ELISA evaluation of the competitive abilities of two Rhizobium meliloti strains

1984 ◽  
Vol 30 (9) ◽  
pp. 1187-1190 ◽  
Author(s):  
W. A. Rice ◽  
P. E. Olsen ◽  
W. J. Page
Keyword(s):  
Rhizobium Meliloti ◽  
Strain Ratio ◽  
Enzyme Linked Immunosorbent Assay ◽  
Western Canada ◽  
Plant Weight ◽  
Single Strain ◽  
Total Plant ◽  
Medicago Sativa L ◽  
Competitive Abilities ◽  
Inoculum Strain

The double antibody sandwich enzyme-linked immunosorbent assay (DAS-EL1SA) was used to determine the competitive abilities of Rhizobium meliloti strains BALSAC and NRG-185 which are used in commercial alfalfa inoculants for eastern and western Canada, respectively. The ratio of NRG-185:BALSAC in the inoculum applied to aseptically grown alfalfa (Medicago sativa L.) was adjusted to 0:100, 1:99, 50:50, 90:10, 99:1, or 100:0. The ratios between nodules containing only the BALSAC strain and nodules containing only strain NRG-185 were similar to their respective inoculum strain ratios. Nodules containing both strains occurred only with the inoculum strain ratio of 50:50. Total plant weights were highest with the two single strain inocula and were decreased 5–19% with dual strain inoculation. The decrease in total plant weight was significantly correlated with decreases in nodule number and nodule weight. The results suggest that R. meliloti strains BALSAC and NRG-185 have equal competitive abilities, but are somewhat antagonistic, resulting in decreased nodulation and plant growth when both are present in an inoculum.

Impact of cultivars and herbicides on weed management in alfalfa

2006 ◽  
Vol 86 (3) ◽  
pp. 875-885 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya
Keyword(s):  
British Columbia ◽  
Weed Control ◽  
Weed Management ◽  
Forage Quality ◽  
Western Canada ◽  
Downy Brome ◽  
Weed Species ◽  
Standard Type ◽  
Southern Alberta ◽  
Medicago Sativa L

Weeds, especially dandelion (Taraxacum officinale Weber in F.H. Wigg.), tend to infest a forage alfalfa (Medicago sativa L.) stand 2 to 4 yr after establishment. To develop better weed management systems, experiments were conducted at Lethbridge, Alberta, from 1995 to 2002 and Creston, British Columbia, from 1998 to 2001, which included the alfalfa cultivars Beaver (standard type) and AC Blue J (Flemish type) and annual applications of metribuzin and hexazinone. These herbicides are registered for weed control in irrigated alfalfa in Alberta and alfalfa grown for seed. In addition, two sulfonylurea herbicides, metsulfuron and sulfosulfuron, and glyphosate were included. All of the herbicides except glyphosate controlled or suppressed dandelion and mustard family weeds. Metsulfuron at 5 g a.i. ha-1 almost completely controlled dandelion at both locations. However, after metsulfuron application at Lethbridge, dandelion was replaced with an infestation of downy brome, which is unpalatable for cattle. None of the herbicides increased total forage (alfalfa + weed) yield, and in some instances herbicides reduced forage quality by causing a shift from a palatable to an unpalatable weed species. However, it was observed that AC Blue J consistently yielded more than Beaver, and weed biomass was consistently less in the higher-yielding cultivar. AC Blue J was developed primarily for the irrigated area in southern Alberta and for southern British Columbia. Therefore, additional experiments should be conducted to determine which alfalfa cultivars have the greatest ability to compete with weeds in other regions of western Canada. Key words: Alfalfa yield, dandelion, forage quality, weed control

Kinetics of first-cutting regrowth of alfalfa plants and nitrogenase activity in a controlled environment with and without added nitrate

1983 ◽  
Vol 61 (9) ◽  
pp. 2405-2409 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Dry Matter ◽  
Rhizobium Meliloti ◽  
Nitrogenase Activity ◽  
Radical Change ◽  
N Nutrition ◽  
Meliloti Strain ◽  
Medicago Sativa L ◽  
Reducing Activity ◽  
Acetylene Reducing Activity ◽  
Kinetics Of

