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The use of microorganisms aiming to improve the availability of nutrients for plants is an important and necessary practice for agriculture. Thus, studies on the AMF occurrence in the brazilian northeastern and efficiency tests using native plants in the region have been intensified on recent decades. Aiming to determine the most probable number (MPN) of infective propagules in the area with native vegetation on the semi-arid region of Pernambuco, municipality of Sertânia, quantify the soil protein related to easily extractable glomalin (SPREEG) and to total glomalin (SPRTG), experiments were conducted in a greenhouse. For this study 10 composite soil samples were collected, with points randomly defined. Samples were homogenized and analyzed for physical and chemical characteristics. Being used for immediate examination and preparation trap cultures (one three-month cycle of propagation) to AMF, using as host plants sorghum (Sorghum bicolor L. Moench), and peanut (Arachis hypogaea L.). To determine the MPN of infective propagules of AMF in Haplic Luvisols, soil inoculum samples were diluted in the proportions of 0, 1:10, 1:100 and 1:1000 (soil inoculum: diluent soil, v:v) with 5 repetitions each, using maize (Zea mays L.) as host plant. The direct count (DC) differed significantly from the indirect (IC) of AMF with averages of 961.3 and 517.4 glomerospores per 100g soil, respectively. The NMP of infective propagules of AMF propagules found was 23 cm-3 and SPREEG and SPRTG were approximately 0.46 and 0.26 mg glomalin g-1 aggregate, respectively.

Foi determinada a ocorrência de espécies de fungos micorrízicos arbusculares (FMA) em áreas nativa (AN) e impactada (AI) pela mineração de gesso em Araripina, PE, Brasil, utilizando como culturas-armadilha: sorgo e amendoim. Os esporos de FMA foram caracterizados morfologicamente para identificação ao nível de espécie. DNA foi extraído de esporos para caracterização molecular a partir de sequencias da região ITS. No estudo molecular foram identificados três gêneros e quatro espécies (Funneliformis mosseae, Glomus sp., Glomus hoi, Claroideoglomus claroideum), que mostram capacidade para tolerar as condições de estresse da área minerada. Trabalhos em campo devem ser realizados para compreender melhor a dinâmica e funcionalidade dessas espécies de FMA que poderiam ser selecionadas para uso em programas de manejo, na recuperação de áreas similares.

http://dx.doi.org/10.5902/198050989277Sabia (Mimosa caesalpiniaefolia Benth.) has ecological characteristics and symbiotic associations with nitrogen fixing bacteria and arbuscular mycorrhizal fungi. These associations are used as biological tool that could be used as an able alternative to minimize chemical fertilizer use and benefit plant development at environments under nutritional deficit. The objective of this study was to evaluate the growth of Leguminosae Sabia (Mimosa caesalpiniaefolia Benth.) like response to rhizobium and arbuscular mycorrhizal fungi inoculation, to establish growth curves to height and stem based diameter, to determine the N and F contents in plants aerial parts and to evaluate plants survival at field. The strain used was BR3405, The arbuscular mycorrhizal fungi used was Glomus clarum and Gigaspora margarita. The Glomus clarum + Gigaspora margarita + BR3405 and Gigaspora margarita inoculation provided better values for the studied variables (height, diameter, N and P) , and this last one was the best choice to Sabia plantation. The plants showed 100% survival, regardless the treatment ued. There was not significant statistical difference for N and F content in Sabia aerial part., Nevertheless, it was noticed a faster growth in plants with symbiont.

