Bradyrhizobium japonicum mutants defective in root-nodule bacteroid development and nitrogen fixation

1986 ◽  
Vol 144 (4) ◽  
pp. 355-366 ◽  
Author(s):  
B. Regensburger ◽  
L. Meyer ◽  
M. Filser ◽  
J. Weber ◽  
D. Studer ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Bradyrhizobium Japonicum ◽  
Root Nodule

scholarly journals Nodulation and Development of Soybean Submitted to Inoculation With Bradyrhizobium japonicum and Phosphorus Doses

2018 ◽  
Vol 10 (12) ◽  
pp. 321 ◽  
Author(s):  
Erica Chaves ◽  
Rubson da Costa Leite ◽  
Thalita Rodrigues Silva ◽  
Thayny Alves Viana ◽  
Tatiane de Sousa Cruz ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Experimental Design ◽  
Bradyrhizobium Japonicum ◽  
Phosphate Fertilizer ◽  
Dry Mass ◽  
Root Number ◽  
Phosphate Fertilization ◽  
Soybean Plants ◽  
Biological Nitrogen ◽  
Plant Dry Mass

Among the several factors that may influence nodulation and the efficiency of biological nitrogen fixation for soybean plants, nutrient availability is among the most important. This study aimed to evaluate the inoculation with Bradyrhizobium japonicum and doses of phosphorus on the development of soybean in a Vertisol, in Tocantins. The experimental design was completely randomized in a 4 × 2 factorial scheme, with four replications. Four doses of phosphate fertilization (0, 100, 200, and 300 kg ha-1 P2O5) were studied, combined with two inoculation treatments with Bradyrhizobium japonicum (inoculated and not inoculated). The following variables were evaluated: plant height, stem diameter, nodules per plant, dry mass of nodules, dry mass of plant, dry mass of root, number of pods and number of grains per pod. Under greenhouse conditions and soil with good availability of phosphorus, there is no influence of the doses on the inoculation with Bradyrhizobium japonicum. Soils with good availability of phosphorus have low response to the application of phosphate fertilizer.

Investigations on the root nodule bacteria of leguminous plants: XIX. Influence of various factors on the excretion of nitrogenous compounds from the nodules

1937 ◽  
Vol 27 (3) ◽  
pp. 332-348 ◽  
Author(s):  
Artturi Ilmari Virtanen ◽  
Synnöve von Hausen ◽  
Tauno Laine
Keyword(s):  
Amino Acids ◽  
Nitrogen Fixation ◽  
Root Nodule ◽  
Nitrogen Nutrition ◽  
Nitrogen Compounds ◽  
Nodule Bacteria ◽  
Fixed Nitrogen ◽  
Nitrogenous Compounds ◽  
Primary Products ◽  
Equal Effectiveness

1. It has been shown experimentally that the excretion of nitrogen noted by us in cultures of inoculated legumes takes place from the nodule bacteria, probably from the intranodular ones, and not from the roots. No excretion of amino acids occurs in cultures of uninoculated legumes growing on nitrate nitrogen.2. Our earlier hypothesis that the legumes receive their nitrogen nutrition from the nodules in the form of organic nitrogen compounds, particularly amino acids, is in perfect accord with our new observations concerning the process of excretion. All facts indicate that the amino acids concerned are primary products of the nitrogen fixation, and not breakdown products of proteins. Bond's valuable work along quite different lines produced results which support this conclusion. He, however, did not study the chemical nature of the nitrogen compounds in question.3. The excretion of nitrogen occurs in media capable of absorbing the excreted nitrogen compounds (cellulose, kaolin, sand, soil). The demonstration of the excretion is not possible in water cultures except when very large quantities of water are used. On the basis of these facts a hypothesis is advanced to explain the nature of the excretion.4. The term total fixed nitrogen has been used as an expression for the extent of nitrogen fixation, while the term extent of excretion is employed to indicate that percentage of the total fixed nitrogen which is excreted from the nodules.5. The extent of excretion depends largely on the strain used for inoculation. With strains of apparently equal effectiveness in nitrogen fixation, the extent of excretion may vary considerably, so that actually such strains differ in their effectiveness.

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