Rhizobium Inoculation Research Articles

Diverse Bradyrhizobium spp. with Similar Symbiosis Genes Nodulate Peanut in Different Regions of China: Characterization of Symbiovar sv. Arachis.

A total of 219 rhizobial strains isolated from peanut grown in soils from six peanut croplands in Zhengyang county, Henan Province, were typed by PCR-RFLP of IGS sequences. Their phylogenetic relationships were refined on representative strains using sequence analyses of 16S rRNA genes, housekeeping genes (atpD, recA, glnII) and symbiosis genes (nodA, nodC and nifH). The 219 rhizobial isolates were classified into 13 IGS types, and twenty representatives were defined within eight Bradyrhizobium genospecies: B. guangdongense covering 5 IGS types (75.2% of total isolates), B. guangzhouense (2 IGS types, 2.7% total isolates), B. zhengyangense (1 IGS type, 11.3% total isolates) and five novel genospecies (5 IGS types, 0.9 to 3.2% total isolates). All representative strains had identical nodA, nodC and nifH sequences except for one nifH sequence. With this one exception, these sequences were identical to those of the type strains of Bradyrhizobium species and several Bradyrhizobium genospecies isolated from peanut in different regions of China. The nodC sequences of all strains showed < 67% similarity to the closest strains on the Genbank database indicating that they are representative of a novel Bradyrhiobium symbiovar. This study has shown that (1) diverse Bradyrhizobium spp. with similar symbiosis genes nodulate peanut in different regions of China. (2) Horizontal transfer of genes involved in nodulating peanut is common between Bradyrhizobium species in soils used to grow the crop in China. (3) The strains studied here are representative of a novel Bradyrhizobium symbiovar that nodulates peanut in China. We propose the name sv. arachis for this novel symbiovar indicating that the strains were isolated from Arachis hypogaea. Results here have practical implications in relation to the selection of rhizobial inoculants for peanut in China.

Effect of rhizobium inoculation on yield and some quality properties of fresh cowpea

Effect of rhizobium inoculation on yield and some quality properties of fresh cowpea

Foliar nutrient content responses to bio-inoculation of arbuscular mycorrhizal fungi and Rhizobium on three herbaceous forage legumes

Smallholder livestock production in the Eastern Cape Province of South Africa has been hampered by a lack of high-quality feed. As such, improving ruminant nutrition using optimized production of herbaceous forage legumes has been suggested. However, the production of forage legumes for livestock feed is poor in communal areas in the province due to the necessity to use high levels of chemical fertilizers to provide high-quality feed that meets animal nutrient demands. The current study aimed at investigating the effects of arbuscular mycorrhizal fungi (AMF) and Rhizobium inoculation on the chemical composition of three herbaceous forage legumes, namely, Vigna unguiculata (cowpea), Lablab purpureus (lablab), and Mucuna pruriens (mucuna). The field trials were established over two growing seasons (2017/2018 and 2018/2019) at the University of Fort Hare Research Farm (South Africa) and were carried out as a 3 x 2 x 2 factorial experiment arranged in a randomized complete block design (RCBD) with 12 treatments that were replicated 4 times. The 12 treatments included three legume species (cowpea, lablab, and mucuna), two AMF (with and without AMF inoculation), and two Rhizobia inoculations (with or without). The results showed that the dual inoculation of AMF and Rhizobia bacteria significantly (p &amp;lt; 0.05) increased the contents of crude protein, neutral detergent fiber and acid detergent fiber, hemicellulose, ash, magnesium (Mg), phosphorus (P), calcium (Ca), zinc (Zn), and iron (Fe) of three herbaceous forage legumes. Furthermore, solo inoculation with AMF or Rhizobia bacteria resulted in substantially higher potassium (K), Ca, and Mg cation ions, and Ca/P, Zn, manganese (Mn), and Fe concentrations in forage legumes than in other treatments. In conclusion, the dual inoculation produced optimal nutrient accumulation in both growing seasons when compared to single inoculation and uninoculated forages. Therefore, this could assist in alleviating livestock malnutrition in smallholder farming.

Crop rotation and inoculation increase soil bradyrhizobia population, soybean grain yields, and profitability.

