scholarly journals Does inoculation with native rhizobia enhance nitrogen fixation and yield of cowpea through legume-based intercropping in the northern mountainous areas of Vietnam?

2020 ◽  
pp. 1-12
Author(s):  
Trung Thanh Nguyen ◽  
Mary Atieno ◽  
Laetitia Herrmann ◽  
Sutkhet Nakasathien ◽  
Ed Sarobol ◽  
...  

Abstract In the Northern mountainous region of Vietnam, cassava–cowpea intercropping system has been widely promoted with support from the local agricultural department. However, cowpea yield is often limited because of a low Biological Nitrogen Fixation (BNF) activity due to its low natural nodulation and lack of available effective Rhizobium products. The aim of this study was to identify the most effective native rhizobia isolate nodulating cowpea with the potential to increase BNF and yield of cowpea. A greenhouse experiment was initially conducted with five treatments: three native rhizobia isolates (CMBP037, CMBP054, and CMBP065); a control (no inoculation and no N application); and N+ (no inoculation, application of N as KNO3). Field inoculations were carried out and the treatments were as follows: a control (no inoculation); CMBP (037+054) – a mixture of strains from Mau Dong; CMBP065 strain from Cat Thinh. CMBP054 and CMBP065 had the highest nodulation in the greenhouse (46.4 and 60.7 nodules plant−1, respectively) and were rated as effective with symbiotic efficiency (SEF) of 54.56 and 55.73%, respectively. In the field, CMBP (037+054) recorded significantly higher nodulation (19.4 nodules plant−1) than the control (11.7 nodules plant−1). CMBP (037+054) also increased cowpea shoot dry weight, shoot N, and yield by 28.6, 4.9, and 10.5%, respectively, compared to the uninoculated control. This effect was slope dependent (statistically significant in moderate and steep slope, not with gentle slope). Besides, the high expansion rate of intercropping with cowpea showed the high adoption level of these agroecological practices by local farmers. This study reveals the potential of native rhizobia inoculation to enhance soil fertility and sustainable agriculture in the Northern mountainous region of Vietnam and proposes enhanced efforts to promote the availability and utilization of effective inoculants for cowpea.

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Ernest Wandera Ouma ◽  
Anne Mercy Asango ◽  
John Maingi ◽  
Ezekiel Mugendi Njeru

Identification of effective indigenous rhizobia isolates would lead to development of efficient and affordable rhizobia inoculants. These can promote nitrogen fixation in smallholder farming systems of Kenya. To realize this purpose, two experiments were conducted under greenhouse conditions using two common bean cultivars; Mwezi moja (bush type) and Mwitemania (climbing type) along with soybean cultivar SB 8. In the first experiment, the common bean cultivars were treated with rhizobia inoculants including a consortium of native isolates, commercial isolate (CIAT 899), a mixture of native isolates and CIAT 899, and a control with no inoculation. After 30 days, the crop was assessed for nodulation, shoot and root dry weights, and morphological features. In the second experiment, soybean was inoculated with a consortium of native isolates, commercial inoculant (USDA 110), and a mixture of commercial and native isolates. Remarkably, the native isolates significantly (p<0.001) increased nodulation and shoot dry weight across the two common bean varieties compared to the commercial inoculant, CIAT 899. Mixing of the native rhizobia species and commercial inoculant did not show any further increase in nodulation and shoot performance in both crops. Further field studies will ascertain the effectiveness and efficiency of the tested indigenous isolates.


Author(s):  
Omar Zennouhi ◽  
Abderrazak Rfaki ◽  
Mohamed El Mderssa ◽  
Jamal Ibijbijen ◽  
Laila Nassiri

