Oxidizable organic carbon fractions in soils under leguminous nitrogen-fixing trees in a degraded pasture / Frações oxidáveis do carbono em solos sob leguminosas florestais fixadoras de nitrogênio em pastagens degradadas

The chemical fractionation of C by an increasing oxidation gradient, has shown to be a fast and promising methodology to detect changes in C lability. The objectives of the present study presents were: to evaluate the level of lability of soil organic C after conversion of degraded pasture into leguminous trees; evaluate the influence of soil depth on the lability of soil organic C. The experimental area consisted of pure plantations of Acacia auriculiformis, Mimosa caesalpiniifolia and Inga sp., a pasture and a secondary forest. The oxidizable organic carbon was determined by wet oxidation and allowed separation of four fractions according to the lability level (labile, moderately labile, moderately recalcitrant, recalcitrant). Labile fraction was the predominant fraction in all vegetation covers and depths. The conversion of degraded pasture into forest legume plantations and the soil depth promoted changes in the chemical composition of C. The continuous deposition of vegetable residues 13 years of leguminous trees favored the distribution of labile and moderately labile fractions along the soil profile and the recalcitrant fraction in the topsoil. The reference covers contributed to the recalcitrant fraction in the soil below 20 cm depth.

O fracionamento químico de carbono (C) por um gradiente crescente de oxidação, tem se mostrado uma metodologia rápida e promissora para detectar alterações na labilidade de C. Os objetivos do presente estudo foram: avaliar o nível de labilidade do C orgânico do solo após a conversão de pastagens degradadas em leguminosas; avaliar a influência da profundidade do solo na labilidade do C orgânico do solo. A área experimental consistiu em plantios puros de Acacia auriculiformis, Mimosa caesalpiniifolia e Inga sp., uma pastagem e uma mata secundária. O carbono orgânico oxidável foi determinado por oxidação úmida e permitiu a separação de quatro frações de acordo com o nível de labilidade (lábil, moderadamente lábil, moderadamente recalcitrante, recalcitrante). A fração lábil foi a fração predominante em todas as coberturas vegetais e profundidades. A conversão de pastagens degradadas em leguminosas florestais e a profundidade do solo promoveram mudanças na composição química do C. A deposição contínua de resíduos vegetais por 13 anos de leguminosas favoreceu a distribuição das frações lábil e moderadamente lábil ao longo do perfil do solo e da fração recalcitrante na camada superficial do solo. As coberturas de referência contribuíram para a fração recalcitrante no solo abaixo de 20 cm de profundidade.

Genetic and symbiotic characterization of rhizobia nodulating legumes in a mining area in southeast Brazil

ABSTRACT: Identification and selection of nitrogen-fixing bacterial strains for inoculation into native leguminous tree species can assist in the recovery of degraded areas. Additionally, native strains from these areas are genetic resources adapted to these conditions and are thus suitable for selection. The aim of this study was to symbiotically and genetically characterize 18 bacterial strains from the Rhizobium and Bradyrhizobium genera isolated from Machaerium nyctitans, Platypodium elegans, and Ormosia arborea grown in a nursery in an iron mining area. Three experiments were conducted under axenic conditions in a greenhouse. The nodulation capacity of the strains was evaluated by the number (NN) and dry matter (NDM) of nodules. Symbiotic efficiency was evaluated based on the following parameters: SPAD index (SPAD), shoot dry matter (SDM), root dry matter (RDM), and total dry matter (TDM) of the plants, relative efficiency (RE), shoot nitrogen content (SNC), and total nitrogen content in the plant (TNC). The atpD and gyrB housekeeping genes and the nifH gene were sequenced for phylogenetic analysis, and the nodC and nodD symbiotic genes of the strains were amplified. Out of the 18 strains, 16 were authenticated by nodulation capacity in the species of origin. The SPAD variable allowed for the detection of differences between treatments before the SDM. Additionally, the SPAD index showed correlation with TNC, and the strain Bradyrhizobium sp., UFLA01-839, which may represent a new species, was outstanding in Machaerium nyctitans. The nifH, nodD, and nodC genes were detected in UFLA01-839.

Genetic and symbiotic characterization of rhizobia nodulating legumes in a mining area in southeast Brazil

Identification and selection of nitrogen-fixing bacterial strains for inoculation into native leguminous tree species can assist in the recovery of degraded areas. Additionally, native strains from these areas are genetic resources adapted to these conditions and are thus suitable for selection. The aim of this study was to symbiotically and genetically characterize 18 bacterial strains from the Rhizobium and Bradyrhizobium genera isolated from Machaerium nyctitans, Platypodium elegans, and Ormosia arborea grown in a nursery in an iron mining area. Three experiments were conducted under axenic conditions in a greenhouse. The nodulation capacity of the strains was evaluated by the number (NN) and dry matter (NDM) of nodules. Symbiotic efficiency was evaluated based on the following parameters: SPAD index (SPAD), shoot dry matter (SDM), root dry matter (RDM), and total dry matter (TDM) of the plants, relative efficiency (RE), shoot nitrogen content (SNC), and total nitrogen content in the plant (TNC). The atpD and gyrB housekeeping genes and the nifH gene were sequenced for phylogenetic analysis, and the nodC and nodD symbiotic genes of the strains were amplified. Out of the 18 strains, 16 were authenticated by nodulation capacity in the species of origin. The SPAD variable allowed for the detection of differences between treatments before the SDM. Additionally, the SPAD index showed correlation with TNC, and the strain Bradyrhizobium sp., UFLA01-839, which may represent a new species, was outstanding in Machaerium nyctitans. The nifH, nodD, and nodC genes were detected in UFLA01-839.

