Interactions among groups of microorganisms with rhizosphere

As propriedades físico-químicas da rizosfera têm elevada estabilidade, que, associadas ao fornecimento constante de substratos orgânicos e fatores de crescimento, favorecem intensa atividade metabólica das populações, influenciando diretamente e positivamente o tempo de geração microbiano. O solo é um local de grande número e variedade de interações biológicas, incluindo a competição, a predação, o parasitismo, o comensalismo, o mutualismo e a forésia. As interações biológicas possuem a capacidade de sustentar a vida tanto das plantas como dos animais e outros seres que vivem no solo. A comunidade microbiana na rizosfera é representada por populações diversificadas e numerosas em estado de equilíbrio dinâmico, refletindo o ambiente físico, químico, biológico e suas relações. Portanto, o objetivo dessa revisão foi demonstrar que há interação entre grupos de microorganismos com a rizosfera. As populações de microrganismos são importantes constituintes da microflora da rizosfera, seja pelos exsudados de raízes de plantas como fonte de carbono favorecidas pelo metabolismo destes microrganismos, seja pela capacidade de síntese de antibióticos, permitindo o uso de sua capacidade antagonista no biocontrole de fitopatógenos; seja pela influência que promove no estabelecimento de microrganismos benéficos, como diazotróficos e as micorrizas;. e ainda pela formação de actinorrizas, onde é capaz de fixar nitrogênio atmosférico.The physicochemical properties of the rhizosphere have high stability, which, coupled with the constant supply of organic substrates and growth factors, favor intense metabolic activity of the populations, directly and positively influencing the microbial generation time. Soil is a place of great number and variety of biological interactions, including competition, predation, parasitism, commensalism, mutualism and phoresy. The biological interactions have the capacity to sustain the life of both plants and animals and other creatures that live in soil. The rhizosphere microbial community is represented by numerous and diverse populations in a state of dynamic equilibrium, reflecting the physical, chemical, biological environment and their relations. Therefore, the purpose of this review was to demonstrate that there is interaction among groups of microorganisms with the rhizosphere. The populations of microorganisms are important constituents of the microflora of the rhizosphere, either by plant root exudates as a carbon source favored by the metabolism of these microorganisms, or by the ability to synthesize antibiotics, allowing the use of its antagonist capacity in the biocontrol of phytopathogens, or by the influence that promotes the establishment of beneficial microorganisms such as mycorrhizae and diazotrophic; and also by the formation of actinorhizal, where it is able to fix atmospheric nitrogen.Las propiedades fisicoquímicas de la rizosfera tienen una gran estabilidad, que, junto con el suministro constante de sustratos orgánicos y factores de crecimiento, favorecen una intensa actividad metabólica de las poblaciones, con influencia directa e positiva en el tiempo de generación microbiana. El suelo es un lugar de gran cantidad y variedad de interacciones biológicas, incluida la competición, depredación, parasitismo, comensalismo, mutualismo y el foresis. Las interacciones biológicas tienen la capacidad de sostener la vida de las plantas y los animales y otras criaturas que viven en el suelo. La comunidad microbiana en la rizosfera está representada por las poblaciones diversas de numerosos en un estado de equilibrio dinámico, lo que refleja las características físicas, químicas, biológicas, y sus relaciones. Por lo tanto, el propósito de esta revisión fue para demostrar que existe una interacción entre los grupos de microorganismos en la rizosfera. Las poblaciones de microorganismos son componentes importantes de la microflora de la rizosfera, sea por exudados de raíces de plantas como fuente de carbono favorecido por el metabolismo de estos microorganismos, sea por la capacidad de sintetizar los antibióticos, lo que permite el uso de su capacidad antagonista en el control biológico de los patógenos, o por la influencia que promueve en lo establecimiento de microorganismos benéficos como las micorrizas y diazotróficas, y también por la formación de actinorhizal, que es capaz de fijar nitrógeno atmosférico

Variabilidade espacial de atributos físicos de solo coeso sob sistemas de manejo convencional e de plantio direto

