Effects of inoculation method and size of Rhizobium meliloti population in the soil on nodulation of alfalfa

1992 ◽  
Vol 72 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Wendell A. Rice ◽  
Perry E. Olsen

Field experiments were conducted with alfalfa (Medicago sativa L. ’Peace’) planted on a Black Solod (Landry CL) with pH 5.8 in 3 consecutive years. The same experiment was conducted at two adjacent sites in each year. The population of Rhizobium meliloti in the soil was modified at one site by applying and incorporating a suspension of an indigenous isolate to increase the size to 105 g−1. The other site was on unamended soil with a normal indigenous population of less than 102 g−1. Granular inoculant was applied with the seed or below the seed, or, granular or liquid inoculant was applied beside the row after stand establishment. The soil-placed inoculant treatments were compared with an uninoculated control and a standard seed-applied inoculation treatment. All inoculants were prepared with Rhizobium meliloti NRG-61 which had been selected for low-pH tolerance. Root weight, shoot weight, nodule weight, nodule numbers and strain occupancy of nodules were measured in September of the establishment year and again the following June. Granular inoculant applied with or below the seed resulted in greater nodule weights, nodule numbers and percent nodule occupancy at both sites. Granular inoculant applied with or below the seed was more effective at the site with the normal indigenous population of R. meliloti than at the site with the modified population. When granular inoculants were applied, nodule weights were lower on the site with the modified indigenous population than on the soil with the normal indigenous population. Granular inoculants resulted in significant yield increases over the standard seed-applied inoculant only at the site with the normal indigenous population. There were no substantial differences between the sites in the proportion of nodules occupied by the inoculant strain. These results show that strain occupancy measurements do not necessarily reflect the beneficial effect of inoculation. Key words: Enzyme-linked immunosorbent assay (ELISA), granular inoculant, Rhizobium inoculant, seed inoculant, soil inoculant

1998 ◽  
Vol 49 (6) ◽  
pp. 923 ◽  
Author(s):  
M. Hebb ◽  
Alan E. Richardson ◽  
R. Reid ◽  
John Brockwell

Appraisal of the establishment and persistence of inoculant strains, and the diversity of the rhizobial populations in 2 field experiments, required the precise characterisation of isolates from individual nodules. The polymerase chain reaction (PCR) method of generating randomly amplified polymorphic DNA (RAPD) from simple bacterial cell lysates was applied to nodule isolates obtained from field plots of clover (Trifolium spp.) and medic (Medicago spp.) plants inoculated with Rhizobium leguminosarum bv. Trifolium and Rhizobium meliloti. Comparison of the PCR method with gel immune diffusion serology was applied to selected nodule isolates obtained from the clover trial. Agreement between the methods was high (97·6%). Further characterisation of nodule isolates from the 2 field trials proceeded using PCR amplification profiles only, which allowed a large number of isolates to be quickly and precisely identified. Mean recovery of inoculant strains in the first season of the clover trial was 76·5% across 10 hosts, and 45·3% in the second season sampling. Recovery of inoculant strains in the medic trial was assessed only during the second season of growth, which recorded a mean recovery of 53% across 8 hosts. In addition to providing a rapid and reliable means of identifying inoculant strains of R. leguminosarum bv. Trifolium and R. meliloti directly in association with a range of different host plants, the PCR approach also allowed inoculant strain types to be readily identified when recovered as isolates from plots in which they had not been introduced. Analysis of the non-inoculant strains by PCR also indicated that the naturalised populations of rhizobia at both sites were highly diverse.


2020 ◽  
Author(s):  
María del Pilar Martínez-Diz ◽  
Emilia Díaz-Losada ◽  
Marcos Andrés-Sodupe ◽  
Rebeca Bujanda ◽  
María Mercedes Maldonado-González ◽  
...  

