Competition between inoculant and naturalised Rhizobium leguminosarum bv. trifolii for nodulation of annual clovers in alkaline soils

2002 ◽  
Vol 53 (9) ◽  
pp. 1019 ◽  
Author(s):  
M. D. Denton ◽  
D. R. Coventry ◽  
P. J. Murphy ◽  
J. G. Howieson ◽  
W. D. Bellotti
Keyword(s):  
Rhizobium Leguminosarum ◽  
South Australia ◽  
First Year ◽  
Nodule Occupancy ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Field Site ◽  
Chain Reaction ◽  
Edaphic Conditions ◽  
Polymerase Chain

Inoculant rhizobia typically need to compete with naturalised soil populations of rhizobia to form legume nodules. We have used the polymerase chain reaction to test the ability of seed-inoculated rhizobia to compete with naturalised populations of rhizobia and form nodules on clover (Trifolium alexandrinum, T.�purpureum, and T. resupinatum) in alkaline soil. Clover rhizobia, Rhizobium leguminosarum bv. trifolii, were identified at the strain level using either a nif-specific RP01 primer or ERIC primers. Analysis of rhizobia isolated from nodules indicated that strain TA1 competed poorly for nodule occupancy at 2 field sites (Roseworthy and Mallala, South Australia), with the exception that it nodulated T. alexandrinum at a level of 39% at the Roseworthy site in the first year of the trial. Strains CC2483g and WSM409 successfully colonised nodules when inoculated onto a particular clover species (T. resupinatum and T. purpureum, respectively) in the first year of inoculation and persisted in the soil to form nodules in the following year. Nodules frequently contained naturalised strains of rhizobia, distinct from introduced commercial strains. Dominant isolates were specific to a field site and nodulated all 3 clover species in both years of the field trial, with each isolate occupying up to 19% of the total nodules at a field site. It was hypothesised that field isolates had a better alkaline soil tolerance conferring a greater ability to nodulate clovers under these edaphic conditions. The results indicate that soil populations of rhizobia may provide a significant constraint to the introduction of current Australian commercial clover rhizobia into alkaline soils, and a more profitable strategy may be to seek rhizobial inoculants that are adapted to these soils.

Nitrogen fixation in annual Trifolium species in alkaline soils as assessed by the 15N natural abundance method

2011 ◽  
Vol 62 (8) ◽  
pp. 712 ◽  
Author(s):  
Matthew D. Denton ◽  
David R. Coventry ◽  
William D. Bellotti ◽  
John G. Howieson
Keyword(s):  
N2 Fixation ◽  
Rhizobium Leguminosarum ◽  
Farming Systems ◽  
15N Natural Abundance ◽  
Natural Abundance ◽  
Soil Conditions ◽  
Nodule Occupancy ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Mixed Farming

Annual clover species such as Trifolium purpureum Loisel., T. resupinatum L., and T. alexandrinum L. are adapted to alkaline soil conditions and provide certain agronomic advantages over annual medics (Medicago spp.). Annual clovers have not been widely grown in alkaline soils in Australia, and quantifying their dinitrogen (N2) fixation in alkaline soils is important in understanding their potential role in mixed farming systems of southern Australia. Using the 15N natural abundance technique, it was estimated that annual clovers fixed 101–137 kg N/ha at Roseworthy and 59–62 kg N/ha at Mallala, on Calcarosols with soil pH of 8.0 and 8.5, respectively. Species differed in the percentages of fixed N2 estimated in shoot dry matter, which was highest in T. alexandrinum (77–85%), moderate in T. resupinatum (76%), and lowest in T. purpureum (65–74%). Naturally occurring soil rhizobia (Rhizobium leguminosarum bv. trifolii) provided adequate nodulation, as inoculation with different strains of rhizobia had little influence on nodulation or N2 fixation. These results indicate that clovers can provide a significant contribution of fixed N2 to mixed farming systems. Examination of nodules indicated variable nodule occupancy by the inoculant rhizobia and that 69% of shoot N was fixed when clovers were nodulated by the soil populations of rhizobia. A simple model is defined to identify the potential interactions between inoculated legumes and soil rhizobia, and the options for enhancing symbiotic effectiveness are discussed.