The objective of this work was to evaluate the spatial variability of moisture content, bulk density,and porosity of a cohesive soil under conventional and no-tillage management systems. Two regular grids were installed, one for each management type. The soil was collected at the 0.00–0.20-m depth and the spatialvariability of its attributes was analyzed by semivariogram parameters and ordinary kriging geostatistical interpolation. The soil showed greater bulk density and moisture conservation under no-tillage, and greater porosity under conventional tillage.O objetivo deste trabalho foi avaliar a variabilidade espacial da umidade, da densidade e da porosidade de solo coeso cultivado com soja sob sistemas de manejo convencional e de plantio direto. Foram instaladas duas malhas regulares, uma para cada tipo de manejo. O solo foi coletado na profundidade de 0,00–0,20 m,e a variabilidade espacial de seus atributos foi analisada por meio de parâmetros do semivariograma e do interpolador geoestatístico krigagem ordinária. O solo apresentou maior densidade e conservação da umidade no plantio direto, e maior porosidade no manejo convencional

Initial growth of Moringa oleifera Lam. as a function of poultry litter doses and granulometry

There is an increasing use of poultry litter in seedling production. However, studies regarding the effect of different particle-size litter on plant growth are still scarce. This study aimed to evaluate the growth of Moringa oleifera Lam. fertilized with poultry litter doses (0 g dm-3, 40 g dm-3, 80 g dm-3 and 120 g dm-3) with distinct particle sizes (1 mm and 4 mm), with four replications. The following variables were evaluated: plant height; root and stem diameter; leaf, stem, shoot and root dry matter mass; shoot/root dry matter mass ratio; and the Dickson quality index. There was no influence of the particle size on the studied variables, except for plant height. The root diameter decreased with the increase of the poultry litter doses. The accumulation of dry matter mass from the shoot and root increased with the increase of poultry litter doses up to 120 g dm-3. A linear increase of the Dickson quality index, relatively to days and poultry litter doses, was observed. It is recommended to apply 80 g dm-3 of poultry litter to fertilize M. oleifera plants, independently of the granulometry used

Biometric genetics in Cowpea beans (Vigna unguiculata (L.) Walp) II: estimates of genetic gains through selection indices

Low cowpea productivity (Vigna unguiculata (L.) Walp) in the semi-arid region of Paraíba is due, among other factors, to poor-quality cultivars. This research tested biometric models intending to increase productivity of superior cultivars with the following objectives: i. Estimate genetic gains in production components; ii. Identify the selection index model providing the greatest gains through simultaneously selecting a set of variables, and iii. Select cultivars with higher productivity. The experiment was carried out in the experimental field of the Agrifood Science and Technology Center of the Federal University of Campina Grande. Eight cultivars and 13 variables were evaluated. Data were subjected to ANOVA and means were grouped using the Scott and Knott test. Genetic gains were estimated by correlated response, classic selection index, rank sum and index based on desired gains. Direct selection of the secondary pod yield component provides significant genetic gains in main grain yield. Among the methodologies used, the classic selection index provided greater distribution of genetic gains for main grain yield and primary production components. These results allow concluding that Costela de vaca, BRS Marataoã and Paulistinha cultivars should be selected for cultivation and commercial exploitation in the semiarid region of Paraíba. Highlights: Direct selection of the secondary pod yield component provides significant genetic gains in main grain yield. The classic selection index provided greater distribution of genetic gains for main grain yield and primary production components. Cultivars were selected for cultivation and commercial exploitation in the semi-arid region of Paraíba.Low cowpea productivity (Vigna unguiculata (L.) Walp) in the semi-arid region of Paraíba is due, among other factors, to poor-quality cultivars. This research tested biometric models intending to increase productivity of superior cultivars with the following objectives: i. Estimate genetic gains in production components; ii. Identify the selection index model providing the greatest gains through simultaneously selecting a set of variables, and iii. Select cultivars with higher productivity. The experiment was carried out in the experimental field of the Agrifood Science and Technology Center of the Federal University of Campina Grande. Eight cultivars and 13 variables were evaluated. Data were subjected to ANOVA and means were grouped using the Scott and Knott test. Genetic gains were estimated by correlated response, classic selection index, rank sum and index based on desired gains. Direct selection of the secondary pod yield component provides significant genetic gains in main grain yield. Among the methodologies used, the classic selection index provided greater distribution of genetic gains for main grain yield and primary production components. These results allow concluding that Costela de vaca, BRS Marataoã and Paulistinha cultivars should be selected for cultivation and commercial exploitation in the semiarid region of Paraíba. Highlights: Direct selection of the secondary pod yield component provides significant genetic gains in main grain yield. The classic selection index provided greater distribution of genetic gains for main grain yield and primary production components. Cultivars were selected for cultivation and commercial exploitation in the semi-arid region of Paraíba

