scholarly journals Sesbania virgata stimulates the occurrence of its microsymbiont in soils but does not inhibit microsymbionts of other species

2009 ◽  
Vol 66 (5) ◽  
pp. 667-676 ◽  
Author(s):  
Ligiane Aparecida Florentino ◽  
Ana Paula Guimarães ◽  
Márcia Rufini ◽  
Krisle da Silva ◽  
Fátima Maria de Souza Moreira
Keyword(s):  
Soil Samples ◽  
Legume Species ◽  
Cultural Groups ◽  
Symbiotic Efficiency ◽  
Inoculant Strain ◽  
Sesbania Virgata ◽  
High Stimulus ◽  
Macroptilium Atropurpureum ◽  
Plant Stem ◽  
Cultural Types

The legume species Sesbania virgata establishes a specific and efficient symbiosis with Azorhizobium doebereinerae. Previous studies have shown that A. doebereinerae occurrence correlates to the presence of S. virgata. This work aimed to evaluate the occurrence of A. doebereinerae and of other nitrogen-fixing Leguminosae-nodulating bacteria (NFLNB) in soil samples collected adjacent to and 10 m away from the stems of five S. virgata plants in pasture areas. Symbiotic characteristics of isolates from these NFLNB populations were also studied. S. virgata and the four promiscuous legume species Leucaena leucocephala, Macroptilium atropurpureum, Phaseolus vulgaris and Vigna unguiculata were inoculated with soil samples to trap A. doebereinerae and other NFLNB. NFLNB capable of inducing nodulation in at least one of these legumes were found in all samples. M. atropurpureum was the most promiscuous species, as it trapped the highest number of NFLNB cultural types from soil suspensions. The other species were less promiscuous in the following order: V. unguiculata, P. vulgaris, and L. leucocephala. Isolates of the promiscuous legumes were classified into seven cultural groups. One of these groups, isolated from all promiscuous species, showed fast-growth alkali-reaction in culture medium (like Azorhizobium); it was identified as Cupriavidus. This is the first report of symbiosis of Cupriavidus with Papilionoideae species. The symbiotic efficiency of promiscuous hosts with NFLNB varied, but it was always less than that of controls with mineral nitrogen or an inoculant strain. S. virgata was efficiently nodulated only by A. doebereinerae, which occurred mainly in samples collected close to the plant stem, corroborating a high stimulus by its host species. A high diversity of NFLNB occurs as saprophytes close to the S. virgata root system.

Control of the weevil (Amnemus quadrituberculatus) in tropical legume pastures with dieldrin and heptachlor pre-sowing soil treatments

1975 ◽  
Vol 15 (75) ◽  
pp. 545
Author(s):  
JR Rand ◽  
BM Braithwaite
Keyword(s):  
Legume Species ◽  
The Third ◽  
Tropical Legume ◽  
General Decline ◽  
Macroptilium Atropurpureum ◽  
Levels Of Control

Three experiments on chocolate alluvium, chocolate basaltic, and prairie meadow soils, respectively, tested the long term effectiveness of dieldrin and heptachlor pre-sowing treatments in controlling Amnemus quadrituberculatus (amnemus weevil) in tropical legume pastures. The legume species used were Desmodium uncinatum, D. intortum, Glycine wightii and Macroptilium atropurpureum. Both chemicals at rates from 0.56-2.24 kg ha-1 gave high levels of control of the weevil for two years after pasture establishment. Control declined in the third and subsequent years, but in all experiments insecticide treated plots retained the legume components longer than did untreated plots. Heptachlor at 1.12 kg ha-1 proved the best treatment but a general decline in legume density was observed in all experiments.

scholarly journals Diversity and nitrogen fixation efficiency of rhizobia isolated from nodules of Centrolobium paraense