Seedlings of Medicago sativa L. cv. Algonquin were grown in vermiculite and nodulated by Rhizobium meliloti strain 102F70 at two lower levels of N, until flowering when the tops were cut off to leave about 10% shoot stubble. Residual shoot dry matter immediately resumed first-order growth and maintained it throughout regrowth to second flowering. The rate constants of shoot regrowth were 34% lower (at 15 mM NO3−), 25% lower (at 1.5 mM NO3− symbiotically), or 220% higher (at zero NO3− symbiotically) than the values for 1 to 4-week-old seedlings, which indicated a radical change in physiology. Root dry matter resumed exponential growth after a 7-day recession and its recovery and yields were independent of N nutrition. The most pronounced minima occurred in the acetylene-reducing activity of nitrogenase, the kinetics of which paralleled root dry matter except that its redevelopment stopped after two-thirds of the regrowth time. The rate coefficient for the redevelopment of nitrogenase activity equalled that for its development during the seedling stage, which suggested unchanged limitations on that process until its redevelopment stopped.

A rapid screening method for Rhizobium meliloti symbiotic nitrogenase activity

1982 ◽  
Vol 28 (2) ◽  
pp. 265-268 ◽  
Author(s):  
J. C. Sirois ◽  
E. A. Peterson
Keyword(s):  
Positive Relationship ◽  
Rhizobium Meliloti ◽  
Nitrogenase Activity ◽  
Screening Method ◽  
Dry Weight ◽  
Rapid Screening ◽  
Experimental Conditions ◽  
Intact Plants ◽  
Medicago Sativa L ◽  
Rapid Screening Method

A method for screening Rhizobium meliloti isolates for their symbiotic nitrogenase activity with alfalfa (Medicago sativa L.) cv. Apollo is described. The nitrogenase activity of each isolate is assessed by measuring the reduction of acetylene (C2H2) to ethylene (C2H4) by 50 intact plants grown in 10 plastic pouches for 2 weeks. The method is rapid, sensitive, reproducible, and accurate enough to differentiate 29 Rhizobium isolates and 5 authentic strains into 13 subsets. Under the experimental conditions used, nodulation occurred within 5 days of inoculation and there was a significant positive relationship between the nitrogenase activity of those isolates which reduced more than 60 nmol C2H2∙plant−1∙h−1 and the dry weight of the shoots of the nodulated plants in 2 weeks of growth.

EFFECTS OF SEED INOCULATION METHODS WITH PEAT-BASED RHIZOBIUM MELILOTI ON ALFALFA

1975 ◽  
Vol 55 (2) ◽  
pp. 555-563 ◽  
Author(s):  
H. T. KUNELIUS ◽  
UMESH C. GUPTA
Keyword(s):  
Soil Ph ◽  
Dry Matter ◽  
Rhizobium Meliloti ◽  
Sandy Loam ◽  
Good Growth ◽  
Seed Treatments ◽  
Fine Sandy Loam ◽  
Seed Inoculation ◽  
Medicago Sativa L ◽  
Uniform Manner