Aims: The study aimed to evaluate the effect of inoculation by different rhizobacteria on Bituminaria bituminosa plants grown under greenhouse conditions. Study Design: An experimental study. Place and Duration of Study: The study was carried out at the Department of Biology (Environment and valorization of microbial and plant resources Unit), Faculty of Sciences, Moulay Ismail University-Meknes, from November 2019 to February 2020. Methodology: Eleven species and/or isolates belonging to Rhizobium genus are used to inoculate B. bituminosa plants; similarly, fresh and dry crushed nodules previously collected from B. bituminosa shrubs are tested. The bacterial inoculation effects are evaluated through the estimation of inoculated plants’ fresh and dry shoots weight, root dry weight, total nitrogen, nodules number and fresh weight in comparison to non-inoculated plants. The infectivity and efficiency of the bacteria and the biological nitrogen fixation are also evaluated. Results: The results enable us to select the infective strains on the basis of their positive effect on growth and total nitrogen, in order to produce inoculum for B. bituminosa. Efficiency and biological nitrogen fixation are also very high compared to the control, especially with the B.b1 strain isolated from Bituminaria bituminosa and identified as Rhizobium tibeticum. The fresh nodules crushing is also very efficient. as inoculant. Conclusion: The use of symbiotic complex as Rhizobium tibeticum – Bituminaria bituminosa or an inoculum produced from fresh nodules are an eco-friendly alternative for the design of sylvo-pastoral systems ensuring increased soil fertility, fodder productivity and sustainable agroforestry.


2001 ◽  
Vol 14 (7) ◽  
pp. 887-894 ◽  
Author(s):  
Boglárka Oláh ◽  
Erno Kiss ◽  
Zoltán Györgypál ◽  
Judit Borzi ◽  
Gyöngyi Cinege ◽  
...  

In specific plant organs, namely the root nodules of alfalfa, fixed nitrogen (ammonia) produced by the symbiotic partner Sinorhizobium meliloti supports the growth of the host plant in nitrogen-depleted environment. Here, we report that a derivative of S. meliloti carrying a mutation in the chromosomal ntrR gene induced nodules with enhanced nitrogen fixation capacity, resulting in an increased dry weight and nitrogen content of alfalfa. The efficient nitrogen fixation is a result of the higher expression level of the nifH gene, encoding one of the subunits of the nitrogenase enzyme, and nifA, the transcriptional regulator of the nif operon. The ntrR gene, controlled negatively by its own product and positively by the symbiotic regulator syrM, is expressed in the same zone of nodules as the nif genes. As a result of the nitrogen-tolerant phenotype of the strain, the beneficial effect of the mutation on efficiency is not abolished in the presence of the exogenous nitrogen source. The ntrR mutant is highly competitive in nodule occupancy compared with the wild-type strain. Sequence analysis of the mutant region revealed a new cluster of genes, termed the “ntrPR operon,” which is highly homologous to a group of vap-related genes of various pathogenic bacteria that are presumably implicated in bacterium-host interactions. On the basis of its favorable properties, the strain is a good candidate for future agricultural utilization.


2013 ◽  
Vol 37 (4) ◽  
pp. 869-876 ◽  
Author(s):  
Altanys Silva Calheiros ◽  
Mario de Andrade Lira Junior ◽  
Débora Magalhães Soares ◽  
Márcia do Vale Barreto Figueiredo

Biological nitrogen fixation by rhizobium-legume symbiosis represents one of the most important nitrogen sources for plants and depends strongly on the symbiotic efficiency of the rhizobium strain. This study evaluated the symbiotic capacity of rhizobial isolates from calopo (CALOPOGONIUM MUCUNOIDES) taken from an agrisoil under BRACHIARIA DECUMBENS pasture, sabiá (MIMOSA CAESALPINIIFOLIA) plantations and Atlantic Forest areas of the Dry Forest Zone of Pernambuco. A total of 1,575 isolates were obtained from 398 groups. A single random isolate of each group was authenticated, in randomized blocks with two replications. Each plant was inoculated with 1 mL of a bacterial broth, containing an estimated population of 10(8) rhizobial cells mL-1. Forty-five days after inoculation, the plants were harvested, separated into shoots, roots and nodules, oven-dried to constant mass, and weighed. Next, the symbiotic capability was tested with 1.5 kg of an autoclaved sand:vermiculite (1:1) mixture in polyethylene bags. The treatments consisted of 122 authenticated isolates, selected based on the shoot dry matter, five uninoculated controls (treated with 0, 50, 100, 150, or 200 kg ha-1 N) and a control inoculated with SEMIA 6152 (=BR1602), a strain of BRADYRHIZOBIUM JAPONICUM The test was performed as described above. The shoot dry matter of the plants inoculated with the most effective isolates did not differ from that of plants treated with 150 kg ha-1 N. Shoot dry matter was positively correlated with all other variables. The proportion of effective isolates was highest among isolates from SABIÁ forests. There was great variation in nodule dry weight, as well as in N contents and total N.


