Flowering of axillary buds in non-irrigated avocados grown under subtropical climate

O abacateiro (Persea americana Mill.) possui desenvolvimento organizado em fluxos de crescimento e florescimento em panículas, provenientes principalmente de gemas terminais, podendo ocorrer em menor intensidade a partir de gemas axilares. Dessa forma, o presente estudo teve como objetivo avaliar a capacidade de florescimento e a presença de substâncias ergásticas nas células de gemas axilares, bem como determinar a contribuição dos fluxos de crescimento de primavera e verão para a composição floral dos abacateiros \'Geada\', \'Fortuna\', Quintal\', \'Margarida\' e \'Hass\', localizados no sudoeste do Estado de São Paulo, Brasil. Adotou-se o delineamento experimental inteiramente casualizado e por meio da contagem do número de brotações e inflorescências, o acompanhamento do desenvolvimento vegetativo e reprodutivo foi feito em 40 ramos do fluxo de primavera e 40 ramos do fluxo de verão, distribuídos em cinco plantas por cultivar, no período de março a agosto/2016. A capacidade de florescimento de gemas axilares foi avaliada em estruturas coletadas mensalmente entre março e julho de 2016 nos ramos dos fluxos de primavera e verão, sendo as alterações anatômicas do meristema e a presença de substâncias ergásticas (amido, proteínas totais, compostos fenólicos e polissacarídeos) monitoradas a partir de testes histológicos e histoquímicos. Para as análises histológicas, as amostras vegetais foram desidratadas em série gradual de álcoois, emblocados em historesina e coradas em coloração dupla com reagente ácido periódico de Schiff e Naftol Blue Black. O florescimento de todas as cultivares ocorreu no mês de agosto/2016 e a formação de inflorescências foi predominante em ramos provenientes do fluxo de verão para todas as cultivares. Os resultados evidenciam a capacidade de florescimento de gemas axilares dos abacateiros, as quais são anatomicamente idênticas às gemas terminais e apresentaram início do comprometimento com o florescimento, caracterizada pelo aparecimento dos eixos secundários da inflorescência, dois meses antes (entre maio e julho) da época de floração (agosto/setembro).Avocado trees (Persea americana Mill.) has an organized development in fluxes of growth and flowering in panicles, mainly coming from terminal buds, and may occur in less intensity from axillary buds. Thus, the present study had as objective the evaluation of the flowering potential and presence of ergastic substances in axillary buds, as well as to determine the contribution of the spring and summer fluxes growth to the floral composition of the avocado trees \'Geada\', \'Fortuna\' , Quintal \',\' Margarida \'and\' Hass\', located in the southwest of São Paulo State, Brazil. The experimental design was completely randomized and the vegetative and reproductive development was monitored in 40 branches of the spring flux and 40 branches of the summer flux by counting the number of shoots and inflorescences, distributed in five plants per cultivar, in the period from March to August / 2016. The flowering capacity of axillary buds was evaluated in monthly collected structures between March and July of 2016 in the branches of spring and summer fluxes, being the anatomical alterations of the meristem and the presence of ergastic substances (starch, total proteins, phenolic compounds and polysaccharides) monitored from histological and histochemical analyses. For the histological analyzes, the plant samples were dehydrated in a gradual series of alcohols, placed in historesin and stained in double staining with periodic acid reagents of Schiff and Naftol Blue Black. The flowering of all cultivars occurred in August / 2016 and inflorescence formation was more significant in branches from the summer flow for all cultivars. The results showed the flowering ability of axillary buds of the avocado trees, which are anatomically identical to the terminal buds and showed the beginning of the flowering, characterized by the appearance of the secondary axes of the inflorescence two months before (between May and July) of flowering (August / September)

Flowering of axillary buds in non-irrigated avocados grown under subtropical climate

