Populations of Rhizobium leguminosarum biovars phaseoli and viceae in fields after bean or pea in rotation with nonlegumes

1989 ◽  
Vol 35 (6) ◽  
pp. 661-667 ◽  
Author(s):  
R. M. N. Kucey ◽  
M. F. Hynes
Keyword(s):  
Rhizobium Leguminosarum ◽  
Most Probable Number ◽  
Inoculum Potential ◽  
Phaseolus Vulgaris L ◽  
Probable Number ◽  
Pisum Sativum L ◽  
Plasmid Profiles ◽  
Southern Alberta ◽  
Rhizobium Competition ◽  
Legume Inoculants

Populations of Rhizobium leguminosarum bv. phaesoli and bv. viceae in southern Alberta soils were measured over a period of 4 years using a most probable number method. Five fields cropped to bean (Phaseolus vulgaris L.), five fields cropped to pea (Pisum sativum L.), and two fields cropped to wheat were used as test sites. Legume crops had received appropriate legume inoculants. Fields were sampled in the fall of the crop year and in the spring of the following 3 years during which fields were cropped to nonlegumes or left fallow. Numbers of R. leguminosarum bv. phaseoli were 100 to 1000 times higher in fields that had been planted to bean than in fields that had been planted to pea or wheat. Fields that had been planted to pea maintained populations of R. leguminosarum bv. viceae 10 to 100 times higher than fields that had been planted to bean or wheat. Wheat fields, which had never had legumes grown in them, contained between 1 and 100 rhizobia per gram of soil of both biovars of R. leguminosarum, indicating that both biovars are native to southern Alberta soils. The numbers of rhizobia did not decrease in proportion to the population of other bacteria in the soil over the duration of the experiment. Plasmid profiles of soil Rhizobium isolates obtained in the last year of the experiment showed that none of the isolates had plasmid profiles similar to those of strains added as inoculants in the 1st year of the experiment. These results show that fields cropped to legumes and receiving rhizobial inoculants in this study maintained high populations of rhizobia for several years after harvest of the legume crop.Key words: Rhizobium leguminosarum bv. phaseoli, Rhizobium leguminosarum bv. viceae, nodule, plasmid profiles, inoculum potential, rhizobium competition.

Diversity and symbiotic effectiveness of Rhizobium leguminosarum bv. trifolii isolates from pasture soils in south-western Australia

Soil Research ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1319 ◽  
Author(s):  
M. T. Collins ◽  
J. E. Thies ◽  
L. K. Abbott
Keyword(s):  
Western Australia ◽  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
Most Probable Number ◽  
Enzyme Linked Immunosorbent Assay ◽  
Symbiotic Effectiveness ◽  
Probable Number ◽  
Pcr Fingerprinting ◽  
Rapd Pcr ◽  
Inoculant Strain

The abundance of the Australian inoculant strain of Rhizobium leguminosarum bv. trifolii for subterraneum clover (WU95) and the diversity of naturalised rhizobia were assessed in 3 subterranean clover pastures in the Albany region of south-western Western Australia. Most probable number, enzyme linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) techniques were used. A putative strain similar to inoculant strain WU96 was uncommon at one site (South Stirling) and not isolated at 2 other sites. Randomly amplified polymorphic DNA (RAPD) PCR fingerprinting using the RPO1 primer identified 45 different profiles amongst the 208 isolates examined. RAPD-PCR fingerprinting using the primers RPO4 and RPO5 confirmed most groupings based on RPO1 fingerprint patterns and revealed further genetic diversity within some groups. Overall, 54 putative strains were defined by RAPD-PCR fingerprint profiles across the 3 sites. Subterranean clover rhizobia at the Manypeaks and Mount Shadforth sites were dominated by isolates with 1 or 2 RPO1 RAPD profiles at 2 sampling times, while the population at South Stirling was much more diverse. The symbiotic effectiveness of 11 rhizobial isolates, representing the major RPO1 RAPD profile groups within naturalised rhizobial populations, were compared in pot culture with those of the 2 commercial inoculant strains for subterranean clover, WU95 and TA1, on 3 cultivars. Differences in effectiveness among 3 of the 11 isolates were observed in comparison to both the commercial strains and other naturalised isolates. The nitrogen fixing effectiveness of 8 isolates representing different subgroups from one RP01 group was not the same. The use of all 3 primers increased the precision in defining putative strains of Rhizobium leguminosarum bv. trifolii, and although naturalised rhizobia from these pastures are saprophytically competent, their dominance in nodules does not appear to be linked to symbiotic effectiveness.