ABSTRACTBACKGROUNDBlack-foot and Petri diseases are the main fungal diseases associated with young grapevine decline. Two field experiments were established to evaluate the preventive effect of two potential biocontrol agents (BCAs), i.e. Streptomyces sp. E1 + R4 and Pythium oligandrum Po37, and three BCA-commercial products containing Trichoderma atroviride SC1, Trichoderma koningii TK7 and Pseudomonas fluorescens+Bacillus atrophaeus on fungal infection in grafted plants and plant growth parameters.RESULTSThe effectiveness of some BCA in reducing the incidence and severity of both diseases was dependent on the plant part analyzed and the plant age. No single BCA application was able to control both diseases. Streptomyces sp. E1+R4 were able to reduce significantly black-foot disease infection while P. oligandrum Po37 and Trichoderma spp. were able to reduce significantly Petri disease infection. BCA treatments had no effect on the shoot weight, and root weight was significantly lower in all BCA treatments with respect to the control.CONCLUSIONSThe combination of the disease-suppressive activity of two or more beneficial microbes in a biocontrol preparation is required to prevent infection by black-foot and Petri disease fungi in vineyards.


HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 428g-429
Author(s):  
Dyremple B. Marsh ◽  
Lurline E. Marsh ◽  
Brian Cooper

The enzyme-linked immunosorbent assay was used to determine the competitive ability of three Rhizobium strains introduced into Antiguan soil. Strain-specific antisera were prepared against each strain. Field experiments were conducted in Antigua using Rhizobium strains USDA 3384, USDA 3473, and USDA 3474 as a peat-base inoculant and pigeon pea as the test crop. Nodules from the respective treatments were removed and prepared for ELISA studies. There was cross reactivity between the antisera, but it was greatly reduced or eliminated by repeat adsorption with the cells of the cross-reacting strains. Nodule occupancy by plants treated with Rhizobium 3384, 3473, and 3384 was 70%, 90%, and 100%, respectively. Nodules from 3384 and 3474 treated plants contained cells with no antigenic homology to the three antisera. We concluded that these nodules were developed from indigenous Rhizobium strains found in Antiguan soils.


1977 ◽  
Vol 57 (2) ◽  
pp. 197-203 ◽  
Author(s):  
W. A. RICE ◽  
D. C. PENNEY ◽  
M. NYBORG

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.


2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.


1970 ◽  
Vol 9 ◽  
pp. 21-27 ◽  
Author(s):  
Nabin Kumar Dangal ◽  
D. Sharma Poudyal ◽  
S. M. Shrestha ◽  
C. Adhikari ◽  
J. M. Duxbury ◽  
...  

Pot experiment was conducted during July-September 2006 to evaluate some organic amendments such as sesame (Sesamum indicum) biomass, buckwheat (Fagopyrum esculentum) biomass, neem (Azadirachta indica) leaves, chinaberry (Melia azedarch) leaves and chicken manure @ 1, 2 and 3 t ha-1 each against the rice root-knot nematode (Meloidogyne graminicola Golden & Birchfield) in direct seeded rice. The treatments were replicated five times in a randomized complete block design. The number of second stage juveniles (J2) of M. graminicola was significantly low in chicken manure @ 3 t ha-1. The root knot severity index was significantly low in sesame @ 3 t ha-1, chinaberry @ 3, 2 or 1 t ha-1, neem @ 3 t ha-1 and chicken manure @ 2 or 3 t ha-1 amended soil but root lesion severity index was lower only in chicken manure @ 2 t ha-1 treated plots. The fresh shoot weight and length were significantly high in chicken manure amendment @ 2 or 3 t ha-1 at 45th day after seeding. However, the fresh root weight, length, number of leaves and number of J2 recovered from the roots were non-significant. Key words: biomass; juveniles; Meloidogyne graminicola; root-knot severity index; root lesion severity index DOI: 10.3126/njst.v9i0.3160 Nepal Journal of Science and Technology 9 (2008) 21-27


