Respostas de enzimas antioxidantes a bioativador em plântulas de milho sob estresse hídrico.

Edição Especial contendo os Anais do XVIII Congresso Brasileiro de Sementes, Florianópolis, set. 2013

Caracterização do Sintoma Fadiga em Indivíduos após Acidente Vascular Encefálico: Revisão Sistemática

Introduction: The fatigue symptom is one of the most common post stroke. Objective: To present evidence about the characterization of the fatigue symptom resulting from stroke. Methodology: A systematic review of observational studies was carried out by searching the Cinahl, Cochrane, Embase, Eric, Bireme (Lilacs, Medline, Ibecs, Scielo), Library and Information Science Abstracts – LISA (ProQuest), PEDro, PsychInfo, Pubmed, Web of Science. The subject descriptors \u27stroke\u27, \u27fatigue\u27 and \u27perception\u27 were used. The procedures for the selection of studies and data extraction were independently developed by two reviewers. The selected studies were analyzed in full text, contemplating designs, sample characterization, methodology, results and conclusion. Results: Twelve studies were found and four were selected. The total sample consisted of 76 individuals diagnosed with stroke. There is no specific instrument to assess stroke-associated fatigue. There is no clear definition of post-stroke fatigue or consensus among individuals about its description and difference before and after stroke. Regarding the characteristics, fatigue is experienced in physical and mental aspects and described as muscular or mental tiredness, causing a great impact on quality of life. As for relief factors, sleep, rest, and aerobic exercises were the most listed. Conclusion: The fatigue symptom is common after stroke with a multidimensional nature, without a clear definition with biopsychosocial impact

Physiology and morphology of rice plants with silicon supplementation and Dietholate seed treatment under water deficit

Silicon is an enzyme stimulator that promotes signaling for the production of antioxidant, osmoprotective compounds and attenuates interference in photosynthesis in rice plants subjected to water deficit. The aim of this study was to evaluate the possible effects of silicon as a stress reliever in rice plants grown from seeds treated with dietholate under of water deficit conditions. The experimental design was fully randomized with three replicates, 144 experimental units consisting of pots containing 4.4 pounds soil, and a 3x2x2x4 factorial arrangement: three soil water conditions (50% and 100% of soil water retention capacity and water blade of 5.0 cm); two cultivars (IRGA 424 RI and Guri INTA CL); two sources of Si (sodium and potassium metasilicate); and four Si rates (0; 4.0; 8.0 and 16 g L-1). Silicon boosted stomatal density; induced an increase in the maximum photochemical efficiency of photosystem II (PSII) under both water deficit and optimal conditions, boosting photosynthesis; and increased effective quantum yield of PSII and levels of total dry mass. Thus, silicon attenuated the effects of water deficit in plants grown from seeds treated with dietholate

Leaf-Level Field Spectroscopy to Discriminate Invasive Species (Psidium guajava L. and Hovenia dulcis Thunb.) from Native Tree Species in the Southern Brazilian Atlantic Forest

Invasive species are known to have potential advantages over the native community and can be expressed in their leaf functional traits. Thus, leaf-level traits with spectral reflectance can provide valuable insights for distinguishing invasive trees from native trees in complex forest environments. We conducted field spectroscopy measurements in a subtropical area, where we also collected trait data for 12 functional traits of invasive (Psidium guajava and Hovenia dulcis), and native species (Psidium cattleianum and Luehea divaricata). We found that photosynthetic pigments were responsible for the greatest interspecific variability, especially in the green region of the spectrum at 550 nm, therefore contributing to detection of invasive species. In addition, according to LDA and stepwise procedures, the most informative reflectance spectra were concentrated in the visible range that is closely related to pigment absorption features. Furthermore, we aimed to understand the leaf optical properties of the target invasive species by using a combination of narrow bands and linear regression models. P. guajava showed high correlations with specific leaf area, Car/Chl and relative water content. H. dulcis had a strong correlation with water content, specific leaf area and Chla/Chlb. Overall, this methodology proved to be appropriate for discriminating invasive trees, although parameterization by species is necessary

