Manipulation of Light Environment to Produce High-quality Poinsettia Plants

The phytochromes, a family of photoreceptors that maximally absorb red (R) and far-red (FR) light, play an important role in defining the architecture of the plant and consequently its value in the market. In this work, we evaluated the manipulation of light quality as an alternative to the use of plant growth regulators (PGRs) to produce poinsettia plants (Euphorbia pulcherrima Willd. ex Klotzsch) without affecting commercial quality parameters. ‘Freedom Red’ poinsettia plants were cultivated in two light environments characterized by different R/FR ratios in combination with or without one application of PGR. We used a photoselective film that significantly reduced the FR component of the light and a transparent film to obtain high and low R/FR ratios (5.7 and 1.1, respectively). Plants cultivated under a high R/FR ratio were shorter and more compact than those grown under transparent film. Other quality characters like bract and leaf area, dry weight, stem diameter, number of lateral branches, and plant width did not differ significantly between light treatments. Flowering time was slightly delayed in plants grown under a high R/FR ratio compared with those cultivated under the control treatment. Additive effects were detected between light quality and PGR factors indicating that light quality manipulation is an alternative strategy to reduce or to replace the use of PGRs in commercial production systems that usually require several PGR applications.Instituto de FloriculturaFil: Mata, Diego Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Botto, Javier Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

Manejo de la calidad de la luz como alternativa para el control del crecimiento en la producción de plantas ornamentales en maceta en los alrededores de Buenos Aires

Tesis para obtener el grado de Magíster Scientiae en Producción Vegetal, de la Universidad de Buenos Aires, en marzo de 2010La arquitectura de las plantas, es un aspecto importante a tener en cuenta en la producción de plantas ornamentales de buena calidad. El uso de reguladores de crecimiento (RC) es una práctica de manejo habitual para controlar la arquitectura de las plantas. A nivel mundial hay una fuerte restricción para su uso debido a los riesgos de contaminación y a potenciales daños a la salud de los trabajadores. Las plantas ajustan su crecimiento y desarrollo a distintos estímulos del ambiente. Entre ellos, la luz es percibida por distintos fotorreceptores, como los fitocromos que detectan eficientemente cambios espectrales de luz roja (R) y rojo-lejana (RL). El objetivo de esta tesis fue evaluar si la manipulación del ambiente lumínico es una herramienta alternativa al uso de RC para controlar la arquitectura de las plantas ornamentales en condiciones agro-ecológicas y prácticas de manejo utilizadas en las producciones comerciales de los alrededores de Buenos Aires. Los experimentos se llevaron a cabo con plantas de Euphorbia pulcherrima, cuyo esquema productivo a nivel mundial está bien definido, y de Salvia exserta, una especie nativa con alto potencial ornamental. Se diseñaron experimentos incrementando la relación R/RL mediante filtros fotoselectivos o tratamientos lumínicos adicionando luz R, en combinación con o sin la aplicación de RC. El incremento de la relación R/RL mejoró la calidad de las plantas de ambas especies a través de un efecto sobre los distintos componentes de calidad ornamental en niveles comparables a los obtenidos con la aplicación de RC. El incremento de R/RL y el uso de RC tuvieron efectos aditivos lo que permitió obtener plantas más compactas combinando ambas estrategias de manejo. En conjunto, los resultados de esta tesis demuestran que la manipulación del ambiente lumínico constituye una herramienta efectiva y no contaminante para controlar la arquitectura de plantas ornamentales.Plant architecture is an important aspect to take into account when cultivating good quality ornamental plants. Plant growth retardants (PGRs) have been the most common and rapid way of controlling plant architecture. However, the contamination risks and potential hazard to human health have been the principal cause for the increase of limitations on its usage around the world. Plants respond to many environmental factors adjusting its growth and development. Among them, light is perceived by different photoreceptors, like the phytochromes which specifically detect spectral changes associated with red (R) and far red (FR) light. The objective of this thesis was to evaluate whether light quality manipulation of the environment could be used as an alternative to PGRs for controlling plant architecture of ornamental plants under the agro-ecological conditions and culture practices used in commercial production systems around Buenos Aires. The experiments were performed with plants of Euphorbia pulcherrima, which has a production scheme very well defined, and with plants of Salvia exserta, a native species with high ornamental potential. Different experiments were designed increasing the R/FR ratio with a photoselective filter or with R light treatments, in combination with or without PGRs application. The increase in the R/FR of the environment improved final plant quality in both species affecting different plant quality components in a similar way as observed with the application of PGRs. The increase in the R/FR ratio and the PGR application had additive effects resulting in more compact plants when both alternatives were combined. Together, the results of this thesis demonstrate that the manipulation of the light environment is an effective and non pollutant tool for controlling ornamental plant architecture.Instituto de FloriculturaFil: Mata, Diego Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; Argentin