Development and application of polymerase chain reaction-based assays for Rathayibacter toxicus and a bacteriophage associated with annual ryegrass (Lolium rigidum) toxicity

2007 ◽  
Vol 47 (2) ◽  
pp. 177 ◽  
Author(s):  
M. C. Kowalski ◽  
D. Cahill ◽  
T. J. Doran ◽  
S. M. Colegate
Keyword(s):  
Polymerase Chain Reaction ◽  
Immunosorbent Assay ◽  
Potential Application ◽  
South Australia ◽  
Enzyme Linked Immunosorbent Assay ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Annual Ryegrass Toxicity

Annual ryegrass toxicity (ARGT) is responsible for significant stock losses in South Australia and Western Australia. The toxicity is caused by corynetoxins produced by the bacterium Rathayibacter toxicus (with the possible involvement of a bacteriophage), which infects annual ryegrass (Lolium rigidum). Polymerase chain reaction (PCR)-based assays, compatible with an existing enzyme-linked immunosorbent assay for the corynetoxins, have been developed and used to screen L. rigidum for both the presence of R. toxicus and for the bacteriophage isolate NCPPB 3778. The results from analysing bacterially infected galls from toxic grain screenings showed a positive correlation between the presence of the bacterium and corynetoxins but not with the bacteriophage. Analysis of pasture-derived samples of annual ryegrass showed about a 50% correlation of corynetoxins with bacterial presence and about a 5% correlation of phage with the presence of the bacterium. These observations support the potential application of the PCR-based assays in providing a useful, complementary tool in the assessment of the likelihood of pasture and feed to cause ARGT and to enable a better understanding of the complex aetiology of ARGT.

Determining Platypus Relationships

1995 ◽  
Vol 43 (3) ◽  
pp. 283 ◽  
Author(s):  
NJ Gemmell ◽  
TR Grant ◽  
PS Western ◽  
J Walmsley ◽  
JM Watson ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Family Relationships ◽  
Captive Breeding ◽  
South Australia ◽  
Mitochondrial Control Region ◽  
Chain Reaction ◽  
Banding Patterns ◽  
Resident Population ◽  
Novel Method ◽  
Polymerase Chain

In the summer of 1990-91 the first captive breeding of platypus (Omithorhynchus anatinus) in 47 years, and only the second ever, occurred in a small resident population at Warrawong Sanctuary, South Australia. DNA fingerprinting and analyses employing the maternally inherited mitochondrial genome have been used to determine family relationships within this population Using hypervariable DNA sequences cloned from other species to probe blots of DNA from the Warrawong platypuses, individual-specific banding patterns have been observed that allow the identification of family relationships within the population. A novel method for detecting maternal relationships within platypus populations, based on polymerase chain reaction analyses of the highly polymorphic mitochondrial control region, is also presented.

Effects of electrolyte composition on chromium desorption in soils contaminated by tannery waste

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 1077 ◽  
Author(s):  
S. Avudainayagam ◽  
R. Naidu ◽  
R. S. Kookana ◽  
A. M. Alston ◽  
S. McClure ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
South Australia ◽  
Acidic Soil ◽  
Desorption Kinetics ◽  
Equilibration Time ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Electron Microscopic ◽  
Tannery Waste ◽  
Microscopic Studies