Biometric genetics in cowpea beans (Vigna unguiculata (L.) Walp) I: phenotypic and genotypic relations among production components

In the semi-arid region of Paraíba, cowpea has low productivity due to irregular rainfall and poor use of production technologies. An extensive study aimed at selecting more productive cultivars was conducted using biometric models. This first work had the following objectives: i. Quantify direct and indirect effects of primary and secondary components on grain production; ii. Identify variables with greater potential for cultivar selection in the semiarid region of Paraíba and iii. Determine the most appropriate selection strategies for the evaluated variables. The experiment was conducted in an experimental field. The influence of 6 primary and 6 secondary production components was evaluated on grain yield. Data were subjected to ANOVA. Genetic parameters, correlations and path analysis were estimated. Given the strong direct phenotypic and genotypic effects, pod yield results the most promising variable for higher grain yield selection. Direct and simultaneous selections are the most suitable strategies for the set of evaluated variables. However, further studies on selection indices are necessary to maximize genetic gains. Highlights Variables with greater potential were identified for the selection of superior cultivars of cowpea in the semiarid region of Paraíba. The pod yield variable (PP) seems promising for cultivar selection considering higher grain yield (GY).In the semi-arid region of Paraíba, cowpea has low productivity due to irregular rainfall and poor use of production technologies. An extensive study aimed at selecting more productive cultivars was conducted using biometric models. This first work had the following objectives: i. Quantify direct and indirect effects of primary and secondary components on grain production; ii. Identify variables with greater potential for cultivar selection in the semiarid region of Paraíba and iii. Determine the most appropriate selection strategies for the evaluated variables. The experiment was conducted in an experimental field. The influence of 6 primary and 6 secondary production components was evaluated on grain yield. Data were subjected to ANOVA. Genetic parameters, correlations and path analysis were estimated. Given the strong direct phenotypic and genotypic effects, pod yield results the most promising variable for higher grain yield selection. Direct and simultaneous selections are the most suitable strategies for the set of evaluated variables. However, further studies on selection indices are necessary to maximize genetic gains. Highlights Variables with greater potential were identified for the selection of superior cultivars of cowpea in the semiarid region of Paraíba. The pod yield variable (PP) seems promising for cultivar selection considering higher grain yield (GY)

Nocardiosis in Cats - Clinical, Anatomopathological and Morphotintorial Characteristics

