Annual species of Medicago differ greatly in their ability to nodulate on acid soils

1989 ◽  
Vol 40 (4) ◽  
pp. 843 ◽  
Author(s):  
JG Howieson ◽  
MA Ewing
Keyword(s):  
Rhizobium Meliloti ◽  
Acid Soils ◽  
Annual Species ◽  
Selection Of

It is possible that the use of annual species of Medicago may be broadened by the selection of genotypes more capable of achieving nodulation on acid soils when only low numbers of their microsymbiont, Rhizobium meliloti, are present. In this study 36 genotypes from 14 species of Medicago were examined for their ability to nodulate over a range of inoculum levels in a soil of pH 4.9 (1:5,0.01 M CaCl2). Variation both within and between species was evident. M. murex in particular, as well as M. polyrnorphu and M. soleirolii, were outstanding in their ability to achieve nodulation in the acid soils. This character should assume some priority in pasture selection programmes targeted for acid soils.

Symbiotic characteristics of Rhizobium meliloti from the brown acid soils of the Macquarie region of New South Wales.

1961 ◽  
Vol 12 (4) ◽  
pp. 630 ◽  
Author(s):  
J Brockwell ◽  
FW Hely
Keyword(s):  
Rhizobium Meliloti ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Nodule Formation ◽  
Seed Inoculation ◽  
South Wales ◽  
High Level ◽  
Bacterial Groups ◽  
Selection Of

Thirty-three isolates of Rhizobim meliloti were obtained from the brown acid soils of the Macquarie region of New South Wales and their symbiotic behaviour in association with 11 species of Merlicago and three species of Melilotus was investigated in the laboratory. In respect of nodule formation, there were two distinct types of Rhizobiurn and the hosts formed three groups. In respect of nitrogen fixation there were six strain types and seven host, groupings. These host and bacterial groups could be arranged in a series. Several of the strains of rhizobia, and one in particular, were found to fix a high level of nitrogen with a number of hosts, but, except for ;Medicago denticulata Willd. and Melilotus indica (L.) All. which behaved identically in all features of the symbiosis studied, no definit'e groupings on this criterion were apparent in either hosts or bacteria. The possible application of the results to the selection of strains of' Rhizobium meliloti suitable for seed inoculation is discussed.

Calcium modifies pH effects on the growth of acid-tolerant and acid-sensitive Rhizobium meliloti

1992 ◽  
Vol 43 (3) ◽  
pp. 765 ◽  
Author(s):  
JG Howieson ◽  
AD Robson ◽  
LK Abbott
Keyword(s):  
Soil Acidity ◽  
Rhizobium Meliloti ◽  
Acid Soils ◽  
Defined Medium ◽  
Ph Effects ◽  
Poor Growth ◽  
Growth And Survival ◽  
Ph Values ◽  
Acid Tolerant ◽  
Selection Of

The growth of Rhizobium meliloti is sensitive to soil acidity, and its poor growth and survival limits the production from Medicago spp. on acid soils. In the selection of acid tolerant rhizobia for medics, growth in acidified laboratory media has been poorly related to persistence in acid soils. However, the Ca concentration in laboratory media may have been inadequate for growth of some rhizobial strains at low pH. Therefore, acid-tolerant and acid-sensitive strains of R. meliloti were grown in a buffered, defined medium at a range of Ca and P concentrations, and at several pH values. Growth rate was increased by increasing the Ca concentration from 200 to 2000 8M at low (5-70) and moderate (6.50) pH, but not at pH 7.30. Thus, the Ca requirement for the growth of R. meliloti under acid conditions is much higher than previously thought.

EFFECTS OF SOIL ACIDITY ON RHIZOBIA NUMBERS, NODULATION AND NITROGEN FIXATION BY ALFALFA AND RED CLOVER

1977 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
W. A. RICE ◽  
D. C. PENNEY ◽  
M. NYBORG
Keyword(s):  
Nitrogen Fixation ◽  
Soil Ph ◽  
Soil Acidity ◽  
Field Experiments ◽  
Rhizobium Meliloti ◽  
Acid Soils ◽  
Red Clover ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Greenhouse Experiments

The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse experiments using soils from these locations. The pH of the soils (limed and unlimed) varied from 4.5 to 7.2. Rhizobia populations in the soil, nodulation, and relative forage yields (yield without N/yield with N) were measured in both the field and greenhouse experiments. Rhizobium meliloti numbers, nodulation scores, and relative yields of alfalfa decreased sharply as the pH of the soils decreased below 6.0. For soils with pH 6.0 or greater, there was very little effect of pH on any of the above factors for alfalfa. Soil pH in the range studied had no effect on nodulation scores and relative yields of red clover. However, R. trifolii numbers were reduced when the pH of the soil was less than 4.9. These results demonstrate that hydrogen ion concentration is an important factor limiting alfalfa growth on acid soils of Alberta and northeastern British Columbia, but it is less important for red clover. This supports the continued use of measurements of soil pH, as well as plant-available Al and Mn for predicting crop response to lime.