We conducted batch studies to investigate the effect of phosphate and dominant cations present in tannery waste on desorption of chromium (Cr) from surface and subsurface soil horizons from a contaminated tannery waste site at Mount Barker, South Australia. The surface horizon (0–15 cm) of the soil profile was alkaline (pH 7.9) and the subsurface horizon (50–90 cm) was acidic (pH 3.9). Aqua-regia extractable Cr concentration ranged from 62 g/kg in the surface to 0.26 g/kg in the subsurface soils. X-ray diffraction and scanning electron microscopic studies revealed the predominance of carbonate and kaolin minerals in the surface soils, and highly weathered framboidal particles, with morphology similar to that of pyrites, in the subsurface soils. The amount of Cr desorbed from the contaminated soils varied considerably with both the electrolyte’s cationic charge and soil properties. The effect of cations, Ca 2+ and Na + (CaCl 2 , NaCl), and phosphate on desorption of Cr was investigated. While the ionic strength of the solutions was standardised at approximately 0.03 mol/L, the concentration of phosphate (as KH 2 PO 4) was varied from 0 to 3.2 mmol/L. On the basis of studies on solution to soil ratio and desorption kinetics we chose a 20: 1 solution to soil ratio and 2 h equilibration time. In the surface alkaline soil, the amount of Cr released decreased in the order Na + (286 μg/L) ≥ water (256 μg/L) > Ca 2+ (156 μg/L). In contrast subsurface acidic soil showed a reverse trend, i.e. Ca 2+ (52 μg/L) > Na + (29 μg/L) > water (20 μg/ L). Speciation of Cr in the extracts showed predominantly Cr(VI) in the alkaline surface soil and Cr(III) in the subsurface acidic soil. A strong effect of phosphate on the cumulative amount of chromate desorbed was observed. The study shows that the presence of high concentrations of Na + (0.03 mol/L) and phosphate (3.2 mmol/L) in soil solution enhances Cr(VI) mobility. In contrast, Ca 2+ may induce retention of Cr(VI) in Cr-contaminated alkaline soils.

Distribution, abundance and symbiotic effectiveness of Rhizobium leguminosarum bv. trifolii from alkaline pasture soils in South Australia

2000 ◽  
Vol 40 (1) ◽  
pp. 25 ◽  
Author(s):  
M. D. Denton ◽  
D. R. Coventry ◽  
W. D. Bellotti ◽  
J. G. Howieson
Keyword(s):  
N2 Fixation ◽  
Rhizobium Leguminosarum ◽  
South Australia ◽  
Shoot Biomass ◽  
Alkaline Soil ◽  
Symbiotic Effectiveness ◽  
Management Options ◽  
Soil Constraints ◽  
Reference Strains ◽  
Rhizobial Population

The current dissatisfaction with low productivity of annual medic (Medicago spp.) pastures has highlighted the need to seek alternative legumes to provide efficient N2 fixation in low rainfall, alkaline soil environments of southern Australia. Clover species adapted to these environments will have limited N2 fixation if effective rhizobia are not present in sufficient quantities. A survey of 61 sites was conducted across South Australia to determine the size, distribution and effectiveness of Rhizobium leguminosarum bv. trifolii (clover rhizobia) populations resident in these low rainfall, alkaline soil environments. Clover rhizobia were detected at 56 of the sites, with a median density of 230–920 rhizobia/g soil. Most rhizobial populations were poor in their capacity to fix nitrogen. Rhizobial populations from fields provided 11–89% and 10–85% of the shoot biomass of commercial reference strains when inoculated onto host legumes T. purpureum (purple clover) and T. resupinatum (persian clover), respectively. Rhizobial population size was correlated negatively to pH and the percentage of CaCO3 in the soil, and was significantly increased in the rhizospheres of naturalised clover, found at 17 sites. Management options for rhizobial populations to improve legume diversity and productivity are discussed in terms of rhizobial population dynamics and likely soil constraints to successful rhizobial colonisation.

scholarly journals Reactions of two xeric-congeneric species of Centaurea (Asteraceae) to soils with different pH values and iron availability

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12417
Author(s):  
Mateusz Wala ◽  
Jeremi Kołodziejek ◽  
Janusz Mazur ◽  
Alicja Cienkowska
Keyword(s):  
Experimental Comparison ◽  
Alkaline Soil ◽  
Congeneric Species ◽  
Alkaline Soils ◽  
Morphometric Measurements ◽  
Edaphic Conditions ◽  
Different Types ◽  
Chelate Treatment ◽  
Fe Acquisition