Background: Nocardiosis is an infectious bacterial disease that can cause cutaneous/ subcutaneous, pulmonary and systemic lesions in different species of domestic animals. The type of transmission occurs through mechanical lesions on the skin or contamination of wounds, in cases of skin involvement, inhalation of aerosols and ingestion of contaminated materials are involved in the pathogenesis of the respiratory and digestive form of the disease. This paper described 4 cases of nocardiosis in cats, addressing the clinical, anatomopathological and morphotintorial characteristics of Nocardia sp.Cases: Four cases of nocardiosis in cats were reviewed, in which data related to breed, sex, age, origin, clinical signs, macroscopic and histological lesions described in necropsy protocols were evaluated. The histological tissue sections stained with Hematoxylin and Eosin (HE) were evaluated in order to characterize the inflammatory response in each case. In addition, paraffin blocks of fragments from affected organ were selected to perform special histochemical staining techniques of Grocott Methenamine Silver (GMS), modified Ziehl-Neelsen, Gram Brown-Brenn and Giemsa stain which are the most characterized techniques used for histopathological diagnoses and it was also used an immunohistochemical test with polyclonal antibody anti-Nocardia sp. (non-commercial). The animals were adults of both sexes, mixed breed, not castrated and semi-domesticated. Neither immunosuppressive factors nor concomitant diseases were identified in the cases studied. The main clinical signs were apathy, anorexia, dehydration, phlegmon and draining tracts. Macroscopically, skin / subcutaneous tissue (3/4), skeletal muscle (2/4), lymph nodes (2/4), liver (2/4), omentum (1/4), spleen (1/4) were affected. In addition, it could be noted that mandibular bone (1/4), pleural tissue (1/4), left testicle (1/4) and Central Nervous System (CNS) (1/4) were also affected by this disease. Microscopically, regarding all cases, there was a pyogranulomatous inflammation in the affected organs. With respect to cases 1, 3 and 4, filamentous, branched, slightly basophilic structures in loose or individual aggregates in the interior of the pseudo-rosettes and in the necrotic areas were observed in the HE-stained tissue sections. In all cases submitted to special histochemical techniques, filamentous, branched, individual or loose aggregate structures were observed, the samples were impregnated with silver, and bacteria appear as blue using the Brown-Brenn Gram technique, and stained red in the modified Ziehl-Neelsen, and stained faintly pink in Giemsa stain. The bacteria were observed mainly in the border of the pyogranulomas, in the center of the pseudo-rosettes and in the necrotic areas, being compatible with the infection by Nocardia sp. All cases were positive for immunohistochemistry (IHC).Discussion: Nocardiosis was diagnosed in all cats in this study based on the anatomopathological findings associated with the visualization of the agent and its morphotintorial characteristics by using special histochemical stains and being confirmed by IHC. It occurs mainly in the cutaneous and/or subcutaneous tissues, with systemic involvement and death of the affected animals, in addition to affecting bone tissue considered an uncommon site for the disease. The diagnosis can be established based on the anatomopathological findings associated with the morphotintorial characteristics by using special histochemical stains, which are important for evidencing and morphologically characterizing the agent, as well as being confirmed by IHC.Keywords: disease in cat, pyogranulomatous inflammation, Nocardia sp.Título: Nocardiose em gatos - achados clínicos, anatomopatológicos e morfotintoriais Descritores: doença de gato, inflamação piogranulomatosa, Nocardia sp. 

SPATIAL VARIABILITY OF THE STABILITY OF COHESIVE SOIL AGGREGATES UNDER CONSERVATION PRACTICES

The knowledge and characterization of aggregate stability are relevant to select adequate management and to avoid its degradation. Thus, this work aimed to characterize the spatial variability of aggregate stability in cohesive soils under crop conservation systems. The experiment was performedin two different areas of soybean production: no-tillage System (NTS) and livestock farming integration system (LFI), In each production area, a sampling mesh composed of 50 collection points, with a regular spacing of 40 m, at 0.00-0.20 m depth, was carried out. The results were expressed as a percentage of aggregates retained in sieves 2; 1; 0.5 and 0.25 mm, the values obtained were used to calculate the Mean Geometric Diameter (MGD) and Mean Weight Diameter (MWD). In the LFI system, which had a strong degree of spatial dependence (DSD), the attributes showed a moderate DSD, except for MWD. Generally, the reached values of the attributes in the LFI system were lower than those found in the NTS system, showing less variability in the management system with no-tillage. Spatial distribution of the kriging maps demonstrated the LFI system leading to the formation of larger aggregates in the soil when compared to ones to the same attributes in the NTS. All attributes showed a strong to moderate spatial dependence. The soil managed with the LFI system revealed greater aggregate stability when compared to the NTS, which in turn presented less spatial variability than the LFI system and shows a more homogeneous soil.O conhecimento e a caracterização da estabilidade dos agregados são relevantes para selecionar um manejo adequado e evitar sua degradação. Portanto, este trabalho teve como objetivo caracterizar a variabilidade espacial da estabilidade de agregados em solos coesos sob sistemas de conservação de culturas. O experimento foi conduzido em duas áreas distintas de produção de soja: sistema de plantio direto (NTS) e sistema de integração pecuária (LFI). Foi realizada uma amostragem de 50 pontos de coleta, com espaçamento regular de 40 m, na profundidade de 0,00-0,20 m, em cada área de produção. Os resultados foram expressos como porcentagem de agregados retidos nas peneiras 2; 1; 0,5 e 0,25 mm, os valores obtidos foram utilizados para calcular o Diâmetro Médio Geométrico (DMM) e o Diâmetro Peso Médio (DMM). No sistema LFI, que possuía alto grau de dependência espacial (DDS), os atributos apresentaram um DSD moderado, exceto para MWD. De maneira geral, os valores de escopo dos atributos no sistema LFI foram inferiores aos encontrados no sistema NTS, apresentando menor variabilidade no sistema de manejo do plantio direto. A distribuição espacial dos mapas de krigagem mostrou que o sistema LFI leva à formação de agregados maiores no solo em comparação com outros com os mesmos atributos no NTS. Todos os atributos apresentaram dependência espacial de forte a moderada. O solo manejado com o sistema LFI revelou maior estabilidade dos agregados em relação ao NTS, que por sua vez apresentou menor variabilidade espacial do que o sistema LFI e apresenta um solo mais homogêneo