Genetic and symbiotic characterization of rhizobia nodulating legumes in a mining area in southeast Brazil

Identification and selection of nitrogen-fixing bacterial strains for inoculation into native leguminous tree species can assist in the recovery of degraded areas. Additionally, native strains from these areas are genetic resources adapted to these conditions and are thus suitable for selection. The aim of this study was to symbiotically and genetically characterize 18 bacterial strains from the Rhizobium and Bradyrhizobium genera isolated from Machaerium nyctitans, Platypodium elegans, and Ormosia arborea grown in a nursery in an iron mining area. Three experiments were conducted under axenic conditions in a greenhouse. The nodulation capacity of the strains was evaluated by the number (NN) and dry matter (NDM) of nodules. Symbiotic efficiency was evaluated based on the following parameters: SPAD index (SPAD), shoot dry matter (SDM), root dry matter (RDM), and total dry matter (TDM) of the plants, relative efficiency (RE), shoot nitrogen content (SNC), and total nitrogen content in the plant (TNC). The atpD and gyrB housekeeping genes and the nifH gene were sequenced for phylogenetic analysis, and the nodC and nodD symbiotic genes of the strains were amplified. Out of the 18 strains, 16 were authenticated by nodulation capacity in the species of origin. The SPAD variable allowed for the detection of differences between treatments before the SDM. Additionally, the SPAD index showed correlation with TNC, and the strain Bradyrhizobium sp., UFLA01-839, which may represent a new species, was outstanding in Machaerium nyctitans. The nifH, nodD, and nodC genes were detected in UFLA01-839.

The use of rhizobium and mycorrhizae in soil containing rhizobiophage to improve growth and nodulation of cowpea

The interaction between leguminous plants and rhizosphere microorganisms is essential because it can either enhance or inhibit the beneficial effects of individual species. Phages are one of the biotic factors with a negative impact on the beneficial bacteria in soil rhizosphere. In the current study, phage showed lytic activity against Bradyrhizobium sp. Vigna (tal16) with an icosahedral head at a 43.44 nm diameter and a long non-contractile tail, measuring 99.85 nm. This phage belongs to the Siphoviridae family, found in the Met El-Ez area of Dakalia Governorate in Egypt. The results revealed that the presence of phage in soil affected nodulation and growth parameters. Mycorrhizal inoculation aggravated the negative effects of this phage. Cowpea grown in soil containing phage VB_BrV_SD4 showed a reduction in the nodule number, nitrogenase activity, and total N of 40-50 %; however, mycorrhizal inoculation augmented this negative effect with a reduction percentage to 20-28 %. Mycorrhizal inoculation also improved total chlorophyll, carotenoids, legume amount, and the seed protein content.

Germination, wettability, and imbibition of dormant seeds of Desmanthus virgatus after low-pressure plasma treatment / Germinação, molhabilidade e embebição de sementes de (Desmanthus virgatus (L. ) Willd. ) após tratamento a plasma baixa pressão

The use of an alternative technique to increase the germination of an legume species used in animal feed was investigated based on the effects of low-pressure plasma on the wettability, imbibition, and germination of seeds of Desmanthus virgatus. A conventional nitriding reactor with an argon atmosphere (Ar) and controlled temperature at 30º C was used to apply three different exposure times: 1, 3, and 5 minutes, with a set of intact seeds considered as the control. The experimental design was completely randomized, and the means were compared by the Tukey test at 5% probability to analyze the different experimental conditions tested. The statistical analyses were performed with the software Origin 8.0. The apparent contact angle indicated an increase in the wettable surface with the treatment time, verifying the hydrophilic character of the plasma on the seed. Seeds treated for 3 and 5 minutes showed higher germination than the 1-minute treatment and untreated seeds. In the imbibition test, the leached solution showed lower conductivity in the treated samples than in the untreated sample, indicating less nutrient loss to the solution. The pH remained within the neutral range among the treated samples. The superficial changes in the seeds caused significant gains in the germination parameters, promoting improvement in the indices and rate of germination and contributing to the uniformity of the seed lot with the use of low-pressure plasma as a tool for breaking dormancy.(AU)

Foi investigado o uso de técnica alternativa com fins ao aumento da germinação de uma espécie de leguminosa empregada na alimentação animal, a partir dos efeitos do plasma em baixa pressão na molhabilidade, embebição e germinação de Desmanthus virgatus. Utilizou-se reator de nitretação convencional com atmosfera de argônio (Ar) e temperatura controlada em 30º C sob tratamento de três diferentes tempos de exposição 1, 3 e 5 minutos, considerou-se conjunto de sementes intac-tas como controle. O delineamento utilizado foi inteiramente casualizado, os resultados submetidos ao teste de Tukey à 5% para análise das médias entre as condições experimentais testadas, as análises estatísticas foram realizadas no programa Origin 8.0. O ângulo de contato aparente indicou aumento da superfície molhável com o tempo de tratamento comprovando cará-ter hidrofílico do plasma na semente. Sementes tratadas por 3 e 5 minutos apresentaram germinação superior ao tratamento por 1 minuto e em relação as sementes sem tratamento. A solução lixiviada, no teste de embebição apresentou condutividade das amostras tratadas menor que a amostra sem tratamento, indicando menor perda de nutrientes para a solução. O pH per-maneceu-se dentro da faixa de neutralidade para as amostras tratadas. As modificações superficiais nas sementes ocasionaram ganhos significativos nos parâmetros germinativos, promovendo melhoria nos índices e percentagem de germinação, e contri-buindo na uniformidade do lote de sementes com o uso do plasma a baixa pressão como ferramenta para quebra de dormência.(AU)

Diagnostic fingerprints ISSR/SSR for tropical leguminous species Stylosanthes capitata and Stylosanthes macrocephala

