Induction of tolerance to salt stress in soursop seedlings using hydrogen peroxide

The exogenous use of hydrogen peroxide is an alternative in the acclimatization of plants to salt stress due to the greater activity of antioxidant enzymes. In this perspective, this study aimed to evaluate the gas exchange and the growth of soursop seedlings under salt stress using hydrogen peroxide. The study was conducted under greenhouse conditions. The treatments were distributed in randomized blocks, in a 5 x 2 factorial arrangement, related to five levels of electrical conductivity of the irrigation water - ECw (0.6, 1.2, 1.8, 2.4, and 3.0 dS m-1) and two concentrations of hydrogen peroxide - H2O2 (0 and 20 μM), with four replicates and two plants per plot. The effects of the treatments were evaluated by the variables of gas exchange and growth. The increase in water salinity negatively affected the gas exchange and the growth of the soursop seedlings. The gas exchange and growth variables presented deleterious effects caused by the salinity of the irrigation water, mitigated by the exogenous application of hydrogen peroxide at the concentration of 20 μM. The exogenous use of hydrogen peroxide at the concentration of 20 μM can be used to induce salt tolerance in soursop seedlings.The exogenous use of hydrogen peroxide is an alternative in the acclimatization of plants to salt stress due to the greater activity of antioxidant enzymes. In this perspective, this study aimed to evaluate the gas exchange and the growth of soursop seedlings under salt stress using hydrogen peroxide. The study was conducted under greenhouse conditions. The treatments were distributed in randomized blocks, in a 5 x 2 factorial arrangement, related to five levels of electrical conductivity of the irrigation water - ECw (0.6, 1.2, 1.8, 2.4, and 3.0 dS m-1) and two concentrations of hydrogen peroxide - H2O2 (0 and 20 μM), with four replicates and two plants per plot. The effects of the treatments were evaluated by the variables of gas exchange and growth. The increase in water salinity negatively affected the gas exchange and the growth of the soursop seedlings. The gas exchange and growth variables presented deleterious effects caused by the salinity of the irrigation water, mitigated by the exogenous application of hydrogen peroxide at the concentration of 20 μM. The exogenous use of hydrogen peroxide at the concentration of 20 μM can be used to induce salt tolerance in soursop seedlings

Growth and physiology of Annona squamosa L. under different irrigation depths and phosphate fertilization

This study aimed to evaluate the growth and physiology of Annona squamosa seedlings under increasing irrigation depths and phosphorus doses. The experiment was conducted in protected environment, evaluating five irrigation depths and four P2O5- doses, arranged in 5 x 4 factorial scheme, in randomized blocks, with four replicates and one plant per plot. Treatments were irrigation depths of 60, 80, 100, 120 and 140% of the real evapotranspiration of the seedlings – ETr and phosphorus doses of 0, 350, 700 and 1050 mg dm-3 of P2O5-. Plants were evaluated at 120 days after transplanting with respect to growth, gas exchanges, leaf water potential and total dry matter accumulation. Phosphorus dose of 350 mg dm-3 promotes satisfactory dry matter accumulation for A. squamosa seedlings, especially under 100% ETr irrigation. Leaf water potential and gas exchanges of A. squamosa are affected by water stress, through both lack and excess of water. Stomatal conductance is the variable most sensitive to the lack of water, whereas photosynthesis and water use efficiency are the most sensitive to the excess of water. Irrigation depth of 100% ETr is ideal to produce A. squamosa seedlings, but the irrigation depth of 80% ETr can be used to produce these seedlings, disregarding small losses of growth

Morfofisiologia de porta-enxerto de goiabeira irrigado com águas salinizadas sob doses de nitrogênio