Genetika ◽  
2012 ◽  
Vol 44 (2) ◽  
pp. 235-250 ◽  
Author(s):  
Ahmad Dadashpour

The effects of different salt sources (C Cl2, NaCl, and KCl) and concentrations, as measured by electrical conductivity, (0, "control", 1, 3, 5, 7 and 9 dS m-1) on seed germination and seedling growth of ?Ferro?, ?Obez?, ?RS 841? and ?Strong Tosa F1? pumpkin varieties used as rootstock were investigated in this study. The results showed that germination rate, root length, shoot length, fresh root weight, dry root weight, fresh shoot weight and dry shoot weights tend to decrease when the electrical conductivity of the solution is higher than 5 dS m-1, independent of salt sources and in all of the varieties. Three days after seeding, a germination ratio of 5 % was obtained from RS 841 variety in all salt source and concentrations, while a germination ratio over 50 % was obtained in ?Strong Tosa? variety for the same conditions except CaCl2 salt source. Nevertheless, seeds germinated in medium having high concentrations of CaCl2 had lower germination rate and poor seedling growth, compared to media having the same concentrations of NaCl and KCl. It was concluded that all of the varieties studied were more sensitive to the concentrations prepared using CaCl2 than that of the KCl, and NaCl.


Author(s):  
Mahmut Çamlıca ◽  
Gülsüm Yaldız ◽  
Ferit Özen ◽  
Abdurrahman Başol ◽  
Halit Aşkın

Sage and mountain sage belong to Lamiaceae family which have commercial importance from medicinal and aromatic plants in Turkey. The aim of this study was to evaluate the effects of different doses of selenium in salinity conditions on the morphological characteristics of sage (Salvia officinalis L.) and mountain tea (Sideritis sp.). Four different doses of selenium (5, 10, 20, 40 mg/l) were applied in without salinity (0) and salinity (250 mM NaCl/l) medium. The experiment was carried out in the split plot design with three replications in the climate chamber room of the department of field crops. When the examined properties were evaluated; plant height changed between 15.56-23.85 cm, number of branches 10.50-12.78 number/plant, number of leaves 52.78-92.00 number/plant, fresh leaf weight 2.48-7.51 g/plant, dry leaf weight 0.48-3.32 g/plant, fresh root weight 1.52-7.16 g/plant, dry root weight 0.19-1.24 g/plant, root length 26.18-36.07 cm, fresh shoot weight of 1.13-7.15 g/plant and dry shoot weight 0.13-0.38 g/plant. In mountain tea, the properties were determined for plant height as 3.26-5.93 cm, for number of branches as 2.50-6.33 number/plant, for number of leaves as 28.22-91.14 number/plant, for fresh and dry leaf weights as 2.42-11,03 and 0.45-1.91 g/plant, for fresh and dry root weights as 0.71-3.97 and 0.18-0.74 g/plant, for root length as 14.78-33.26 cm, for fresh and dry shoot weights as 0.29-2.28 and 0.12-0.41 g/plant were determined. As a result of this study, 5 mg/l selenium application in salinity conditions in both plants has reached high values in terms of fresh leaf weights. In addition to this, it was found that selenium applications in salinity conditions had positive effects on dry leaf weight in sage and fresh root and fresh shoot weights in mountain tea. As a result of correlation analysis, positive correlations were found between dry leaf weight and other characteristics especially in mountain tea in terms of traits examined in both plants.