2014 ◽  
Vol 49 (4) ◽  
pp. 296-305 ◽  
Author(s):  
Alexandre Cardoso Baraúna ◽  
Krisle da Silva ◽  
Gilmara Maria Duarte Pereira ◽  
Paulo Emílio Kaminski ◽  
Liamara Perin ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
16S Rrna ◽  
Vigna Unguiculata ◽  
Gene Sequencing ◽  
Rpob Gene ◽  
Soil Samples ◽  
Symbiotic Efficiency ◽  
16S Rrna Analysis ◽  
Rhizobium Species ◽  
Nitrogen Treatment

The objective of this work was to isolate and characterize rhizobia from nodules of Centrolobium paraense and to evaluate their symbiotic efficiency. Soil samples collected from four sites of the Roraima Cerrado, Brazil, were used to cultivate C. paraense in order to obtain nodules. Isolates (178) were obtained from 334 nodules after cultivation on medium 79. Twenty-five isolates belonging to six morphological groups were authenticated using Vigna unguiculata and they were characterized by 16S rRNA. Isolates identified as Bradyrhizobium were further characterized using rpoB gene sequencing. A greenhouse experiment was carried out with C. paraense to test the 18 authenticated isolates. Approximately 90% of the isolates grew slowly in medium 79. The 16S rRNA analysis showed that 14 authenticated isolates belong to the genus Bradyrhizobium, and rpoB indicated they constitute different groups compared to previously described species. Only four of the 11 fast-growing isolates nodulated V. unguiculata, two of which belong to Rhizobium, and two to Pleomorphomonas, which was not previously reported as a nodulating genus. The Bradyrhizobium isolates ERR 326, ERR 399, and ERR 435 had the highest symbiotic efficiency on C. paraense and showed a contribution similar to the nitrogen treatment. Centrolobium paraense is able to nodulate with different rhizobium species, some of which have not yet been described.

scholarly journals SITES AND SAMPLING TOOLS IN THE SOIL FERTILITY EVALUATION OF COFFEE PLANTS IN PRODUCTION

2019 ◽  
Vol 14 (3) ◽  
pp. 407
Author(s):  
José Ricardo Mantovani ◽  
José Antônio Lima ◽  
Ciro Pozzi Garcia ◽  
Tiago Teruel Rezende
Keyword(s):  
Organic Matter ◽  
Chemical Analysis ◽  
Block Design ◽  
Soil Samples ◽  
Soil Sampling ◽  
Sampling Point ◽  
Randomized Block Design ◽  
Coffee Plants ◽  
Plant Stem ◽  
Definition Of

In soil sampling, the collection site and the tool used may induce errors that can compromise the results of the chemical analysis and, consequently, the definition of corrective and fertilizer doses. The objective in this study was to evaluate soil sampling sites and tools in a coffee growing area. The experiment was carried out in a field in the municipality of Alfenas-MG, in a 35-year coffee field. A randomized block design was used in a 3 x 5 factorial scheme and 4 replications, totaling 60 experimental units. The treatments consisted of 3 sampling sites: in the fertilizer strip (located in the projection of the plant canopy); between rows; and in the total area, with 1/3 of the samples collected under the canopy and close to the plant stem, 1/3 in the canopy projection and 1/3 collected between rows; and 5 sampling tools: Dutch auger; screw auger; probe; hoe and drill. Soil samples were collected at a depth of 0 to 0.2 m, and each composite sample was obtained by assembling and mixing 20 single samples. At each sampling point, an area of 2m<sup>2</sup> was delimited, in which simple samples were collected in all the evaluated places and with all the tools used. The following parameters were determined in the soil samples: pH in CaCl2; potential acidity (H+Al); organic matter; P, extracted by Mehlich; K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup> and base saturation. In a coffee-growing area, he fertilizer strip (canopy projection) has topsoil with higher acidity and lower contents of organic matter and nutrients P, K<sup>+</sup>, Ca<sup>2+</sup> and Mg<sup>2+</sup> than between rows. The tools used for soil sampling do not influence the results of soil chemical analysis in the coffee-growing area.