Use of copper hydroxide in the cultivation of lisianthus seedlings (Eustoma grandiforum L.) under floating system

Previous experiences demonstrated the efficiency of the floating system for growing lisianthus (Eustoma grandiflorum L.) seedlings. Using this system, root growth usually expands through the plug cell drainage hole into the solution originating some difficulties at transplant. Pruning roots could facilitate transplant as seedlings could be taken out of the tray more easily. However, root damages at the cutting point are a possible access for pathogens. The use of Cu(OH)2 in the nutrient solution as a chemical pruning method was evaluated. Lisianthus seeds were sown in floating trays and placed in nutrient solutions containing 0, 12, 23, 46, 92 and 138 g L-1 Cu(OH)2. After 30, 40, 47 and 54 days, fresh and dry weights of seedlings were recorded. When seedlings reached four expanded leaves they were transplanted to soil in a greenhouse. At flowering, shoots were harvested to evaluate flower stem quality. Total root and shoot fresh and dry weights were higher for seedlings cultivated with 0.023 or higher doses of Cu(OH)2. However, roots mass inside the tray cell were higher in all treatments compared to the control. The use of Cu(OH)2 during plug stage improved transplant size and no effect on further plant growth and development was observedEn el sistema de almácigos flotantes el crecimiento de las raíces generalmente excede el volumen de la celda pudiendo ocasionar algunas dificultades en el trasplante. La poda mecánica de raíces podría permitir que los plantines sean extraídos de la bandeja con mayor facilidad. Sin embargo, daños en las raíces debido al corte podrían ser vías de ingreso de patógenos. Semillas de lisianthus (Eustoma grandiflorum L.) fueron sembradas en bandejas flotantes utilizando soluciones nutritivas con 0, 12, 23, 46, 92 y 138 mg L-1 de Cu(OH)2 para evaluar su uso como agente de poda química. Luego de 30, 40, 47 y 54 días, se registró el peso fresco y seco de los plantines. Posteriormente se trasplantaron a un cantero dentro de un invernáculo y en floración se cosecharon para determinar la calidad de la vara. El peso fresco y seco de los plantines fue mayor al control en los tratamientos con 23 mg L-1 o mayores concentraciones de Cu(OH)2. Sin embargo, la masa de raíces dentro de la celda fue mayor en todos los tratamientos respecto del control. El uso de Cu(OH)2 durante la producción de plantines mejoró el tamaño del plantín y no tuvo efecto en el crecimiento y desarrollo posterior del cultivo.Inst. de FloriculturaFil: Barbaro, Lorena Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Karlanian, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Mata, Diego Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; Argentin

Uso de hidróxido de cobre en plantines de lisianthus : (eustoma grandiflorum L.) cultivados en sistema de raíces flotantes

