Nodulation Status Research Articles

Water deficit response in nodulated soybean roots: a comprehensive transcriptome and translatome network analysis

BackgroundSoybean establishes a mutualistic interaction with nitrogen-fixing rhizobacteria, acquiring most of its nitrogen requirements through symbiotic nitrogen fixation. This crop is susceptible to water deficit; evidence suggests that its nodulation status—whether it is nodulated or not—can influence how it responds to water deficit. The translational control step of gene expression has proven relevant in plants subjected to water deficit.ResultsHere, we analyzed soybean roots’ differential responses to water deficit at transcriptional, translational, and mixed (transcriptional + translational) levels. Thus, the transcriptome and translatome of four combined-treated soybean roots were analyzed. We found hormone metabolism-related genes among the differentially expressed genes (DEGs) at the translatome level in nodulated and water-restricted plants. Also, weighted gene co-expression network analysis followed by differential expression analysis identified gene modules associated with nodulation and water deficit conditions. Protein-protein interaction network analysis was performed for subsets of mixed DEGs of the modules associated with the plant responses to nodulation, water deficit, or their combination.ConclusionsOur research reveals that the stand-out processes and pathways in the before-mentioned plant responses partially differ; terms related to glutathione metabolism and hormone signal transduction (2 C protein phosphatases) were associated with the response to water deficit, terms related to transmembrane transport, response to abscisic acid, pigment metabolic process were associated with the response to nodulation plus water deficit. Still, two processes were common: galactose metabolism and branched-chain amino acid catabolism. A comprehensive analysis of these processes could lead to identifying new sources of tolerance to drought in soybean.

Nodulation in Rhynchosia schimperi: A Rare Legume of Indian Thar Desert

Rhycnhosia schimperi Hochst. ex Boiss. is a rare plant of Indian Thar Desert and mostly confined to the Jaisalmer and Barmer district of Rajasthan. There are least information is available on the nodulation in it. In India the comprehensive study on nodulation in native legumes of Thar Desert was done by Gehlot et. al. in 2012. In which they have reported nodulation in more than 30 native legumes (excluding Rhynchosia schimperi) with detail study on the morphology & histology of nodules and their associated rhizobia. The present investigation was done to know the nodulation status as well as the morphology & histology of nodules and their associated micro-symbionts in Rhynchosia schimperi. The study reveal good amount of nodulation was found in it. The nodules were found perennial and mucunoid type and mainly two types of bacteria viz. fast growing probably Ensifer sp. and slow growing Badirhizobium sp. were found in it.

Multifarious microbial biostimulants promote growth in Arachis hypogaea L.

Plant Growth Promoting Rhizobacteria (PGPR), a microbial biostimulant has been widely studied to stimulate plant growth through induction of natural biological processes. However, lack of successful validation under open field remains a barrier to mark their standard in agriculture. Therefore, the aim of the research was to highlight the potential of PGPR biostimulants via in vitro studies and subsequently to demonstrate the in planta evaluation in oilseed crop, Arachis hypogaea L. (Groundnut) under pot and field trials. The two rhizobacterial strain was identified as Pseudomonas fluorescens and Bacillus subtilis by 16s rRNA gene sequence analysis. Both the strains were functionally screened for plant growth promoting traits. Pot and field trials were conducted where seeds were inoculated with PGPR biostimulants and harvested at 30 and 90 days. Biostimulant treatments were applied as single and co-inoculation in groundnut and the growth factors, biochemical parameters, yield, and seed quality were analyzed. The study inferred that the consortium of PGPR biostimulants significantly (p < 0.05) showed highest growth, photosynthetic pigments, nodulation status, leghaemoglobin content, yield attributes, and also biofortification of seed nutrients in oilseed crop under both pot and field conditions than un-inoculated control. This study supports the idea of the application of PGPR as microbial biostimulants through successful open field trial to facilitate its implementation as a feasible and potential agricultural product to synthetic fertilizers thereby influencing sustainable and stable crop production.

