110 research outputs found

    Molecular and morphophysiological responses cocoa leaves with different concentrations of anthocyanin to variations in light levels

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    Theobroma cacao gives higher yield when cultivated in full sun under irrigation system with fertilization, because is a species little conservative in relation the efficiency of water use. On the other hand, T. cacao is usually cultivated under shade conditions in ‘Cabruca’ and agroforestry systems but with low yield. It has been observed under field conditions that the genotypes of T. cacao with high concentration of anthocyanins in young leaves are more tolerant to high irradiance stress when grown in full sun. The accumulation of flavonoids or other UVabsorbing compounds in the leaf epidermis is one of the most important mechanisms to screening out UV-B radiation. The aim of this study was to evaluate the effects of different levels of light on three clonal cacao genotypes (‘Catongo’, SCA-6 and SJ-2), contrasting in relation to accumulation of anthocyanin levels in young leaves, by evaluations of photosynthesis, activity of guaiacol peroxidase (GPX), chloroplastid pigment contents and vacuolar (anthocyanins) flavonoids contents, anatomical characteristics and gene expression of the leaf. In summary, (i) the anthocyanins contents in leaf level did not provide protection against photoinhibition in T. cacao, (ii) the ‘Catongo’ and SJ-2 genotypes showed greater phenotypic plasticity to the morphology and the chloroplastidic pigment contents in the leaf, while the SCA-6 genotype allocated more in the flavonoids content and hsp70 gene expression; (iii) the relative expression of the genes psbA and psbO, did not vary between genotypes under irradiance stress

    Molecular and morphophysiological responses cocoa leaves with different concentrations of anthocyanin to variations in light levels

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    Theobroma cacao gives higher yield when cultivated in full sun under irrigation system with fertilization, because is a species little conservative in relation the efficiency of water use. On the other hand, T. cacao is usually cultivated under shade conditions in ‘Cabruca’ and agroforestry systems but with low yield. It has been observed under field conditions that the genotypes of T. cacao with high concentration of anthocyanins in young leaves are more tolerant to high irradiance stress when grown in full sun. The accumulation of flavonoids or other UVabsorbing compounds in the leaf epidermis is one of the most important mechanisms to screening out UV-B radiation. The aim of this study was to evaluate the effects of different levels of light on three clonal cacao genotypes (‘Catongo’, SCA-6 and SJ-2), contrasting in relation to accumulation of anthocyanin levels in young leaves, by evaluations of photosynthesis, activity of guaiacol peroxidase (GPX), chloroplastid pigment contents and vacuolar (anthocyanins) flavonoids contents, anatomical characteristics and gene expression of the leaf. In summary, (i) the anthocyanins contents in leaf level did not provide protection against photoinhibition in T. cacao, (ii) the ‘Catongo’ and SJ-2 genotypes showed greater phenotypic plasticity to the morphology and the chloroplastidic pigment contents in the leaf, while the SCA-6 genotype allocated more in the flavonoids content and hsp70 gene expression; (iii) the relative expression of the genes psbA and psbO, did not vary between genotypes under irradiance stress

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Growth reduction effects of paclobutrazol applied at different cacao seedling stages

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    Foram avaliados os efeitos do paclobutrazol na morfologia e crescimento de plântulas de cacau (Theobroma cacao L.). O experimento foi disposto em quatro blocos ao acaso num arranjo de parcelas subdivididas, com quatro repetições. Nas parcelas foram de­signados estágios de crescimento (folhas cotiledonares maduras, primeiro, segundo e terceiro lançamentos), e nas subparcelas, dosagens de paclobutrazol (0, 30 e 60 ppm). Foram realizadas mensurações periódicas do diâmetro, altura e número de folhas. No final do experimento, foram determinados a área foliar e os pesos secos da raiz, caule e folhas. A aplicação de paclo­butrazol diminuiu o diâmetro, a altura, o número de folhas e a área foliar total das plântulas. O efeito dependeu da concentração e do estágio de crescimento. O peso seco de todas as par­tes da planta diminuiu com a aplicação de paclobutrazol. As maiores reduções nos pesos secos da raiz, caule e folhas (74%, 82% e 77%, respectivamente) foram encontradas na combinação 60 ppm-folhas cotiledonares. A menor redução foi no tratamento 60 ppm-terceiro lançamento (22%, 38% and 39% para raiz, caule e folhas, respectivamente). Houve mais partição de assimilados para a raiz do que para a parte aérea, na maioria das combinações.The effects of paclobutrazol on the morphological and growth characteristics of cacao (Theobroma cacao L.) seedlings were evaluated. The experiment was arranged in four randomized blocks in a split-plot lay-out. Main plots were assigned to growth stages (mature cotyledonary leaves, first, second and third flushes) and sub-plots to paclobutrazol dosages (0, 30, and 60 ppm). Periodic measurements were taken of stem diameter, height and leaf number. At the end of the experiment leaf area and dry weights of root, stem and leaves were obtained. In general, paclobutrazol decreased diameter, height, leaf number and leaf area in all concentrations. The effect depended on concentration and stage of growth. Dry weight of all plant parts decreased with the application of paclobutrazol. The highest root, stem and leaf dry weight reductions, 74%, 82% and 77%, respectively, were found at the 60 ppm-cotyledonary stage treatment. The lowest reduction was at the 60 ppm-third flush combination (22%, 38% and 39% for root, stem and leaf, respectively). There was more partitioning of assimilates to roots than to shoots in most of the treatment combinations

    Photosynthetic irradiance-response in leaves of dwarf coconut palm (Cocos nucifera L. ‘nana’, Arecaceae): Comparison of three models

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    Experimental data of irradiance-response curves of photosynthesis, obtained from independent experiments with the Brazilian Green Dwarf coconut palm genotype, were used to fit three empirical models with the aim to compare their adequacies. The non-rectangular and rectangular hyperbolas and the exponential models were compared. The rectangular hyperbola and the exponential models were quantitatively adequate to describe the irradiance-response of photosynthesis in dwarf coconut in all the situations studied. The photosynthetic parameters showed good correlation with the measured values when estimated by the rectangular hyperbola and exponential but the later estimated a more realistic light-saturated rate and the apparent quantum yield of photosynthesis. The NRH was less adequate for estimate the light-saturated photosynthesis and dark respiration universally, but could be used for research purposes since it contains an important qualitative parameter, the convexity term relating physical to total resistances to CO2 diffusion into the chloroplasts. The results allow suggesting the exponential model as a rapid, simple, quantitatively and qualitatively adequate option for accessing information from the photosynthetic irradiance-response in dwarf coconut palm
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