Sabia (Mimosa caesalpiniaefolia Benth.) has ecological characteristics and symbiotic associations with nitrogen fixing bacteria and arbuscular mycorrhizal fungi. These associations are used as biological tool that could be used as an able alternative to minimize chemical fertilizer use and benefit plant development at environments under nutritional deficit. The objective of this study was to evaluate the growth of Leguminosae Sabia (Mimosa caesalpiniaefolia Benth.) like response to rhizobia and arbuscular mycorrhizal fungi inoculation, to establish growth curves to height and stem based diameter, to determine the N and F contents in plants aerial parts and to evaluate plants survival at field. The strain used was BR3405, The arbuscular mycorrhizal fungi used was Glomus clarum and Gigaspora margarita. The Glomus clarum + Gigaspora margarita + BR3405 and Gigaspora margarita inoculation provided better values for the studied variables (height, diameter, N and P) , and this last one was the best choice to Sabia plantation. The plants showed 100 % survival, regardless the treatment ued. There was not significant statistical difference for N and F content in Sabia aerial part., Nevertheless, it was noticed a faster growth in plants with symbiont.

O objetivo deste trabalho foi verificar a influência de diferentes plantas hospedeiras e de ciclos de multiplicação em potes de cultura sobre a detecção e avaliação da diversidade de fungos micorrízicos arbusculares (FMA) no semiárido, em áreas de caatinga preservadas e impactadas por mineração de gesso no semiárido (Araripina, PE). Foram selecionadas quatro áreas de coleta: AN - caatinga nativa preservada, AM - arredores da mina, AR-rejeito e AI - interface entre o depósito de rejeito e uma área de caatinga degradada pela mineração, todas com solo do tipo Latossolo Amarelo, variando de franco-arenoso a argiloso, com pH de 5,7 a 7,5; 8 a 161 mg.dm-3 P e 0,23 a 79,8 mg.dm-3 Fe. Amostras foram retiradas desses solos para exame imediato e preparo de culturas-armadilha para FMA, utilizando-se como plantas hospedeiras amendoim (Arachis hypogaea L.) e sorgo granífero (Sorghum bicolor (L.) Moench) cultivar IPA-7301011. Logo após a coleta e depois de cada ciclo de multiplicação na cultura-armadilha (três ciclos de três meses cada), foram avaliados em amostras de raízes e de solo rizosférico: colonização radicular, número de esporos, diversidade e similaridade de espécies de FMAs entre as áreas. As plantas de amendoim apresentaram valores mais altos de colonização radicular (76,5 a 99,5%) que as de sorgo (21% a 73%). Maior produção de esporos ocorreu no 2º e no 3º ciclo de culturas-armadilha. Foram identificadas 25 espécies de FMAs nas áreas estudadas, onde se destacaram Glomus intraradices Schenck & Smith, Glomus mosseae Gerdemann & Trappe e Paraglomus occultum Morton & Redecker, pela alta densidade de esporos produzidos. As áreas apresentaram índice de similaridade de espécies de FMAs variando de 40 a 67%, com os maiores índices entre as áreas impactadas.The objective of this report was to verify the influence of host plants and successive multiplication cycles on pot cultures for detection of the diversity of arbuscular mycorrhizal fungi (AMF) in the semiarid, in area with native, preserved "caatinga" and areas impacted by gypsum mining in Araripina, PE. Four areas were selected: AN - "caatinga" native, preserved caatinga; AM - surroundings of the mine; AR - waste and AI - interface between the waste deposit area and an area degraded by mining, all of them with Yellow Latosol, varying from franc sandy to clay, with pH 5.7 to 7.5; 8 to 161 mg.dm-3 P and 0.23 to 79.8 mg.dm-3 Fe. Soil samples were taken for exam and preparation of AMF trap cultures, using peanut (Arachis hypogaea L.) and sorghum (Sorghum bicolor (L.) Moench cv IPA-7301011) as hosts. Soon after the collection and after each multiplication cycle in trap cultures (3 cycles/3 months each), root colonization, spore number, diversity and similarity of species were evaluated in soil and root samples. The peanut plants presented higher values of root colonization (76.5 to 99.5%) than those of sorghum (21% to 73%). Higher spore production occurred in the second and third multiplication cycles. Twenty-five AMF species were identified in the areas, with Glomus intraradices Schenck & Smith, Glomus mosseae Gerdemann & Trappe, and Paraglomus occultum Morton & Redecker producing higher spore density than the other species identified. The index of similarity of AMF species varied from 40 to 67%, with the highest values found in the impacted areas.