SUBSTRATE AND FERTILIZATION IN THE QUALITY OF Myrocarpus frondosus SEEDLINGS

 Myrocarpus frondosus is a native species with high commercial timber value. Thus, the objective of this research was to evaluate the quality of seedlings of Myrocarpus frondosus in the nursery and to indicate the most adequate substrate and fertilization for the production of seedlings. The experiment was conducted in a completely randomized design, with four replications, in a factorial scheme, composed of four combinations of substrates: S1-100% commercial substrate (CS); S2 - 80% CS and 20% carbonated rice husk (CRH); S3 - 60% CS and 40% CRH; S4 - 40% CS and 60% CRH, and four fertilizations: NF – No fertilization; CRF – controlled release fertilizer (ammonium sulfate, simple superphosphate and potassium chloride); RRF – ready release fertilizer and micronutrients. Physical and chemical analyses were performed on the substrate. At 300 days after emergence, the following morphological variables were evaluated: (height, stem diameter, H/SD ratio, leaf area, root length, aerial dry mass, root dry mass, total dry mass, Dickson quality index) and the physiological variables chlorophyll a, chlorophyll b, carotenoids, initial fluorescence, maximum fluorescence, Fv/Fm ratio and electron transport rate). Regardless of the substrate and fertilization, slow growth of the species was observed, even for the best treatment, which was verified from the height (17.87 cm) and stem diameter (2.62 mm). The use of the commercial substrate (40%) with carbonated rice husk (60%) associated with the concentration of 6 g L-1 of controlled release fertilizer is recommended, since they present the best results for the morphological and physiological variables in the nursery in general

DIFFERENT SHADING INTENSITIES INTERFERE WITH THE GROWTH OF Myrocarpus frondosus ALLEMÃO SEEDLINGS IN THE NURSERY?

Native tree species present different responses depending on their adaptability to varying degrees of sunlight. The objective of this study was to evaluate the growth of Myrocarpus frondosus seedlings under different shade conditions in a nursery. The experimental design included randomized blocks in a factorial scheme, corresponding to treatments of full sun (0%), or one of three shading intensities (30%, 50%, and 70%), with evaluation times of 30, 90, 150, 210, 270, 330, and 390 days after emergence – d.a.e. The evaluation of the morphological attributes height (H) and stem diameter (SD) were determined every 60 days, and H/SD ratio were calculated. At 390 d.a.e, the following attributes were evaluated: aerial dry matter, (ADM), root dry matter (RDM), total dry matter, (TDM), Dickson quality index (DQI), leaf area (LA), root volume (RV), and root length. The pigment contents of chlorophyll a, chlorophyll b, and chlorophyll a/b ratio were also identified, along with carotenoid content, maximum quantum yield PSII (Fv/Fm), and electron transport rate (ETR). Myrocarpus frondosus requires shading in its initial stage of growth, at an ideal intensity of 50% or 70% for producing seedlings.

Susceptibility to weathering damage and oxidative stress on soybean seeds with different lignin contents in the seed coat.

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Toxicidade de cádmio e respostas de sensibilidade em Enterolobium contortisiliquum

