Rhizobium Inoculation and Micronutrient Addition Influence the Growth,Yield,Quality and Nutrient Uptake of Garden Peas(Pisum sativum L.)

Garden pea productivity and qualities are hampered in zinc(Zn),boron(B),and molybdenum(Mo)deficient soil.Thus,the combination of micronutrients(i.e.,Zn,B,and Mo)and rhizobium is necessary to increase the productivity and quality of garden peas,since this management for garden peas is neglected in Bangladesh.Therefore,the present study was made to assess the effectiveness of rhizobium inoculant singly or in combination with the micronutrients(i.e.,Zn,B,and Mo)on growth,yield,nutrient uptake,and quality of garden peas.Treatments were:T_(1)=Control,T_(2)=Rhizobium inoculation at 50 g/kg seed,T_(3)=T_(2)+Zn_(3)Mo1,T_(4)=T_(2)+B_(2)Mo1,T_(5)=T_(2)+Zn_(3)B_(2),T_(6)=T_(2)+Zn_(3)B_(2)Mo1 and T_(7)=Zn_(3)B_(2)Mo1.All treatments were arranged in a randomized complete block design and repeated all treatments in three times.The application of 3 kg Zn,2 kg B,and 1 kg Mo ha^(−1)with inoculation of Rhizobium at 50 g kg^(−1)seed(T_(6))facilitated to increase of 44.8%in the green pod and 29.7%seed yield over control.The same treatment contributed to attaining the maximum nodulation(25.3 plant^(−1)),Vitamin C(43.5 mg 100 g^(−1)),protein content(22.2%),and nutrient uptake as well as accumulation in garden peas.Among all treatment combinations,treatment T_(6)was found superior to others based on microbial activities,soil fertility,and profitability.The results of the study found that the application of 3 kg Zn,2 kg B,and 1 kg Mo ha^(−1)in combination with Rhizobium inoculation(50 g kg^(−1)seed)can improve the yield and quality of garden peas.The results of the study have the potential for the areas,where there is no use of Rhizobium inoculant or Zn,B,and Mo fertilizer for cultivation of garden pea.

Evaluation of Rhizobium tropici-Derived Extracellular Polymeric Substances on Selected Soil Properties, Seed Germination, and Growth of Black-Eyed Peas (Vigna unguiculata)

Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.

High efficient broad-spectrum Bradyrhizobium elkanii Y63-1

Soybean(Glycine max),the primary source of high-quality plant protein,plays a crucial role as a grain and oil crop in China.Harnessing the full potential of symbiotic nitrogen fixation in soybean production holds immense significance for agriculture and ecology alike.Zhongdou 63,a newly developed early-maturing summer soybean cultivar in 2021,exhibits remarkable traits such as high yield,superior quality,multi-resistance,and wide adaptability.In this study,eight distinct rhizobia strains from diverse regions were meticulously screened to identify highly effective strains specifically suited for Zhongdou 63.The aboveground biomass,plant height,chlorophyll content,root length,nodule number,and nodule dry weight of Zhongdou 63 were measured and the data were subjected to statistical analysis.The results demonstrated that Y63-1 is a predominant strain of Zhongdou 63.Subsequently,we conducted further investigations on the broad-spectrum nodulation characteristics of Y63-1.Ten representative soybean cultivars were individually inoculated with Y63-1 and subsequently analyzed for nodule numbers and nodule dry weight in their symbiotic systems with rhizobia.The findings revealed that Y63-1 effectively formed nodules with all ten soybean varieties tested.In summary,our current study identified highly efficient broad-spectrum Bradyrhizobium elkanii strain Y63-1 as the predominant strain in Zhongdou 63 and provided a theoretical foundation for enhancing yield potential not only in Zhongdou 63 but also in other varieties through inoculation with highly efficient rhizobia in production.