Stylosanthes capitata Vogel and Stylosanthes macrocephala M.B.Ferreira & Sousa Costa are two forage leguminous species of agronomic importance for animal husbandry in tropical environments. The physical mixture of both species (80 % S. capitata and 20 % S. macrocephala) comprises the commercial cultivar Estilosantes Campo Grande. However, proximity of fields for seed production may contaminate seed lots, compromising seeds quality. The combined use of dominant and co-dominant molecular markers is an appropriate strategy to certificate genetic purity and perform diversity studies of cultivars. In this research, a set of ISSR (Inter-Simple Sequence Repeat polymorphic DNA) and SSR (Simple Sequence Repeat polymorphic DNA) molecular markers were standardized to characterize S. capitata and S. macrocephala species and evaluate the genetic purity of commercial samples. Four ISSR markers (UBC 2, 864, 885, 886) and SSR marker SC18-01 G4B showed precise species-specific electrophoretic fingerprints for both species. Electrophoretic patterns of ISSR molecular markers should be displayed first to confirm the sample identification. The structure analysis showed that the less contaminated sample was S. capitata with 97 % of its genetic composition assigned to a single genetic cluster vs. 95 % for S. macrocephala. S. capitata has greater genetic diversity (ISSRHe:0.292; SSRHe:0.57) than S. macrocephala (ISSRHe:0.285; SSRHe:0.16); however, this difference was only significant with SSR molecular markers. As these genetic resources have considerable ecological, agronomic and economic importance, tools for accurate species identification and genetic studies are essential for further seed multiplication, as well as for improvement and conservation of cultivars.

Diagnostic fingerprints ISSR/SSR for tropical leguminous species Stylosanthes capitata and Stylosanthes macrocephala

Stylosanthes capitata Vogel and Stylosanthes macrocephala M.B.Ferreira & Sousa Costa are two forage leguminous species of agronomic importance for animal husbandry in tropical environments. The physical mixture of both species (80 % S. capitata and 20 % S. macrocephala) comprises the commercial cultivar Estilosantes Campo Grande. However, proximity of fields for seed production may contaminate seed lots, compromising seeds quality. The combined use of dominant and co-dominant molecular markers is an appropriate strategy to certificate genetic purity and perform diversity studies of cultivars. In this research, a set of ISSR (Inter-Simple Sequence Repeat polymorphic DNA) and SSR (Simple Sequence Repeat polymorphic DNA) molecular markers were standardized to characterize S. capitata and S. macrocephala species and evaluate the genetic purity of commercial samples. Four ISSR markers (UBC 2, 864, 885, 886) and SSR marker SC18-01 G4B showed precise species-specific electrophoretic fingerprints for both species. Electrophoretic patterns of ISSR molecular markers should be displayed first to confirm the sample identification. The structure analysis showed that the less contaminated sample was S. capitata with 97 % of its genetic composition assigned to a single genetic cluster vs. 95 % for S. macrocephala. S. capitata has greater genetic diversity (ISSRHe:0.292; SSRHe:0.57) than S. macrocephala (ISSRHe:0.285; SSRHe:0.16); however, this difference was only significant with SSR molecular markers. As these genetic resources have considerable ecological, agronomic and economic importance, tools for accurate species identification and genetic studies are essential for further seed multiplication, as well as for improvement and conservation of cultivars.(AU)

Effect of arsenate on germination and early development parameters of three forage leguminous plants / Efeito do arsenato nos parâmetros de germinação e desenvolvimento inicial de três plantas leguminosas forrageiras

The Chacopampean plain is one of the most arsenic affected areas in Argentina, especially in groundwater, used both for animal drinking and forage irrigation. The main objective of this study was to determine the effect of arsenic (As) present in irrigation water on the germination parameters of red clover (Trifolium pratense L.), white clover (Trifolium repens L.), and alfalfa (Medicago sativa L.) seeds exposed to different concentrations of As(V). The germination and viability parameters of seeds from the three species were not affected by elevated concentrations of As. However, As significantly reduced the radicle and hypocotyl lengths of the three forage specimens. The inhibition level of the plants increased with the increase in the  concentration of As. Regarding to hypocotyl length/radicle length ratio, the results evidenced that both the hypocotyl and radicle of clover species are affected in the same degree, while alfalfa radicles seemed more affected than hypocotyls at higher concentrations of As. Our results showed that irrigation with solutions containing As affect seedling growth parameters differently in the three species, and the effect of As is mostly evidenced when in high concentrations.

A planície de Chacopampeana é uma das áreas mais afetadas pelo arsênico na Argentina, principalmente em águas subterrâneas, usada tanto para água potável animal quanto para irrigação forrageira. O principal objetivo deste estudo é determinar o efeito do arsênio (As) presente na água de irrigação sobre os parâmetros de germinação de sementes forrageiras: trevo vermelho (Trifolium pratense L.), trevo branco (Trifolium repens L.) e alfafa (Medicago sativa L.) expostos a diferentes concentrações de As (V). Verificou-se que os parâmetros de germinação e viabilidade das sementes das três espécies não foram afetados pelas concentrações elevadas de As. No entanto, reduziu significativamente o comprimento da radícula e o comprimento do hipocótilo das três mudas de forragem, e seu nível de inibição é maior com o aumento da concentração de As. Quanto à relação comprimento de hipocótilo/comprimento da radícula, os resultados evidenciaram que nas espécies de trevo tanto o hipocótilo quanto a radícula são afetados no mesmo grau, enquanto as radículas de alfafa pareceram mais afetadas do que os hipocótilos em concentrações maiores de As. Nossos resultados mostraram que a irrigação com soluções contém Afetar os parâmetros de crescimento de plântulas de maneira diferente nas três espécies, e foi demonstrado que o efeito do As é principalmente evidenciado em altas concentrações.