Soil contamination with heavy metals brings with it several environmental problems. Among these metals, cadmium (Cd) stands out as an extremely harmful element to plant development and may even cause possible loss or suppression of vegetation in various soils worldwide. Thus, it is necessary to identify tolerant species to reestablish the ecological conditions of the environment. The present study aimed to evaluate Cd tolerance in Enterolobium contortisiliquum seedlings by assessing the effects of Cd on morphophysiological and biochemical variables and determining its potential as a phytoremediator species. The experimental design was completely randomized with four replications. Five Cd concentrations (0, 25, 50, 75, and 100 µmol L-1) were assessed. At the end of the exposure period to the treatments, we measured photosynthetic, morphological (shoot and root dry weight and root morphology), and biochemical (concentration of photosynthetic pigments, hydrogen peroxide content, membrane lipid peroxidation, and guaiacol peroxidase and superoxide dismutase activity) variables in plants. Even with the activation of antioxidant enzymes, cadmium concentrations negatively affected the photosynthetic pigments and  photosynthetic rate of Enterolobium contortisiliquum, which reduced biomass production and photosystem functions, evidencing its sensitivity to excess Cd. Based on these characteristics, E. contortisiliquum seedlings can be used as a bioindicator for cadmium-contaminated areas.A contaminação do solo por metais pesados traz consigo diversos problemas ambientais. Dentre esses metais, destaca-se o cádmio (Cd) como um elemento extremamente prejudicial ao desenvolvimento das plantas, podendo inclusive causar possível perda ou supressão da vegetação em diversos solos ao redor do mundo. Assim, é necessário identificar espécies tolerantes para restabelecer as condições ecológicas do ambiente. Neste estudo, o objetivo foi avaliar a tolerância ao Cd em mudas de Enterolobium contortisiliquum, avaliando os efeitos do Cd sobre variáveis morfofisiológicas e bioquímicas para determinar seu potencial como espécie fitorremediadora. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições, composto por cinco concentrações de Cd: 0, 25, 50, 75 e 100 µmol L-1. Ao final do período de exposição aos tratamentos, foram medidas as variáveis fotossintéticas, morfológicas (massa seca da parte aérea e da raiz e morfologia da raiz) e bioquímicas (concentração de pigmentos fotossintéticos, teor de peróxido de hidrogênio, peroxidação lipídica da membrana e atividade da guaiacol peroxidase e superóxido dismutase). Mesmo com a ativação de enzimas antioxidantes, as concentrações de cádmio afetaram negativamente os pigmentos fotossintéticos e a taxa fotossintética de Enterolobium contortisiliquum. Isso resultou em uma redução na produção de biomassa e nas funções do fotossistema, fato que indica sua sensibilidade ao excesso de Cd. Devido a essas características, mudas de E. contortisiliquum podem ser utilizadas como bioindicadoras de áreas contaminadas por cádmio

GROWTH AND PHYSIOLOGICAL ATTRIBUTES OF Cordia trichotoma SEEDLINGS IN RESPONSE TO FERTILIZATION WITH PHOSPHORUS AND POTASSIUM

The cultivation of native tree species of economic and environmental interest, such as Cordia trichotoma, still depends on nutritional information. This study aimed to identify the effect of phosphorus (P) and potassium (K) application on the growth and photosynthetic activity of seedlings of Cordia trichotoma. In a greenhouse, ten treatments were tested considering three levels of P (150, 300, and 450 mg dm-3 ), three of K (50, 100, and 150 mg dm-3 ) and a control sample (with no fertilization). Pots filled with Red Argisol were used. At 180 days after prick, the following variables were evaluated: shoot height, stem diameter, area dry matter, root dry weight, leaf area, chlorophyll a fluorescence and photosynthetic pigments. The supplementation with P and K promoted increased growth and photosynthetic capacity of the seedlings. The treatment with 450 mg dm-3 of P and 50 mg dm-3 of K provided the highest growth and the best use of the light energy by the photosystem II (Fv/Fm = 0.76), as well as lower energy loss index (Fo = 172.5). It is recommended the application of 450 mg dm-3 of P and 50 mg dm-3 of K, with the aim at higher growth and photosynthetic rate of seedlings of C. trichotomaThe cultivation of native tree species of economic and environmental interest, such as Cordia trichotoma, still depends on nutritional information. This study aimed to identify the effect of phosphorus (P) and potassium (K) application on the growth and photosynthetic activity of seedlings of Cordia trichotoma. In a greenhouse, ten treatments were tested considering three levels of P (150, 300, and 450 mg dm-3), three of K (50, 100, and 150 mg dm-3) and a control sample (with no fertilization). Pots filled with Red Argisol were used. At 180 days after prick, the following variables were evaluated: shoot height, stem diameter, area dry matter, root dry weight, leaf area, chlorophyll a fluorescence and photosynthetic pigments. The supplementation with P and K promoted increased growth and photosynthetic capacity of the seedlings. The treatment with 450 mg dm-3 of P and 50 mg dm-3 of K provided the highest growth and the best use of the light energy by the photosystem II (Fv/Fm = 0.76), as well as lower energy loss index (Fo = 172.5). It is recommended the application of 450 mg dm-3 of P and 50 mg dm-3 of K, with the aim at higher growth and photosynthetic rate of seedlings of C. trichotoma