The irrigation with saline water reduces crop growth and yield, resulting in the need of new techniques that enable the use of this natural resource in fruit growing. In this sense, the objective of this study was to evaluate the effect of saline irrigation water associated with different nitrogen doses on guava rootstock cv. Paluma morphophysiology. The experiment was carried out in a completely randomized blocks design, testing 5 electrical conductivity of irrigation water - ECw (0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1) and four nitrogen doses for fertilization (541.1; 773.0; 1004.9 and 1236.8 mg dm-3), in a 5x4 factorial, with four repetitions. The increase in the ECw from 0.3 dS m-1 negatively affected the morphophysiology of guava rootstock cv. Paluma, especially during the younger phase of the crop. The N dose of 541 mg dm-3 stimulated the increase of most morphophysiological variables in guava rootstock during the period studied. The nitrogen fertilization did not reduced the salt stress effect on the evaluated variables.A irrigação com água salina reduz a crescimento e a produtividade das culturas, havendo necessidade de técnicas que possibilitem o uso deste recurso natural de forma viável na fruticultura. Neste sentido, objetivou-se com o trabalho avaliar o efeito da salinidade da água de irrigação associado a distintas doses de nitrogênio sob a morfofisiologia de porta-enxerto de goiabeira cv. Paluma. Foi utilizado blocos inteiramente casualizado, testando 5 condutividades elétricas da água de irrigação - CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e 4 doses de adubação nitrogenada (541,1; 773,0; 1004,9 e 1236,8 mg dm-3), em esquema fatorial 5 x 4, com 4 repetições. O aumento da CEa a partir de 0,3 dS m-1 afetou negativamente a morfofisiologia de porta-enxerto de goiabeira cv. Paluma, principalmente, na fase mais jovem. A dose de N de 541,1 mg dm-3 estimulou o crescimento da maioria das variáveis nos porta-enxerto de goiabeira nos períodos estudados. A adubação nitrogenada não reduziu o efeito do estresse salino sobre as variáveis avaliadas

Colicistite aguda alitiásica condutas que reduzem a taxa de internação em Terapia de Unidade Intensiva: uma revisão sistemática: Acute althiasic cholicistitis conducts that reduce the hospitalization rate in Intensive Unit Therapy: a systematic review

Os cálculos biliares se encontram em mais de 10% da população mundial, sendo que esta incidência se torna maior com o avanço da idade. Sendo assim a colecistite pode ser considerada como uma emergência comum no mundo, sendo que na maior parte dos casos é decorrente da inflamação da parede interna da vesícula devido á impactação do cálculo e decorrente obstrução no ducto cístico, produzindo assim dor repentina e aguda, entretanto a colecistite aguda alitiásica ocorre sem que haja cálculos em seu interior. Esse trabalho possui como sua pergunta de pesquisa qual conduta deve ser adotada para reduzir a taxa de internação em UTI’s em pacientes que apresentem colicistite aguda alitiásica. E assim como seu objetivo geral demonstrar a conduta adequada para manejo de pacientes que apresentem colicistite aguda alitiásica. E como seus objetivos específicos: Identificar do que se trata um quadro de colicistite aguda alitiásica; Auxiliar na tomada de conduta pelos profissionais acerca do tratamento adequado; Disponibilizar informações acerca do assunto. Esse trabalho trata-se de uma revisão sistemática de artigos extraídos das plataformas do PubMed, BVS, Lilacs, Medline, Scielo, esses que possuem datas dos últimos 5 anos e escritos nos seguintes idiomas: português, inglês e espanhol. Com isso conclui-se que ainda são escassos os estudos acerca do tema, portanto é necessário que os médicos consigam de forma significativa o diagnóstico com agilidade, e para isso o conhecimento sobre assunto por uma equipe multidisciplinar deve ser amplamente desenvolvido

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

Crescimento do algodoeiro colorido pós-poda em solos com distintas PSTs e doses de esterco