Coeficiente de erodibilidade em sulcos e entressulcos de Argissolos coesos estimado pela cor do solo

The objective of this work was to estimate the rill and interrill erodibility coefficient through soil color parameters. Three areas were selected, which were cultivated with soybean in cohesive Ultisols of the eastern region of the state of Maranhão, Brazil. In each area, 121 samples were collected at a depth of 0.00–0.20 m. The values of diffuse reflectance spectroscopy in the visible range were determined, in order to obtain the values of hue, value, and chroma. From these color constituents, the redness index was calculated for each sample. Models were developed to evaluate the effect of each color component on rill and interril erodibility. These components showed R2 ranging from 0.37 to 0.70. The generated models obtained R2 of 0.70 and 0.73 for interill and rill, respectively. Soil color determined by diffuse reflectance spectroscopy can be used as an alternative method to estimate the erodibility coefficient of cohesive Ultisols.O objetivo deste trabalho foi estimar o coeficiente de erodibilidade em sulcos e entressulcos, por meio de parâmetros da cor do solo. Foram selecionadas três áreas cultivadas com soja, em Argissolos Amarelos coesos do Leste Maranhense. Em cada área, foram retiradas 121 amostras na profundidade de 0,00–0,20 m. Foram determinados os valores de espectroscopia de reflectância difusa na faixa do visível, para obtenção dos valores de matiz, valor e croma. A partir destes constituintes da cor, foi calculado o índice de avermelhamento para cada amostra. Foram desenvolvidos modelos para avaliar o efeito de cada componente da cor sobre a erodibilidade em sulcos e entressulcos. Esses componentes apresentaram R2 que variou de 0,37 a 0,70. Os modelos gerados obtiveram R2 de 0,70 e 0,73, para entressulcos e sulcos, respectivamente. A cor do solo determinada por espectroscopia de reflectância difusa pode ser utilizada como método alternativo para estimar o coeficiente de erodibilidade de Argissolos Amarelos coesos

Diferentes densidades amostrais na caracterização da variabilidade espacial de atributos granulometricos de um argissolo amarelo distrocoeso típico

A amostragem adequada deve ser a menor possível, porém, com uma acurácia representativa, a fim de produzir resultados confiáveis. Nesse contexto, objetivou-se caracterizar a distribuição espacial dos atributos granulométricos de um Argissolo Amarelo distrocoeso típico, em função de diferentes densidades de amostragem. Foram estabelecidas três grades amostrais quadradas com 80, 100 e 121 pontos em uma área de produção de soja de 6,2 ha, na profundidade de 0,0-0,2 m. Foram analisados os atributos argila, silte e areia total. O coeficiente de variação indicou média variabilidade para argila e silte, e baixa variabilidade para areia total, nas três amostragens estudadas. O silte apresentou grau de dependência espacial forte nas três grades amostrais, enquanto a argila e areia total apresentaram grau de dependência espacial moderado nas três densidades de amostragem. O aumento do intervalo de amostragem e a redução do número de amostras não promoveram o aumento da raiz quadrada do erro médio e do quadrado médio do erro nas estimativas por krigagem nas diferentes intensidades amostrais estudadas. Não havendo diferença significativa entre estes parâmetros para as intensidades amostrais analisadas. Os mapas de krigagem demonstraram semelhança entre a distribuição espacial dos atributos nas três intensidades amostrais utilizadas. Em uma área de 6,2 ha, a quantidade de pontos amostrais (80, 100 e 121 pontos) não interferiu significativamente na análise da variabilidade espacial dos atributos granulométricos do solo e no detalhamento das informações dos mapas interpolados por krigagem