The evaluation of native rhizobia strains potential as related to efficiency, competitiveness, and adaptation in regions subjected to high temperature is important to the study of nitrogen symbiotic fixation. The objective of this research was the morphologic characterization of rhizobia isolated from samples of a red yellow argisol of Serra Talhada municipality, Pernambuco State, Brazil, and selection for high temperature and kanamicina and nalidixic acid antibiotics resistance. The study was carried out at Institute of Agricultural Research of Pernambuco (IPA). The isolates were cultivated in YMA media to evaluate colonie characteristics as acidity or alkalinity production, growing velocity, color, shape and transparency, elevation, and mucus production. All isolates were compared to the standard strain Bradyrhizobium sp. 6145, recommended for cowpea. The morphological and physiological diversity of the isolates enabled the identification of distinct groups. The isolates 1, 2 and 4 presented higher resistance to high temperature and adaptation to survive in regions subjected to thermal stress periods. The isolate 1 showed the highest resistance to tested antibiotics. KEY-WORDS: Rhizobia; morphologic characteristics; high temperature. A avaliação do potencial de estirpes nativas de rizóbio em relação à eficiência, competitividade e adaptação às regiões sujeitas à alta temperatura é importante no estudo da fixação simbiótica de nitrogênio. O objetivo do trabalho foi efetuar a caracterização morfológica de isolados de rizóbios a partir de amostras de um argissolo vermelho amarelo do Município de Serra Talhada (PE), e selecioná-los quanto a resistente a alta temperatura e aos antibióticos kanamicina e ácido nalidíxico. O estudo foi conduzido na Empresa Pernambucana de Pesquisa Agropecuária (IPA) Os isolados foram crescidos em meio YMA e obsevado: formação de álcali e ácido, tempo de crescimento, cor, transparência, elevação, forma e produção de muco. Todos os isolados foram comparados à estirpe padrão Bradyrhizobium sp. 6145, recomendada para o caupi. A diversidade morfológica e fisiológica dos isolados permitiu a obtenção de diferentes grupos. Os isolados 1, 2 e 4 apresentaram maior resistência à temperatura elevada mostrando-se mais adaptados a sobreviver em regiões sujeitas a períodos de estresse térmico. O isolado 1 obteve maior resistência aos antibióticos testados. PALAVRAS-CHAVE: Rizóbio; características morfológicas; alta.

O objetivo deste estudo foi verificar a viabilidade da co-inoculação de sementes de caupi (Vigna unguiculata (L.) Walp.) com bactérias fixadoras de nitrogênio dos gêneros Bradyrhizobium sp. (BR-2001 e NFB-700) e Paenibacillus polymyxa [(Loutit (L.)]e sua eficiência na absorção de cálcio, ferro e fósforo pelas plantas de caupi, sob diferentes métodos de inoculação. Foi utilizado um Argissolo Amarelo coletado em fevereiro de 2002, localizado a BR 101 Norte, km 53, latitude 07º34'00'', longitude 35º00'00'' e altitude 14m, em Itapirema (Goiana, Estado de Pernambuco). As inoculações foram efetuadas na semente e no solo a uma profundidade de 3,5 cm, usando-se a cultivar IPA-205. Foram determinadas as concentrações de cálcio, ferro e fósforo na matéria seca da parte aérea das plantas de caupi. A co-inoculação do caupi com as estirpes de Bradyrhizobium sp. introduzidas no solo proporciona aumentos nas concentrações de cálcio, ferro e fósforo. PALAVRAS-CHAVE: Co-infecção; cálcio; ferro; fósforo; Vigna unguiculata. The objective of this study was to verify the viability of the co-inoculation of caupi seeds (Vigna unguiculata (L.) Walp.) with nitrogen fixing bacteria of Bradyrhizobium sp. (BR-2001 and NFB-700) and Paenibacillus polymyxa [(Loutit (L.)] strains and their efficiency in calcium, iron, and phosphorus absorption by caupi plants under different inoculation methods. A Yellow Argisol was collected in February, 2002, located at the km 53 of BR 101 North highway, latitude 07ºSouth34'00'', longitude 35ºWest00'00'' and altitude 14m, in Itapirema (Goiana, Pernambuco State, Brazil). The inoculations were made in seeds and soil to a depth of 3.5 cm using IPA-205 cultivar. The variables evaluated were calcium, iron, and phosphorus concentration in the aerial part dry matter. The co-inoculation of caupi with strains of Bradyrhizobium sp. introduced in the soil provided calcium, iron, and phosphorus concentration increase. KEY-WORDS: Co-infection; calcium; iron; phosphorus; Vigna unguiculata.