scholarly journals ABSENCE OF A CORRELATION BETWEEN NITRATE REDUCTASE AND SYMBIOTIC NITROGEN FIXATION EFFICIENCY IN RHIZOBIUM MELILOTI

1980 ◽  
Vol 60 (1) ◽  
pp. 209-212 ◽  
Author(s):  
H. ANTOUN ◽  
L. M. BORDELEAU ◽  
D. PRÉVOST ◽  
R. A. LACHANCE
Keyword(s):  
Nitrogen Fixation ◽  
Nitrate Reductase ◽  
Dry Matter ◽  
Symbiotic Nitrogen Fixation ◽  
Rhizobium Meliloti ◽  
Specific Activities ◽  
Selection Of

Specific activities of the assimilatory and "regulatory" types of nitrate reductase were studied in 41 strains of Rhizobium meliloti having different symbiotic nitrogen fixation activities. Both nitrate reductase enzymes were present in very effective and ineffective strains and no significant correlation was found between the specific activities of the two enzymes and the dry matter yields of alfalfa obtained with the 41 strains. Measurements of the specific activities of the two nitrate reductase enzymes in the vegetative bacteria cannot be used as a rapid physiological test for the selection of very effective strains of R. meliloti.

Phylogenetic grouping and identification of Rhizobium isolates on the basis of random amplified polymorphic DNA profiles

1993 ◽  
Vol 39 (7) ◽  
pp. 665-673 ◽  
Author(s):  
John J. Dooley ◽  
Stephen P. Harrison ◽  
Lance R. Mytton ◽  
Malcolm Dye ◽  
Ann Cresswell ◽  
...  
Keyword(s):  
Rhizobium Leguminosarum ◽  
Rhizobium Meliloti ◽  
Random Amplified Polymorphic Dna ◽  
Dna Amplification ◽  
Distinct Group ◽  
Principal Coordinate Analysis ◽  
The Other ◽  
Phylogenetic Grouping ◽  
Dna Profiles ◽  
Selection Of

Through the use of a single, random 15mer as a primer, between 1 and 12 DNA amplification products were obtained per strain from a selection of 84 Rhizobium and Bradyrhizobium isolates. A principal-coordinate analysis was used to analyse the resulting amplified DNA profiles and it was possible to assign isolates to specific groupings. Within the species Rhizobium leguminosarum, the biovar phaseoli formed a distinct group from the other biovars of the species, viciae and trifolii, which grouped together. Isolates of Rhizobium meliloti and Bradyrhizobium species formed their own clear, specific groups. Although it was possible to identify individual isolates on the basis of differences in their amplified DNA profiles, there was evidence that some amplified segments were conserved among individuals at the biovar and species levels.Key words: Rhizobium, DNA amplification, random primers.

Soil pH is a major determinant of the numbers of naturally occurring Rhizobium meliloti in non-cultivated soils in central New South Wales

1991 ◽  
Vol 31 (2) ◽  
pp. 211 ◽  
Author(s):  
J Brockwell ◽  
A Pilka ◽  
RA Holliday
Keyword(s):  
Soil Ph ◽  
Rhizobium Meliloti ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Alkaline Soils ◽  
Naturally Occurring ◽  
South Wales ◽  
Dominant Soil ◽  
The Relationship

Measurements were made of soil pH, frequency of occurrence of annual species of Medicago (medics) and populations of Rhizobium meliloti at 84 sites on 7 dominant soil groups of the Macquarie region of central-western New South Wales. Over all sites, soil pH (0-10 cm; 1:5 soil: water) ranged from 5.26 to 8.07, medic frequency from 0 to 100% and most probable numbers of R. meliloti from undetectable to 675 000/g soil. There was a highly significant (P<0.001) relationship between soil pH and number of R. meliloti. Above pH 7.0, the mean soil population of R. meliloti was 89000/g; below pH 6.0, it was 37/g. Medics occurred most frequently on the more alkaline soils and with least frequency on the more acid soils, but the relationship between soil pH and medic frequency was weaker than between pH and R. meliloti number. Medics were more tolerant of low soil pH than their rhizobia were; at 2 sites, of pH 5.49 and 5.35, medics occurred at 100% frequency but R. meliloti was undetected. There was an indication of some acidification in these soils over a period of 35 years but this remains to be confirmed.