Crop rotation and rhizobial inoculation are strategies to increase yield by means of organic matter addition and modulation of microbial diversity. However, the extent to which these agricultural practices change soil Bradyrhizobium populations, soybean grain yield, and economic benefits to farmers is unclear. Thus, this study aimed to evaluate the interaction between crop rotation and inoculation of soybean (Glycine max) cultivated in two contrasting soils (clayey and sandy soil) on biological nitrogen fixation components, grain yields, and profits. Field experiments with a three-year crop rotation system were carried out to compare effects of inoculation and crop rotations on soil chemical attributes, bradyrhizobia most probable number (MPN) and diversity, soybean nodulation, grain yield, and economic indicators of inoculation in different crop rotations. The crop rotation did not affect the soil MPN cells of bradyrhizobia, but the inoculation and the soil sampling time did, ranging from 3.61-4.42 to 4.40-4.82 in the sandy soil, while in the clayey soil they were from 5.19-6.34 to 6.61-7.14 in Log10 per g of soil with higher population after harvest of summer crops. In the clayey soil, crop rotation influenced soybean nodulation. The grain yield of inoculated soybean in the clayey soil was higher than that in the sandy soil. Soybean inoculation with Bradyrhizobium spp. increased the profitability of agricultural production systems by up to 45% in clayey soil and up to 7% in sandy soil.

Combined application of macro and micro nutrients and Rhizobium inoculation to nodulation and yield response of chickpea (Cicer Arietinum L.) at Halaba Woreda, Southern Ethiopia

The effects of combining the application of recently introduced blended fertilizer with Rhizobium inoculation on chickpea nodulation and productivity are not being studied in Halaba special woreda. Hence, the application of blended fertilizer and rhizobium inoculation for chickpea production under rain-fed conditions at Halaba Special District, Southern Ethiopia is crucial. Factorial combination of eight fertilizers (Control, NP, NPS, NPSB, NPSB+K, NPS+Zn, NPSB+Zn and NPSB+K+Zn) and inoculation and without inoculation of rhizobium biofertilizer was used as an experimental factor laid out in a randomized complete block design with three replications. Fertilizer application significantly influenced crop phenology, nodulation, growth parameters, yield and yield components, except number of seeds pod-1 and harvest index. Maximum days to 50% flowering (48.33) and 95% physiological maturity (112.3) were obtained on NPSB+K and without fertilizer treatment respectively. The Highest number of nodules (23.25), nodules dry weight (0.13 g), number of branches plant-1 (17.64) and plant height (43.34 cm) were recorded on NPSB, NPSB+K+Zn, NPSB+Zn and NPS+Zn respectively. Similarly, the higher number of pods plant-1(61.6), and hundred seed weight (28.0 g) were observed for blended fertilizer treatments of NPSB+K and NPS+Zn respectively. Maximum grain yield (1.85 ton ha-1) was obtained for blended fertilizer of NPSB+K application with an increment 57.9% over control treatment. Rhizobium inoculation increased the number of nodules plant-1 (23.29), nodules dry weight (0.11 g), number of branches plant-1 (17.70), number of pods plant-1 (59), number of seeds pod-1 (1.17) and hundred seed weight (27.7 g). Maximum grain yield (1.84 ton ha-1) was recorded on rhizobium inoculated and it increased chickpea grain yield by 33.3% over uninoculated. Regarding the economic feasibility of fertilizers greater net benefits with acceptable MRR 1802, 866 and 257 were recorded for blended fertilizers of NPS, NPS+Zn and NPSB, respectively. Given the fact that the three fertilizers had statistically similar grain yields, the blended fertilizer NPS is a better choice among the three alternatives. Similarly, a higher net benefit with acceptable MRR (4189%) was recorded for Rhizobium inoculation. Therefore, blended fertilizer; NPS and Rhizobium inoculation were found to be relevant and recommended for chickpea production in the study area.

Comparative efficacy of different salt tolerant rhizobial inoculants in improving growth and productivity of Vigna radiata L. under salt stress