2017 ◽  
Vol 12 (2) ◽  
pp. 345-354
Author(s):  
Hemant Kumar ◽  
S. B. Lal ◽  
A. M. Wani

Estimation of phenotypic and genotypic correlation between various traits provides necessary information in breeding program, when selection is based on two or more characters. The intensity and trend of association among characters may be estimated by genetic coefficients of correlations and genotypic and phenotypic coefficient of correlation depending on the type of materials studied. The knowledge of genetic inter-relationship between characters is also of theoretical and practical interest because a genotypic correlation may drive genetic linkage or from developmental induced relationships between components that are only indirectly the consequences of gene action. Terminalia arjuna is a medium to large sized fast growing versatile tree popularly known as Arjun. It has immense economic potential in various industries viz., pharmaceutical, timber, paper, soap, tannin, dye, match, food, fodder and fuel. Thirty candidate plus trees (CPTs) of T. arjuna were selected as seed source from 30 different provinces of Uttar Pradesh for the study of correlation study morphological & biomass traits. After 12 months of growth under nursery condition, data were collected and analyze for association studies. Present study concludes that magnitudes of phenotypic correlation coefficients were lower compare to corresponding genotypic values. A strong positive and highly significant phenotypic correlation with collar diameter, bark content, fresh shoot weight, dry shoot weight, fresh root weight, dry root weight and total biomass of seedling were exhibited. Therefore, these characters may be given proper emphasis during selection and breeding program of Arjun tree species where the amount of leaf, bark and biomass production is of immense importance.


Akta Agrosia ◽  
2018 ◽  
Vol 21 (2) ◽  
pp. 55-60
Author(s):  
Marwanto Marwanto ◽  
Nasiroh Nasiroh ◽  
Bambang G. Mucitro ◽  
Merakati Handajaningsih

The beneficial effects of manure on soil properties, growth, and crop productivity have promoted its use for replacing the application of N fertilizer. However, it is not well understood to what extent N fertilizer was able to be substituted by cow manure. Accordingly, this pot experiment aimed to compare the effect of inorganic N fertilizer application alone with that of the combined use of inorganic N fertilizer with cow manure based on the same amount of total N on growth parameters, yield attributes, and nitrogen (N) uptake of black rice. The experiment was conducted under a screen house condition in Agriculture Faculty, Bengkulu University located at 15 meters altitude above sea level during the summer season of 2015. There were six treatments viz. T1 = 100% N from urea + 0% N from cow manure (0.52 g N + 0.00 g cow manure) pot-1, T2 = 80% N from urea  + 20% N from cow manure  (0.42 g N + 9.55 g cow manure) pot-1, T3 = 60% N from urea + 40% N from cow manure (0.31 g N  + 19.10 g cow manure) pot-1, T4 = 40% N from urea + 60% N from cow manure (0.21 g N + 28.65 g cow manure) pot-1, T5 = 20% N from urea + 80% N from cow manure (0.10 g N+ 38.20 g cow manure) pot-1, and T6 = 0% N from urea + 100% N from cow manure (0.00 g N  + 47.75 g cow manure) pot-1. The amount of inorganic N fertilizer in the form of urea and cow manure applied was calculated based on the recommended rate of 115.00 kg ha-1 for N fertilizer and 10.50 ton ha-1 for cow manure. These treatments were arranged in a Completely Randomized Design and repeated three times. The results showed that the treatments significantly (P ?0.005) affected growth parameters as measured by plant height, the number of leaves, fresh shoot weight, fresh root weight, dry shoot weight, dry root weight, yield attributes as determined by the total number of tillers, the total number productive tillers, grain yield per pot, and N uptake. The highest values for all these variables were obtained in the treatment receiving recommended rate of urea only (100% N from urea + 0% N from cow manure as equivalence) and the lowest in the treatment receiving a100% N from cow manure (0% N from urea + 100% N from cow manure). However, combined treatments of cow manure and inorganic N fertilizer such as 80% N from urea  + 20% N from cow manure, 60% N from urea + 40% N from cow manure 40% N from urea + 60% N from cow manure showed a parity statistically with the treatment receiving 100% N from urea only in maintaining the values for all these variables. Overall, the combined use of inorganic N fertilizer (urea) and cow manure as an equivalence promoted growth and yield of black rice by improving N uptake. Keywords: integrated nutrient management, soil chemical property, Nitrogen uptake, combined fertilizer application, black rice


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