Previous experiences demonstrated the efficiency of the floating system for growing lisianthus (Eustoma grandiflorum L.) seedlings. Using this system, root growth usually expands through the plug cell drainage hole into the solution originating some difficulties at transplant. Pruning roots could facilitate transplant as seedlings could be taken out of the tray more easily. However, root damages at the cutting point are a possible access for pathogens. The use of Cu(OH)2 in the nutrient solution as a chemical pruning method was evaluated. Lisianthus seeds were sown in floating trays and placed in nutrient solutions containing 0, 12, 23, 46, 92 and 138 g L-1 Cu(OH)2. After 30, 40, 47 and 54 days, fresh and dry weights of seedlings were recorded. When seedlings reached four expanded leaves they were transplanted to soil in a greenhouse. At flowering, shoots were harvested to evaluate flower stem quality. Total root and shoot fresh and dry weights were higher for seedlings cultivated with 0.023 or higher doses of Cu(OH)2. However, roots mass inside the tray cell were higher in all treatments compared to the control. The use of Cu(OH)2 during plug stage improved transplant size and no effect on further plant growth and development was observed.En el sistema de almácigos flotantes el crecimiento de las raíces generalmente excede el volumen de la celda pudiendo ocasionar algunas dificultades en el trasplante. La poda mecánica de raíces podría permitir que los plantines sean extraídos de la bandeja con mayor facilidad. Sin embargo, daños en las raíces debido al corte podrían ser vías de ingreso de patógenos. Semillas de lisianthus (Eustoma grandiflorum L.) fueron sembradas en bandejas flotantes utilizando soluciones nutritivas con 0, 12, 23, 46, 92 y 138 mg L-1 de Cu(OH)2 para evaluar su uso como agente de poda química. Luego de 30, 40, 47 y 54 días, se registró el peso fresco y seco de los plantines. Posteriormente se trasplantaron a un cantero dentro de un invernáculo y en floración se cosecharon para determinar la calidad de la vara. El peso fresco y seco de los plantines fue mayor al control en los tratamientos con 23 mg L-1 o mayores concentraciones de Cu(OH)2. Sin embargo, la masa de raíces dentro de la celda fue mayor en todos los tratamientos respecto del control. El uso de Cu(OH)2 durante la producción de plantines mejoró el tamaño del plantín y no tuvo efecto en el crecimiento y desarrollo posterior del cultivo.Fil: Barbaro, Lorena Alejandra. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Karlanián, Mónica Alejandra. Instituto Nacional de Tecnología Agropecuaria (Argentina)Fil: Mata, Diego Alejandro. Instituto Nacional de Tecnología Agropecuaria (Argentina

Floricultura. Pasado y presente de la floricultura argentina

La floricultura estudia el oficio y el arte de cultivar flores y plantas ornamentales, además de todo el desarrollo tecnológico, productivo, económico, comercial y social que implica. Las flores y las plantas han estado presentes en la vida del ser humano desde siempre. Hoy se valora no solo por el impacto emocional que provoca una flor o una planta para una mejor calidad de vida y como forma de expresión de sentimientos, sino también por el impacto ambiental, a través del saneamiento del aire y del suelo. Todo esto ha llevado a un desarrollo mundial de la floricultura con fuerte impacto en la economía de más de 145 países, tanto de los países consumidores como de los países productores. En la Argentina, la producción comercial tiene casi un siglo de existencia, comenzando en los alrededores de la Ciudad de Buenos Aires y estando extendida hoy en casi todo el territorio nacional. El desarrollo que ha tenido en varias zonas del país en los últimos 20 años, muestra la importancia económica, productiva y social que tiene la floricultura. La existencia de zonas agroecológicas aptas en varias zonas del país abre un potencial para desarrollar nuevos nichos con grandes perspectivas para aprovechar la demanda internacional.Instituto de FloriculturaFil: Morisigue, Daniel Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Mata, Diego Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Facciuto, Gabriela Rosa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; ArgentinaFil: Bullrich, Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Floricultura; Argentin