Agronomic and environmental drivers of population size and symbiotic performance of Rhizobium leguminosarum bv. viciae in Mediterranean-type environments

2012 ◽  
Vol 63 (5) ◽  
pp. 467 ◽  
Author(s):  
E. A. Drew ◽  
M. D. Denton ◽  
V. O. Sadras ◽  
R. A. Ballard
Keyword(s):  
Population Size ◽  
Dry Matter ◽  
Rhizobium Leguminosarum ◽  
Field Pea ◽  
Environmental Drivers ◽  
Annual Rainfall ◽  
Maximum Temperature ◽  
Most Probable Number ◽  
Probable Number ◽  
Commercial Strain

The population size and symbiotic performance (ability to fix N2) of rhizobia (Rhizobium leguminosarum bv. viciae) capable of nodulating field pea (Pisum sativum) were assessed in 114 soils from Mediterranean-type environments of southern Australia. All soils were collected in autumn, before the growing season, and had a history of crop legumes including field pea, faba bean, lentil, or vetch. The most probable number (MPN) technique, with vetch as a trap plant, was used to estimate the numbers of pea rhizobia in soils. Of the soils tested, 29% had low numbers of pea rhizobia (<100 rhizobia/g), 38% had moderate numbers (100–1000/g), and the remaining 33% had >1000/g. Soil pH, the frequency of a host crop in the rotation, and the number of summer days with a maximum temperature >35°C were strongly correlated with the pea rhizobia population size. Symbiotic performance (SP) of pea rhizobia in soils was assessed for soils with a MPN >100 rhizobia/g. An extract of the soils was used to inoculate two field pea cultivars growing in a nitrogen-deficient potting media in the greenhouse. Plants were grown for 5 weeks after inoculation and shoot dry matter was expressed as a percentage of the dry matter of plants grown with a commercial strain R. leguminosarum bv. viciae, SU303. Symbiotic performance ranged from 25 to 125%. One-quarter of the soils assessed had suboptimal SP (i.e. <70%). Soil and climatic variables were weakly associated with SP, with pH and average annual rainfall accounting for 17% of the variance. This research highlights the complexity of factors influencing population size and symbiotic performance of pea rhizobia in soils. Options for the improved management of populations of pea rhizobia in Mediterranean environments are discussed. Specifically, our data indicate that inoculation of pea crops is likely to be beneficial where pH(H2O) <6.6, particularly when summers have been hot and dry and when a host has been absent for ≥5 years, as numbers of rhizobia are likely to be below the thresholds needed to optimise nodulation and crop growth. New inoculation technologies and plant breeding will be required to overcome large populations of pea rhizobia with suboptimal SP.

scholarly journals Distribution of a Population of Rhizobium leguminosarum bv. trifolii among Different Size Classes of Soil Aggregates

1998 ◽  
Vol 64 (3) ◽  
pp. 970-975 ◽  
Author(s):  
Ieda C. Mendes ◽  
Peter J. Bottomley
Keyword(s):  
Cover Crop ◽  
Rhizobium Leguminosarum ◽  
Soil Aggregates ◽  
Aggregate Size ◽  
Red Clover ◽  
Size Class ◽  
Most Probable Number ◽  
Probable Number ◽  
Size Classes ◽  
Soil Population

ABSTRACT A combination of the plant infection-soil dilution technique (most-probable-number [MPN] technique) and immunofluorescence direct count (IFDC) microscopy was used to examine the effects of three winter cover crop treatments on the distribution of a soil population ofRhizobium leguminosarum bv. trifolii across different size classes of soil aggregates (<0.25, 0.25 to 0.5, 0.5 to 1.0, 1.0 to 2.0, and 2.0 to 5.0 mm). The aggregates were prepared from a Willamette silt loam soil immediately after harvest of broccoli (September 1995) and before planting and after harvest of sweet corn (June and September 1996, respectively). The summer crops were grown in soil that had been either fallowed or planted with a cover crop of red clover (legume) or triticale (cereal) from September to April. The Rhizobiumsoil population was heterogeneously distributed across the different size classes of soil aggregates, and the distribution was influenced by cover crop treatment and sampling time. On both September samplings, the smallest size class of aggregates (<0.25 mm) recovered from the red clover plots carried between 30 and 70% of the total nodulatingR. leguminosarum population, as estimated by the MPN procedure, while the same aggregate size class from the June sampling carried only ∼6% of the population. In June, IDFC microscopy revealed that the 1.0- to 2.0-mm size class of aggregates from the red clover treatment carried a significantly greater population density of the successful nodule-occupying serotype, AR18, than did the aggregate size classes of <0.5 mm, and 2 to 5 mm. In September, however, the population profile of AR18 had shifted such that the density was significantly greater in the 0.25- to 0.5-mm size class than in aggregates of <0.25 mm and >1.0 mm. The populations of two otherRhizobium serotypes (AR6 and AS36) followed the same trends of distribution in the June and September samplings. These data indicate the existence of structural microsites that vary in their suitabilities to support growth and protection of bacteria and that are influenced by the presence and type of plant grown in the soil.