RESPONSE OF SOYBEAN (GlycinemaxL. Merrill) PRODUCTIVITY TO BIOFERTILIZER INOCULANTS COMBINED WITH ORGANIC FERTILIZERUNDER SANDY SOIL CONDITIONS

One of the most important food sources for humans is the soybean crop because it is an important source ofprotein and oil, which makes it important to improve its productivity under stress conditions, especially in sandy lands.Therefore, the study aimed to improve soybean productivity by using biological fertilizers in the presence of organicfertilizer and low concentration of mineral fertilizer under new sandy soil conditions.The experiment was carried out intwo summer seasons of 2020 and 2021 at the Ismailia Research Station, Ismailia Governorate. The used inoculates inthe experiment were,an identified Streptomyces strain,Bacillus megatherium, (SEWRI) and Bradyrhizobiumjaponicum(Okaden) as,biofertilizer agents.Activated dose of N-fertilizer was used in seven different treatments. Results showedthat Bradyrhizobia+Bacillus+actinomycetes+20 kg nitrogen fertilizer/fed was effective in the presence of organicfertilizer compared to organic fertilizer-free soil or un-inoculated+70 kg N/fed. Bradyrhizobia+ Bacillus+Actino+20 kgN/fed (T14) was the most effective treatment in the presence of organic fertilizer compared to organic fertilizer-free soilor uninoc.+70 kg N/fed. Promising expected yields of each of seeds and straw (Ton/fed) of soybean plants cultivatedunder different fertilizers and biofertilizers conditions expected was clear from increasing the yield seed up to1.8400Ton/fed in the presence of organic fertilizer (T14) compared to 1.4565 when soybean was cultivated in theabsence of organic fertilizer (T01). This could be supported by the amounts of NPK, N-percentage, and protein content,numbers of branches and pods and dehydrogenase activity in soil. Significant differences between the straw yield in thepresence and absences of organic fertilizer as well as biofertilizers were recorded. Organic fertilizer applicationrecorded the highest significant increases in nodulation status, growth and straw nitrogen content as well as harvestparameter of soybean compared with those un-received organic fertilizer

Effect of Foliar Application of Manganese on Plant Growth, Nodulation and Biochemical Attributes of Mungbean (Vigna radiata L.) under Salinity Stress

Background: Salinity is one of the considerable factors which wanes crop productivity especially in arid and semi-arid realms of the world. The stress created by high soil salinity can cause osmotic stress, specific ion toxicity, nutritional imbalance, hormonal dysfunction and oxidative damage. A study was carried out to determine the effect of manganese (Mn) on growth rate index (GRI), Nodulation status, total nitrogen content, total amino acid content and total protein content of mungbean plants under salinity. Methods: Three indices were used to evaluate the effect of salt stress on development of mungbean plants (100, 200 and 300 mM NaCl). Untreated plants served as control expect. Mn was supplied to the plants in form of manganese chloride (MnCl2). The plant samples were analyzed for 65 days at every 10-day interval. Result: The results revealed that low level of salinity (100 mM NaCl) showed a significant increment in all the above observed parameters, while higher concentrations (200 mM and 300 mM) decreased the mentioned attributes. Foliar spraying with Mn (0.15%) mitigated the deleterious impacts of salinity and enhanced growth, nodulation and biochemical parameters. Thus, foliar treatment with Mn can be used in increasing the tolerance capacity of the plant and to enhance the nitrogen fixing ability of the plant under salinity.

Effect of rhizobial isolates and nitrogen fertilizers on nursery performance, nodulation behavior and nitrogenase activity of Dalbergia sissoo Roxb. seedlings

Nursery practice in Dalbergia sissoo seedlings was performed in order to establish the efficacy of the rhizobial inoculants for future nurseries. The rhizospheric bacteria were isolated from different geographic locations of Himachal Pradesh and Uttrakhand. The nursery was set up by sowing the seeds collected from these locations. The rhizospheric bacterial inoculants isolated from D. sissoo rhizosphere were treated in the nursery for the establishment of a successful nursery. The nursery was observed for root, shoot parameters, and nodulation status showing variation in these characters with different geographic locations. From the same nursery, rhizobia were isolated from root nodules in YEMA media. Based on PGPR traits, two rhizobia, i.e., PGPR1 (DBD1) and PGPR2 (DRT5) were treated in the second nursery along with different levels of nitrogenous fertilizers. The consortium of PGPR1+PGPR2 was observed to be the best treatment that significantly increased the growth parameters, i.e., root, shoot parameters and nodulation status, and nitrogenase activity in D. sissoo seedlings.