Effect of arsenate on germination and early development parameters of three forage leguminous plants / Efeito do arsenato nos parâmetros de germinação e desenvolvimento inicial de três plantas leguminosas forrageiras

The Chacopampean plain is one of the most arsenic affected areas in Argentina, especially in groundwater, used both for animal drinking and forage irrigation. The main objective of this study was to determine the effect of arsenic (As) present in irrigation water on the germination parameters of red clover (Trifolium pratense L.), white clover (Trifolium repens L.), and alfalfa (Medicago sativa L.) seeds exposed to different concentrations of As(V). The germination and viability parameters of seeds from the three species were not affected by elevated concentrations of As. However, As significantly reduced the radicle and hypocotyl lengths of the three forage specimens. The inhibition level of the plants increased with the increase in the  concentration of As. Regarding to hypocotyl length/radicle length ratio, the results evidenced that both the hypocotyl and radicle of clover species are affected in the same degree, while alfalfa radicles seemed more affected than hypocotyls at higher concentrations of As. Our results showed that irrigation with solutions containing As affect seedling growth parameters differently in the three species, and the effect of As is mostly evidenced when in high concentrations.(AU)

A planície de Chacopampeana é uma das áreas mais afetadas pelo arsênico na Argentina, principalmente em águas subterrâneas, usada tanto para água potável animal quanto para irrigação forrageira. O principal objetivo deste estudo é determinar o efeito do arsênio (As) presente na água de irrigação sobre os parâmetros de germinação de sementes forrageiras: trevo vermelho (Trifolium pratense L.), trevo branco (Trifolium repens L.) e alfafa (Medicago sativa L.) expostos a diferentes concentrações de As (V). Verificou-se que os parâmetros de germinação e viabilidade das sementes das três espécies não foram afetados pelas concentrações elevadas de As. No entanto, reduziu significativamente o comprimento da radícula e o comprimento do hipocótilo das três mudas de forragem, e seu nível de inibição é maior com o aumento da concentração de As. Quanto à relação comprimento de hipocótilo/comprimento da radícula, os resultados evidenciaram que nas espécies de trevo tanto o hipocótilo quanto a radícula são afetados no mesmo grau, enquanto as radículas de alfafa pareceram mais afetadas do que os hipocótilos em concentrações maiores de As. Nossos resultados mostraram que a irrigação com soluções contém Afetar os parâmetros de crescimento de plântulas de maneira diferente nas três espécies, e foi demonstrado que o efeito do As é principalmente evidenciado em altas concentrações.(AU)

Maize-crotalaria intercropping systems / Sistemas de consórcio entre milho e crotalária

The objective of this study was to identify a maize-crotalaria intercropping system feasible for producing straw while maintaining maize yield. A study with a completely randomized block design was performed in 2015 and 2016, with 7 × 2 + 1 split plot and three replications in a clayey Red Oxisol. Seven intercropping systems were allocated to each plot, and two crotalaria species (Crotalaria spectabilis and C. ochroleuca) cultivated with maize in monoculture were allocated to each subplot. Crotalaria yield, total chlorophyll content, nitrogen content, plant height, plant dry matter, thousand grain mass, and corn grain yield were evaluated. C. spectabilis was more sensitive to water level variations during the crop cycle than C. ochroleuca. Crotalaria sown before maize planting with maize seeds incorporated in the soil presented a relatively higher phytomass but decreased corn grain yield. The management system in which crotalaria was sown in the inter-row with a ridge planter at the time of maize planting and the system in which crotalaria was sown in the maize sowing furrow were feasible for straw production because they did not decrease corn grain yield and did not affect maize harvesting operations.(AU)

Objetiva-se nesta pesquisa encontrar um sistema de consórcio entre milho e crotalária que seja viável para produção de palhada mantendo a produtividade do milho. Para isso foi instalado nos anos de 2015 e 2016, um experimento em delineamento em blocos casualizados, com arranjo de parcelas subdivididas 7x2+1 e três repetições em Latossolo Vermelho de textura argilosa, sendo alocado nas parcelas sete formas de consórcio e nas subparcelas as espécies de crotalárias (Crotalaria spectabilis e Crotalaria ocrholeuca) com tratamento adicional sendo o milho solteiro. Foram avaliados atributos produtivos das crotalárias, clorofila e nitrogênio total, altura massa seca da parte aérea, massa de mil grãos e produtividade de grãos. A C. spectabilis se mostrou mais sensível as oscilações hídricas durante o ciclo de desenvolvimento que a C. ochroleuca. As crotalárias semeadas antes da cultura do milho com as sementes incorporadas apresentam maior produção de fitomassa, porém, diminuem a produtividade do milho. O manejo em que a crotalária é semeada na entrelinha do milho utilizando sulcador no momento da semeadura do milho bem como aquele em que a crotalária é semeada no sulco de semeadura do milho são viáveis por proporcionarem produção de palhada, não reduzirem a produtividade do milho e não interferirem nas operações de colheita do milho.(AU)

Caracterização de rizobios noduladores de feijão-fava (Phaseolus lunatus L) em solos de três estados do nordeste brasileiro / Characterization of lima bean-nodulating rhizobia in soils from three northeastern Brazilian States

The aim of this study was to characterize lima bean nodulating rhizobial from soils of northeastern Brazil. Soil samples were collected in regions with production of lima bean in the Ceara, Piaui and Maranhao states. The experiment was conducted in pots containing soil from each region, sowed with lima bean. Nodules were sampled for isolation and characterization at 35 days after plant emergence. A total of 75 isolates were found and submitted to morphological and physiological characterization. Morphologically, the majority of isolates exhibited circular and convex colonies with entire border and smooth surface. Physiologically, all isolated presented fast growth, and the majority of isolates presented acid reaction, moderate ability to produce mucus with gummy consistency and colonies with cream coloration. The isolates found in this study presented similar characteristics to genera Rhizobium, Sinorhizobium, Allorhizobium e Mesorhizobium.