Worldwide, salinity severely affects agricultural production of crops such as mung bean in arid and semi-arid regions. In saline conditions, various species of Rhizobium can be used to enhance nodulation and induce salinity tolerance in maize. The present study conducted a pot experiment to determine the efficiency of three rhizobial isolates under different salinity conditions, such as 1.41, 4 and 6 dS m−1, on mung bean growth parameters, antioxidant status and yield. Results revealed that salt stress imparted adverse effects on the growth, antioxidants, yield and nodulation of mung bean. Under high salt stress conditions, fresh weights were reduced for roots (78.24%), shoots (64.52%), pods (58.26%) and height (32.33%) as compared to un-inoculated control plants. However, an increase in proline content (46.14%) was observed in high salt stressed plants. Three Rhizobium isolates (Mg1, Mg2, and Mg3), on the other hand, mitigated the negative effects of salt stress after inoculation. However, effects of Mg3 inoculation were prominent at 6 dS m−1 and it enhanced the plant height (45.10%), fresh weight of shoot (58.68%), root (63.64%), pods fresh weight (34.10%), pods number per plant (92.04%), and grain nitrogen concentration (21%) than un-inoculated control. Rhizobium strains Mg1, and Mg2 expressed splendid results at 1.41 and 4 dS m−1 salinity stress. The growth promotion effects might be due to improvement in mineral uptake and ionic balance that minimized the inhibitory effects caused by salinity stress. Thus, inoculating with these strains may boost mung bean growth and yield under salinity stress.

Aluminium Application and Rhizobia Inoculation Effects on Growth, Yield and Nutrients Uptake of Three Kenyan Soy Bean Genotypes

Soy bean (Glycine max L.) grains are important legume crops commonly grown in Kenya. Soy bean genotypes are grown in western Kenyan soils that are highly saturated with aluminium ions. Aluminium toxicity mainly limits crop production. Many soy bean genotypes do not tolerate high acidity in soils. Aluminium stress have effects on root growth, which limits plant growth and development. Inoculation of plants with Rhizobia can restore nitrogen under acid affected soils to produce competitive crop yields. There is little information on response of soy bean genotypes grown in Western Kenya to aluminium toxicity under rhizobium inoculation. This study was designed to determine the effect of aluminium application and Rhizobia inoculation on growth, yield and nutrients uptake of soy bean genotypes. Eight treatments of Al (AlCl3.6H2O) levels and Rhizobia were imposed. Randomized Complete Block Design with three replicates was used. Parameters determined included; number of branches, days to 50% flowering, pod clearance, number of pods, days to harvest maturity and nitrogen, phosphorus and potassium contents. Tukey’s HSD test at 5% level was used to separate treatment means. Mean of branches for NAMSOI was significantly higher compared to mean branches for GAZZELLE and TGX at treatment 4 (T4) on 61 DAT, respectively. Mean number of days to 50% flowering of NAMSOI was significantly higher than that of GAZZELLE and TGX genotypes, respectively at T3.There was a statistically significant interaction between the effects of treatments and genotypes on NPK concentrations in plants. These findings show that Bradyrhizobium japonicum inoculation alleviates Al effects to a level that is significant to improve soy bean yield. Therefore, genotypes GAZELLE and NAMSOI under Rhizobia inoculation were identified to be more tolerant to Al-stress, hence are recommended for growing in Al prone soils. It provides the best conditions in improving soy bean production under Al stress prone soils.

Genetic diversity assessment and selection of Bradyrhizobium strains for Inceptisols based on symbiotic performance

The symbiotic association of pigeonpea (Cajanus cajan (L.) Millsp.) with rhizobia plays a pivotal role in plants’ growth and development. The present study was carried out at Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh during 2018–2020 to explore the diversity of rhizobia present in the Cajanus cajan root under Inceptisols and identify an elite strain that exhibits exceptional plant growth promotion and of nitrogenase activity for efficient nitrogen fixation. The bacterial identification using 16s rDNA sequencing revealed bacteria strains Bradyrhizobium japonicum (S12), Bradyrhizobium subterraneum (S1, S7, S8, S10, S13), Bradyrhizobium yuanmingense (S2, S3, S4, S6, S9, S11) while two bacteria were the endophytes identified as Pseudomonas azotoformans (S5) and Paenibacillus seodonensis (S15). Genetic diversity using UPGMA clustering revealed remarkable genetic variations, classifying 14 strains into three primary clusters and four secondary clusters. Strains S1, S3, S6, S9, and S13 exhibited elevated nitrogenase activity, indicative of their proficient nitrogen fixation capability. In plant growth experiments, all strains demonstrated significant growth of the plants compared to control. The notable growth enhancement by these five strains can be attributed to their remarkable efficiency in nitrogen fixation, as indicated by significantly higher nodule formation and nitrogenase activity. These findings provide valuable insights for identifying potential rhizobial inoculants to enhance pigeonpea productivity.

Characterization and expression profiles of WUSCHEL-related homeobox (WOX) gene family in cultivated alfalfa (Medicago sativa L.)