Impact of applied Vermicompost tea and Humic Acid on Nodulation Status, Vegetative growth, and yield attributes of Bean (Phaseolus vulgaris L) plants.

Impact of applied Vermicompost tea and Humic Acid on Nodulation Status, Vegetative growth, and yield attributes of Bean (Phaseolus vulgaris L) plants.

Actinorhizal plants of Turkey: formation of nodules, cluster roots and ectomycorrhizal roots

None of the known native actinorhizal species in Turkey, Alnus glutinosa and A. orientalis (Betulaceae), Datisca cannabina (Datiscaceae), Elaeagnus angustifolia and Hippophae rhamnoides (Elaeagnaceae), and the widely-planted exotic Casuarina cunninghamiana (Casuarinaceae), have confirmed records of actinorhizae in Turkey. This study determined the capacity of representative actinorhizal plants in Turkey to form nodules, cluster roots and ectomycorrhizal roots in a typical central Anatolian soil with and without amendment of soil and nodule extracts, as well as in soil from Adana and Izmir. Nodulation was confirmed experimentally for E. angustifolia and C. cunninghamiana in Niğde soil (the latter only with addition Adana or Izmir soil), but only observationally for A. glutinosa during sample collection in Rize. Cluster roots developed strongly in C. cunninghamiana, and likewise ectomycorrhizal roots in Allocasuarina verticillata (included as a reference species) but only to a lesser extent in C. cunninghamiana. The nodulation status of the natives, D. cannabina and H. rhamnoides, remains to be investigated.

Transcriptomic and photosynthetic responses to grafting of the Nod1 gene in nodulated and non-nodulated soybeans

Legume plants form symbiotic relationships with rhizobia to convert N2 into ammonia, and the nodulation status can affect plant development including photosynthesis. However, the relationship between nitrogen fixation and photosynthesis during carbon and nitrogen metabolism remains unclear. This study was undertaken to unravel regulation of nodulation and photosynthesis using a spontaneous nonnodulated soybean mutant by grafting. The results of inheritance and gene mapping showed that the nonnodulated mutant was controlled by a recessive gene overlapped with the reported rj1 locus, and might be a new rj1 allele with 1 bp deletion in the fourth exon in comparison to the sequence of normal nodulation plants. According to grafting results, soybean nodulation is obviously determined by the roots, not the seedlings. Moreover, nitrogen content along with related metabolic enzyme activity, and photosynthetic capacity were enhanced by nonnodulated scions grafted with nodulated roots. Contrary results were obtained for nodulated scions grafted with nonnodulated roots. A total of 853 differentially expressed genes (DEGs) in the leaves and 1874 in the roots were identified by transcriptome analyses of the grafting treatments. We identified 285 differential gene ontology (GO) terms and 57 differential pathway terms identified in the leaves, while 856 differential GO terms and 207 differential pathway terms in the roots. Twenty DEGs interacting at translation level were selected, and the results of transcriptome analyses were verified by q-PCR. These findings indicated that the nodulation-related Nod allelic gene increases the nitrogen content of nonnodulated plants, which affects the enzymes involved in nitrogen metabolism, leading to changes in hormone levels and further regulation of photosynthesis and carbon metabolism.

Morphological, Biochemical and Molecular Characterization of Rhizobia of Faba Bean Plants Grown in North Nile Delta Egypt.