O objetivo deste estudo foi caracterizar isolados de rizóbios noduladores de feijão-fava oriundos de solos dos estados do Ceará, Piauí e Maranhão. Amostras de solos foram coletadas de áreas produtoras de feijão-fava nos estados do Ceará, Piauí e Maranhão. O experimento foi realizado em vasos, contendo solo de cada local, semeados com feijão-fava.  A coleta dos nódulos para isolamento e caracterização foi realizada aos 35 dias após a emergência das plantas. O total de 75 isolados foram obtidos e submetidos a caracterização morfológica e fisiológica. Morfologicamente, a maioria dos isolados exibiram colônias circulares, convexas, com bordas inteiras e de superfície lisa. Fisiologicamente, todos os isolados apresentaram crescimento rápido e a maioria apresentou reação ácida, habilidade moderada de produzir muco com consistência gomosa e colônias com coloração creme. Os isolados encontrados nestes solos apresentaram características morfológicas e fisiológicas similares àquelas encontradas nos gêneros Rhizobium, Sinorhizobium, Allorhizobium e Mesorhizobium.

Maize-crotalaria intercropping systems / Sistemas de consórcio entre milho e crotalária

The objective of this study was to identify a maize-crotalaria intercropping system feasible for producing straw while maintaining maize yield. A study with a completely randomized block design was performed in 2015 and 2016, with 7 × 2 + 1 split plot and three replications in a clayey Red Oxisol. Seven intercropping systems were allocated to each plot, and two crotalaria species (Crotalaria spectabilis and C. ochroleuca) cultivated with maize in monoculture were allocated to each subplot. Crotalaria yield, total chlorophyll content, nitrogen content, plant height, plant dry matter, thousand grain mass, and corn grain yield were evaluated. C. spectabilis was more sensitive to water level variations during the crop cycle than C. ochroleuca. Crotalaria sown before maize planting with maize seeds incorporated in the soil presented a relatively higher phytomass but decreased corn grain yield. The management system in which crotalaria was sown in the inter-row with a ridge planter at the time of maize planting and the system in which crotalaria was sown in the maize sowing furrow were feasible for straw production because they did not decrease corn grain yield and did not affect maize harvesting operations.

Objetiva-se nesta pesquisa encontrar um sistema de consórcio entre milho e crotalária que seja viável para produção de palhada mantendo a produtividade do milho. Para isso foi instalado nos anos de 2015 e 2016, um experimento em delineamento em blocos casualizados, com arranjo de parcelas subdivididas 7x2+1 e três repetições em Latossolo Vermelho de textura argilosa, sendo alocado nas parcelas sete formas de consórcio e nas subparcelas as espécies de crotalárias (Crotalaria spectabilis e Crotalaria ocrholeuca) com tratamento adicional sendo o milho solteiro. Foram avaliados atributos produtivos das crotalárias, clorofila e nitrogênio total, altura massa seca da parte aérea, massa de mil grãos e produtividade de grãos. A C. spectabilis se mostrou mais sensível as oscilações hídricas durante o ciclo de desenvolvimento que a C. ochroleuca. As crotalárias semeadas antes da cultura do milho com as sementes incorporadas apresentam maior produção de fitomassa, porém, diminuem a produtividade do milho. O manejo em que a crotalária é semeada na entrelinha do milho utilizando sulcador no momento da semeadura do milho bem como aquele em que a crotalária é semeada no sulco de semeadura do milho são viáveis por proporcionarem produção de palhada, não reduzirem a produtividade do milho e não interferirem nas operações de colheita do milho.

The Role of ß-Mannanase (Hemicell) in Improving Poultry Productivity, Health and Environment

The poultry nutritionists constantly attempt to identify and alleviate the factors responsible for adverse effects on nutrient utilization and production performance in avian species, which are necessary for successful productivity of poultry. Enhanced feed utilization can reduce levels of some nutrients in the diet with concomitant mitigation in nutrient excretion into the environment, reduction of eutrophication and acidification potentials of excreta. Commercial enzymes have been used to improve feed efficiency and utilization in poultry. Among many anti-nutritional factors, the existence of ß-mannans in poultry feed ingredients including soybean and other leguminous seeds has been associated with negative effects on nutrient digestibility and high intestinal viscosity that adversely affects innate immunity and microbial proliferation in poultry gut. The ß-mannanase (a commercial product named as Hemicell) can hydrolyze ß-mannan, an anti-nutritional fiber present in many poultry feed ingredients. Supplement of ß-mannanase to ß-mannan-rich diets may boost the population of intestinal beneficial bacteria, increase the digestibility of mannans, enhance the immunity, suppresses the growth of harmful intestinal bacteria, enhance the digestion and absorption of nutrients in intestinal tracts and reduce the environmental pollution due to poultry excreta. Supplementation of -mannanase at the level of 200 and 400 mg/kg in poultry diets has positively improved blood glucose and anabolic hormone homeostasis, FCR, digestible energy, and digestible amino acids. This review describes the promising beneficial effects of -mannanase, which may be used in the poultry feed industry for economic benefits. Another objective of this review is to explore the underlying mechanisms of ß-mannanase that can influence growth, digestion coefficients of nutrients, health and metabolism of nutrients in poultry birds and also the knowledge regarding the useful application of this feed enzyme in the commercial poultry feed industry.(AU)

Caracterização de rizobios noduladores de feijão-fava (Phaseolus lunatus L) em solos de três estados do nordeste brasileiro / Characterization of lima bean-nodulating rhizobia in soils from three northeastern Brazilian States