Effect of Rhizobium Inoculation on Phosphorus Uptake,Yield and Quality of Soybean Plants

[Objective] This study aimed to investigate the effect of inoculation with various rhizobium strains on growth status, phosphorus uptake, yield and quality of soybean plants. [Method] Using Dongnong 42 and Dongnong 46 as experimental soybeans, four treatments were designed, including non-inoculated CK group and three treatment groups inoculated respectively with rhizobium strains R2, R, and Rs, to analysis the effects of rhizobium inoculation on growth status, phosphorus uptake, yield and quality of soybean plants. [Result] Inoculation with different rhizobium strains could significantly increase the biomass and phosphorus content of the roots and shoots of Dongnong 42, to be specific, rhizobium strain R2 showed the best ef- fect, followed by Rs, and those of roots were improved greater than the shoots; in- oculation with rhizobium could significantly increase the yield of Dongnong 42, and R5 showed the best effect, but the yield of Dongnong 46 was decreased; after in- oculated with rhizobium, the protein content and fat content of soybean were signifi- cantly increased, and R2 showed the best effect, but the effects on different varieties varied, to be specific, the protein content of Dongnong 42 was significantly in- creased, while the fat content of Dongnong 46 was significantly increased; different rhizobium strains inoculated to different soybean varieties showed different effects. Inoculation with suitable rhizobium can improve plant growth characteristics, promote phosphorus uptake of plants, increase soybean yield, and effectively improve soy- bean quality. [Conclusion] This study provides theoretical basis for solving the prob- lem of soil phosphorus deficiency, increasing soybean yield and improving soybean quality in the future.

Rhizobium sp．N613胞外多糖分离纯化及抗S180肉瘤的研究

目的研究Rhizobiumsp.N613胞外多糖(REPS)的分离纯化条件和抑瘤活性。方法用酸化、加热、凝聚剂和絮凝剂进行发酵液预处理实验,经正交试验优化REPS醇沉制取条件。用凝胶柱色谱,紫外光谱扫描检测经Sevag法脱蛋白质所得REPS的纯度。采用动物移植性实体瘤的瘤重实验法研究REPS对小鼠S180肉瘤的抑瘤作用,并对荷瘤小鼠眼眶取血进行白细胞及淋巴细胞计数。结果发酵液预处理参数为:盐酸调节pH5.0,70℃加热20min,依次加入5g.L-1Al2(SO4)3.18H2O和0.2g.L-1海藻酸钠。优化的醇沉制取条件为:调节溶液pH7.0,乙醇浓度65%,醇沉时间8h。REPS经检测为均一多糖。抑瘤实验结果表明,REPS各剂量组对小鼠S180肉瘤均有抑制作用,其中REPS纯多糖剂量为10mg.kg-1的抑瘤率达44.17%。与荷瘤对照组相比,REPS能够显著促进白细胞和淋巴细胞的增生。结论初步摸索到了发酵液预处理操作的技术参数与醇沉制取的条件。所得REPS对小鼠S180肉瘤有显著的抑制作用。

辅酶Q_(10)高产菌Rhizobium radiobacter的选育及发酵条件优化

以放射型根瘤菌(Rhizobiumradiobacter)WSH2601为出发菌株,经紫外线和亚硝基胍复合诱变,获得遗传稳定性好的抗放线菌素D突变株WSH?F06.在摇瓶中考察了碳、氮源等营养条件以及接种量、装液量和初始pH等环境条件对突变株WSH?F06细胞生长和积累辅酶Q10的影响.通过诱变和优化发酵条件,突变株WSH?F06的辅酶Q10产量和胞内含量分别达到34mg/L和2.4mg/g,比出发菌株在同样条件下提高了16%.

快生型大豆根瘤菌(Rhizobium fredii)内源质粒在培养及共生过程中的稳定性

以湖北洪湖公离的快生型大豆根瘤菌为材料，考察了它们的内源质粒在培养过程及共生过程中的稳定性．结果表明，所有供试菌株的质粒在培养条件下比较稳定，传代50次后没有明显变异．对其中2个菌株与4种不同的大豆宿主共生过程中质粒的稳定性研究，发现HA12－1－12的共生质粒和隐性质粒高度构定，HA7－2－2的质粒却发生了不同程度的变异．质粒检测的结果及RFLP分析表明，HA7－2－2共生质粒的稳定性高于隐性质粒，而且共生质粒上携带的nodDABC和nifHDK基因相当保守，不易受宿主的影响而产生变异．盆栽试验的结果也说明，虽然HA7－2－2的内源质粒在共生过程中发生了遗传重排，但它的共生性状没有明显的变异．

