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Search Results: 1 - 10 of 9784 matches for " nitrogen-fixing nodule bacteria "
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Soil Management and Efficiency of Rhizobia Strains of Cowpea Vigna unguiculata (L.) Walp. in the Tropics
Donizetti dos Santos,José Geraldo; Ferreira Aguiar,Alana das Chagas; Silva Junior,Edilson Máximo; Lemes Dadalto,Danubia; Rodrigues Sousa,Merijane; Ribeiro Xavier,Gustavo; Gomes de Moura,Emanoel;
Chilean journal of agricultural research , 2011, DOI: 10.4067/S0718-58392011000400015
Abstract: in the humid tropics, the largest obstacle to the implementation of sustainable farming systems is the reduced efficiency of nutrient use by crops. this study assesses the effectiveness of five selected rhizobia strains in symbiosis with cowpea (vigna unguiculata (l.) walp.), with the objective of replacing n fertilization in the predominant agricultural system used by smallholder farmers. the study was carried out in three adjacent areas with distinct agricultural uses: conventional tillage, itinerant agriculture, and a no-till system. the experimental design was in randomized complete blocks with four replicates and seven treatments: five rhizobia strains (br3262, br3267, br3299, inpa3-11b, and ufla 3-84) and two controls without inoculation (one without mineral n and another fertilized with 74 kg n ha-1). we measured the dry mass of 100 grains, nodules and shoots, as well as cowpea yields and calculated relative and absolute efficiency indices for dry biomass production of cowpea shoots. agricultural uses affected the number and dry mass of the nodules and, consequently, the mass of the dry plant matter and bean yield. in terms of yield, there was a major difference between the conventional and the itinerant systems. yield was around four times as high in the itinerant system (1009.9 kg ha-1 compared to 243.7 kg ha-1). under conditions of cohesion-prone soils, the system of conventional tillage reduces the possibility of cultivation of a second harvest in the year even with inoculation or n fertilization.
Soil Management and Efficiency of Rhizobia Strains of Cowpea Vigna unguiculata (L.) Walp. in the Tropics Manejo de Suelo y Eficiencia de Cepas de Rizobio de Frijol Vigna unguiculata (L.) Walp. en los Trópicos
José Geraldo Donizetti dos Santos,Alana das Chagas Ferreira Aguiar,Edilson Máximo Silva Junior,Danubia Lemes Dadalto
Chilean Journal of Agricultural Research , 2011,
Abstract: In the humid tropics, the largest obstacle to the implementation of sustainable farming systems is the reduced efficiency of nutrient use by crops. This study assesses the effectiveness of five selected rhizobia strains in symbiosis with cowpea (Vigna unguiculata (L.) Walp.), with the objective of replacing N fertilization in the predominant agricultural system used by smallholder farmers. The study was carried out in three adjacent areas with distinct agricultural uses: conventional tillage, itinerant agriculture, and a no-till system. The experimental design was in randomized complete blocks with four replicates and seven treatments: five rhizobia strains (BR3262, BR3267, BR3299, INPA3-11B, and UFLA 3-84) and two controls without inoculation (one without mineral N and another fertilized with 74 kg N ha-1). We measured the dry mass of 100 grains, nodules and shoots, as well as cowpea yields and calculated relative and absolute efficiency indices for dry biomass production of cowpea shoots. Agricultural uses affected the number and dry mass of the nodules and, consequently, the mass of the dry plant matter and bean yield. In terms of yield, there was a major difference between the conventional and the itinerant systems. Yield was around four times as high in the itinerant system (1009.9 kg ha-1 compared to 243.7 kg ha-1). Under conditions of cohesion-prone soils, the system of conventional tillage reduces the possibility of cultivation of a second harvest in the year even with inoculation or N fertilization. En los trópicos húmedos, el mayor obstáculo para la aplicación de sistemas de agricultura sostenible es la reducción de la eficiencia del uso de nutrientes por los cultivos. Este estudio evalúa la eficacia de cinco cepas de rizobios seleccionados en simbiosis con frijol (Vigna unguiculata (L.) Walp.), con el objetivo de sustituir la fertilización nitrogenada en el sistema de uso de suelo predominante utilizado por los peque os agricultores. El estudio se llevó a cabo en tres zonas adyacentes de distintos usos agrícolas: labranza convencional, agricultura itinerante, y un sistema de no laboreo. El dise o experimental fue en bloques al azar con cuatro repeticiones y siete tratamientos: cinco cepas de rizobios (BR3262, BR3267, BR3299, INPA3-11B y UFLA 3-84) y dos controles sin inocular (uno sin N mineral y otro fertilizado con 74 kg de N ha-1). Se midió el peso en seco de 100 granos, de los nódulos y de los brotes, así como los rendimientos de frijol y se calcularon los índices de eficiencia relativa y absoluta para la producción de biomasa seca de los