A ocorrência de fungos micorrízicos arbusculares (FMAs) foi investigada em áreas cultivadas com leucena (Leucaena leucocephala L.) e sabiá (Mimosa caesalpiniaefolia Benth), no Estado de Pernambuco. Amostras de solo foram coletadas em cinco estações experimentais da Empresa Pernambucana de Pesquisa Agropecuária (IPA), nas cidades de Arcoverde, com plantio de leucena (AL) e sabiá (AS); Caruaru, com plantio de leucena (CL); e Itambé (IS), São Bento do Una (SBS) e Serra Talhada (STS), com plantio de sabiá. O número de esporos variou de 69 (STS) a 437/50 g de solo (CL) e a colonização micorrízica, de 11 (CL) a 64% (IS). Nas áreas com plantio de leucena, a colonização foi inferior a 15%, enquanto naquelas com cultivo de sábia houve variação de 36 a 64%. Foram observadas 24 espécies de FMAs, pertencentes aos gêneros: Acaulospora (6), Archaeospora (1), Entrophospora (1), Gigaspora (3), Glomus (6), Paraglomus (1) e Scutellospora (6). As áreas CL e STS foram as que apresentaram maior número de espécies (14). Acaulospora scrobiculata, Archaeospora leptoticha e Glomus etunicatum foram encontradas em todas as áreas.The occurrence of arbuscular mycorrhizal fungi (AMF) in plantations of Leucaena leucocephala L. (leucaena) and Mimosa caesalpiniaefolia Benth (sabia) in the State of Pernambuco was investigated. Soil samples were collected in five research centers of the Agricultural Research Institute of Pernambuco (IPA), in the cities of Arcoverde - plantation of leucaena (AL) and sabiá (AS); Caruaru (CL) - leucaena plantation; Itambé (IS), São Bento do Una (SBS) and Serra Talhada (STS) - plantation of sabiá. Mycorrhizal spores were extracted from soil, with the highest number (437/50g of soil) being found in the CL region and the lowest (69/50g of soil) in the STS region. The mycorrhizal colonization ranged from 11% (CL) to 64% (IS). The colonization was inferior to 15% in areas of leucaena plantation, however, in areas of sabiá, it ranged from 36% to 64%. Twenty-four AMF species were identified in the genus: Acaulospora (6), Archaeospora (1), Entrophospora (1), Gigaspora (3), Glomus (6), Paraglomus (1) and Scutellospora (6). The highest species number was recorded in the CL and STS regions (14). Acaulospora scrobiculata, Archaeospora leptoticha and Glomus etunicatum were found in all regions.