O abacateiro (Persea americana Mill.) possui desenvolvimento organizado em fluxos de crescimento e florescimento em panículas, provenientes principalmente de gemas terminais, podendo ocorrer em menor intensidade a partir de gemas axilares. Dessa forma, o presente estudo teve como objetivo avaliar a capacidade de florescimento e a presença de substâncias ergásticas nas células de gemas axilares, bem como determinar a contribuição dos fluxos de crescimento de primavera e verão para a composição floral dos abacateiros \'Geada\', \'Fortuna\', Quintal\', \'Margarida\' e \'Hass\', localizados no sudoeste do Estado de São Paulo, Brasil. Adotou-se o delineamento experimental inteiramente casualizado e por meio da contagem do número de brotações e inflorescências, o acompanhamento do desenvolvimento vegetativo e reprodutivo foi feito em 40 ramos do fluxo de primavera e 40 ramos do fluxo de verão, distribuídos em cinco plantas por cultivar, no período de março a agosto/2016. A capacidade de florescimento de gemas axilares foi avaliada em estruturas coletadas mensalmente entre março e julho de 2016 nos ramos dos fluxos de primavera e verão, sendo as alterações anatômicas do meristema e a presença de substâncias ergásticas (amido, proteínas totais, compostos fenólicos e polissacarídeos) monitoradas a partir de testes histológicos e histoquímicos. Para as análises histológicas, as amostras vegetais foram desidratadas em série gradual de álcoois, emblocados em historesina e coradas em coloração dupla com reagente ácido periódico de Schiff e Naftol Blue Black. O florescimento de todas as cultivares ocorreu no mês de agosto/2016 e a formação de inflorescências foi predominante em ramos provenientes do fluxo de verão para todas as cultivares. Os resultados evidenciam a capacidade de florescimento de gemas axilares dos abacateiros, as quais são anatomicamente idênticas às gemas terminais e apresentaram início do comprometimento com o florescimento, caracterizada pelo aparecimento dos eixos secundários da inflorescência, dois meses antes (entre maio e julho) da época de floração (agosto/setembro).Avocado trees (Persea americana Mill.) has an organized development in fluxes of growth and flowering in panicles, mainly coming from terminal buds, and may occur in less intensity from axillary buds. Thus, the present study had as objective the evaluation of the flowering potential and presence of ergastic substances in axillary buds, as well as to determine the contribution of the spring and summer fluxes growth to the floral composition of the avocado trees \'Geada\', \'Fortuna\' , Quintal \',\' Margarida \'and\' Hass\', located in the southwest of São Paulo State, Brazil. The experimental design was completely randomized and the vegetative and reproductive development was monitored in 40 branches of the spring flux and 40 branches of the summer flux by counting the number of shoots and inflorescences, distributed in five plants per cultivar, in the period from March to August / 2016. The flowering capacity of axillary buds was evaluated in monthly collected structures between March and July of 2016 in the branches of spring and summer fluxes, being the anatomical alterations of the meristem and the presence of ergastic substances (starch, total proteins, phenolic compounds and polysaccharides) monitored from histological and histochemical analyses. For the histological analyzes, the plant samples were dehydrated in a gradual series of alcohols, placed in historesin and stained in double staining with periodic acid reagents of Schiff and Naftol Blue Black. The flowering of all cultivars occurred in August / 2016 and inflorescence formation was more significant in branches from the summer flow for all cultivars. The results showed the flowering ability of axillary buds of the avocado trees, which are anatomically identical to the terminal buds and showed the beginning of the flowering, characterized by the appearance of the secondary axes of the inflorescence two months before (between May and July) of flowering (August / September)

Avances en la propagación del aguacate

Resumen Por ser una especie de polinización cruzada y altamente heterocigótica, la multiplicación del aguacate por semilla origina una progenie altamente variable en relación a las características morfológicas y biológicas. Por ese motivo, se hizo relevante la adopción de métodos de propagación más eficientes, que resulten en plántulas de mejor calidad en términos de producción y resistencia a enfermedades. La injertación es el más utilizado para la propagación comercial de aguacate en los principales países productores. Originalmente, la implementación de plantaciones de aguacate se realizó a partir de plántulas obtenidas de portainjertos provenientes de semillas, siendo ese método de multiplicación el que aún predomina en Brasil. Sin embargo, tal procedimiento confiere en el campo mucha variabilidad y diferencias de productividad, calidad y vigor entre las plantas. En países que adoptan mayor nivel tecnológico, el portainjerto pasó a ser obtenido a partir de métodos clonales (Frolich y Platt, Brokaw, Allesbeste) asociados a otras técnicas como la etiolación y el anillado de los brotes. La presente revisión bibliográfica tiene como objetivo abordar los principales métodos de propagación utilizados en aguacate, sus avances y la importancia del mejoramiento genético y de las nuevas investigaciones en la obtención de cultivares de portainjerto y copa que atiendan las demandas del mercado

Cultivo do mirtilo: atualizações e desempenho inicial de variedades de baixa exigência em frio no Estado de Säo Paulo

