Effect of two sources of zinc on the physiological quality of seed and nutrition of rice (Oriza sativa) seedlings

Rice seeds coating with microparticulate zinc oxide can maximize the absorption of this micronutrient by the seedling and favor seeds vigor when compared with zinc sulfate. This work aimed to evaluate the sources and doses of zinc in seed quality and in the nutrition of rice seedlings. The experiment consisted of a completely randomized design with four replications, five doses of zinc in the form of oxide (0; 20; 40, 80 and 160 g kg-1), and a control treatment of zinc in the form of sulfate (40 g kg-1). The following parameters were evaluated: germination, accelerated aging, seedlings emergence, emergence speed index, cold test, dry matter, and zinc concentration in the root and shoot of the seedlings. Seed coating with zinc, regardless of the source, improved seed physiological quality and seedling nutrition of the rice cultivar. Zinc sources did not change the germination; however, the oxide form provided better seed vigor, except for the highest dose (160 g kg-1). The increase in the dose of zinc oxide increased the concentration of this nutrient in rice seedlings dry matter. Zinc coating of rice seeds in the form of microparticulate, depending on the dose, can maximize the seeds vigor and increase the concentration of this micronutrient in the seedlings when compared with zinc sulfate, which is the traditional source used by producers. Highlights Zinc (Zn) coating does not affect germination, but influences the vigor of rice seeds. The Zn sources affect the Zn concentration in the shoot dry matter. Both ZnO and ZnSO 4 showed higher shoot dry matter, when compared with the absence of Zn in rice seeds. Oxide zinc (ZnO) promotes greater root dry matter of rice when compared with zinc sulfate (ZnSO 4 ).Rice seeds coating with microparticulate zinc oxide can maximize the absorption of this micronutrient by the seedling and favor seeds vigor when compared with zinc sulfate. This work aimed to evaluate the sources and doses of zinc in seed quality and in the nutrition of rice seedlings. The experiment consisted of a completely randomized design with four replications, five doses of zinc in the form of oxide (0; 20; 40, 80 and 160 g kg-1), and a control treatment of zinc in the form of sulfate (40 g kg-1). The following parameters were evaluated: germination, accelerated aging, seedlings emergence, emergence speed index, cold test, dry matter, and zinc concentration in the root and shoot of the seedlings. Seed coating with zinc, regardless of the source, improved seed physiological quality and seedling nutrition of the rice cultivar. Zinc sources did not change the germination; however, the oxide form provided better seed vigor, except for the highest dose (160 g kg-1). The increase in the dose of zinc oxide increased the concentration of this nutrient in rice seedlings dry matter. Zinc coating of rice seeds in the form of microparticulate, depending on the dose, can maximize the seeds vigor and increase the concentration of this micronutrient in the seedlings when compared with zinc sulfate, which is the traditional source used by producers. Highlights Zinc (Zn) coating does not affect germination, but influences the vigor of rice seeds. The Zn sources affect the Zn concentration in the shoot dry matter. Both ZnO and ZnSO 4 showed higher shoot dry matter, when compared with the absence of Zn in rice seeds. Oxide zinc (ZnO) promotes greater root dry matter of rice when compared with zinc sulfate (ZnSO 4 )

Physiological, biochemical, and ultrastructural characterization of selenium toxicity in cowpea plants

Selenium (Se) is considered a beneficial element for plants; however, in high concentrations, it causes negative effects on plant physiology and development. This study reports the first physiological, nutritional, and ultrastructural description of Se toxicity in cowpea growing under field conditions. Selenium was supplied as a foliar application of sodium selenite at varying concentrations (0, 50, 100, 200, 400, 800, 1200, and 1600 g ha−1). An increased yield was observed with the application of 50 g ha−1 Se. Application of concentrations higher than 50 g ha−1 caused leaf toxicity. Increased lipid peroxidation and hydrogen peroxide concentration and reduced total sugars, sucrose, and carotenoid concentration were observed at highest doses tested (1200 and 1600 g ha−1). Applications of more than 50 g ha−1 Se reduced the phloem diameter, caused chlorosis of the leaf blade with a coalescence of lesions, and caused pink salt deposits to appear. Lesions were observed mainly near the trichomes on the adaxial surface of the leaf blade. An analysis of the element distribution with microprobe X-ray fluorescence spectrometry (μ-XRF) revealed accumulation of Se, calcium (Ca), potassium (K), copper (Cu), and manganese (Mn) near the primary vein and in the necrotic brown areas of the leaf lesions. In contrast, Na was homogeneously distributed in the leaf tissue

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Teste de germinação em sementes de Cucumis metuliferus E. Mey

O kino (Cucumis metuliferus E. Mey) é uma olerícola de ampla distribuição geográfica, com aumento significativo em relação à comercialização no mundo inteiro, devido não só à sua vida útil ser muito longa em temperatura ambiente, como também pela constante busca do mercado consumidor por produtos exóticos. Assim, a demanda e a comercialização de suas sementes estão aumentando, gerando a necessidade do estabelecimento de padrões estaduais e federais e do desenvolvimento de metodologias adequadas para a avaliação da qualidade delas. Dessa maneira, o objetivo deste trabalho foi determinar a metodologia quanto ao substrato, temperatura e tempo de contagem para o teste de germinação em sementes de kino. As avaliações constaram de quatro substratos: rolo de papel, sobre papel, entre areia e sobre areia e quatro temperaturas: 20, 25 e 30°C constantes e 20-30°C alternada. O efeito dos substratos e temperaturas sobre o desempenho das sementes foi avaliado pelo teste de germinação, índice de velocidade e tempo médio de germinação. O experimento foi instalado em delineamento inteiramente ao acaso, com os tratamentos distribuídos em esquema fatorial 4 x 4 (substratos x temperaturas), com quatro repetições. O teste de germinação em sementes de kino deve ser realizado no rolo de papel, à temperatura constante de 25°C ou alternada de 20-30°C, com a contagem inicial e final, no quinto e décimo dia, respectivamente