<b>Background and Objective:</b> Rhizobia are bacteria including genes codes for enzymes involved in the fixing of the atmospheric nitrogen. A set of twenty rhizobial isolates were studied to determine their morphological, biochemical, molecular characteristics using the 16S rRNA gene in addition to assess their growth and symbiotic performance. <b>Materials and Methods:</b> Rhizobial isolates were isolated from root nodules of <i>Vicia faba </i>L. plants. The isolates were morphologically characterized by determining cell shapes, size, Gram stain reaction, motility, sporulation, bacterial growth performance was determined by IAA production and biomass density. Symbiotic performance was measured by evaluation of nodulation status and shoot/root dry weight. Sequencing of 16S rRNA and phylogenetic analysis were done for the five promising isolates. Statistical analysis was performed using a one-sample Student t-test. <b>Results:</b> Only five rhizobial isolates (Rh 32, Rh 6-A, Rh 3-4, Rh RL3 and Rh 8-A) were selected according to their growth and symbiotic performance and subjected to further molecular characterizations. All isolates were found to have remarkable nodulation status, IAA production, nitrogenase activity and increasing the root and shoot dry weight. The five selected rhizobial isolates were identified by partial sequencing of 16S rRNA genes and registered in the GenBank database. The alignment and phylogenetic analyses of 16S rRNA sequences closely related in the GenBank revealed that all isolates belonging to <i>Rhizobium leguminosarum</i> bv. viciae. <b>Conclusion:</b> The results confirmed that the five Rhizobial strains will be promising as a source of genes for nitrogen fixation and plant growth promotion.

Studying the Effect of Different Fertilizers Types and Methods of Application on Nodulation, Growth and Yield of Some Chickpea Varieties Under Rainfed Conditions

This experiment was conducted in Sharya-Duhok area, Iraqi Kurdistan region under rainfed conditions during the season of 2018-2019 to study the nodulation status, growth and yield performance of two local varieties of chickpea (Shamy and Marakshy) in relation to three different fertilizers types and methods of application i.e. bio fertilizer (Corabac G) and seed priming in super phosphate 2% and Diammonium phosphate (DAP) in addition to control treatment. The experiment was designed by Randomized complete block design with four replications. The results clearly showed significant reduction in both number and dry weight of nodules per plant in fertilizer treatment as compared to untreated (control treatment), except seed priming in super phosphate 2% as it significantly enhanced the nodule dry weight displaying non responding of chickpea to soil fertilization in regards of nodules development. However the final seedyield was not significant in the study, but its highly correlated to the above ground biomass (r =0.74**) and number of seeds per plant (r = 0.33*); Shamy variety of chickpea was superior in number of branches, number of pods and seeds per plant, while the Marakshy variety was superior in the plant height, height of lowest pod, and weight of seeds. Regarding fertilizers treatments effects, both seed priming in super phosphate and DAP fertilizer treatments were significantly surpassed in number of branches, pods and seeds per plant. Shamy variety performed better in number of branches and seeds per plant with DAP fertilizer, while Marakshy produced the same traits better in seed priming treatment. Bio-fertilizer (Corabac G) was inferior in most of the studied traits of chickpea. Accordingly, the obtained results conclude that the nodulation in chickpea not respond to the soil application of fertilizers, while positively to seed treatment (priming). The results also suggest both method of fertilization (DAP and seed priming) for improving yield related componets, but Corabac G bio fertilizer is not recommended under similar conditions.

EVALUATION OF SOME CHICKPEA GENOTYPES TO BACTERIAL INOCULATION

Field experiment was carried out during the two successive seasons (2015-2016 and 2016-2017) at Sids Research Station, Agricultural Research Center (ARC), Bani Swif Governorate, Egypt, to evaluate the response of some new chickpea genotypes cultivated under Egyptian soil conditions for rhizobial inoculation alone or in combination with foliar inoculation of Pink Pigmented Facultatively Methylotrophic bacteria (PPFMs) as Plant Growth Promoting Rhizobacteria (PGPR). Nodulation status, some vegetative growth and yield parameters were determined. The obtained results cleared that all chickpea genotypes tested were positively responded to the native soil rhizobia and formed root nodules. Rhizobial inoculation alone or in combination with foliar application of PPFMs bacteria (5 L fed-1) scored significant increases in nodule numbers, plant dry weight, yield per plant as well as seed yield at the both seasons as compared to untreated treatments. Using rhizobial inoculation and PPFMs bacteria emphasized the superiority and gave of the highest values at all tested parameters. Generally, the second season gave the highest values at all plant tested parameters as compared to uninoculated ones. Chickpea genotypes GT3, GT4 and GT7 emphasized higher response to cultivated under Egyptian soil conditions and gave higher values for nodules number and dry weight, growth parameters i.e. plant dry weight and plant N-content and yield parameters i.e. yield per plant, seed index and seed yield ton. fed-1 as compared to chickpea variety G195.