The research was conducted in protected environment in the CCTA / UFCG which aimed to evaluate the growth of naturally colored hp fiber cotton plants. BRS Topaz, the second post-pruning production cycle in saline-sodic soils manure. It used the randomized block design in a factorial 5 x 4, with 3 repetitions and the treatments consisted of five percentages of exchangeable sodium - PST (13.6; 22.4; 30.1; 39.0 and 48.0 %) and four doses of cattle manure (0, 5, 10 and 15%). To cease production of cotton plants (first cycle) held a drastic pruning, where, after the shoots (second cycle) were evaluated after 51 and 91 days after pruning (DAP) variables: branch length (CR), branch diameter (DR), stem diameter (DC) and number of leaves (NF). Doses of 10% organic matter favored branch length and 15% of the diameter of the branch and cotton plants cv stem. BRS Topaz after 51 and 91 days after pruning. Exchangeable sodium in percentages of up to 48% did not influence the length and diameter of branches, the stem diameter and the number of cotton leaves at 51 and 91 days after pruning. The interaction between the factors (PST x MO) has promoted significant effect on stem diameter of cotton plants at 91 DAP.A pesquisa foi conduzida em ambiente protegido no CCTA/UFCG onde objetivou-se avaliar o crescimento de plantas de algodoeiro de fibra naturalmente colorida cv. BRS Topázio, no segundo ciclo produtivo pós-poda, em solos salino- sódico sob esterco bovino. Usou-se o delineamento de blocos casualizados em esquema fatorial 5 x 4, com 3 repetições, cujos tratamentos consistiram de cinco percentagens de sódio trocável - PST (13,6; 22,4; 30,1; 39,0 e 48,0%) e quatro doses de esterco bovino (0; 5; 10 e 15%). Ao encerrar a produção das plantas de algodoeiro (primeiro ciclo) realizou-se uma poda drástica, onde, após as brotações (segundo ciclo) avaliaram-se aos 51 e 91 dias após a poda (DAP) as variáveis: comprimento do ramo (CR), diâmetro do ramo (DR), diâmetro do caule (DC) e número de folhas (NF). Doses de 10% de matéria orgânica favoreceu o comprimento do ramo e, de 15% o diâmetro do ramo e do caule de plantas de algodoeiro cv. BRS Topázio aos 51 e 91 dias após a poda. Percentagens de sódio trocável de até 48% não influenciou o comprimento e o diâmetro de ramos, o diâmetro do caule e o número de folhas do algodoeiro aos 51 e 91 dias após a poda. A interação entre os fatores (PST x MO) promoveu efeito significativo sobre o diâmetro do caule de plantas de algodoeiro aos 91 DAP

Crescimento de porta-enxerto de goiabeira sob águas salinizadas e doses de nitrogênio

A salinidade da água de irrigação pode afetar a exploração de cultivos principalmente nas regiões áridas e semiáridas, entretanto, algumas alternativas podem favorecer a exploração agrícola nestas condições. Desse modo, objetivou-se com este trabalho, avaliar a interação entre adubação nitrogenada e a salinidade da água de irrigação sob o crescimento de porta-enxerto de goiabeira ‘Crioula’ em condição de semiárido do nordeste do Brasil. O experimento foi conduzido em tubetes sob condições de ambiente protegido no CCTA/UFCG. Utilizou-se o delineamento experimental em blocos casualizados, com os tratamentos dispostos em esquema fatorial 5 x 4, correspondentes a  cinco níveis de condutividade elétrica da água – CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e quatro doses de nitrogênio (70, 100, 130 e 160% de N da dose recomendada para a cultura), com 4 repetições e 5 plantas por parcela. A dose de 70% de N (541,1 mg de N dm-1 de solo) proporciona maior diâmetro de caule de porta-enxerto de goiabeira crioula aos 70 e 145 dias após a emergência (DAE), sobre a área foliar e altura de planta aos 145 DAE e na taxa de crescimento absoluto diâmetro do caule dos 25 a 145 DAE. A irrigação com água cuja salinidade era acima de 0,3 dS m-1 afeta positivamente a razão de área foliar e de forma negativa, o número de folhas, a área foliar e o diâmetro do caule. Houve interação significativa entre os fatores adubação nitrogenada e salinidade da água de irrigação apenas para a variável número de folhas aos 145 DAE.Guava rootstocks growth in salted water and nitrogen levelsAbstract: Salt stress suffered by plants due to concentration of irrigation water salts reduces the ability of exploitation of cultures especially in arid and semiarid regions. Thus, the aim of this study was to evaluate the effect of salinity of irrigation water on the growth of rootstock of guava 'Crioula' associated with increasing doses of nitrogen fertilizer. The experiment was conducted in plastic pots under greenhouse conditions in the CCTA / UFCG. We used the experimental randomized block design, with the treatments in a factorial 5 x 4, corresponding to five levels of electrical conductivity of the water - CEa (0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1) and four nitrogen rates (70, 100, 130 and 160% of the recommended dose N for guava cultivation seedlings cv. Paluma) with 4 replications and 5 plants per plot. The dose of 70 % of N- ( 541.1 mg N dm- 1 of soil ) provides greater production plant leaf area, height 145 DAE , but to stem diameter was significant in both periods studied the rootstock guava cv. Crioula. Irrigation CEa above 0.3 dS m-1 negatively affect the number of leaves, leaf area, stem diameter, leaf area ratio and absolute growth rate of stem diameter. There was interaction between the factors salinity of irrigation water and nitrogen fertilization for variable number of leaves at 145 DAE rootstock of guava "Crioula"