天山根瘤菌（Rhizobium tianshanense）全细胞蛋白电泳和多位点酶电泳分析

用全细胞可溶性蛋白电泳和多位点酸电泳对１５株天山根瘤菌（Ｒｈｉｚｏｂｉｕｍ ｔｉａｎｓｈａｎｅｎｓｅ）和其它１０株快慢生根瘤菌进行聚类分析，结果表明Ｒ．ｔｉａｎｓｈａｎｅｎｓｅ种内菌株关系密切而与其它种不同。分析时将全细胞蛋白电泳图谱分为２５４等份，根据每等份内条带的有无进行聚类，结果与数值分类基本一致，说明用该方法对全细胞蛋白电泳结果进行聚类可以作为根瘤菌的分群手段；用所有出现的１０９种迁移率对１７种多位点酶的电泳结果作聚类分析，得到与全细胞蛋白电泳相似的结果。

Rhizobiumsp.N613合成胞外多糖的发酵动力学研究

对Rhizobiumsp.N613合成胞外多糖(REPS)的分批发酵过程和发酵动力学进行了研究。应用Logistic方程和Luedeking-Piret方程,得到了描述Rhizobiumsp.N613菌体生长、REPS合成和底物消耗的动力学模型。模型反映了该菌株合成REPS分批发酵过程的动力学特征,模型值与实验数据拟合良好。对Rhizobiumsp.N613发酵动力学模型和合成REPS的生理学特性进行了分析,优化了合成REPS的发酵工艺,补料分批发酵实验结果表明,REPS产量从8.21 g.L-1提高到11.31 g.L-1。

小分子Rhizobium sp. N613胞外多糖的羧甲基化及其抗肿瘤活性

目的建立小分子Rhizobium sp. N613胞外多糖羧甲基化的制备工艺并研究其抗肿瘤活性。方法以乙醇为溶剂,用一氯乙酸对小分子Rhizobium sp. N613胞外多糖(LREPS)进行羧甲基化修饰,通过正交试验考察了乙醇体积分数、一氯乙酸用量、氢氧化钠用量、醚化温度及时间对羧甲基化LREPS(CM-LREPS)羧甲基取代度(DS)的影响,并获得一系列CM-LREPS产物。红外图谱表征CM-LREPS分子结构。选取4组取代度(0.285,0.531,0.659和0.899)的CM-LREPS样品进行了小鼠肝癌腹水瘤H22抑瘤效果检验。结果红外图谱分析表明,实现了LREPS的羧甲基化。抗肿瘤试验表明,取代度为0.659的CM-LREPS效果最佳,抑瘤率高达59.2%。以取代度和抑瘤率为检测指标,确定CM-LREPS最佳制备工艺条件为:乙醇质量分数为90%,LREPS用量为2.0 g,一氯乙酸用量为3.0 g,氢氧化钠用量为4.0 g,醚化温度为40°C,反应时间为4 h。结论建立了CM-LREPS制备工艺并获取了相关抗肿瘤技术参数,为该多糖制剂的生产应用奠定了一定基础。

快生型大豆根瘤菌(Rhizobium fredii)15067与褐球固氮菌(Azotobacter chroococcum)10006的16S rDNA分析

分别对快生型大豆根瘤菌(Rhizobium fredii)15067和褐球固氮菌(Azotobacter chroococ-cum)10006两个菌株进行了16S rDNA的全序列测定,将此全序列与已知相关的16S rDNA进行了比较及聚类分析,得到系统发育树状图。在系统发育树中,根瘤菌15067隶属于中华根瘤菌属,与Sinorhizobium xinjiangenseIAM 14142,SinoRhizobium frediiSjzZ 4构成一个分支,其中与S.frediiSjzZ4的相似性最高,达99.72%;固氮菌10006处于固氮菌属分支中,其中和Azotobacter chroococcumAM12A,Azotobacter chroococcum的相似性均高达99.93%。为确定两株菌株的分类地位、进一步发掘和利用菌株的优良性状提供了参考依据。

