Brote por Salmonella enteritidis en trabajadores de un hospital

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Chávez-de la Peña Ma. Eugenia

2001-01-01

Full Text Available Objetivo. Describir y determinar las causas de un brote de enfermedad gastrointestinal por Salmonella enteritidis, ocurrido en junio de 1998, entre el personal trabajador de la salud (TS que labora en un hospital de tercer nivel de atención, en la ciudad de México. Material y métodos. Se incluyó a todo aquel empleado que presentó diarrea o fiebre asociada a síntomas gastrointestinales, a partir del día 8 de junio de ese año, posterior a la ingestión de alimentos en el comedor del hospital (caso, y en aquellos asintomáticos (controles que ingirieron alimentos durante el mismo periodo y en el mismo lugar. Se les aplicó un cuestionario para conocer los alimentos ingeridos, se realizó hemocultivo a sujetos con fiebre mayor de 38 °C y coprocultivo a todos, incluido el personal de la cocina. En el análisis estadístico se utilizó razón de momios (RM, intervalos de confianza al 95% (IC 95%, ji cuadrada y valor de p= 0.05 para conocer la significancia estadística. Resultados: Desarrollaron síntomas 155 TS, y de éstos 129 completaron la encuesta; se encuestaron además 150 TS asintomáticos. Los síntomas más comunes fueron diarrea (85%, dolor abdominal (84%, cefalea (81.4%, náusea (78.3% y escalofríos (74.4%. Ocho hemocultivos fueron negativos; 59 casos (46% y seis controles (4% tuvieron coprocultivos positivos a Salmonella enteritidis. De los alimentos ingeridos, las tortas de carne capeadas con huevo (RM 19.39, IC 95% 9.09-41.4, la crema de mamey, así como el yogur fueron significativamente más frecuentes en casos que en controles. Los cultivos de los alimentos resultaron negativos. Conclusión. Muy probablemente este brote se debió a la ingestión de alimentos contaminados (tortas preparadas con huevo, papa y carne con insuficiente cocción. Este brote enfatiza la necesidad de mantener un programa de evaluación de la calidad de los alimentos en hospitales. El texto completo en inglés de este artículo está disponible en

Mortalidad por enfermedad de Chagas: A propósito de los brotes de Chagas agudo como enfermedad reemergente de transmisión alimentaria

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Rísquez, Alejandro

2009-01-01

Tras la ocurrencia de los primeros brotes de Chagas agudos en la capital (diciembre 2007) y Estado Vargas (marzo 2009) por trasmisión oral, se procedió a una revisión de la mortalidad por la enfermedad registrada entre 1997 y 2006, cuyos datos se analizaron de acuerdo a la edad, sexo y forma de presentación. El número absoluto de muertes sigue siendo elevado con promedio de 796 muertes anuales, de predominio en el sexo masculino, la mayoría en después de los 60 años de edad. Llama la atención...

Brote de influenza en Pucallpa, Ucayali, Perú. 2002

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Julio Mayca P

2003-10-01

Full Text Available Comunicar un brote de influenza basado en la notificación de un probable brote de infección respiratoria en diciembre de 2002 por el Centro de Salud Nueva Requena (Pucallpa. Estudio transversal analítico que incluyó casos con fiebre no mayor de 72 horas, y por lo menos dos síntomas relacionados. Se tomó hisopado nasal-faríngeo, detectándose mediante inmunofluorescencia indirecta (IFI: influenza A, B, adenovirus, parainfluenza y virus sincicial respiratorio (VSR. Se recolectaron 14 muestras, reportándose principalmente fiebre (92,8%, rinorrea (92,8% y tos (42,8% Se encontró influenza B y parainfluenza 2 en 05 casos. Los diagnósticos encontrados coinciden con la literatura nacional. Es necesario implementar un sistema de vigilancia, descentralizando el diagnóstico laboratorial y las campañas educativas poblacionales.