2021 ◽  
Vol 9 (2) ◽  
pp. 91-105
Author(s):  
Mulugeta Mekonnen ◽  
Ameha Kebede

This particular work was devoted to isolate and assess the symbiotic efficiency of faba bean (Vicia faba L.)-nodulating rhizobia isolate at few faba bean growing areas of the eastern Hararghe highlands of Ethiopia. Overall 50 rhizobia isolates were obtained from soil samples of three Woredas (districts) of the eastern Hararghe highlands using the host trap method. Out of these 50 isolates, 40 were presumptively identified as rhizobia. Among these 40 rhizobia isolates, only 31 were successful to nodulate faba bean, and authenticated as true faba bean nodulating rhizobia. Concerning the symbiotic efficiency, about 52%, 35%, and 13% of the rhizobial isolates were found to be highly effective, effective, and lowly-effective, respectively. The correlation data on the sand experiment displayed that nodule dry weight was associated positively and significantly (r = 0.494, p<0.05) with shoot dry weight while shoot dry weight was associated positively and significantly (r=0.41, p<0.05) with plant total nitrogen. Positive correlations were also observed concerning shoot dry weight and dry weight of nodules (r = 0.7, p<0.05) on unsterilized soil. Among the observed rhizobium isolates, EHHFR (4A, 6A) showed the highest symbiotic efficiency above 110%, tolerated NaCl concentration ranging from 2% to 6% and 2% to 8%, respectively, and a pH range of 4.5 to 8 and 5 to 8, respectively. Thus, based on their symbiotic efficiency at the greenhouse level and relative tolerance to extreme conditions these faba bean nodulating rhizobia isolates were recommended to be used as nominees for the future development of faba bean rhizobial inoculants after being tested on field conditions.


2016 ◽  
Vol 13 (4) ◽  
pp. 734-744
Author(s):  
Baghdad Science Journal

The current study was conductedas a pot experiment to determine the effect of soil texture on biological nitrogen fixation (BNF) of six most efficient local isolates, specified, of Bradyrhizobium. Cowpea (Vignaunguiculata L.), as a legume host crop, was used as a host crop and 15N dilution analysis was used for accurate determination of the amount of N biologically fixed under experimental parameters specified. Soils used are clay loam, sandy clay loam and sandy loam. Biological Nitrogen Fixation (BNF), in different soil textural classes, was as in the following order: medium texture soil > heavy texture soil > light textured soil. Statistical analysis showed that there is a significant variation in BNF % among six Iraqi isolates in the three soil textural classes. There is a significant variation in the number of the nodules of the six Isolates in one soil texture. However, nodules number does not agree with the BNF% in the same soil for any isolates. Statistical analysis of the data showed that there were significant differences in plant dry weight among the soil textural classes all over local isolates used in this study. Data also showed that there were significant differences in dry weight under different isolates.


2016 ◽  
Vol 41 (1) ◽  
pp. 163-171 ◽  
Author(s):  
MA Razzaque ◽  
MM Haque ◽  
MA Karim ◽  
ARM Solaiman

A pot culture experiment was conducted at the Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur during kharif II, 2012 to evaluate the nodulation, biological nitrogen fixation and yield potential of genotypes of mungbean under varying levels of N application. There were 10 mungbean genotypes viz. IPSA 12, GK 27, IPSA 3, IPSA 5, ACC12890055, GK 63, ACC12890053, BU mug 4, BARI Mung 6 and Binamoog 5, each genotype treated with six levels of N (0, 20, 40, 60, 80 and 100 kg N ha-1) . Among the genotypes, the IPSA 12 at 40 kg N ha-1 produced the maximum number of nodules (14.54 plant-1) as well as the highest nitrogen fixation (2.684 mmol C2H4). This resulted in the highest seed yield (14.22 g plant-1). The genotype ACC12890053 recorded the lowest nodulation (6 plant-1), nitrogen fixation (1.134) and seed yield (7.33 g plant-1).Bangladesh J. Agril. Res. 41(1): 163-171, March 2016