The WUSCHEL-related homeobox (WOX) family members are plant-specific transcriptional factors, which function in meristem maintenance, embryogenesis, lateral organ development, as well as abiotic stress tolerance. In this study, 14 MsWOX transcription factors were identified and comprehensively analyzed in the cultivated alfalfa cv. Zhongmu No.1. Overall, 14 putative MsWOX members containing conserved structural regions were clustered into three clades according to phylogenetic analysis. Specific expression patterns of MsWOXs in different tissues at different levels indicated that the MsWOX genes play various roles in alfalfa. MsWUS, MsWOX3, MsWOX9, and MsWOX13-1 from the three subclades were localized in the nucleus, among which, MsWUS and MsWOX13-1 exhibited strong self-activations in yeast. In addition, various cis-acting elements related to hormone responses, plant growth, and stress responses were identified in the 3.0 kb promoter regions of MsWOXs. Expression detection of separated shoots and roots under hormones including auxin, cytokinin, GA, and ABA, as well as drought and cold stresses, showed that MsWOX genes respond to different hormones and abiotic stress treatments. Furthermore, transcript abundance of MsWOX3, and MsWOX13-2 were significantly increased after rhizobia inoculation. This study presented comprehensive data on MsWOX transcription factors and provided valuable insights into further studies of their roles in developmental processes and abiotic stress responses in alfalfa.

The Use of rhizobia and vesicular-arbuscular mycorrhiza to improve drought resistance of Kudzu (Pueraria phaseoloides (Roxb.)Benth.) in coastal land

A study was conducted to examine the association between Rhizobium and VAM fungi on the kudzu plant growth and response to drought stress in coastal dry land. The research was carried out in three phases: (1) germination of kudzu seeds; (2) multiplication of VAM and Rhizobia inoculums; and (3) inoculation of fungi and/or bacteria on plants grown at various soil moisture content. At the inoculation phase, the pot experiment was carried out for 8 weeks with a pot experiment arranged based on a 4 x 4 treatment factorial Completely Randomized Design with three replications to test the source of the inoculum and soil moisture content (25%, 50%, 75%, 100%). Observations were made on: (1) Rhizobial infection activity and nodulation; (2) VAM infection activity; (3) plant growth, and 4) population dynamics of rhizobacteria. The results showed that the rhizobia inoculation alone was not able to increase the bacterial infection activity and root nodulation, the VAM fungal infection, and plant growth. Inoculation with VAM fungi alone was able to stimulate infection activity of nodule-forming bacteria and root nodulation, VAM fungal infection activity, and plant growth. The combination of VAM fungal and rhizobial inoculation was able to stimulate fungal infection activity and growth of plant roots and shoots, but not always able to stimulate bacterial infection activity and root nodulation. Inoculation of VAM fungi alone was able to stimulate the plant growth rates even up to a drought stress level of 75%. This means that inoculation of VAM fungi alone was able to increase drought resistance and maintain the plant growth rates at high levels of drought stress.

The Effect of Different Rhizobial Symbionts on the Composition and Diversity of Rhizosphere Microorganisms of Chickpea in Different Soils.

Chickpea (Cicer arietinum L.) is currently the third most important legume crop in the world. It could form root nodules with its symbiotic rhizobia in soils and perform bio-nitrogen fixation. Mesorhizobium ciceri is a prevalent species in the world, except China, where Mesorhizobium muleiense is the main species associated with chickpea. There were significant differences in the competitive ability between M. ciceri and M. muleiense in sterilized and unsterilized soils collected from Xinjiang, China, where chickpea has been grown long term. In unsterilized soils, M. muleiense was more competitive than M. ciceri, while in sterilized soils, the opposite was the case. In addition, the competitive ability of M. ciceri in soils of new areas of chickpea cultivation was significantly higher than that of M. muleiense. It was speculated that there might be some biological factors in Xinjiang soils of China that could differentially affect the competitive nodulation of these two chickpea rhizobia. To address this question, we compared the composition and diversity of microorganisms in the rhizosphere of chickpea inoculated separately with the above two rhizobial species in soils from old and new chickpea-producing regions. Chickpea rhizosphere microbial diversity and composition varied in different areas and were affected significantly due to rhizobial inoculation. In general, eight dominant phyla with 34 dominant genera and 10 dominant phyla with 47 dominant genera were detected in the rhizosphere of chickpea grown in soils of Xinjiang and of the new zones, respectively, with the inoculated rhizobia. Proteobacteria and Actinobacteria were dominant at the phylum level in the rhizosphere of all soils. Pseudomonas appeared significantly enriched after inoculation with M. muleiense in soils from Xinjiang, a phenomenon not found in the new areas of chickpea cultivation, demonstrating that Pseudomonas might be the key biological factor affecting the competitive colonization of M. muleiense and M. ciceri there. Different chickpea rhizobial inoculations of M. muleiense and M. ciceri affected the rhizosphere microbial composition in different sampling soils from different chickpea planting areas. Through high throughput sequencing and statistical analysis, it could be found that Pseudomonas might be the key microorganism influencing the competitive nodulation of different chickpea rhizobia in different soils, as it is the dominant non-rhizobia community in Xinjiang rhizosphere soils, but not in other areas.