A eficiência das estirpes de Bradyrhizobium com características Hup+ (SR e USDA-110), Hup- (29W) e Hup hr (SEMIA-587) foi avaliada em caupi (Vigna unguiculata L.), cultivares IPA-202, BR-3 e VITA-4. Os resultados mostraram que VITA-4, em relação à nodulação, revelou-se superior às demais, e apresentou interação efetiva com as estirpes SEMIA-587 e USDA-110. Entretanto, quanto à eficiência nodular, a combinação IPA-202 x SEMIA-587 alcançou maior atividade da nitrogenase (ARA) com eficiência relativa próxima a 1,0. A ARA detectada nas estirpes SR e SEMIA-587 foi similar, porém, superior às estirpes USDA-110 e 29W, evidenciando que as estirpes Hup+ e Hup hr alcançaram maiores atividades enzimáticas. Os teores de leghemoglobina (Lb) detectados nas estirpes SR e USDA-110 foram positivamente relacionados com as respectivas ARA, contudo, a relação entre teor de Lb e ARA obtido para 29W-Hup- foi variável, sugerindo que, na ausência da hidrogenase, o sistema da nitrogenase fica afetado podendo influir no fluxo de Lb ao bacteróide. A avaliação do teor de N mostrou que não houve diferença entre cultivares, entretanto, foi detectada diferença significativa entre as estirpes. As estirpes Hup+ obtiveram maiores acúmulos de N, evidenciando que os sistemas simbióticos que menos liberam H2, acumulam mais N no hospedeiro.The effectiveness of Bradyrhizobium strains with characteristics Hup+ (SR and USDA-110), Hup- (29W) and Hup hr (SEMIA-587), was evaluated in cowpea (Vigna unguiculata L.), cultivars IPA-202, BR-3 and VITA-4. Results showed that nodulation in VITA-4 was superior, with a positive interaction when inoculated with strains SEMIA-587 and USDA-110. However, when comparing nodule efficiency, the combination IPA-202 x SEMIA-587 presented the highest nitrogenase activity, with a relative efficiency around 1.0. Nitrogenase activities were similar in plants inoculated with the strains SR and SEMIA-587, and higher, with strains USDA-110 and 29W. These results indicate that strains with Hup+ and Hup hr were able to achieve higher enzymatic activities. Leghemoglobin (Lb) content detected in strains SR and USDA-110 was positively correlated to nitrogenase activity. However, correlations between Lb and nitrogenase activity were highly variable in nodules containing strain 29W-Hup-, indicating that imbalances in the nitrogenase system in the absence of hydrogenase may affect the flow of Lb to the bacteroids. Significant differences on the plant N content were found among the strains studied, but not among cultivars. Plant inoculated with Hup+ strains were more efficient to accumulate N, indicating that N-fixing systems retaining H2 may accumulate additional N in the host.

Foi determinada a ocorrência de espécies de fungos micorrízicos arbusculares (FMA) em áreas nativa (AN) e impactada (AI) pela mineração de gesso em Araripina, PE, Brasil, utilizando como culturas-armadilha: sorgo e amendoim. Os esporos de FMA foram caracterizados morfologicamente para identificação ao nível de espécie. DNA foi extraído de esporos para caracterização molecular a partir de sequencias da região ITS. No estudo molecular foram identificados três gêneros e quatro espécies (Funneliformis mosseae, Glomus sp., Glomus hoi, Claroideoglomus claroideum), que mostram capacidade para tolerar as condições de estresse da área minerada. Trabalhos em campo devem ser realizados para compreender melhor a dinâmica e funcionalidade dessas espécies de FMA que poderiam ser selecionadas para uso em programas de manejo, na recuperação de áreas similares.

This paper evaluates the possible use of liquid preservation methods for rhizobia long term conservation under ambient temperature conditions. Saline solution (sterile distilled water + NaCl), glycerol and carboxymethycellulose (CMC) were evaluated for preservation of Rhizobium tropici and Bradyrhizobium japonicum cultures up to 180 days and regarding their capacity to promote common bean (Phaseolus vulgaris [L.]) and soybean (Glycine max [L.]) nodulation. The total population was determined after 0; 1; 7; 15; 21; 30; 60; 90; 120; 150 and 180 days of conservation and conserved bacteria were evaluated for symbiotic characteristics after 15, 60 and 120 days of conservation. Although there were significant species x conservation method interactions, both saline solution and CMC may be used for short storage terms, allowing the production of inoculant for field experiments, and its test for purity and concentration before field establishment. The utilized techniques have low cost and easier usage as inoculants, compared to the traditional turf-based products, and if determined feasible by further research it could be a low cost addition to the standard microbiological techniques, particularly as working culture preservation media.