Brote causado por Escherichia coli en Chalco, México

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Cortés-Ortiz Iliana Alejandra

2002-01-01

Full Text Available Objetivo. Identificar el agente causal del brote de diarrea asociado con el desbordamiento del canal de aguas negras en Chalco. Material y métodos. Estudio retrospectivo y transversal, efectuado en el Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, de la Secretaría de Salud, con 1 550 hisopos rectales para el aislamiento e identificación bioquímica de V. cholerae y enterobacterias, obtenidos de la población del Valle de Chalco, que presentó diarrea y vómito durante el desastre natural acontecido el 31 de mayo de 2000. El análisis de los resultados se efectuó por la diferencia entre las proporciones de dos poblaciones (prueba de Ji cuadrada. Las cepas de E. coli se hibridaron por "colony blot" para los grupos ETEC, EIEC, EPEC y EHEC. Resultados. El 0.45% correspondió a Salmonella: S. agona, S. infantis, S. enteritidis, S. muenchen, S. typhimurium; 0.06% a Shigella flexneri 3a, y 76.6% a E. coli: 62.2% a ETEC (44.6 % con LT, 11.2% con ST, y 44.1% con ambas sondas, 0.84% a EIEC (sonda ial, 0.84% a EPEC (sonda bundle-forming pilus BFP, 0.08% a E. coli enterohemorrágica no-O157:H7 (sonda pCVD419, y 36.02% no hibridó. No se encontró asociación entre E. coli patógena con la edad y género. Conclusiones. Escherichia coli podría ser responsable del brote de diarrea. Es importante conocer el agente etiológico del brote para encaminar las estrategias en el estudio y control sanitario del mismo.

Enfermedad diarreica por rotavirus en brotes epidémicos Diarrheal disease caused by rotavirus in epidemic outbreaks

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Jesús Reyna-Figueroa

2012-02-01

Full Text Available OBJETIVO: Determinar el perfil epidemiológico de los brotes de enfermedad diarreica aguda por rotavirus (RV ocurridos en pacientes pediátricos, mediante una revisión crítica de la literatura publicada entre 2000 y 2010. MÉTODOS: Se realizó una búsqueda de artículos publicados desde enero de 2000 hasta abril de 2010, recogidos por las bases de datos Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed y Science Direct. En los estudios que cumplieron con los criterios de inclusión, se identificaron posibles factores de confusión y se atribuyeron riesgos de sesgo con base en el número de ítems considerados inadecuados en cada caso. Se describieron las características epidemiológicas y microbiológicas de los brotes. RESULTADOS: Solo 14 (10,8% de los 129 títulos identificados formaron parte de la muestra, los cuales sumaron 91 092 casos de diarrea aguda notificados. En 5 250 de estos casos se realizó la búsqueda de RV, la cual arrojó 1 711 (32,5% aislamientos positivos. Se observó que el RV del grupo A fue el agente causal en 100% de los brotes, mientras que el genotipo G9 fue documentado en 50% de los artículos. CONCLUSIONES: El RV, principalmente el serotipo G9, fue uno de los principales agentes responsables de los brotes de EDA en la última década. Un cuidadoso estudio de brote puede aportar información valiosa para el control y la prevención de la enfermedad por RV.OBJECTIVE: Determine the epidemiological profile of outbreaks of acute diarrheal disease caused by rotavirus (RV occurring in pediatric patients, based on a critical review of the literature published between 2000 and 2010. METHODS: A search was carried out for articles published from January 2000 to April 2010, collected by the Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed, and Science Direct databases. In the studies that met the inclusion criteria, possible confounding factors were identified and risks of bias were attributed based on the

La brucelosis como enfermedad profesional: estudio de un brote de transmision aerea en un matadero

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Rodríguez Valín Mª Elena

2001-01-01

Full Text Available FUNDAMENTO: La aparición de un número elevado de casos de brucelosis entre los trabajadores de un matadero en Zaragoza, en el que se sacrificaba ganado ovino procedente de las campañas de saneamiento ganadero, hizo iniciar una investigación para esclarecer el origen del brote. MÉTODOS: El estudio se estructuró en tres partes: 1 Descripción del brote; 2 Estudio de la estructura y actividad del matadero en cuanto al número de animales sacrificados, carga de trabajo del personal y riesgo por zona de trabajo y 3 Estudio de casos y controles no apareado. RESULTADOS: No hubo diferencias significativas entre las tasas de ataque por secciones de trabajo. El análisis del sacrificio reveló una variación concomitante entre las curvas de sacrificio de ovino de saneamiento y la epidémica. El estudio de casos y controles no reveló diferencias significativas para los siguientes factores de riesgo: trabajo en zona de riesgo, uso de medidas de protección y realización de cortes y heridas. CONCLUSIONES: El brote está relacionado con el sacrificio de ovino de saneamiento. El que no se observaran diferencias significativas por secciones o por trabajar en la zona de riesgo es compatible con una exposición generalizada. Tampoco se observaron diferencias entre los trabajadores respecto a la realización de cortes y heridas o el uso de medidas de protección, lo que da importancia a la transmisión aérea.