快生型大豆根瘤菌（Rhizobium fredii）3．7Kb增效片段的亚克

利用柯氏质粒ｐＬＡＦＲ１为载体构建了快生型大豆根瘤菌Ｂ５２菌株的基因文库，并通过植物结瘤试验筛选到一个３．７Ｋｂ增效片段，将其导入慢生型大豆根瘤菌２２１０，能提高其共生固氮效率。所得高效菌株ＨＮ３２在黑龙江、四川和广西大面积应用，平均增产１１．４％（５）。本文测定了３．７Ｋｂ片段的核苷酸序列，计算机分析发现含有两个开放阅读框架（ＯＲＦｓ）。ＯＲＦ１编码含１９０个氨基酸的多肽，与已报道基因和多肽的同源性很低，但其Ｎ端１９个氨基酸与发根农杆菌的乳糖转移酶高度同源。ＯＲＦ２编码含２３５个氨基酸的多肽，与碗豆根瘤菌的ｈｕｐＥ及苜蓿根瘤菌的糖基转移酶基因显示５４％的同源性。

Flocculating Properties and Production of the Compound Bioflocculant by Rhizobium Radiobacter F2 and Bacillus Sphaeicus F6

A compound bioflocculant CBF,produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source,nitrogen source and C / N ratio,metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of p H. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+,Mg2+,Fe2+,Al3+and Fe3+. In addition,it was stable at 4-30 ℃ in the presence of Ca Cl2. It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions( p H 7. 0- 9. 0),and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6- 14 mg / L at p H 8. 0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.

Study on Acid Tolerance in Rhizobium meliloti and Its Symbiosis System

Soil pH is a main factor that affects the nodule formation and nitrogen fixation. The largely reduced nitrogen fixation effect caused by acid soil is the ma- jor limitation of alfalfa growth in the south of China. Thus selection of anti-acid nodule for inoculating on alfalfa is of great significance in practical production. Using nine candidate rhizobia （ Rhizobium meliloti L. ） as study objects, their colony diameters and the nodule number of each strain inoculated alfalfa variety were investigated at different pH conditions. The YNCY006 strain presented the strongest resistance to acid, while YNCY007 strain presented the weakest. For nedulation, GT13R alfalfa inoculated with YNCY006 or YNCY008 strains was the best symbiosis system in the acidic soil.

Effect of Dual Inoculation of Arbuscular Mycorrhiza and <i>Rhizobium</i>on the Chlorophyll, Nitrogen and Phosphorus Contents of Pigeon Pea (<i>Cajanus cajan</i>L.)

The pot experiments were conducted in the Department of Life Science and Bioinformatics of Assam University, Silchar. The aim of the present study was to investigate the effect of dual inoculation of Arbuscular mycorrhiza (AM) (Glomus fasciculatum) and Rhizobium on the chlorophyll, nitrogen and phosphorus contents of pigeon pea (Cajanus cajan L.). The results revealed an overall increase in chlorophyll, nitrogen and phosphorus contents in the inoculated plants than uninoculated ones. Maximum chlorophyll contents were recorded in the plants dually inoculated with Glomus fasciculatum and Rhizobium. The combined application of Glomus fasciculatum and Rhizobium also remarkably increased the nitrogen and phosphorus contents of pigeon pea. The dual inoculation with microsymbionts revealed synergistic effect. The results suggest that dual inoculation of Glomus fasciculatum and Rhizobium have the potential to enhance the chlorophyll, nitrogen and phosphorus contents of pigeon pea.

Effect of Rhizobium inoculation on Growth and Nodulationof Albizzia procera, Albizzia lebbeck and Leucaena leucocephala

Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined withAlbizzia procera, Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilizedsoil media. Inoculation resulted in nodule number increases of 28.6, 29.02 and 23.9 times in sterilized soiland 3.4, 3.6 and 3.27 times in non-sterilized soil for A. parocera A. lebbeck and L. leucocephala seedlingsrespectively. Total dry mass increased by 127.6%, 66.7% and 60.7% in sterilized soil and 100%, 95.5%and 52.65% in non-sterilized soil for these three legume trees, respectively, after a period of two months.Significalltly high inoculation responses of root length, root diameter, collar diameter, shoot length, and drymass of root, shoot, leaves and nodules were also observed in both sterilized and non-sterilized soil media ascompared to respective control treatments. The response to inoculation was strong in sterilized and modestin non-sterilized soils. The significantly higher response to Rhizobium inoculation over control in all thespecies tested suggested that application of Rhizobium greatly enhanced plant growth, nodulation, biomassproduction and nitrogen-fixing activity of the nodules.