Centaurea scabiosa L. and C. stoebe Tausch are known to co-exist naturally in two extremely different types of open dry habitats in the temperate zone, alkaline xerothermic grasslands and acidic dry grasslands. However, knowledge about their preferences to edaphic conditions, including soil acidity (pH), and iron (Fe) availability is scarce. Therefore, experimental comparison of soil requirements (acidic Podzol vs alkaline Rendzina) of these species was carried out. The study was designed as a pot experiment and conducted under field conditions. Fe availability was increased by application of Fe-HBED. Reactions of plants to edaphic conditions were determined using growth measurements, leaf morphometric measurements, chlorosis scoring, chlorophyll content and chlorophyll a fluorescence (OJIP) quantification as well as determination of element content (Ca, Mg, Fe, Mn, Zn and Cu). Growth and leaf morphometrical traits of the studied congeneric species were affected similarly by the soil type and differently by the chelate treatment. Increased availability of Fe in Rendzina contrasted the species, as treatment with 25 µmol Fe-HBED kg−1 soil promoted growth only in C. stoebe. Both species turned out to be resistant to Fe-dependent chlorosis which was also reflected in only minor changes in chlorophyll a fluorescence parameters. Both species showed relatively low nutritional demands. Surprisingly, Fe-HBED did not stimulate Fe acquisition in the studied species, nor its translocation along the root:shoot axis. Furthermore, contrary to expectations, C. scabiosa took up less Fe from the acidic than alkaline soil. C. scabiosa not only absorbed more Ca and Zn but also translocated greater amounts of these elements to shoots than C. stoebe. Both species acquired more Mg on Podzol than on Rendzina which suggests adaptation allowing avoidance of aluminum (Al) toxicity on acidic soils. Overall, it seems that C. scabiosa prefers alkaline soils, whilst C. stoebe prefers acidic ones.

Symbiotic competence of rose clover (Trifolium hirtum All.)

2008 ◽  
Vol 59 (9) ◽  
pp. 802 ◽  
Author(s):  
J. Brockwell ◽  
N. A. Fettell ◽  
Alison M. Bowman ◽  
W. Smith ◽  
G. Sweeney ◽  
...  
Keyword(s):  
Rhizobium Leguminosarum ◽  
South Australia ◽  
Annual Rainfall ◽  
Natural Fertility ◽  
Alkaline Soils ◽  
South Wales ◽  
Low Concentrations ◽  
The Rose ◽  
Trifolium Hirtum ◽  
Intrinsic Characteristic

Rose clover (Trifolium hirtum All.) is a forage plant that is well adapted to acidic and mildly alkaline soils of low natural fertility in southern Australia and to climates with a winter-dominant annual rainfall of 300 mm and above. Reports of low concentrations of nitrogen in rose clover foliage have been attributed to poor N2 fixation and may have discouraged its use in Australia. This investigation, conducted in tube culture, examined the ability of four lines of rose clover to nodulate and fix N2 with effective strains of clover rhizobia (Rhizobium leguminosarum bv. trifolii) and with soils (as a source of naturalised rhizobia) collected from field sites in New South Wales and South Australia. Comparisons with other Trifolium spp. were also made. It was confirmed that there was a low concentration of N in the shoots of the rose clover cvv. SARDI Rose and Hykon. This occurred even where rose clover nodulated and fixed N2 effectively with well known inoculant strains of clover rhizobia and with soil samples collected in the field (provided that the populations of resident clover rhizobia in the soil were at least 150/g). Individual plants were uniform in response to inoculation. Rose clover cv. SARDI Rose was closely related to six of the nine other lines of clover with which it was compared. It was concluded that the registered cultivars of rose clover, cvv. SARDI Rose and Hykon, are symbiotically competent plants. It appears that low N in rose clover foliage is an intrinsic characteristic of the species unconnected with its symbiotic characteristics.