Isolation and Identification of Phosphate Solubilizing and Nitrogen Fixing Bacteria from Soil in Wamena Biological Garden, Jayawijaya, Papua
SULIASIH,SRI WIDAWATI
Biodiversitas , 2005,
Abstract: A study was undertaken to investigate the occurrence of phosphate solubilizing bacteria (PSB) and nitrogen-fixing bacteria (NFB) from soil samples of Wamena Biological Garden (WbiG). Eleven soil samples were collected randomly to estimate microbial population which used plate count method. The result showed that the microbial population ranged from 5.0x103-7.5x106 cells of bacteria/gram of soil and 5.0x103-1.5x107 cells of bacteria/gram of soil for PSB and NFB respectively. There were 17 isolates which have been identified till genus and species. The isolated microorganism were identified as PSB i.e. Bacillus sp., B. pantothenticus, B. megatherium, Flavobacterium sp., F. breve, Klebsiella sp., K. aerogenes, Chromobacterium lividum, Enterobacter alvei, E. agglomerans, Pseudomonas sp., Proteus sp. and as NFB i.e. Azotobacter sp., A. chroococcum, A. paspalii, Rhizobium sp., and Azospirillum sp.
Associative diazotrophic bacteria in grass roots and soils from heavy metal contaminated sites
Moreira, Fátima M.S.;Lange, Anderson;Klauberg-Filho, Osmar;Siqueira, José O.;Nóbrega, Rafaela S.A.;Lima, Adriana S.;
Anais da Academia Brasileira de Ciências , 2008, DOI: 10.1590/S0001-37652008000400014
Abstract: this work aimed to evaluate density of associative diazotrophic bacteria populations in soil and grass root samples from heavy metal contaminated sites, and to characterize isolates from these populations, both, phenotypically (zinc, cadmium and nacl tolerance in vitro, and protein profiles) and genotypically (16s rdna sequencing), as compared to type strains of known diazotrophic species. densities were evaluated by using nfb, fam and jnfb media, commonly used for enrichment cultures of diazotrophic bacteria. bacterial densities found in soil and grass root samples from contaminated sites were similar to those reported for agricultural soils. azospirillum spp. isolates from contaminated sites and type strains from non-contaminated sites varied substantially in their in vitro tolerance to zn+2 and cd+2, being cd+2 more toxic than zn+2. among the most tolerant isolates (ufla 1s, 1r, s181, s34 and s22), some (1r, s34 and s22) were more tolerant to heavy metals than rhizobia from tropical and temperate soils. the majority of the isolates tolerant to heavy metals were also tolerant to salt stress as indicated by their ability to grow in solid medium supplemented with 30 g l-1 nacl. five isolates exhibited high dissimilarity in protein profiles, and the 16s rdna sequence analysis of two of them revealed new sequences for azospirillum.
Solubilisation of inorganic phosphates by inoculant strains from tropical legumes
Marra, Leandro Marciano;Oliveira, Silvia Maria de;Soares, Cláudio Roberto Fonsêca Sousa;Moreira, Fatima Maria de Souza;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000500015
Abstract: microbial solubilisation of low soluble inorganic phosphates is an important process contributing for the phosphorus available to plants in tropical soils. this study evaluates the ability of inoculant strains for tropical legumes to solubilise inorganic phosphates of low solubility that are found in tropical soils. seven strains of leguminosae nodulating bacteria (lnb) were compared with one another and with a non-nodulating positive control, burkholderia cepacia (lmg 1222t). four of the strains are used as inoculants for cowpeas (vigna unguiculata) (bradyrhizobium sp. ufla 03-84; bradyrhizobium elkani inpa 03-11b and bradyrhizobium japonicum br3267) or for common beans (phaseolus vulgaris) (rhizobium tropici ciat 899t). rhizobium etli ufla 02-100 and rhizobium leguminosarum 316c10a are also efficient nodulators of beans and cupriavidus taiwanensis lmg 19424t nodulates on mimosa pudica. two experiments, with solid and liquid media, were performed to determine whether the strains were able to solubilise cahpo4, al(h2po4)3 or fepo4.2h2o. on solid gelp medium none of the strains dissolved fepo4.2h2o, but lmg 1222, ufla 03-84 and ciat 899 solubilised cahpo4 particularly well. these strains, along with lmg 19424 and br 3267, were also able to increase the solubility of al(h2po4)3. in liquid gelp medium, lmg 1222 solubilised all phosphate sources, but no legume nodulating strain could increase the solubility of al(h2po4)3. the strains ciat 899 and ufla 02-100 were the only legume nodulating bacteria able to solubilise the other phosphate sources in liquid media, dissolving both cahpo4 and fepo4.2h2o. there was a negative correlation between the ph of the culture medium and the concentration of soluble phosphate when the phosphorus source was cahpo4 or fepo4.2h2o. the contribution of these strains to increasing the phosphorus nutrition of legumes and non-legume plant species should be investigated further by in vivo experiments.