The aim of this study was to characterize lima bean nodulating rhizobial from soils of northeastern Brazil. Soil samples were collected in regions with production of lima bean in the Ceara, Piaui and Maranhao states. The experiment was conducted in pots containing soil from each region, sowed with lima bean. Nodules were sampled for isolation and characterization at 35 days after plant emergence. A total of 75 isolates were found and submitted to morphological and physiological characterization. Morphologically, the majority of isolates exhibited circular and convex colonies with entire border and smooth surface. Physiologically, all isolated presented fast growth, and the majority of isolates presented acid reaction, moderate ability to produce mucus with gummy consistency and colonies with cream coloration. The isolates found in this study presented similar characteristics to genera Rhizobium, Sinorhizobium, Allorhizobium e Mesorhizobium.(AU)

O objetivo deste estudo foi caracterizar isolados de rizóbios noduladores de feijão-fava oriundos de solos dos estados do Ceará, Piauí e Maranhão. Amostras de solos foram coletadas de áreas produtoras de feijão-fava nos estados do Ceará, Piauí e Maranhão. O experimento foi realizado em vasos, contendo solo de cada local, semeados com feijão-fava.  A coleta dos nódulos para isolamento e caracterização foi realizada aos 35 dias após a emergência das plantas. O total de 75 isolados foram obtidos e submetidos a caracterização morfológica e fisiológica. Morfologicamente, a maioria dos isolados exibiram colônias circulares, convexas, com bordas inteiras e de superfície lisa. Fisiologicamente, todos os isolados apresentaram crescimento rápido e a maioria apresentou reação ácida, habilidade moderada de produzir muco com consistência gomosa e colônias com coloração creme. Os isolados encontrados nestes solos apresentaram características morfológicas e fisiológicas similares àquelas encontradas nos gêneros Rhizobium, Sinorhizobium, Allorhizobium e Mesorhizobium.(AU)

Experimental poisoning by Crotalaria lanceolata and Crotalaria pallida seeds in broilers

ABSTRACT: Crotalaria lanceolata E. Mey. and Crotalaria pallida Aiton. are leguminous plants of family Fabaceae found in most of the Brazilian territory. They were initially used as green manure and due their easy spread they are currently considered weeds in crops. Soybean and corn contamination can occur through the mechanical harvesting of these grains along with seeds of the Crotalaria species, which end up in the formulation of feed for production animals. Crotalaria spp. genus has toxic pyrrolizidine alkaloids (PA). Most plant species belonging to this genus can cause acute or chronic liver injury. In a first stage, one-day old broilers were divided into three groups: Group A (C. pallida seeds), Group B (C. lanceolata seeds), and Group C (Control). Groups A and B were divided into five subgroups, each with eight broilers, which received the following doses of the respective seeds in feed as of the 7th day of age: daily doses of 0.4%, 0.8% and 2.5%, and single doses of 15% and 25%. Four broilers in each study group were euthanized at 28 days of age - completing 21 days of seed consumption, and the four remaining broilers were euthanized at 42 days of age - completing 35 days of seed consumption. In a second stage, experiments were conducted using seeds of both the aforementioned plants with 28-day old broilers. These were divided into three groups of four animals each: Group D (C. pallida seeds) and Group E (C. lanceolata seeds), which received the respective seeds at daily doses of 1% and 2% in feed for 20 days, and Group F (Control). These broilers were euthanized when they were 80 days old. C. lanceolata seeds showed higher toxicity to broilers than C. pallida seeds, both supplied as of the 7th day of life. Clinical signs included inappetence, ruffled feathers, and brown diarrhea. The following gross lesions were observed: subcutaneous edema, ascites, hydropericardium, yellowish liver with hypertrophy or atrophy and enhanced lobular pattern, and distended gallbladder. Histologic lesions present in all birds in varying degrees were characterized by tumefaction and vacuolar degeneration of hepatocytes. The following clinical conditions and gross lesions were observed in the broilers: hepatocyte megalocytosis and karyomegaly, slight biliary epithelial hyperplasia, eosinophilic spheroids, and nuclear invagination with loss of hepatocyte cord architecture.

RESUMO: Crotalaria lanceolata E. Mey. e Crotalaria pallida Aiton. são leguminosas da família Fabaceae presentes na maioria do território brasileiro. Inicialmente foram utilizadas como adubação verde e devido sua fácil disseminação são consideradas invasoras de culturas. Através da colheita mecanizada da soja e milho pode ocorrer a contaminação destes grãos com sementes dessas espécies e entrar na formulação de ração para animais de produção. O gênero Crotalaria spp. possui alcaloides pirrolizidínicos de ação tóxica. A maioria das espécies desse gênero causam lesões hepáticas, com evolução aguda, ou, crônica. Frangos de corte de um dia de vida foram divididos em três grupos: Grupo A (sementes de C. pallida - doses diárias de 0,4%, 0,8%, 2,5% e doses únicas de 15% e 25%), Grupo B (sementes de C. lanceolata - doses diárias de 0,4%, 0,8%, 2,5% e doses únicas de 15% e 25%) e Grupo C (Controle). Os Grupos A e B foram divididos em cinco subgrupos, com oito frangos cada, que a partir do sétimo dia de vida, receberam as doses estabelecidas. Quatro frangos de cada grupo foram sacrificados aos 28 dias, e os quatro restantes aos 42 dias de vida. Também foram conduzidos experimentos com as sementes dessas duas plantas com aves de 28 dias, as quais foram divididas em três grupos: Grupo D (C. pallida - doses de 1% e 2% diariamente, durante vinte dias), Grupo E (C. lanceolata - doses de 1% e 2% diariamente, durante vinte dias) e Grupo F (Controle). Cada grupo composto por quatro aves. Estas aves foram sacrificadas ao completarem 80 dias de vida. Sementes de C. lanceolata demonstraram maior toxicidade para frangos de corte do que sementes de C. pallida. Os sinais clínicos foram inapetência, penas arrepiadas e diarreia acastanhada. Na macroscopia observou-se edema subcutâneo, ascite, hidropericárdio, fígado de coloração amarelada com hipertrofia e, ou, atrofia, evidenciação do padrão lobular e vesícula biliar distendida. As lesões histológicas presentes em todas as aves, em diferentes graus caracterizaram-se por tumefação e degeneração vacuolar de hepatócitos. Nas aves que manifestaram alterações clínicas e lesões macroscópicas, havia megalocitose, cariomegalia, hiperplasia do epitélio biliar, leve, esferoides eosinofílicos e invaginação nuclear com perda da arquitetura dos cordões de hepatócitos.