Effect of Chemical Mutagenesis on Salt Tolerance of Common Beans (Phaseolus vulgaris L.) Nodulating Rhizobium

The chemical mutation is one of the important factors in the enrichment of the salt resistance capacity of the rhizobium isolates. Therefore, this study focused on 10 isolates of rhizobium collected from soil samples of Babile, Hararghe region, Ethiopia. All the collected isolates turned into a moderately yellow, yellow, and deep yellow color in yeast extract mannitol agar medium (YEMA) containing bromothymol blue after 48 h of incubation. It indicated that all the isolates were acid-producing Rhizobia. Moreover, based on colony morphology and diameter, 70% of the isolates displayed large mucoid colonies, and 30% of the isolates showed large watery colonies in YEMA media. Among the 10 isolates, 9(90%), 9(90%), 6(60%), 6(60%), 2(20%), and 1(10%), were grown at different salinity levels such as 2%, 4%, 6%, 8%, 9% and 10% of NaCl, correspondingly. The most salt-resistant wild isolate was HUCR 6 collected from Babile soil grown at 10% NaCl salinity level. A total of six mutants were considered after chemical mutagenesis based on their capacity to survive in the extreme salinity levels (11 to 14%). Mutant isolates such as HUCRM 4, HUCRM 5, and HUCRM 6 were the most tolerant Rhizobium that grew at the salinity level of 11 to 14% NaCl. The most sensitive mutant isolate was HUCRM 10 followed by the isolates HUCRM 8 and HUCRM 9 was the next sensitive mutant Rhizobia that grew only at 11% of NaCl concentration. Compared to the Rhizobium wild isolates, the mutant isolates were observed to be more tolerant to a medium containing higher concentration of NaCl, as high as 11% to 14%. Besides, 80% of the mutant isolates demonstrated effective nodulation with the common beans. The mutant isolate (HUCRM 4) showed better performance in relation to root nodule performance of Rhizobium species and increased the plant biomass production. In this study, mutant isolates HUCRM 6, which is tolerated to 14% NaCl, and HUCRM 4, HUCRM 5, and HUCRM 6 isolates tolerated at 12% salinity level. Finally, based on their symbiotic efficiency and tolerance to extreme salt levels, these mutant isolates (HUCRM 4, HUCRM 5 and HUCRM 6) were encouraged to be used for the development of Rhizobium inoculants of common beans grown under extreme saline conditions. J. Bio-Sci. 30(2): 13-22, 2022

Effect of Molybdenum on Leaf Chlorophyll and Biomass Yield of Cowpea (Vigna unguiculata)

Molybdenum (Mo) is an essential micronutrient for plant. It is plays an important key role in chlorophyll synthesis. The Experiment was conducted in Pot house at Department of Soil Science and Agricultural Chemistry, College of Agriculture, JNKVV, Jabalpur during Kharif season 2014.The soil of experimental site belongs to Kheri-series and taxonomically comes under the order Vertisols, sub order Sterts, great group Haplusterts, sub group TypicHaplusterts. In all total 14 number of treatment combinations were tried under factorial randomized block design replicated thrice. The result revealed that variations in observation were found with treatment of Rhizobium inoculation. Seed treatment of Mo @ 0.5 g ammonium molybdate kg-1 seed (StM1) responded better, followed by soil application of Mo @ 1.0 kg Mo ha-1 soil (SaM1) as main effects. With higher dose of Mo as seed treatment (StM2) exerted significantly negative effect. Whereas higher dose of soil application of Mo (SaM2) was merginally higher over no application of Mo which was seemed to be the buffer action of soil to nulify adverse effect of the micronutrient.