Response of Rhizobium-Faba Bean Symbiosis System to Rhizobacterial Inoculation and Arbuscular Mycorrhizal Fungi under Graded Levels of Natural Rock Phosphate in Sandy Soil

Two field trials were conducted during two winter growing seasons of 2016/2017 and 2017/2018, using drip irrigation system. The target of this study was to evaluate the response of Rhizobium-faba bean symbiosis system to rhizobacterial inoculation (Serratia marcescens and Bacillus megaterium) and AM-fungi under graded levels of natural rock phosphate (15,30 and 45 kg P2O5/fed).The experimental design was arranged in a completely randomized block design with four replicates. The number and dry weight of nodules, N2-ase activity, plant height, dry weight of shoot and their contents of N, P and K ,the number of pods plant-1 and the number of seeds pod-1as well as 100-seed weight, the biological yield, seed yield and seed crude protein percentage were evaluated. The study was also concerned with the impacts of such microbial inocula and rock phosphate on dehydrogenase and phosphatase activities in soil rhizosphere. The obtained results elicited that the uninoculated plants were poorly nodulated. While, inoculating faba bean seeds with efficient Rhizobium exerted great improvement in nodulation status and N2-ase activity. The microbiological properties of rhizosphere soil, which expressed by dehydrogenase enzyme activity and the activity of phosphatases displayed higher response to applied biofertilizers. In fact, the splendid effect was observed with the use of inoculation approach (mixture of Rhizobium, Serratia, Bacillus and AM-fungi), which caused promotive impression in nodulation, the activity of rhizosphere soil enzymes, plant growth aspects and all faba bean yield charactersin relative to other combinations or plants inoculated with Rhizobium only. Irrespective of inoculation, there is an increase in nodulation status, all vegetative growth characters, the activity of rhizosphere soil enzymes and faba bean yield with increasing natural rock-phosphate rate from 60 to 180 kg/fed(15 to 45 kg P2O5/fed).Hence, data confirmed the superiority of treatment comprising (Rhizobium conjugated mixture of PGPR's and AM-fungi)in combination with 30 or 45 kg P2O5/fed, which surpassed the other tested combinations and caused a significant augmentation in all studied faba bean parameters. While, inoculation with Rhizobium combined with PGPRs or AM-fungi and fertilized with 45 kg P2O5/fed came in the second rank. Obtained findings displayed a considerable evidence that inoculation of faba bean seeds with Rhizobium combined with a mixture of rhizobacteria may revealing a good practice for improving faba bean growth and yield characters and leading to healthier food, particularly when this practice supported by effective AM-fungi and natural rock phosphate (30 kg P2O5/fed).

Effect of Bio-Organic Amendments on Growth, Yield, Nodulation Status, and Microbial Activity in the Rhizosphere Soil of Peanut Plants under Sandy Soil Conditions

In a field experiment, plant growth, nodulation status, yield, mineral content, and the rhizosphere enzyme activities of peanut (Arachis hypogaea L), cultivated in sandy loam soil were studied under the effect of the amendment with humic acid and the inoculation with plant growth promoting rhizobacteria (PGPR) that applied as foliar andor as seed coating. Bradyrhizobium was used as a single inoculum andor accompanied with PGPR (Azospirillum sp.+ Paeniacillus polymyxa+ Serratia marcescens) with or without humic acid. Results revealed that inoculation with Bradyrhizobium as a single inoculum or accompanied with PGPR, increased significantly shoot dry weight, and yield of peanut under coating and foliar applications. Incorporation of humic acid at two rates of 3L/fed and 5L/fed as foliar and seed coating gave the highest significant values for all tested parameters. inoculation with Bradyrhizobium as single inoculum or accompanied with PGPR enhanced the nodulation status and nitrogenase activity. Also, the values of nodules and nitrogenase activity achieved by coating application method were higher than those recorded by foliar application. In addition, the combined application of coinoculation Bradyrhizobium and PGPR accompanied with humic acid led to significant increases in the content of N, P, and K in shoot plant and in soil. Likewise, humic acid amendment can stimulate the microbial activities in the rhizosphere soil. Higher values of dehydrogenase activity in the rhizosphere soil and carbon dioxide were found with coinoculation and foliar application of humic acid.