Cloning and Sequencing of a 3.7kb Enhancing Fragment from Rhizobium fredii B52

The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively.

Maize Crop N Uptake from Organic Material of <i>Gliricidia sepium </i>Coinoculated with <i>Rhizobium</i>and Arbuscular Mycorrhizal Fungus in Sub-Saharian Africa Sandy Soil

The effect of green manure of gliricidia (Gliricidia sepium (Jacq.) Walp) leguminous plants applied for cereal maize cultivation and N uptake by cereal were investigated and analyzed in relation to influence of dual inoculation of gliricidia with microbial symbionts. Two pot experiments were conducted in greenhouse. The first trial was set up to enhance growth of gliricidia with exotic and indigenous rhizobial strains and arbuscular mycorrhizal fungus and the second to determine the effect of gliricidia organic material on maize growth. Direct 15N-labelling techniques were used to estimate N-fixed by gliricidia plant and N uptake of maize cereal crop from green manuring was calculated. Growth of gliricidia trees estimated by aboveground biomass production and N fixed were positively affected by dual inoculations. This study showed that shoot dry weight and N accumulation of maize cultivated under gliricidia green manure were influenced by its application and indirectly by microbial treatments. The N recovery by the maize accounted 17.32% to 26.52% of N applied as gliricidia organic material. Gliricidia green manure N accumulation and release, and afterward microbial inoculations were substantially determining on maize crop N uptake and growth in sandy soil of Sub-Saharian Africa.

Growth response of Pterocarpus santalinus seedlings to native microbial symbionts(arbuscular mycorrhizal fungi and Rhizobium aegyptiacum)under nursery conditions

The objective of this research was to improve the growth and biomass of Pterocarpus santalinus L.f.(an endangered leguminous tree)using native microbial symbionts such as arbuscular mycorrhizal fungi and Rhizobium associated with native populations of P.santalinus.The native arbuscular mycorrhizal fungi isolated from P.santalinus soils were identifi ed as(1)Glomus fasciculatum;(2)Glomus geosporum;and Glomus aggregatum.A nitrogenfi xing microbial symbiont was isolated from the root nodules of P.santalinus and identifi ed as Rhizobium aegyptiacum by 16s rRNA gene sequencing.These microbial symbionts were inoculated individually and in combination into P.santalinus seedling roots.After 90 days,growth and biomass had improved compared with uninoculated controls.Shoot and root lengths,number of leaves,stem circumference,number of root nodules,biomass,nutrient uptake and seedling quality index were signifi cantly increased by a combined inoculation of arbuscular mycorrhizal fungi+Rhizobium aegyptiacum.It was concluded that native microbial symbionts positively infl uenced P.santalinus seedling growth which will be helpful for successful fi eld establishment.

Optimization of Protective Agent Formulation for Soybean Rhizobium Strain HW-05 by Response Surface Methodology

[Objective] This study aimed to investigate the protective effects of proteins, salts, sugars and trace elements on soybean rhizobium strain HW-05 by response surface methodology. [Method] Different types, combinations, ratios and concentrations of protective agents were designed. Under simulated conditions, the optimal protective agent formulation was screened for improving the survival rate and survival time of soybean rhizobium strain HW-05. The optimal combination of significant factors was determined by Box-Behnken central composite design. [Result] Three significant factors affecting effective number of viable cells were screened, including peptone, xanthan gum and NaCl. The final concentration of each compound was optimized 0. 13% peptone, 0.011% xanthan gum, 0.30% NaCl. [Conclusion] After addition of protective agent and preservation at room temperature for six months, effective number of viable cells of soybean rhizobium strain HW-05 reached 3.185 ×10^8 CFU/ml. The survival rate of HW-05 cells was improved by more than 25% compared with the control group （2.458×10^8 CFU /ml）.