The Role of ß-Mannanase (Hemicell) in Improving Poultry Productivity, Health and Environment

The poultry nutritionists constantly attempt to identify and alleviate the factors responsible for adverse effects on nutrient utilization and production performance in avian species, which are necessary for successful productivity of poultry. Enhanced feed utilization can reduce levels of some nutrients in the diet with concomitant mitigation in nutrient excretion into the environment, reduction of eutrophication and acidification potentials of excreta. Commercial enzymes have been used to improve feed efficiency and utilization in poultry. Among many anti-nutritional factors, the existence of ß-mannans in poultry feed ingredients including soybean and other leguminous seeds has been associated with negative effects on nutrient digestibility and high intestinal viscosity that adversely affects innate immunity and microbial proliferation in poultry gut. The ß-mannanase (a commercial product named as Hemicell) can hydrolyze ß-mannan, an anti-nutritional fiber present in many poultry feed ingredients. Supplement of ß-mannanase to ß-mannan-rich diets may boost the population of intestinal beneficial bacteria, increase the digestibility of mannans, enhance the immunity, suppresses the growth of harmful intestinal bacteria, enhance the digestion and absorption of nutrients in intestinal tracts and reduce the environmental pollution due to poultry excreta. Supplementation of -mannanase at the level of 200 and 400 mg/kg in poultry diets has positively improved blood glucose and anabolic hormone homeostasis, FCR, digestible energy, and digestible amino acids. This review describes the promising beneficial effects of -mannanase, which may be used in the poultry feed industry for economic benefits. Another objective of this review is to explore the underlying mechanisms of ß-mannanase that can influence growth, digestion coefficients of nutrients, health and metabolism of nutrients in poultry birds and also the knowledge regarding the useful application of this feed enzyme in the commercial poultry feed industry.

Nutritional composition of ‘Ponta Negra’ forage sorghum silage enriched with dried Leucaena leucocephala forage / Composição nutricional da silagem de sorgo forrageiro Ponta Negra aditivada com forragem de leucena (Leucaena leucocephala) desidratada

The aim of this study was to evaluate fermentation and chemical characteristics and the in situ degradability of sorghum silages enriched with dried Leucaena. The experiment was conducted as completely randomized design with four treatments (0 - control silage, silage without leucaena; 10.0, 20.0, or 30.0% inclusion of Leucaena) and five replicates, totaling 20 experimental units. The inclusion levels of leucaena influenced (P 0.05), with all silages having values above 90%. Gas loss decreased (P < 0.05) as the level of leucine increased in sorghum silage. A linear increase was observed for dry matter (P ≤ 0.0001) and crude protein (P = 0.0008) contents in response to Leucaena inclusion. There was a linear (P < 0.05) linear effect on neutral detergent fiber, hemicellulose and acid detergent fiber. As leucaena inclusion levels increased, for each 1% inclusion a reduction of 0.179 was observed; 0.059 and 0.119% for the values of neutral detergent fiber, hemicellulose and acid detergent fiber respectively. The inclusion of leucaena influenced (P < 0.05) the increase of silage lignin levels, probably due to the higher lignin content of the legume. The soluble fraction (a) of the silages increased along with the Leucaena inclusion levels, with highest values observed at the inclusion of 20 and 30% of the legume, respectively. Potential degradation (A) increased linearly with the levels of Leucaena added to the silage; the highest value for this variable was observed at 30% inclusion. Effective degradability (ED) increased up to the inclusion level of 20% (46.77%). Degradation rate (c) decreased markedly with the use of 30% Leucaena...

O objetivo deste trabalho foi avaliar as características fermentativas e químicas e a degradabilidade in situ de silagens de sorgo enriquecidas com Leucaena desidratada. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro tratamentos (0 - silagem controle, silagem sem leucena; 10,0, 20,0 ou 30,0% de inclusão de leucena) e cinco repetições, totalizando 20 unidades experimentais. Os níveis de inclusão da leucena influenciaram (P 0,05), sendo que todas as silagens apresentaram valores acima de 90%. A perda de gases reduziu (P < 0,05), à medida que aumentou o nível de leucina na silagem de sorgo. A linear increase was observed for dry matter (P ≤ 0, 0001) and crude protein (P = 0.0008) contents in response to Leucaena inclusion. Observou-se efeito (P < 0,05) linear decrescente a fibra em detergente neutro, hemicelulose e fibra em detergente ácido. À medida que se elevou os níveis de inclusão da leucena, para cada 1% de inclusão foi observada redução de 0,179; 0,059 e 0,119% para os valores de fibra em detergente neutro, hemicelulose e fibra em detergente ácido, respectivamente. A inclusão de leucena influenciou (P < 0.05) o aumento dos níveis de lignina da silagem, provavelmente pelo maior teor de lignina da leguminosa. A fração solúvel (a) das silagens aumentou juntamente com os níveis de inclusão de leucena, com maiores valores observados na inclusão de 20 e 30% da leguminosa, respectivamente. A degradação potencial (A) aumentou linearmente com os níveis de Leucaena adicionados à silagem; o maior valor para essa variável foi observado em 30% de inclusão. A degradabilidade efetiva (DE) aumentou até o nível de inclusão de 20% (46,77%). Taxa de degradação (c) diminuiu acentuadamente com o uso de 30% de Leucena...