ABSTRACT: This study evaluated the activity of rhizobia isolates inoculated in large (18 mm) and small (11 mm) seeds on lima bean growth, nodulation and N fixation. Selected rhizobia isolates were compared with a reference strain CIAT899 and two controls without inoculation. Large seeds contributed for highest plant growth, nodulation and N fixation than small seeds. The isolates UFPI-59, UFPI-18 and UFPI-38 promoted the highest values of shoot and root dry weight, respectively. The isolates UFPI-32 promoted the highest values of nodule number, while UFPI-59 promoted the highest values of nodule dry weight. The isolates UFPI-38 and UFPI-59 promoted the highest accumulation of N. This study showed that seed size really influences lima bean growth, nodulation and BNF. Considering rhizobia isolates, UFPI-59, UFPI-38, and UFPI-18 contributed for plant growth, promoted better nodulation and effectiveness on biological N fixation.

ABSTRACT: This study evaluated the responses of lima bean (Phaseolus lunatus L.) to application of composted tannery sludge on nodulation, N uptake and plant growth. For eight years, the compost was applied at rates of: 0, 2.5, 5, 10, and 20 Mg ha-1 (dry basis). Plants of lima bean showed higher nodulation in treatments with compost; however, nodules reported in these treatments presented lower biomass, size and diversity than those reported in treatment without compost. Accumulation of N increased with the application of the highest rate (20 Mg ha-1), while there was an increase in chromium content in shoot with the increase in compost rates. Thus, the use of composted tannery sludge, in long-term, increases the accumulation of chromium in plants, increasing nodulation, while decrease rhizobia diversity in nodules.

Plant growth-promoting bacteria (PGPB) are found in plant tissues and promote plant growth by secretion of hormones and enzymes, or by facilitating the nutrient uptake. This study assessed forty PGPB isolates to determine their effects on maize and sorghum growth. These isolates were also compared with uninoculated plants, as negative (-N; without N fertilization) and positive (+N; with N fertilization) controls. Plant height, stem diameter, shoot and root dry mass, leaf N accumulation and chlorophyll content were evaluated. For both the maize and sorghum, the height, stem diameter and shoot dry mass in plants inoculated with PGPB were similar to those of uninoculated plants supplied with N, and the responses for root mass were higher than in plants supplied with N. However, the PGPB isolates did not promote N accumulation and chlorophyll content similar to those of uninoculated plants supplied with N. The IPACC26 and IPACC30 isolates, both identified as Bacillus subtilis, resulted in better responses for plant growth and N accumulation than the other isolates.

O objetivo deste trabalho foi avaliar o efeito da inoculação com Azospirillum brasilense e adubação nitrogenada sobre a produtividade do milho verde. O estudo foi conduzido no município de Teresina, PI, em 2011 e 2012, e os tratamentos foram dispostos em delineamento de blocos ao acaso sob arranjo fatorial de 5x2, sendo cinco doses de nitrogênio (N) (0, 50, 100, 150 e 200 kg N ha-1) com e sem inoculação. No tratamento com inoculação, foi utilizado um produto formulado contendo A. brasilense, estirpes Abv5 e Abv6. Houve aumento significativo no número e na massa das espigas comerciais com a inoculação de A. brasilense em relação ao tratamento sem inoculação. A combinação de inoculação com A. brasilence e nitrogênio aumenta em mais de 30% a produção de espigas de milho verde.