The Selection of Sugarcane Families That Display Better Associations with Plant Growth Promoting Rhizobacteria
Valeria Rosa Lopes,Joao C. Bespalhok-Filho,Luiza Maria de Araujo,Fabio Vieira Rodrigues
Journal of Agronomy , 2012,
Abstract: The capacity of the sugarcane plant to respond to Plant Growth Promoting Rhizobacteria (PGPR) is associated with both the efficiency of the bacterial strain and the capacity of the plant to respond to inoculation. For this reason, the appropriate selection of both the bacterial strain and the sugarcane genotype is required for generating optimal results from PGPR inoculations. To address this issue, this study sought to evaluate the response of 54 sugarcane families to inoculation with Azospirillum brasilense strains. In particular, four months after germination, 54 families from crosses between clones of sugarcane were treated either with an inoculant named Triazo, which was composed of a mixture of the Abv5, Abv6 and Abv7 strains of A. brasilense, or with the IC26 strain of A. brasilense. The treated plants were then planted in fields. These plants were assessed 14 months after they had been planted on the basis of various productivity parameters. Significant differences among the inoculants were observed for stalk length, stalk diameter and Brix. Significant interactions between the families and bacteria occurred with respect to stalk diameter and Brix; the interaction coefficients could have either positive (0.7272 for Brix and 0.4061 for stalk diameter) or negative (-0.5514 for Brix and -0.1858 for stalk diameter) values, depending on the family and the inoculant that were considered. Therefore, the inoculation of the seedling in the first phase of selection is recommended for a sugarcane breeding program that seeks to select genotypes with better responses to PGPR inoculation.
溶磷菌和固氮菌溶解磷矿粉时的互作效应
冯瑞章?,姚拓?,周万海?,龙瑞军?,齐文娟?
生态学报 , 2006,
Abstract: 采用4株溶磷菌(lx81、dm84、?jm92、lx191)、和3株固氮菌(chw5、chw6、cho6)单独和混合接种后测定培养液有效磷含量、ph值及总有机酸含量的方法,研究溶磷菌和固氮菌溶解磷矿粉时的互作效应。结果表明,相对于单独接种溶磷菌:lx81与3株固氮菌分别混合培养能提高磷矿粉的溶解能力,4株溶磷菌与?chw6,lx81、dm84、lx191与cho6分别混合培养及jm92+chw5组合溶磷量极显著增加(p<0.01);dm84+chw5、lx191+chw5、jm92+cho6组合的溶磷量下降(p<0.01)。除lx81+chw6、lx81+cho6培养液ph值降低外,混合培养的其它组合培养液ph值均较单独接种溶磷菌时升高。有机酸测定结果表明,?lx81、jm92与chw5、cho6分别混合培养、chw6+lx81组合有机酸含量升高(p<0.01),其它7种组合的有机酸含量均较单独接种溶磷菌的值下降(p<0.01)。溶磷菌和固氮菌单菌培养时溶磷量与ph值、溶磷量与总有机酸含量及ph值与总有机酸含量之间呈现线性相关;dm84、lx191与3株固氮菌分别混合培养溶磷量与ph值之间、lx81与3株固氮菌分别混合培养溶磷量与总有机酸含量之间呈现线性相关,其它组合的溶磷量与ph值、总有机酸含量间没有相关性。溶磷菌和固氮菌混合培养对溶解磷矿粉既有协同作用也有拮抗作用。