Nutritional composition of ‘Ponta Negra forage sorghum silage enriched with dried Leucaena leucocephala forage / Composição nutricional da silagem de sorgo forrageiro Ponta Negra aditivada com forragem de leucena (Leucaena leucocephala) desidratada

The aim of this study was to evaluate fermentation and chemical characteristics and the in situ degradability of sorghum silages enriched with dried Leucaena. The experiment was conducted as completely randomized design with four treatments (0 - control silage, silage without leucaena; 10.0, 20.0, or 30.0% inclusion of Leucaena) and five replicates, totaling 20 experimental units. The inclusion levels of leucaena influenced (P <0.05) the pH values, and for each 1% inclusion there was a reduction of 0.0023 points in the pH value, and in all silages presented values. Dry matter recovery did not show effect (P > 0.05), with all silages having values above 90%. Gas loss decreased (P < 0.05) as the level of leucine increased in sorghum silage. A linear increase was observed for dry matter (P ≤ 0.0001) and crude protein (P = 0.0008) contents in response to Leucaena inclusion. There was a linear (P < 0.05) linear effect on neutral detergent fiber, hemicellulose and acid detergent fiber. As leucaena inclusion levels increased, for each 1% inclusion a reduction of 0.179 was observed; 0.059 and 0.119% for the values of neutral detergent fiber, hemicellulose and acid detergent fiber respectively. The inclusion of leucaena influenced (P < 0.05) the increase of silage lignin levels, probably due to the higher lignin content of the legume. The soluble fraction (a) of the silages increased along with the Leucaena inclusion levels, with highest values observed at the inclusion of 20 and 30% of the legume, respectively. Potential degradation (A) increased linearly with the levels of Leucaena added to the silage; the highest value for this variable was observed at 30% inclusion. Effective degradability (ED) increased up to the inclusion level of 20% (46.77%). Degradation rate (c) decreased markedly with the use of 30% Leucaena...(AU)

O objetivo deste trabalho foi avaliar as características fermentativas e químicas e a degradabilidade in situ de silagens de sorgo enriquecidas com Leucaena desidratada. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro tratamentos (0 - silagem controle, silagem sem leucena; 10,0, 20,0 ou 30,0% de inclusão de leucena) e cinco repetições, totalizando 20 unidades experimentais. Os níveis de inclusão da leucena influenciaram (P < 0,05) os valores de pH, sendo que para cada 1% de inclusão houve redução de 0,0023 pontos no valor do pH, sendo que em todas as silagens apresentaram valores ideias. A recuperação de matéria seca não apresentou efeito (P > 0,05), sendo que todas as silagens apresentaram valores acima de 90%. A perda de gases reduziu (P < 0,05), à medida que aumentou o nível de leucina na silagem de sorgo. A linear increase was observed for dry matter (P ≤ 0, 0001) and crude protein (P = 0.0008) contents in response to Leucaena inclusion. Observou-se efeito (P < 0,05) linear decrescente a fibra em detergente neutro, hemicelulose e fibra em detergente ácido. À medida que se elevou os níveis de inclusão da leucena, para cada 1% de inclusão foi observada redução de 0,179; 0,059 e 0,119% para os valores de fibra em detergente neutro, hemicelulose e fibra em detergente ácido, respectivamente. A inclusão de leucena influenciou (P < 0.05) o aumento dos níveis de lignina da silagem, provavelmente pelo maior teor de lignina da leguminosa. A fração solúvel (a) das silagens aumentou juntamente com os níveis de inclusão de leucena, com maiores valores observados na inclusão de 20 e 30% da leguminosa, respectivamente. A degradação potencial (A) aumentou linearmente com os níveis de Leucaena adicionados à silagem; o maior valor para essa variável foi observado em 30% de inclusão. A degradabilidade efetiva (DE) aumentou até o nível de inclusão de 20% (46,77%). Taxa de degradação (c) diminuiu acentuadamente com o uso de 30% de Leucena...(AU)

Elaboração e análise físico química de um alimento tipo queijo a base de leguminosa adicionado de inulina / Elaboration and physical chemical analysis of a cheese food based on leguminous added inulin

Devido à grande demanda por produtos saudáveis e funcionais, aliado ao grande aumento de indivíduos intolerantes à lactose, alérgicos a proteína do leite e vegetarianos faz-se necessário desenvolvimento de produtos que atendam as características desse novo mercado. Portanto, o objetivo desse estudo foi elaborar um alimento tipo queijo à base de leguminosas sem lactose, vegetariano, adicionado do prebiótico, a inulina, um composto funcional. Foram desenvolvidas três amostras de alimento tipo queijo a base de feijão branco, adicionados com três proporções de inulina com diferentes quantidades em grama (g) 5, 10 e 15, e avaliados quanto a composição centesimal, segundo Instituto Adolfo Lutz (2008). Os dados da análise físico-química para FQF1, FQF2 e FQF3, determinaram alta umidade, quanto ao teor de cinzas não houve diferença significativa, já para a análise de fibra solúvel e insolúvel, mostrou que FQF3 obteve diferença significativa entre FQF1 e FQF2, apresentando alto conteúdo de fibras. A quantidade de proteína variou entre 3,81 a 4,59% e baixo teor de lipídeos. Os resultados mostram que é possível desenvolver um produto a base de feijão, sendo de origem vegetal com composição adequada, baixo teor de lipídios e consideráveis conteúdo de fibra e proteína.(AU)