Drought Stress Effects on Vegetable Crop Productivity: Melatonin's Mitigating Role and Rhizobium Inoculants for Enhanced Nitrogen Fixation under Water Scarcity

Drought Stress Effects on Vegetable Crop Productivity: Melatonin's Mitigating Role and Rhizobium Inoculants for Enhanced Nitrogen Fixation under Water Scarcity

The role of Molybdenum in relation to Rhizobium sp. in increasing biological Nitrogen fixation and soybean growth

Soybean is a legume that can form a mutualism symbiosis with Rhizobium bacteria to bind N. Increasing the effectiveness of N fixation by Rhizobia requires the role of micronutrient Molybdenum (Mo), because Mo is needed for nitrate reductase enzyme for NO3 - assimilation. The objective of the research was to evaluate the role of Mo and Rhizobium sp. inoculation in the growth of soybean and increase the root nodules number. A factorial randomized block design was used in the research. The first factor was inoculation of Rhizobium sp. (0; 5 and 10 ml/plant), and the second factor was the application of Mo (0; 200; 400 and 600 g/ha). The research result showed that inoculation of Rhizobium sp. up to 10 ml/plant increased plant height, number of leaves and leaf area. Application of molybdenum up to 400 g/ha was able to increase the number of nodules formed. There was no significant interaction between Rhizobium sp. inoculation and application of Mo in all observed variables.

Effect of Integrated Application of Bio-Fertilizer and Soil Amendments on Growth Parameters of Groundnut (Arachis hypogaea L.)

The pot experiment entitled “Effect of integrated application of bio-fertilizer and soil amendments on Growth parameters of Groundnut (Arachis hypogaea L.)’’ was conducted at the Research Farm of School of Agriculture, ITM University, during kharif season 2022. The soil of the experimental field was sandy loam, having a pH of 8.13, EC of 0.54 ds m-1, organic carbon 0.40%, available N, P, K of 180, 11.09 and 283.40 kg ha-1 respectively and exchangeable Ca+Mg of 1.5 me 100 g-1soil. The pot experiment was laid out in CRD (Completely Randomized Design) with six treatments and six replications. The treatment combinations were: T1- Control, T2- Recommended Dose of Fertilizer (N, P2O5 and K2O @ 20, 40 and 20 kg ha-1 respectively), T3- FYM (10 t ha-1), T4- Rhizobium (Bradyrhizobium japonicum) @ 200 gm 10 kg-1 seeds, T5- RDF + Rhizobium, T6- Rhizobium + FYM. The nodulation (number of nodules and nodules dry weight) was increased with combine application of rhizobium inoculation and FYM over the time (30 and 60 DAS) followed by RDF and rhizobium inoculation. The growth attributes viz. plant biomass, shoot length, root length was significantly improved with the integration of bio-fertilizer, FYM and inorganic fertilizers. The highest result for plant biomass (22.34 gm plant-1) and shoot length (21.78 cm) were recorded in rhizobium inoculation and FYM treatment combination but root length (8.87 cm) was recorded highest in combine application of RDF with rhizobium. Application of rhizobium with FYM (25.74 gm pot-1) produce the highest pod yield followed by RDF and rhizobium (23.65 gm pot-1) combination. The combination of RHZ + FYM has much more favorable results on growth and yield of groundnut and it also enhance the nodulation.

Arbuscular Mycorrhizal Fungus Funneliformis mosseae Improves Soybean Growth Even in Soils with Good Nutrition

Arbuscular mycorrhizal fungi (AMF) improve plant growth and may be useful in maintaining and even restoring soil. However, data on the latter function are sparse and only indirect, which is especially true for conventional management conditions with adequate nutrient availability. Our study focused on utilizing the prevalent AMF species, Funneliformis mosseae, to enhance Glycine max production, while also exploring its partly explored impact on soil aggregation. Working in greenhouse conditions, we examined whether, in a nutrient-sufficient environment, AMF would improve crop biomass accumulation and nutrition, as well as the stability of soil aggregates (SAS). We also looked for a synergistic effect of dual inoculation using AMF and symbiotic rhizobium. Plants were or were not inoculated with AMF or Bradyrhizobium japonicum in a two-factorial design. AMF inoculation increased soybean biomass, but AMF inoculation had no impact on P and N input to the shoots. Mycorrhiza did not affect either glomalin abundance or SAS. All the impacts were, however, independent from rhizobial inoculation, which was ineffective in this nutrient-available environment. Our assay suggests that arbuscular mycorrhiza may have a positive effect on soybean growth even under conventional management with adequate nutrition. The positive effects of AMF on soybean growth, together with the fact that AMF generally do not thrive in good nutrient availability, should be taken into account when planning mineral fertilization levels.

