strains were obtained from root nodules of native legumes at both sites and were classed as Rhizobium sp. and Bradyrhizobium sp., respectively. This division was supported by the pattern of serological affinities of the isolates and by differences in their protein profiles demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two atypical types of root-nodule bacteria were found at Bridge Hill Ridge: non-nodulating, fast-growing isolates and an abnormally slow-growing Bradyrhizobium sp.

scholarly journals A Convenient, Soil-Free Method for the Production of Root Nodules in Soybean to Study the Effects of Exogenous Additives

2018 ◽  
Author(s):  
Swarup Roy Choudhury ◽  
Sarah M. Johns ◽  
Sona Pandey
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Root Nodules ◽  
Growth Conditions ◽  
Nodule Development ◽  
Nodule Formation ◽  
Legume Crop ◽  
Simple Protocol ◽  
Biological Nitrogen

Legumes develop root nodules that harbour endosymbiotic bacteria, rhizobia. These rhizobia convert nitrogen to ammonia by biological nitrogen fixation. A thorough understanding of the biological nitrogen fixation in legumes and its regulation is key to develop sustainable agriculture. It is well known that plant hormones affect nodule formation; however, most studies are limited to model legumes due to their suitability for in vitro, plate-based assays. Specifically, it is almost impossible to measure the effects of exogenous hormones or other additives during nodule development in crop legumes such as soybean as they have huge root system in soil. To circumvent this issue, the present research develops suitable media and growth conditions for efficient nodule development under in vitro, soil free conditions in an important legume crop, soybean. Moreover, we also evaluate the effects of all major phytohormones during soybean nodulation under identical conditions. This versatile, inexpensive, scalable and simple protocol provides several advantages over previously established methods. It is extremely time-and resource-efficient, does not require special training or equipment, and produces highly reproducible results. The approach is expandable to other large legumes as well as for other exogenous additives.

Increasing biological nitrogen fixation by white clover-rhizobia symbiosis

2019 ◽  
pp. 231-234 ◽  
Author(s):  
Shengjing Shi ◽  
Laura Villamizar ◽  
Emily Gerard ◽  
Clive Ronson ◽  
Steve Wakelin ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Biological Nitrogen Fixation ◽  
Root Nodules ◽  
N Fixation ◽  
Nodule Occupancy ◽  
Coating Technology ◽  
Vitro Assay ◽  
Biological Nitrogen

Biological nitrogen fixation (BNF) is the process of converting atmospheric nitrogen to ammonia through legume–rhizobia symbiosis. The nitrogen fixed by rhizobia in root nodules is available for plant use. This process can be harnessed to improve N fertility on farm. Field surveys across New Zealand (NZ), within a farm and within paddocks, have revealed large spatial variability of rhizobial population size and symbiotic effectiveness with white clover. These results indicate that naturalised rhizobia may not be supporting optimal BNF. Over 500 strains of clover-nodulating rhizobia were isolated from NZ pasture soils, with more than 90 demonstrating greater N-fixation capacity with white clover than the commercial inoculant strain TA1. Seven NZ isolates were tested for nodule occupancy and all seven had significantly higher occupancy rates than TA1 in an in vitro assay, indicating increased competitiveness of those strains. In addition, novel seed-coating technology improved the survival of TA1 and isolate S10N9 from 1 month to more than 4 months compared with a standard coating formulation. There is potential to increase the symbiotic capacity of white clover in pastures through use of more effective and competitive rhizobial strains, along with their improved survival on seed provided by a new coating technology.

scholarly journals Legume root nodule symbiosis: An evolving story in biology and biotechnology

2013 ◽  
Vol 35 (4) ◽  
pp. 14-18 ◽  
Author(s):  
Nicholas J. Brewin
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Root Nodule ◽  
Root Nodule Symbiosis ◽  
Evolution Of Life ◽  
Living Organisms ◽  
Life On Earth ◽  
Biological Nitrogen ◽  
Global Nitrogen Cycle ◽  
Nodule Symbiosis