Nutrient uptake dynamics of Gloriosa for cut flower

Gloriosa superba L. is a recently introduced tropical species in Argentina, cultivated as a cut flower. It is extremely important to know the nutritional demands of the crop to provide the optimal amounts of nutrients at each stage, achieving quality and good yield in flowers, reducing production costs and environmental impact. The objective of this work was to determine the dynamics of nutrient absorption in the cultivation of G. superba for cut flowers, to facilitate the creation of a fertilization program, in order to avoid crop deficiencies and contribute to sustainable production. Tuber composition analyzes were carried out and, on the other hand, an essay was installed in greenhouse beds, taking samples at seven moments of the cycle. Fresh matter and dry matter of stems, leaves, flowers, tubers, roots and chemical analysis of aerial organs were measured to obtain the absorption curve. It was verified that only around 20% of each nutrient is provided by the tuber, being necessary the external contribution from initial stages of the crop. The rate of growth and accumulation of dry matter was shown as a double sigmoid, with maximum peaks      in the vegetative stage of stem elongation and beginning of flowering. Nutrient amounts were absorbed in the following order: N>K>Mg>Ca>P>Fe>Mn>Zn>Cu. Fertilization rich in N, P, and Fe is recommended in the vegetative stage, balanced during the visible shoot stage, and rich in Ca, K, Mg, Mn, Zn, and Cu during flowering

Wild ornamental germplasm exploration and domestication based on biotechnological approaches. In vitro colchicine treatment to obtain a new cultivar of Scoparia montevidiensis

The genus Scoparia is native from Argentina. The diversity of colours and shape of their flowers bestows this genus a very interesting ornamental potential. The purpose of the present study is to explore the Scoparia species germplasm by means of in vitro polyploidization in order to improve their ornamental qualities. Accessions of S. montevidiensis var. montevidiensis, S. montevidiensis var. glandulifera, S. nudicaulis, S. hasleriana and S. dulcis were collected and maintained under greenhouse conditions. The Murashige-Skoog medium, supplemented with 0.25 mg/L BAP was used for the nodal segments multiplication of the five Scoparia species. Except for S. hasleriana, the multiplication rate of the other species ranged between 10 and 12 shoots per explant. The colchicine doses tested with S. montevidiensis were: 0.0; 0.1; 0.05; 0.01 and 0.001% (24 and 48 hrs). From a total of 364 recovered plants, 4 solid tetraploid and 16 chimeras were detected. Significant differences were observed for the size of flower, leaves, and the stem diameter among the tetraploid plants and between them and the control. The tissue culture proved to be a powerful tool both to multiply the Scoparia material incorporated to our germplasm collection and to obtain new improved varieties of this beautiful genus

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Pandemia desde la academia: experiencias transdisciplinarias de la universidad cuencana en tiempos de COVID-19

Pandemia es una palabra con origen profundo que en el tiempo se ha cargado con la historia de pueblos y naciones, alcanzando su plena expresión en nuestra sociedad globalizada. No solamente por las estadísticas que atraen la atención de todo el mundo y nos obligan a razonar de manera lógico-numérica, cuantitativa, olvidando que muchas veces los números son personas, y no rinden la justa cuenta de todos aquellos seres humanos que representan estas cifras. Una pandemia logra su máxima expresión al alcanzar el mayor número de personas, esto refleja en su etimología proveniente del griego pan (todo) y demos (pueblo) y desde sus orígenes ha significado principalmente una cosa, la “reunión del pueblo”. Dicha noción invita a reflexionar sobre el porqué de las medidas sanitarias, del aislamiento y confinamiento, y, más aún, nos recuerda la importancia de la unión como decisión ancestral al origen de nuestras sociedades, columna portante de la familia, fortaleza de cualquier sistema en desequilibrio. Reconociendo esto, se evidencia la capacidad de transformar juntos las debilidades en fortalezas, de saber demostrar nuestro mejor impulso a la solidaridad y colaboración cuando sentimos que nos necesitan, que permite terminar con alegría un capítulo con la seguridad de que el próximo será mucho mejor. Este espíritu es responsable de la iniciativa de quienes enfrentamos los desafíos del contexto desde la unión, con la aspiración de formar seres humanos en un espacio compartido de generación de conocimiento y conformación de valores humanos y sociales que llamamos Universidad