COVID-19 test positivity rate dynamics in West Sumatra, Indonesia: a retrospective study

2021 ◽  
Author(s):  
Syandrez Prima Putra ◽  
Mutia Lailani ◽  
Liganda Endo Mahata ◽  
SM Rezvi ◽  
Andani Eka Putra
Keyword(s):  
Retrospective Study ◽  
Secondary Data ◽  
First Year ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Monthly Basis ◽  
West Sumatra ◽  
Polymerase Chain ◽  
One Year ◽  
And Control

Abstract Background: COVID-19 test positivity rate (TPR) is essential to estimate and control SARS-CoV-2 transmission in a population at a specific time, yet the TPR trends at a provincial level in Indonesia are unclear. This study aimed to determine the COVID-19 TPR dynamics of the Indonesian West Sumatra province in the first year of documented cases.Methods: We conducted a retrospective study using secondary data of the COVID-19 quantitative reverse transcription-polymerase chain reaction (q-RT-PCR) test in West Sumatra Province from April 2020 to March 2021. To examine trends, we estimated TPR(s) on an annual, quarterly, and monthly basis in the province, its regions (cities/ regencies), and districts.Results: From a total of 410,424 individuals taking the COVID-19 q-RT-PCR examination during one year, the provincial TPR was 8.11%. The third quarter (October 2020 – December 2020, 12.18%) and October 2020 (15.62%) had the highest TPR quarterly and monthly, respectively. The TPR of cities was almost certainly twice that of regencies. Annual TPR varied significantly (p<0.001) across regions, districts, and periods.Conclusion: The COVID-19 TPR trends in West Sumatra at the first year of the pandemic were generally higher than the global recommendation. Further study on population density, public mobility, and implementation of health protocol in the province should be valuable to understand TPR dynamics.

Molecular identification of potential intermediate hosts of Aulonocephalus pennula from the order Orthoptera

2018 ◽  
Vol 93 (2) ◽  
pp. 166-171 ◽  
Author(s):  
C. Henry ◽  
M.Z. Brym ◽  
A. Kalyanasundaram ◽  
R.J. Kendall
Keyword(s):  
Life Cycle ◽  
Northern Bobwhite ◽  
Intermediate Hosts ◽  
Field Site ◽  
Chain Reaction ◽  
Future Studies ◽  
Lack Of Information ◽  
Increased Sensitivity ◽  
Polymerase Chain ◽  
Orthopteran Species

AbstractAulonocephalus pennula is a heteroxenous nematode that commonly infects a declining game bird, the northern bobwhite quail (Colinus virginianus). There is a lack of information on the life cycle of A. pennula and the potential effects of infection on bobwhites. In order to better understand the life cycle of this parasite, various species from the order Orthoptera were collected from a field site in Mitchell County, Texas. Using polymerase chain reaction (PCR), nine potential intermediate hosts were identified from the 35 orthopteran species collected. Later, ten live specimens were collected to identify larvae within the potential intermediate hosts. Larvae were present in three of these and were sent for sequencing. Similarly, the presence of larvae was confirmed from extra tissues of samples identified as positive with PCR. This was the first study to document potential intermediate hosts, but future studies are needed to confirm that these species are capable of transmitting infection to bobwhite. However, this study demonstrates that PCR has increased sensitivity and may be a valuable tool when determining intermediate hosts.

High performance Nanogold™-in situ hybridzation and its use in the detection of hybridized and PCR-amplified microscopical preparations

1996 ◽  
Vol 54 ◽  
pp. 896-897
Author(s):  
G. W. Hacker ◽  
I. Zehbe ◽  
J. Hainfeld ◽  
A.-H. Graf ◽  
C. Hauser-Kronberger ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Messenger Rna ◽  
High Performance ◽  
Detection System ◽  
Direct Methods ◽  
Genetic Alterations ◽  
Chain Reaction ◽  
Protein Encoding ◽  
Polymerase Chain

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.

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