Bioprospecção de bactérias solubilizadoras de fosfato em solos com diferentes fertilidades

As bactérias solubilizadoras de fosfato (BSF) possuem capacidade para liberar o fósforo (P) que está adsorvido no solo, convertendo fosfato insolúvel em formas solúveis, tornando-o disponível para a absorção pelas plantas. Estas bactérias podem ser encontradas naturalmente no ambiente, tendo o solo como maior reservatório. Além de serem consideradas benéficas e seguras, as BSF representam uma alternativa viável para uso agrícola, pois podem ser multiplicadas e devolvidas à rizosfera (inoculantes, bioestimulantes, biofertilizantes, biopesticidas) para estimular o crescimento das plantas por meio de mecanismos diretos e/ou indiretos. No entanto, encontrar isolados eficientes e adaptados às diversas culturas e sistemas de cultivo permanece um grande desafio. Esta pesquisa teve por objetivo prospectar BSF a partir do solo de diferentes áreas e selecionar, por meio de ensaios in vitro, cepas eficientes e com maior potencial para uso agrícola, bem como, avaliar os efeitos da inoculação em sementes de arroz de terras altas. A partir de amostras de solo coletadas em área conservada do bioma Amazônia, área agrícola produtiva do bioma Cerrado e área degradada com subsolo exposto do bioma Cerrado, foram obtidos 32 isolados solubilizadores. Destes, três foram selecionados pela capacidade de solubilização in vitro para fosfato de cálcio e/ou fosfato de ferro, e com início de solubilização precoce. Identificados como Pantoea sp., Enterobacter sp. e Klebsiella sp., os mesmos não apresentaram danos à sanidade das sementes de arroz, ou à germinação e emergência das plântulas, além de promoverem aumento do comprimento das raízes

Studying the link between physiological performance of Crotalaria ochroleuca and the distribution of Ca, P, K and S in seeds with X-ray fluorescence.

This study describes the use of X-ray fluorescence spectroscopy in Crotalaria ochroleuca seed technology. This work evaluated X-ray fluorescence techniques to estimate the physiological performance of different C. ochroleuca seed coat colours based on the concentration and distribution of Ca, P, K, and S in seed structures. The treatments consisted of seeds separated by coat colours (yellow, green, and red) and a control treatment (colour mix according to their natural occurrence in commercial lots), and was carried out in a completely randomized design, with four replications. The physiological performance was evaluated by analyzing the water content, germination, first germination count, germination speed index, electrical conductivity, seedling emergence, and seedling length and dry mass. X-ray fluorescence spectroscopy techniques were carried out with quantitative analyses (Ca, P, K, and S concentration in the seed coat and the whole seed) and qualitative analyses (macronutrient mapping). The EDXRF and μ-XRF techniques are efficient and promising to differentiate the physiological performance of C. ochroleuca seeds, based on the concentration and distribution of Ca, P, K, and S in different structures. Ca is predominant in the seed coat, and K, S, and P are found throughout the embryonic axis. Seeds of yellow and green coats have higher nutrients concentration and distribution in the embryonic axis, revealing high germinative capacity and physiological performance. Seeds of red coat have higher nutrients concentration in the seed coat and lower assimilation, showing less vigour, which interferes directly in the quality of commercial lots

Relações entre profissionais de saúde e usuários durante as práticas em saúde Relationships between health professionals and users throughout health care practices

Apresenta-se uma revisão integrativa sobre estudos que abordam as relações entre profissionais de saúde e usuários durante as práticas em saúde. Objetivou-se identificar os aspectos pesquisados no cotidiano dos serviços acerca dessas relações. A coleta foi realizada nas bases Lilacs e Pubmed segundo os descritores: acolhimento; relações profissional-família; relações profissional-paciente; humanização da assistência; e a palavra 'vínculo' associada ao descritor Sistema Único de Saúde. Selecionaram-se 290 estudos publicados entre 1990 e 2010. Por meio da análise temática, foram criados cinco núcleos de sentido: a relevância da confiança na relação profissional-usuário; sentimentos e sentidos na prática do cuidado; a importância da comunicação nos serviços de saúde; modo de organização das práticas em saúde; e (des)colonialismo. Identificou-se que as relações estabelecidas nas práticas de saúde têm uma dimensão transformadora. No entanto, permanece o desafio de humanizar os serviços de saúde. A enfermagem se destaca na produção do conhecimento nessa temática.<br>This article presents an integrative review about studies that address the relationships between health professionals and users in health care practices. It aimed to identify aspects that were researched on the daily life of the services concerning such relationships. Data were collected from the Lilacs and Pubmed databases based on these descriptors: user embracement; professionalfamily relations; professionalpatient relations; humanization of the care; and the bonding word associated to the Single Health System descriptor. Two hundred and ninety studies, published from 1990 to 2010, were selected. Through thematic analyses, five meaning cores were created: the relevance of the confidence in the professionaluser relationship; feelings and senses in the health care practice; the importance of communications in health care services; ways to organize health care practices and (de)colonialism. It was found that relationships established in health care practices have a transformative dimension. However, the challenge to humanize health care services remains. Nursing stands out in the production of knowledge on such theme