2016 ◽  
Vol 46 (9) ◽  
pp. 1594-1600
Author(s):  
Giovanna Moura Calazans ◽  
Christiane Abreu de Oliveira ◽  
José Carlos Cruz ◽  
Walter José Rodrigues Matrangolo ◽  
Ivanildo Evódio Marriel

ABSTRACT: Cratylia argentea is a leguminous shrub native to the cerrado, which has great potential for forage production and recovery of degraded areas. This study aimed to isolate, characterize, and select efficient rhizobial strains in symbiosis with Cratylia argentea . Rhizobacteria were isolated from the nodules of 12-month-old plants and cultivated in pots containing cerrado soil. Twenty-five bacterial strains were obtained, which displayed extensive variability with respect to morphological and symbiotic characteristics. Cratylia argentea seeds were planted in pots containing 5kg of cerrado soil and maintained in the greenhouse. The treatments consisted of 25 rhizobial isolates, two controls (without nitrogen and without inoculation), with or without nitrogen fertilization (5mgN·plant-1·week-1), and four replications. Plants were cultivated for 150 days after planting seeds to evaluate nodule number, nodule dry weight, shoot and root dry weight, shoot and root N content, and relative and symbiotic efficiency. Thirteen isolates improved shoot dry weight (up to 65.8%) and shoot nitrogen concentration (up to 76%) compared with those of control treatments. Two isolates, 4 (CR42) and 22 (CR52), conferred higher symbiotic efficiency values of approximately 20%. Therefore, these two rhizobial isolates displayed the highest potential as beneficial inoculants to optimize the symbiotic efficiency for Cratylia and to increase the incorporation of nutrients and biomass into the productive system in the cerrado.


1977 ◽  
Vol 57 (2) ◽  
pp. 433-439 ◽  
Author(s):  
L. M. BORDELEAU ◽  
H. ANTOUN ◽  
R. A. LACHANCE

Symbiotic nitrogen fixation with 49 isolates of Rhizobium meliloti was studied under controlled environment with alfalfa cv. Saranac. It was shown that plant yield in dry weight can be used as an indirect measurement of nitrogen fixation, and as a criterion for selecting efficient strains of R. meliloti. Statistical study on yields of three cuttings has established that the second cutting gives the most necessary information to correctly evaluate the symbiotic efficiency of the isolates. Six very efficient strains were selected.


2017 ◽  
Vol 40 (04) ◽  
Author(s):  
Minakshi Kalkal ◽  
Krishan Kumar ◽  
Radhey Sham Waldia ◽  
Surjit Singh Dudeja

Twenty genotypes of chickpea were evaluated to study the interaction of chickpea genotypes, mesorhizobial strains and vesicular arbuscular mycorrhiza for 14 nitrogen fixing and yield attributing traits viz. days to 50% flowering, days to maturity, plant height (cm), number of branches per plant, number of pods per plant, 100 seed weight (g), seed yield per plant (g), number of nodules per plant, nodule weight per plant (g), root dry weight per plant (g), shoot dry weight per plant (g), nitrogen content in shoot (%), nitrogen content in grain (%) and VAM infection(%). The analysis of variance revealed the existence of significant amount of genetic variability in the material for all the traits. All the genotypes were treated with three treatments separately (Mesorhizobium sp. Strain CH 1233 (S1); Mesorhizobium sp. Strain CH 810 (S2); vesicular arbuscular mycorrhiza (VAM) (Glomus fasiculatum) and one set was used as uninoculated control. These were grown separately following randomized block design with three replications in each treatment. Comparative analysis indicated the differences between the treatments and behaviour of the genotypes in different environments. In general S1 and VAM showed beneficial interaction for maximum number of traits for all the genotypes. The effect of VAM was the most apparent among treatments. On overall basis, genotypes viz. HC 3, HC 5, GL 94022, ICC 5003LN, HK 2, GNG 663 and BG 362 were observed to be better performing and responsive to bio inoculants having one or more superior traits. These genotypes performing better for specific traits can be used as parents in hybridization programme for improvement of that particular trait.


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