Crescimento de porta-enxerto de goiabeira sob águas salinizadas e doses de nitrogênio

Salt stress suffered by plants due to concentration of irrigation water salts reduces the ability of exploitation of cultures especially in arid and semiarid regions. Thus, the aim of this study was to evaluate the effect of salinity of irrigation water on the growth of rootstock of guava 'Crioula' associated with increasing doses of nitrogen fertilizer. The experiment was conducted in plastic pots under greenhouse conditions in the CCTA / UFCG. We used the experimental randomized block design, with the treatments in a factorial 5 x 4, corresponding to five levels of electrical conductivity of the water - CEa (0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1) and four nitrogen rates (70, 100, 130 and 160% of the recommended dose N for guava cultivation seedlings cv. Paluma) with 4 replications and 5 plants per plot. The dose of 70 % of N- ( 541.1 mg N dm- 1 of soil ) provides greater production plant leaf area, height 145 DAE , but to stem diameter was significant in both periods studied the rootstock guava cv. Crioula. Irrigation CEa above 0.3 dS m-1 negatively affect the number of leaves, leaf area, stem diameter, leaf area ratio and absolute growth rate of stem diameter. There was interaction between the factors salinity of irrigation water and nitrogen fertilization for variable number of leaves at 145 DAE rootstock of guava "Crioula".A salinidade da água de irrigação pode afetar a exploração de cultivos principalmente nas regiões áridas e semiáridas, entretanto, algumas alternativas podem favorecer a exploração agrícola nestas condições. Desse modo, objetivou- se com este trabalho, avaliar a interação entre adubação nitrogenada e a salinidade da água de irrigação sob o crescimento de porta-enxerto de goiabeira „Crioula‟ em condição de semiárido do nordeste do Brasil. O experimento foi conduzido em tubetes sob condições de ambiente protegido no CCTA/UFCG. Utilizou-se o delineamento experimental em blocos casualizados, com os tratamentos dispostos em esquema fatorial 5 x 4, correspondentes a cinco níveis de condutividade elétrica da água – CEa (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e quatro doses de nitrogênio (70, 100, 130 e 160% de N da dose recomendada para a cultura), com 4 repetições e 5 plantas por parcela. A dose de 70% de N (541,1 mg de N dm-1 de solo) proporciona maior diâmetro de caule de porta-enxerto de goiabeira crioula aos 70 e 145 dias após a emergência (DAE), sobre a área foliar e altura de planta aos 145 DAE e na taxa de crescimento absoluto diâmetro do caule dos 25 a 145 DAE. A irrigação com água cuja salinidade era acima de 0,3 dS m-1 afeta positivamente a razão de área foliar e de forma negativa, o número de folhas, a área foliar e o diâmetro do caule. Houve interação significativa entre os fatores adubação nitrogenada e salinidade da água de irrigação apenas para a variável número de folhas aos 145 DAE