The evolution of biological nitrogen fixation is central to the evolution of life on earth. Nitrogen is an essential component of proteins and nucleic acids and its restricted availability to living organisms has often been a major factor limiting growth. Despite the overwhelming abundance of N2 gas in the atmosphere, di-nitrogen is chemically inaccessible to most forms of life. For their growth and metabolism, most organisms use the ‘fixed’ forms of nitrogen, either as ammonium (NH4+) or as nitrate (NO3-), or derivatives thereof. However, the major input into the global nitrogen cycle is through the reductive process of biological nitrogen fixation which converts atmospheric N2 into ammonia (NH3). This process evolved in bacteria and/or archaea over 2.5 billion years ago while the planet still had a reducing atmosphere. Today, biological nitrogen fixation is still restricted to the bacteria and archaea. The legume root nodule symbiosis allows the host plant to benefit directly by association with soil bacteria, collectively termed rhizobia, which fix nitrogen as endosymbionts.

scholarly journals Biological nitrogen fixation by two Acacia species and associated root-nodule bacteria in a suburban Australian forest subjected to prescribed burning

2019 ◽  
Vol 20 (1) ◽  
pp. 122-132 ◽  
Author(s):  
Frédérique Reverchon ◽  
Kadum M. Abdullah ◽  
Shahla Hosseini Bai ◽  
Emanuel Villafán ◽  
Timothy J. Blumfield ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Root Nodule ◽  
Prescribed Burning ◽  
Nodule Bacteria ◽  
Root Nodule Bacteria ◽  
Acacia Species ◽  
Biological Nitrogen

The inorganic biochemistry of molybdoenzymes

1988 ◽  
Vol 21 (3) ◽  
pp. 299-329 ◽  
Author(s):  
Robert C. Bray
Keyword(s):  
Nitrogen Fixation ◽  
Trace Element ◽  
Xanthine Oxidase ◽  
Biological Nitrogen Fixation ◽  
Root Nodules ◽  
Atmospheric Nitrogen ◽  
Mammalian Enzyme ◽  
The 1950S ◽  
Biological Nitrogen

Molybednum-containing enzymes (Coughlan, 1980; Spiro, 1985) occupy a significant place in the development of the field now termed inorganic biochemistry. The importance of the metal as a biological trace element depends on its involvement in the known, and perhaps other as yet unknown, molybdoenzymes. That it plays a role in biological nitrogen fixation, the process whereby the enzyme nitrogenase in the root nodules of plants converts atmospheric nitrogen into ammonia, was recognized in the 1930s. The metal is also a constituent of a variety of other enzymes, having first been found in a mammalian enzyme, xanthine oxidase, in the 1950s.

Phosphorus-Rhizobium interaction studies on biological nitrogen fixation and yield of lentil

1988 ◽  
Vol 110 (1) ◽  
pp. 141-144 ◽  
Author(s):  
K. K. Dhingra ◽  
H. S. Sekhon ◽  
P. S. Sandhu ◽  
S. C. Bhandari
Keyword(s):  
Nitrogen Fixation ◽  
Grain Yield ◽  
Biological Nitrogen Fixation ◽  
Field Experiments ◽  
Nitrogenase Activity ◽  
Root Nodules ◽  
Dry Weight ◽  
Biological Nitrogen ◽  
Phosphorus Application ◽  
Intact Root

SummaryField experiments were conducted at the Punjab Agricultural University, Ludhiana from 1980–1 to 1984–5 to study the response of lentil genotypes to phosphorus application and Rhizobium inoculation. The number and dry weight of nodules increased consistently with increasing rates of application of phosphorus from 0 to 60 kg P2O5/ha. Nitrogenase activity of intact root nodules increased from 17 530 to 22 390 nmol/h per g dry weight of nodules with 20 kg P2O6/ha and to 27391 and 29170 nmol/h per g with 40 and 60 kg P2O5/ha, respectively. Rhizobium inoculation also increased nodulation, nitrogenase activity and grain yield. Interaction between phosphorus and Rhizobium inoculation was significant in 3 out of 5 years, indicating that the combination of Rhizobium and 20 kg P2O6/ha gave yield equivalent to 40 kg P2O6/ha without Rhizobium.

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