Saranac alfalfa (Medicago sativa L.) was grown on Charlottetown fine sandy loam (CHFSL) and Culloden sandy loam (CSL) in the greenhouse and field. Uninoculated, inoculated with peat-based rhizobia (I), inoculated and molybdenum-treated (IMo), inoculated and lime-coated (ILC), and inoculated, lime-coated and Mo-treated (ILCMo) seeds were included. At soil pH 5.0 and 5.3 in the greenhouse, the dry weights of alfalfa ranged from 214 to 727 mg/plant in the four cuttings from the ILC and ILCMo seed. The dry weights of alfalfa from the I and IMo seed were 1.3 to 99.7% of those from the ILCMo seed. Alfalfa from the ILC and ILCMo seed was well nodulated, whereas I and IMo seed resulted in poor nodulation. The 1973 field experiment showed that ILC and ILCMo seed at soil pH 5.5 and 5.6 resulted in alfalfa dry matter (DM) yields of 4,050 and 4,830 kg/ha which were equal to DM yields from plots with a pH of 6.0 and 6.1 seeded with inoculated seed. In plots with pH 5.5 and 5.6, total DM yields from I and IMo seed were 26.0–49.7% lower than those from ILCMo seed. In 1972, seed treatments on CHFSL at pH 5.6 did not influence the DM yields of alfalfa, whereas on CSL at pH 5.2 the crop failed to establish except from ILC and ILCMo seed and in limed plots at pH 5.9. In the first cutting, high N concentrations of alfalfa tissue coincided with good growth and good nodulation. The Mo concentrations of alfalfa tissue were not influenced in a uniform manner by seed treatments and varied from 0.11 to 0.49 ppm in the first cut tissue.

A quantitative study of the effects of gibberellic acid on the growth of Festuca arundinacea

1968 ◽  
Vol 19 (2) ◽  
pp. 221 ◽  
Author(s):  
DG Morgan
Keyword(s):  
Gibberellic Acid ◽  
Festuca Arundinacea ◽  
Dry Matter ◽  
Growth Analysis ◽  
Shoot Growth ◽  
Plant Weight ◽  
Matter Production ◽  
Whole Plant ◽  
Total Plant ◽  
Net Assimilation

Single plants of Festuca arundinacea (cv. S170) were treated with gibberellic acid (GA) and the sequence of effects on the growth of the whole plant and of various organs followed by means of growth analysis. The first effect of GA was to change the distribution of dry matter between shoot and root and between tillers within the shoot without affecting total plant weight. Shoot growth was increased and resulted in a larger amount of photosynthetic tissue with a higher net assimilation rate; total plant weight increased as a consequence of these effects. The significance of these results in interpreting previous work on the effects of GA on dry matter production in grasses and other plants is discussed.

scholarly journals Macroarray Detection of Plant RNA Viruses Using Randomly Primed and Amplified Complementary DNAs from Infected Plants

2007 ◽  
Vol 97 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Bright Agindotan ◽  
Keith L. Perry
Keyword(s):  
Rna Viruses ◽  
Detection System ◽  
Leaf Roll ◽  
Simultaneous Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Potato Leaf ◽  
Viral Rnas ◽  
Anchor Primer ◽  
Total Plant ◽  
Primer Sequence

Membrane-based macroarrays provide a relatively inexpensive technology with the potential to detect hundreds of pathogens in a single assay. For the simultaneous detection of a large number of pathogens, it is necessary to obtain sufficient nucleic acids for labeling, and any amplification reactions need to be performed using unbiased, pathogen-non-specific primers. A nonradioactive macroarray system is described to test for plant RNA viruses using 70-mer oligonucleotide probes immobilized on nylon membranes. Starting with a total plant RNA extract, complementary DNA (cDNA) and second-strand syntheses were carried out using an anchor primer sequence with random pentamers coupled at the 3′ end. Subsequent synthesis by polymerase chain reaction using the anchor primer alone resulted in a relatively unbiased amplification of plant and viral RNAs. These cDNAs were chemically labeled and the product used as a target in hybridization analyses. The system was validated using RNA extracts from plants infected with Cucumber mosaic virus, Potato virus Y, and Potato leaf roll virus (PLRV). Despite the relative excess of host-derived nonviral sequences, viral RNAs were amplified between 100- and 1,000-fold and were detected in single and mixed infections. The macroarray sensitivity was comparable to that of double-antibody sandwich enzyme-linked immunosorbent assay, with PLRV being detected in sap dilutions of 1:100. The potential for the development of a relatively inexpensive multipathogen detection system is discussed.

Rising CO2 and pollen production of common ragweed (Ambrosia artemisiifolia L.), a known allergy-inducing species: implications for public health.