MicroRNA 4407 modulates nodulation in soybean by repressing a root-specific ISOPENTENYLTRANSFERASE (GmIPT3).

MicroRNAs (miRNAs) are important regulators of plant biological processes, including soybean nodulation. One miRNA, miR4407, was identified in soybean roots and nodules. However, the function of miR4407 in soybean is still unknown. MiR4407, unique to soybean, positively regulates lateral root emergence and root structures and represses a root-specific ISOPENTENYLTRANSFERASE (GmIPT3). By altering the expression of miR4407 and GmIPT3, we investigated the role of miR4407 in lateral root and nodule development. Both miR4407 and GmIPT3 are expressed in the inner root cortex and nodule primordia. Upon rhizobial inoculation, miR4407 was downregulated while GmIPT3 was upregulated. Overexpressing miR4407 reduced the number of nodules in transgenic soybean hairy roots while overexpressing the wild-type GmIPT3 or a miR4407-resistant GmIPT3 mutant (mGmIPT3) significantly increased the nodule number. The mechanism of miR4407 and GmIPT3 functions was also linked to autoregulation of nodulation (AON), where miR4407 overexpression repressed miR172c and activated its target, GmNNC1, turning on AON. Exogenous CK mimicked the effects of GmIPT3 overexpression on miR172c, supporting the notion that GmIPT3 regulates nodulation by enhancing root-derived CK. Overall, our data revealed a new miRNA-mediated regulatory mechanism of nodulation in soybean. MiR4407 showed a dual role in lateral root and nodule development.

Economic Analysis of Seed Inoculation and Phosphorus Doses Application in Cowpea (Vigna unguiculata L.)

The study about the economic returns of cowpea (Vigna unguiculata) by the use of rhizobium seed inoculation and different phosphorus doses was conducted at Bharatpur, Chitwan, from February to May 2022. The experiment was conducted in a two-factor randomized complete block design (RCBD) with three replications and eight treatments. Treatments were set as factor A: seed inoculation i.e., un-inoculated and inoculated; and factor B: four different phosphorus doses (20, 40, 60, 80 kg ha­-1). The cowpea variety ‘Prakash’ was used. Results revealed that the application of seed inoculation provides the highest returns compared to an un-inoculated one; similarly, in case of phosphorus dose of 40 kg P2O5 ha-1 gives the maximum economic returns compared to other phosphorus doses. Furthermore, the interaction of rhizobium inoculation with 40 kg ha­-1 gives the highest gross income (NRs. 216005), net return (NRs. 110829.39) and B: C (2.05) compared to all other single inoculation or phosphorus or interaction treatments ( 1 $ = NRs. 132.53) . From the result, it is concluded that the use of rhizobium inoculation along with 40 kg P2O5 ha­-1 would be economically profitable for the farmers under the Terai conditions of Nepal.

Effect of Rhizobium Inoculation and Phosphate Fertilizer on The Growth of Soybean (Glycine max L) Grobogan Variety

Various strategic efforts to increase food production continue to be made in an effort to achieve self-sufficiency and food security. Soybean is a national strategic commodity to support government programs in an effort to increase production with the aim of achieving self-sufficiency. The purpose of this study was to determine the effect of the combination of phosphate fertilizer and rhizobium biofertilizer on the growth of soybean (Glycine max L) Grobogan variety. The research was conducted from June to September 2022 at the Ma'had Al Zaytun Agricultural Complex, Indramayu Regency. The method used is the method of randomized block design with a combination pattern. There were 9 treatment combinations of SP-36 phosphate fertilizer and rhizobium inoculation. SP-36 Fertilizer consists of 3 levels, namely 100, 150 and 200 kg/ha and Rhizobium with 3 levels, namely 0.05, 0.10 and 0.15 g/planting hole. Each combination was repeated three times so that there were 27 trial plots. Each experimental plot is 6 m2. The observed data were processed using analysis of variance and the Scott-Knott test. The results showed.that the combination-of SP-36 Phosphate fertilizer-and Rhizobium inoculation had-a significant effect on all observations both plant height, number of trifoliate leaves, number of branches, root volume.