Taxonomic Appraisal of Nodulation in the Leguminosae of Pakistan

ABSTRACT: Rhizobia are gram negative bacteria that infect roots of leguminous plants and form root nodules. Legume-rhizobia symbioses are of practical importance in providing sustainable food supply and increased agricultural productivity. Existing lists published on the nodulating ability of Pakistani legumes were merged to compile a comprehensive list. The list contained 225 species distributed in 75 genera that were native to Pakistan. Legumes were arranged according to the recommendations of International Legume Database and Information Center (ILDIS) for legumes of south Asia. Out of 225 species examined, 28 belonged to Caesalpinioideae, 29 belonged to Mimosoideae and 168 belonged to Papilionoideae. The percentage of nodulation in Caesalpinioideae, Mimosoideae and Papilionoideae was 0%, 96%, 99% respectively. Conflicting reports on the nodulation status of some Caesalpiniod legumes have been discussed. Doubtful reports on nodulation may arise from inaccurate identification of root nodules. This is particularly due to the fact that structures like galls, tumors, knots, hypertrophies and mycorrhizae that grow on the roots bear superficial resemblance with nodules. It is interesting to note that major cases of doubtful nodulation reported in the past for Leguminosae concern Caesalpinioideae. The matter needs investigation at the molecular level. Present results confirm early findings that nodule formation is more commonly present than absent in Mimosoideae and Papilionoideae, the reverse is true for Caesalpinoideae.

Antifungal activities of Punica granatum L. peel-compost tea for controlling damping-off disease caused by R. solani

Rhizoctonia solani is common fungal pathogen to lupine plants (Lupinus albus L.) causing damping-off disease resulting in serious economic losses. In vitro experiment was conducted to evaluate the efficacy of individual compost tea and pomegranate peel-compost tea prepared using water and alkaline water against R. solani. Three pomegranate types(two Palestinian and one Egyptian) were used. Greenhouse experiment was also conducted using the Palestinian sour pomegranate peel which showed a significant antifungal activity. Lupine plants were treated with compost alone or combined with pomegranate peel powder and their extracts to control lupine damping-off disease in comparison with untreated infected soil (control), and the fungicide (Rizolex-T). In vitro experiment, results showed that pomegranate peel-compost tea significantly decreased linear growth of the R. solani compared to individual compost tea. Alkaline water led to a significant reduction in the fungal growth compared to water. Under greenhouse conditions, all applied treatments significantly induced reduction in the damping-off percentage and improved the nodulation status and growth parameters compared to infested control. The maximum survived plants percentage and growth parameters of lupine plants were recorded for pomegranate peel-compost tea treatment, followed by the fungicide. Whereas the best nodulation status was achieved by the fungicide and pomegranate peel-compost tea. It could be concluded that pomegranate peel-compost tea may provide a high efficacy to pomegranate peel and compost in combination, so it might be used in a commercial scale for controlling damping-off disease.

GROWTH, NODULATION, YIELD AND MINERAL TISSUE CONTENT OF PEANUT IN RESPONSE TO FOLIAR AND COATING APPLICATION OF HUMIC ACID AND PLANT GROWTH –PROMOTING RHIZOBACTERIA

The aim of this investigation was to study the effect of adding humic acid and plant growth promoting rhizobacteria (PGPR), as foliar and coating application on plant growth, nodulation status and yield of peanut under field conditions. Results indicate that, using microbial inoculation with Brady rhizobium as single inoculation and coinoculation with PGPR ( Azospirillum sp.+ Bacillus polymyxa+ Serratia marcescens) as mixed inocul, conjugated with humic acid at two rates 3L/fed and 5L/fed. signicantly increased shoot dry weight, nodulation status and yield of peanut plant under coating and foliar applications. Incorporation of humic acid as foliar and coating application led to highest significant for all parameters above control. Also, coating application method was higher than foliar application. Shoot mineral content of N,P and K were increased by using coinoculation and addition of humic acid