Distribución de bacterias potencialmente fijadoras de nitrógeno y su relación con parámetros fisicoquímicos en suelos con tres coberturas vegetales en el sur de la Amazonia colombiana
Mantilla-Paredes,Andrea J; Cardona,Gladys. I; Pe?a-Venegas,Clara P; Murcia,Uriel; Rodríguez,Mariana; Zambrano,Maria M;
Revista de Biología Tropical , 2009,
Abstract: distribution of potentially nitrogen-fixing bacteria and its relationship with physicochemical parameters in soils with three vegetation types in the southern colombian amazon region. potentially nitrogen-fixing microaerobic and aerobic bacteria were isolated from several colombian amazon soils (forest, pastures and chagras) and two landscapes (floodable and non floodable areas). the abundance and distribution of bacteria were evaluated, as well as their relationship with soil physical and chemical characteristics. landscape had a direct influence on the abundance of the microaerobic bacteria, with higher numbers in forest and pasture soils in non- floodable zones. the aerobic isolates (n=51) were grouped into 19 morphologies, with the highest numbers found in forest soil in floodable zones. a higher number of aerobic morphologies was shared among forest sites (nonmetric multidimensional scaling and analysis of similarity p<0.05), and 40% of the distribution was explained by lime percentage and al concentration. rev. biol. trop. 57 (4): 915- 927. epub 2009 december 01.
Nitrogen fixation of termite and bacteria isolated from its hindgut
白蚁及其肠道细菌的固氮作用研究

梅建凤,吕琴,闵航,陈玉成
浙江大学学报(农业与生命科学版) , 2002,
Abstract: 台湾家白蚁(CoptotermesformosanusShiraki)工蚁具有较高的固氮活性,刚收集的工蚁其固氮活性达0.0944μg/g.h-1.固氮活性的高低受白蚁食物含氮量、白蚁生理状态的影响,某些杀菌剂能使白蚁固氮活性丧失.从台湾家白蚁肠道中分离到2株兼性厌氧固氮菌HN1和YN菌株,经鉴定皆为柠檬酸菌属的菌株(Citrobactersp.),均在厌氧条件下表现固氮活性.最大或然数法计数表明,每只白蚁肠道固氮菌数量约为7500个.
Studies on the interactions between phosphate-solubilizing bacteria and nitrogen-fixing bacteria in rock phosphate solubilization
溶磷菌和固氮菌溶解磷矿粉时的互作效应

FENG Rui-Zang,YAO Tuo,ZHOU Wan-Hai,LONG Rui-Jn,QI Wen-Jan,
冯瑞章
,姚拓,周万海,龙瑞军,齐文娟

生态学报 , 2006,
Abstract: 采用4株溶磷菌(Lx81、Dm84、Jm92、Lx191)、和3株固氮菌(ChW5、ChW6、ChO6)单独和混合接种后测定培养液有效磷含量、pH值及总有机酸含量的方法,研究溶磷菌和固氮菌溶解磷矿粉时的互作效应。结果表明,相对于单独接种溶磷菌:Lx81与3株固氮菌分别混合培养能提高磷矿粉的溶解能力,4株溶磷菌与ChW6,Lx81、Dm84、Lx191与Ch06分别混合培养及Jm92+ChW5组合溶磷量极显著增加(P〈0.01);Dm84+ChW5、Lxl91+ChW5、Jm92+Ch06组合的溶磷量下降(P〈0.01)。除Lx81+ChW6、Lx81+Ch06培养液pH值降低外,混合培养的其它组合培养液pH值均较单独接种溶磷菌时升高。有机酸测定结果表明,Lx81、Jm92与ChW5、Ch06分别混合培养、ChW6+Lx81组合有机酸含量升高(P〈0.01),其它7种组合的有机酸含量均较单独接种溶磷菌的值下降(P〈0.01)。溶磷菌和固氮菌单菌培养时溶磷量与pH值、溶磷量与总有机酸含量及pH值与总有机酸含量之间呈现线性相关;Dm84、Lx191与3株固氮菌分别混合培养溶磷量与pH值之间、Lx81与3株固氮菌分别混合培养溶磷量与总有机酸含量之间呈现线性相关,其它组合的溶磷量与pH值、总有机酸含量间没有相关性。溶磷菌和固氮菌混合培养对溶解磷矿粉既有协同作用也有拮抗作用。
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