2000 ◽  
Vol 27 (10) ◽  
pp. 893 ◽  
Author(s):  
Lewis H. Ziska ◽  
Frances A. Caulfield
Keyword(s):  
Public Health ◽  
Atmospheric Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Ambrosia Artemisiifolia ◽  
Pollen Production ◽  
Potential Growth ◽  
Plant Weight ◽  
Common Ragweed ◽  
Total Plant ◽  
The Impact

Although environmental factors such as precipitation and temperature are recognized as influencing pollen production, the impact of rising atmospheric carbon dioxide concentration ([CO2]) on the potential growth and pollen production of hay-fever-inducing plants is unknown. Here we present measurements of growth and pollen production of common ragweed (Ambrosia artemisiifolia L.) from pre-industrial [CO2] (280 mol mol–1) to current concentrations (370 mol mol–1) to a projected 21st century concentration (600 mol mol–1). We found that exposure to current and elevated [CO2] increased ragweed pollen production by 131 and 320%, respectively, compared to plants grown at pre-industrial [CO2]. The observed stimulations of pollen production from the pre-industrial [CO2] were due to an increase in the number (at 370 mol mol–1) and number and size (at 600 mol mol–1) of floral spikes. Overall, floral weight as a percentage of total plant weight decreased (from 21% to 13%), while investment in pollen increased (from 3.6 to 6%) between 280 and 600 mol mol–1 CO2. Our results suggest that the continuing increase in atmospheric [CO2] could directly influence public health by stimulating the growth and pollen production of allergy-inducing species such as ragweed.

scholarly journals Aplikasi Integrasi Pupuk NPK Dengan Waktu Pemberian Pupuk Organik Cair Pada Tanaman Pakcoy (Brassica rapa L.)

2018 ◽  
Vol 14 (1) ◽  
pp. 14-20
Author(s):  
Yance N Ayal ◽  
Henry Kesaulya ◽  
Francina Matulessy
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Root Length ◽  
Organic Fertilizer ◽  
Growth And Yield ◽  
Leaf Number ◽  
Root Weight ◽  
Plant Weight ◽  
Total Plant ◽  
Npk Fertilizer

This research was aimed to get the optimum NPK fertilizer dosage with the time of liquid organic fertilizer application to support the growth and yield of pakcoy (Brassica rappa L.). The study used a Randomized Block Design with three replications. Observation variables included plant height, leaf number, leaf area, total plant weight, root length, root weight and total plant weight percentage. The results showed that N0 (without NPK fertilizer) was the best based on the plant height and leaf number. Liquid organic fertilizer given at 3-time applications per plant (W3) contributed significantly to leaf number at 35 days after planting and gave the highest yield of leaves, with 17,45 leaves. The treatment of NPK compound fertilizer dosage with the time of liquid organic fertilizer gave significant effects on the leaf area, total plant weight, root length, and root weight. Keywords: liquid organic fertilizer, NPK, pakcoy   ABSTRAK Penelitian ini bertujuan untuk mendapatkan dosis pupuk NPK dengan waktu plikasi pupuk organik cair yang tepat untuk menunjang pertumbuhan danp roduksi tanaman pakcoy (Brassica rappa L.). Penelitian mengunakan Rancangan Acak Kelompok dengan tiga ulangan. Peubah-peubah pengamatan meliputi tinggi tanaman, jumlah daun, luas daun, berat total tanaman, panjang akar, berat akar dan persentase berat total tanaman. Hasil penelitian menunjukkan bahwa perlakuan N0 (tanpa pupuk NPK) merupakan yang terbaik dari penelitian ini terhadap parameter tinggi tanaman dan jumlah daun. Waktu pemberian pupuk organik cair 3 kali/tanaman (perlakuan W3) memberikan kontribusi yang signifikan terhadap jumlah daun 35 hari setelah tanam dan menghasilkan daun terbanyak dengan jumlah 17,45 helai. Perlakuan dosis pupuk majemuk NPK dengan waktu pemberian pupuk organik cair memberikan pengaruh yang nyata sampai sangat nyata terhadap luas daun, berat total tanaman, panjang akar serta berat akar. Kata kunci: NPK, pakcoy, pupuk organik cair

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