RESPONSE OF SOYBEAN PLANTS TO INOCULATION WITH RHIZOBIA AND CYANOBACTERIA

Field experiments were carried out on a clayey alluvial soil to evaluate the effect of (Bradyrhizobium japonicum (B.j), ,Nostoc muscorum, Anabaena oryzae, B.j. +Nostc, B.j.+Anabaena, and B.j.+Nostc+Anabaena , on soybean (Glycine max L.) vegetative growth, root nodulation status , yield and its components. Also, microbial activity in soybean rhizosphere soil and technology characters of seeds (protein, oil, and carbohydrate content) were determined. Results indicated that, inoculation with Brady rhizobium or cyanobacteria improved plant growth parameters, i.e., plant height, number of branches, number and dry weight of pods above the control (60kgN) . However, co-inoculation of Brady rhizobium with the two cyanobacteria significantly enhanced those parameters, where they scored significant increases in number and dry weight of root nodules, as well as nitrogenase activity of the root system, as compared with the single inoculation with Brady rhizobium alone or the control. The mixed inoculation improved dehydrogenase activity in the rhizosphere soil, as well as the seed content of oil, protein and carbohydrate were achieved. Also, the highest yield and its components were also recorded with the mixed inoculation.

Evaluation of Elemental Sulphur Application with Rhizobia Inoculation on Peanut Yield and its Quality Grown in Sandy Soil at Egypt

TWO field experiments were conducted during the summer of ….. two successive seasons of 2011 and 2012, to identify the response of peanut (Arachis hypogaea L., cv. Giza 5)to soil application of elemental sulphur (at rate of 15, 30 and 45 Kg s/fed before sowing) and Rhizobia(Bradyrhizobium japonicum) inoculation, individually or in combination, for determination of the yield criteria, pods yield, 100 seeds yield, seeds & straw yield and shilling percentage at harvest, as well as seed oil, oil yield, protein content and protein yield. The associated amelioration in plant macro and micronutrient contents and uptake, and soil biological activities (nodulation status, nitrogenase, dehydrogenase, CO2 evolution and total bacterial counts) were assessed in this study. The obtained results indicated that Rhizobium inoculation or S addition alleviated the adverse effect of soil nutrient deficiency and caused significant increases in all the studied parameters of peanut and soil. Rhizobium inoculation individually caused insignificant increases in all the studied parameters over S addition solely at 45 kgs/fed. The joint addition of sulphur at all rates with Rhizobium inoculation gave high significant increases in all prior studied parameters and soil biological parameters at 50 and 80 days after peanut sowing followed by the individual treatments.

English

Five species of Acacia (Acacia ehrenbergiana Hayne, A. nilotica (L.) Delile, A. seyal Delile, A. tortilis (Forssk.) Hayne and A. laeta Delile) indigenous to Tamanrasset (Algeria) were investigated for their nodulation status and nodular endophytic diversity. A. ehrenbergiana showed the highest nodulation ability across the different sites in this region, indicating the widespread occurrence of compatible rhizobia in the soils. Altogether 81 strains were purified. Among this endophytic strain collection, only four bacterial endophytes nodulated their respective host plants. On the basis of partial 16S rDNA sequencing, they were affiliated to Ensifer sp., Ensifer teranga, Mesorhizobium sp. and Rhizobium sp. Among the 79 non- symbiotic endophytes, 24 representative strains on the basis of PCR-RFLP profile obtained with MSPI enzyme digestion were characterized. They belonged to nine genera, namely: Paenibacillus, Ochrobactrum, Stenotrophomonas, Pseudomonas, Microbacterium, Rhizobium, Agrobacterium, Brevibacillus and Advenella. The isolated nodular endophytes in this study revealed a strong tolerance profile to salinity and high temperature. Principal component analysis confirmed that no correlation was found between bacterial tolerance to a maximum temperature of growth and soil depth of sampling. This tolerance profile was distributed over the three levels of soil depth sampling: 20, 40 and 60 cm. On the other hand, there was no relationship between in vitro tolerances of rhizobial strains to NaCl and high temperature and corresponding edaphoclimatic characteristics of the sampling sites. This study is a contribution to nodular bacterial diversity knowledge of desert African Acacia species growing in preserved ecosystems. Key words: Acacia spp., bacterial endophytic diversity, desert, nodules, salinity tolerance, temperature tolerance.