scholarly journals Comparing Two Methods of Estimating the Population of Indigenous Rhizobia

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 894B-894
Author(s):  
Marutani M. ◽  
E. Manalastas
Keyword(s):  
Leucaena Leucocephala ◽  
Test Tube ◽  
Soil Samples ◽  
Most Probable Number ◽  
N Fixation ◽  
Leguminous Plants ◽  
Probable Number ◽  
Modified Method ◽  
Biological N Fixation ◽  
Macroptilium Atropurpureum

The growth pouch method and test-tube method were compared to determine to most probable number of indigenous rhizobia population on the island of Guam. Soil samples were collected from three locations, with soil types of Akina, Pulantat, and Guam cobbly clay. Macroptilium atropurpureum and Leucaena leucocephala were used as indicator plants of Bradyrhizobium spp. and Rhizobium spp., respectively. An advantage of the test-tube method is requiring less replenishment of N-free solution during the incubation period. The modified method is used in classrooms to demonstrate the phenomenon of biological N fixation by leguminous plants.

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.

Symbiotic efficiency of pigeonpea (Cajanus cajan) with different sources of nitrogen

2021 ◽  
pp. 1-4
Author(s):  
Francina L. Bopape ◽  
Eastonce T. Gwata ◽  
Ahmed I. Hassen ◽  
Marvellous M. Zhou
Keyword(s):  
Dry Weight ◽  
Soil Samples ◽  
Grain Legume ◽  
N Fixation ◽  
Symbiotic Efficiency ◽  
Native Soil ◽  
Rhizobial Isolate ◽  
Production Area ◽  
Biological Nitrogen ◽  
Different Sources

Abstract Pigeonpea is an important grain legume. It contributes to the improvement of soil fertility through biological nitrogen (N) fixation. However, the symbiotic efficiency of pigeonpea with native soil rhizobia has not been determined adequately. This study was designed to determine the variation in the N fixation ability of pigeonpea inoculated with the native rhizobia. Forty soil samples were collected from diverse locations across South Africa and used for inoculating pigeonpea seed. Each pigeonpea genotype was inoculated separately with each soil sample and raised in a nitrogen-depleted growth medium in the greenhouse. A split-plot experimental design was used in the study. Several N fixation variables of pigeonpea were measured. There was >40.0% difference in the number of nodules between genotypes ‘Ex-PP-MD-321’ and ‘Mpuma-B-Spot’ but the nodule dry weight between the two genotypes was >80.0%. In contrast, the heaviest dry shoots (0.4513 g), weighed 52.0% heavier than those that were observed for ‘Mpuma-B-Spot’. Pigeonpea showed differential N fixation ability with the nodules, suggesting that there was potential to select for optimum host × rhizobial isolate combinations for the process and to expand the production area of the crop.

The Factor Structure and Measurement Invariance of Positive and Negative Affect

2016 ◽  
Vol 32 (4) ◽  
pp. 265-272 ◽  
Author(s):  
Mohsen Joshanloo ◽  
Ali Bakhshi
Keyword(s):  
Negative Affect ◽  
Measurement Invariance ◽  
Factor Structure ◽  
Factor Model ◽  
Positive And Negative Affect ◽  
Cultural Groups ◽  
Invariance Testing ◽  
The Usa ◽  
Scalar Invariance ◽  
Gender Groups

Abstract. This study investigated the factor structure and measurement invariance of the Mroczek and Kolarz’s scales of positive and negative affect in Iran (N = 2,391) and the USA (N = 2,154), and across gender groups. The two-factor model of affect was supported across the groups. The results of measurement invariance testing confirmed full metric and partial scalar invariance of the scales across cultural groups, and full metric and full scalar invariance across gender groups. The results of latent mean analysis revealed that Iranians scored lower on positive affect and higher on negative affect than Americans. The analyses also showed that American men scored significantly lower than American women on negative affect. The significance and implications of the results are discussed.

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