scholarly journals Semienclosed Tube Cultures of Bean Plants (Phaseolus vulgaris L.) for Enumeration of Rhizobium phaseoli by the Most-Probable-Number Technique †

1986 ◽  
Vol 52 (4) ◽  
pp. 954-956 ◽  
Author(s):  
Ricardo S. Araujo ◽  
Jaime Maya-Flores ◽  
Deborah Barnes-McConnell ◽  
Charles Yokoyama ◽  
Frank B. Dazzo ◽  
...  
Keyword(s):  
Phaseolus Vulgaris ◽  
Most Probable Number ◽  
Rhizobium Phaseoli ◽  
Phaseolus Vulgaris L ◽  
Probable Number ◽  
Bean Plants

scholarly journals Development of a Real-Time PCR Assay for Detection and Quantification of Rhizobium leguminosarum Bacteria and Discrimination between Different Biovars in Zinc-Contaminated Soil

2011 ◽  
Vol 77 (13) ◽  
pp. 4626-4633 ◽  
Author(s):  
Catriona A. Macdonald ◽  
Ian M. Clark ◽  
Penny R. Hirsch ◽  
Fang-Jie Zhao ◽  
Steve P. McGrath
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Rhizobium Leguminosarum ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Most Probable Number ◽  
Rrna Gene ◽  
Probable Number ◽  
Content Type ◽  
Gene Copies

ABSTRACTPrimers were designed to target 16S rRNA andnodDgenes ofRhizobium leguminosarumfrom DNA extracted from two different soil types contaminated with Zn applied in sewage sludge. Numbers of rhizobia estimated using 16S rRNA gene copy number showed higher abundance than those estimated by bothnodDand the most-probable-number (MPN) enumeration method using a plant trap host. Both 16S rRNA gene copies and the MPN rhizobia declined with increased levels of Zn contamination, as did the abundance of the functional genenodD, providing compelling evidence of a toxic effect of Zn onR. leguminosarumpopulations in the soil. Regression analysis suggested the total Zn concentration in soil as a better predictor of rhizobial numbers than both NH4NO3-extractable and soil solution Zn.R. leguminosarumbv. viciaenodDgene copies were generally less sensitive to Zn thanR. leguminosarumbv. trifoliinodD.The latter were generally below detection limits at Zn levels of >250 mg kg−1. Although there were differences in the actual numbers estimated by each approach, the response to Zn was broadly similar across all methods. These differences were likely to result from the fact that the molecular approaches assess the potential for nodulation while the MPN approach assesses actual nodulation. The results demonstrate that the use of targeted gene probes for assessing environmental perturbations of indigenous soil rhizobial populations may be more sensitive than the conventional plant bioassay and MPN methods.

Symbiotic performance of Mediterranean Trifolium spp. with naturalised soil rhizobia

2011 ◽  
Vol 62 (10) ◽  
pp. 903 ◽  
Author(s):  
E. A. Drew ◽  
N. Charman ◽  
R. Dingemanse ◽  
E. Hall ◽  
R. A. Ballard
Keyword(s):  
Dry Matter ◽  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Most Probable Number ◽  
Diverse Populations ◽  
Symbiotic Efficiency ◽  
Probable Number ◽  
Mediterranean Origin ◽  
Inoculant Strain