A produção comercial de mirtilos na América do Sul tem passado por mudanças importantes nos últimos anos, em função do aumento da oferta de frutos frescos dos principais países produtores, causando forte queda de preços em plena safra, entre os meses de dezembro e fevereiro. Uma alternativa para esta situação é a produção de mirtileiros de maturação precoce ou muito tardia, fora da época de meia-estação, caracterizada pelos menores preços da fruta. Em 2010, foram introduzidas no Brasil novas variedades de mirtileiros de baixa exigência em frio desenvolvidas pela Universidade da Flórida, que podem ser cultivadas em regiões quentes e apresentam uma frutificação mais precoce, quando comparadas com as variedades tradicionalmente cultivadas no Brasil. Essas novas variedades apresentam grande potencial para a produção precoce de mirtilos no País em regiões sem frio hibernal, aumentando significativamente a rentabilidade da cultura. Para viabilizar esta produção, é necessário validar estratégias de manejo para estas variedades, devido à falta de informação técnica sobre seu cultivo nas condições edafoclimáticas brasileiras. Atualmente, estäo sendo conduzidas as primeiras pesquisas fitotécnicas no Estado de Säo Paulo para avaliar o crescimento e a produção destas variedades na ausência total de frio, situação de ocorrência particular em poucos países produtores do mundo

Association of Country Income Level With the Characteristics and Outcomes of Critically Ill Patients Hospitalized With Acute Kidney Injury and COVID-19

Introduction: Acute kidney injury (AKI) has been identified as one of the most common and significant problems in hospitalized patients with COVID-19. However, studies examining the relationship between COVID-19 and AKI in low- and low-middle income countries (LLMIC) are lacking. Given that AKI is known to carry a higher mortality rate in these countries, it is important to understand differences in this population. Methods: This prospective, observational study examines the AKI incidence and characteristics of 32,210 patients with COVID-19 from 49 countries across all income levels who were admitted to an intensive care unit during their hospital stay. Results: Among patients with COVID-19 admitted to the intensive care unit, AKI incidence was highest in patients in LLMIC, followed by patients in upper-middle income countries (UMIC) and high-income countries (HIC) (53%, 38%, and 30%, respectively), whereas dialysis rates were lowest among patients with AKI from LLMIC and highest among those from HIC (27% vs. 45%). Patients with AKI in LLMIC had the largest proportion of community-acquired AKI (CA-AKI) and highest rate of in-hospital death (79% vs. 54% in HIC and 66% in UMIC). The association between AKI, being from LLMIC and in-hospital death persisted even after adjusting for disease severity. Conclusions: AKI is a particularly devastating complication of COVID-19 among patients from poorer nations where the gaps in accessibility and quality of healthcare delivery have a major impact on patient outcomes

Thrombotic and hemorrhagic complications of COVID-19 in adults hospitalized in high-income countries compared with those in adults hospitalized in low- and middle-income countries in an international registry

Background: COVID-19 has been associated with a broad range of thromboembolic, ischemic, and hemorrhagic complications (coagulopathy complications). Most studies have focused on patients with severe disease from high-income countries (HICs). Objectives: The main aims were to compare the frequency of coagulopathy complications in developing countries (low- and middle-income countries [LMICs]) with those in HICs, delineate the frequency across a range of treatment levels, and determine associations with in-hospital mortality. Methods: Adult patients enrolled in an observational, multinational registry, the International Severe Acute Respiratory and Emerging Infections COVID-19 study, between January 1, 2020, and September 15, 2021, met inclusion criteria, including admission to a hospital for laboratory-confirmed, acute COVID-19 and data on complications and survival. The advanced-treatment cohort received care, such as admission to the intensive care unit, mechanical ventilation, or inotropes or vasopressors; the basic-treatment cohort did not receive any of these interventions. Results: The study population included 495,682 patients from 52 countries, with 63% from LMICs and 85% in the basic treatment cohort. The frequency of coagulopathy complications was higher in HICs (0.76%-3.4%) than in LMICs (0.09%-1.22%). Complications were more frequent in the advanced-treatment cohort than in the basic-treatment cohort. Coagulopathy complications were associated with increased in-hospital mortality (odds ratio, 1.58; 95% CI, 1.52-1.64). The increased mortality associated with these complications was higher in LMICs (58.5%) than in HICs (35.4%). After controlling for coagulopathy complications, treatment intensity, and multiple other factors, the mortality was higher among patients in LMICs than among patients in HICs (odds ratio, 1.45; 95% CI, 1.39-1.51). Conclusion: In a large, international registry of patients hospitalized for COVID-19, coagulopathy complications were more frequent in HICs than in LMICs (developing countries). Increased mortality associated with coagulopathy complications was of a greater magnitude among patients in LMICs. Additional research is needed regarding timely diagnosis of and intervention for coagulation derangements associated with COVID-19, particularly for limited-resource settings