EFFECTS OF CaCO3 AND INOCULUM LEVEL ON NODULATION AND GROWTH OF ALFALFA IN AN ACID SOIL

1975 ◽  
Vol 55 (3) ◽  
pp. 245-250 ◽  
Author(s):  
W. A. RICE
Keyword(s):  
Rhizobium Meliloti ◽  
Acid Soil ◽  
Relative Yield ◽  
Acid Soils ◽  
Inoculum Level ◽  
Al Content ◽  
N Yield ◽  
Ineffective Nodule ◽  
Medicago Sativa L ◽  
Nodule Tissue

The effects of CaCO3 and inoculum level on nodulation and growth of alfalfa (Medicago sativa L.) in an acid soil were studied by measuring alfalfa yield, nodule numbers and nodule weights in relation to various levels of CaCO3 amendment and to the number of Rhizobium meliloti applied per seed. When sufficient CaCO3 was applied to the soil (4 mg CaCO3/g soil) to reduce soluble Al to sub-toxic levels, the relative yield (yield without N/yield with N) of alfalfa increased from 0.7 with no inoculum to 1.0 with 3 × 107 rhizobia per seed. Increasing the inoculum level from no inoculum to 3 × 107 rhizobia per seed decreased the amount of ineffective nodule tissue from 0.65 to 0.27 mg/pot without CaCO3 added, and from 0.60 to 0.06 mg/pot with the addition of 4.0 mg CaCO3/g soil. When no inoculum was applied, the amount of effective nodule tissue was increased from 0 to 0.91 mg/pot by adding 4.0 mg CaCO3/g soil. Application of inoculum increased the amount of effective nodule tissue at all levels of CaCO3. The results demonstrate the importance of liming to decrease the soluble Al content of acid soils for alfalfa production, and show that high inoculum levels can be used to improve alfalfa yields on acid soils.

scholarly journals Isolation and Selection of Rhizobium Tolerant to Pesticides and Aluminum from Acid Soils in Indonesia

2013 ◽  
Vol 16 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Erni Martani ◽  
Sebastian Margino ◽  
Didiek Indradewa ◽  
Agus Supriyo
Keyword(s):  
Ph Value ◽  
Soil Analysis ◽  
Root Nodules ◽  
Acid Soil ◽  
Acid Soils ◽  
Soybean Plant ◽  
High Concentration ◽  
Diffusion Technique ◽  
Wide Range ◽  
Selection Of

Application of Rhizobium as inoculum in acid soil requires specific characters, namely high tolerance to pesticide residues, soil acidity, and high concentration of Aluminum. This study was conducted to isolate Rhizobium having these characters. Inspite of acid soils from Kalimantan, Sumatra, Sulawesi and Java; root nodules of legumes planted in those regions were used as source of isolates. Rhizobial isolation was done using direct isolation andenrichment technique. A paper disc diffusion technique was used in selecting tolerance to pesticides. The selected isolates were examined the tolerance to pH, Al, and ability to form root nodule with soybean. From soil analysis, it could be seen the correlation between pH value and Al concentration. It means that the lower pH value the higher Al concentration. The number of Rhizobium isolates and its tolerance to paraquat was depended on soil type. From 173 strains of isolated Rhizobium, 24 strains were tolerance to pesticides and Aluminum. They were able to grow in wide range of pH, namely 3 – 8, or some of them in 5 - 8. Around 92% of the selected bacteria could form root nodules with soybean plant in different number and size. Hopefully, these isolates can be applied in the pesticide polluted agricultural lands, especially in acid soils with high concentration of Al, and it can also increase soybean production.Keywords: Acid soils, aluminium, Rhizobium, pesticides

An exploratory survey of the ecology of Rhizobium meliloti in inland New South Wales and Queensland

1962 ◽  
Vol 13 (5) ◽  
pp. 864 ◽  
Author(s):  
FW Hely ◽  
J Brockwell
Keyword(s):  
Rhizobium Meliloti ◽  
New South ◽  
Plant Size ◽  
Annual Species ◽  
Test Species ◽  
High Frequencies ◽  
South Wales ◽  
Exploratory Survey ◽  
Dry Conditions ◽  
Medicago Sativa L

The ability of Rhizobium meliloti occurring naturally at 26 sites to nodulate three test species of Medicago was investigated. Bacteria able to nodulate Medicago sativa L. were found, in the absence of this host, at all sites sampled and frequently in appreciable numbers, even under dry conditions. Bacteria able to nodulate Medicago denticulata Willd. were found at 25 sites, but usually in lower numbers; they also occurred independently of this species. Organisms able to nodulate Medicago laciniata (L.) Mill. were detected at 18 sites but only in low numbers; they were found at eight sites in the absence of M. laciniata and were not detected at three sites where this medic was present. High numbers of bacteria able to nodulate M. sativa and M. denticulata were related to high frequencies of Medicago minima (L.) Bart. in the field. Associations were found between high numbers of Rh. Meliloti in the topsoil and the texture of the soil, the plant size of the annual species of Medicago in the sample area, and the condition of the native grasses.

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