Naturalised soil rhizobia that nodulate clover occur in high number and are known to vary in their symbiotic performance (SP) with subterranean clover (Trifolium subterraneum L.). However, the extent of suboptimal fixation across a range of other clover species is not well understood. T. subterraneum and nine other annual clover species of Mediterranean origin were evaluated for their SP in combination with the naturalised clover rhizobia in 71 Australian soils and five strains of Rhizobium leguminosarum bv. trifolii that have been used in the inoculants produced for clovers. The most probable number method, using subterranean clover as the trap plant was used to estimate the number of clover rhizobia in the soils. Ninety-two percent of soils tested contained more than 1000 rhizobia/g. An extract of each soil, or strain of rhizobia was used to inoculate plants growing in N-deficient media in the greenhouse. Plants were grown for 4 weeks after inoculation and shoot dry matter determined and expressed as a percentage of the ‘best’ soil rhizobia treatment, to provide a proportional measure of SP for each clover species. SP (mean of clover species) ranged from 96% with the current inoculant strain for annual clovers (WSM1325) down to 48% with former inoculant strain WU95. When inoculated with soils predominantly from mainland Australia, SP (mean of soil treatments) of the different Trifolium spp. was 55% (resupinatum), 53–47% (subterraneum), 50% (nigrescens), 49% (michelianum), 48% (isthmocarpum), 38% (hirtum), 35% (purpureum), 32% (vesiculosum), 25% (spumosum) and 21% (glanduliferum). Within each of the clover species, SP resulting from individual soil treatments ranged from 100% (by definition for the best soil treatment) down to close to zero. Trifolium glanduliferum formed nodules readily with the inoculant strains but nodulation was erratic with the rhizobia in many soils. It is therefore proposed that the naturalised rhizobia in many soils are unlikely to be inoculant strains. This research demonstrates symbiotic efficiency across annual clover species is compromised where diverse populations of clover rhizobia have naturalised in soils.

Host plant effect on competition among strains of Rhizobium leguminosarum

1990 ◽  
Vol 36 (12) ◽  
pp. 864-869 ◽  
Author(s):  
Michael F. Hynes ◽  
Michael P. O'Connell
Keyword(s):  
Host Plant ◽  
Rhizobium Leguminosarum ◽  
Previous History ◽  
Plasmid Profile ◽  
Plasmid Profiles ◽  
Faba Beans ◽  
Group 5 ◽  
Group 2 ◽  
Host Plant Effect ◽  
Rhizobium Competition

Analysis of plasmid profiles was used to type Rhizobium leguminosarum biovar viciae strains isolated from nodules of peas, lentils and faba beans grown in two different soils. One soil was from a native pasture with no previous history of cultivation, the other was from a plot in a rotation study which included lentils every 2 years. The results indicated a strong preference of both peas and faba beans for strains having certain specific plasmid profiles. Strains belonging to one plasmid profile group (group 2) formed over half the nodules on peas grown in soil from the rotation plot but were never found on faba beans grown in the same soil, while strains from another group (group 5) formed nearly all of the nodules on faba beans grown in soil from the rotation plot, but no nodules on peas. Competitiveness for pea nodulation was correlated with an ability to catabolize homoserine, an amino acid found in large quantities in pea root exudate. Strains having plasmid profiles corresponding to those of strains that have been used in commercial inoculants over the last few years were isolated only rarely, regardless of the soil and host plant studied. Key words: Rhizobium, competition, plasmids, legumes, nodulation.

Analysis of Coliform and Colifecal Total Pollution Test on Various Types of Drinking Water Using the MPN (Most Probable Number) Method

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Wanda Aulya ◽  
Fadhliani Fadhliani ◽  
Vivi Mardina
Keyword(s):  
Drinking Water ◽  
Fecal Coliform ◽  
Pathogenic Bacteria ◽  
Microbiological Quality ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Inspection Method ◽  
Sample Number ◽  
Probable Number ◽  
Fecal Coliform Bacteria

Water is the main source for life and also the most severe substance caused by pollution. The mandatory parameters for determining microbiological quality of drinking water are total non-fecal Coliform bacteria and Coliform fecal (Escherichia coli). Coliform bacteria are a group of microorganisms commonly used as indicators, where these bacteria can be a signal to determine whether a water source has been contaminated by bacteria or not, while fecal Coliform bacteria are indicator bacteria polluting pathogenic bacteria originating from human feces and warm-blooded animals (mammals) . The water inspection method in this study uses the MPN (Most Probable Number) method which consists of 3 tests, namely, the presumption test, the affirmation test, and the reinforcement test. The results showed that of 15 drinking water samples 8 samples were tested positive for Coliform bacteria with the highest total bacterial value of sample number 1, 15 (210/100 ml), while 7 other samples were negative. From 8 positive Coliform samples only 1 sample was stated to be negative fecal Coliform bacteria and 7 other samples were positive for Coliform fecal bacteria with the highest total bacterial value of sample number 1 (210/100 ml).

Sign in / Sign up

Export Citation Format

Share Document