LA BRUCELOSIS COMO ENFERMEDAD PROFESIONAL: ESTUDIO DE UN BROTE DE TRANSMISION AEREA EN UN MATADERO

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Ma. Elena Rodríguez Valín

2001-01-01

Full Text Available Fundamento: La aparición de un número elevado de casos de brucelosis entre los trabajadores de un matadero en Zaragoza, en el que se sacrificaba ganado ovino procedente de las campañas de saneamiento ganadero, hizo iniciar una investigación para esclarecer el origen del brote. Métodos: El estudio se estructuró en tres partes: 1 Descripción del brote; 2 Estudio de la estructura y actividad del matadero en cuanto al número de animales sacrificados, carga de trabajo del personal y riesgo por zona de trabajo y 3 Estudio de casos y controles no apareado. Resultados: No hubo diferencias significativas entre las tasas de ataque por secciones de trabajo. El análisis del sacrificio reveló una variación concomitante entre las curvas de sacrificio de ovino de saneamiento y la epidémica. El estudio de casos y controles no reveló diferencias significativas para los siguientes factores de riesgo: trabajo en zona de riesgo, uso de medidas de protección y realización de cortes y heridas. Conclusiones: El brote está relacionado con el sacrificio de ovino de saneamiento. El que no se observaran diferencias significativas por secciones o por trabajar en la zona de riesgo es compatible con una exposición generalizada. Tampoco se observaron diferencias entre los trabajadores respecto a la realización de cortes y heridas o el uso de medidas de protección, lo que da importancia a la transmisión aérea.

Brotes de leptospirosis humana en la provincia de Ciego de Ávila, Cuba Human leptospirosis outbreak in the district of Ciego de Ávila, Cuba

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Miguel Suárez Hernández

1999-02-01

Full Text Available Se analizan los brotes de leptospirosis ocurridos en la provincia de Ciego de Ávila en el periodo de 1980 a 1995. En la etapa se notifican 40 brotes. Las actividades principales vinculadas a los mismos fueron la atención al cultivo de la caña de azúcar, al cultivo del plátano, el baño en río y las inundaciones. Se nota un incremento de brotes a partir del mes de junio. En los meses de octubre y noviembre se reportan las mayores incidencias. Los grupos de edades que más casos aportaron fueron de 10-14 años, 15-19 años y 30-34 años. El sexo más afectado fue el masculino. Los grupos más afectados fueron los estudiantes, pobladores urbanos y trabajadores agrícolas cañeros. De los 40 brotes, 21 fueron confirmados por medio de la prueba de microaglutinación y 19 por la prueba hemolitica, siendo los serogrupos más frecuentes Pomona y Australis.Forty leptospirosis outbreaks occurred in Ciego de Avila province from 1980 to 1995. The main events involved in the outbreaks were floods, bathing in rivers and activities related to sugar cane and banana cultivation. The number of cases increased after June, with higher incidences reported in October and November. The most affected age groups were 10-14 years, 15-19 years and 30-34 years. Men were more affected than women. Students, people residing in the urban zone and farmers were the most affected groups. A total of 21 outbreaks out of 40 were confirmed by the microagglutination test and the remaining 19 by the hemolytic test. Pomona and Australis were the serogroups most frequently detected by microagglutination.

Análisis de un brote de meningitis viral en la provincia de Tucumán, Argentina

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Freire María Cecilia

2003-01-01

Full Text Available OBJETIVO: Confirmar la existencia de un brote de meningitis viral en 1996 en la provincia de Tucumán, Argentina, y estudiar sus características epidemiológicas. MÉTODOS: Se analizó información obtenida del Sistema Nacional de Vigilancia Epidemiológica (SINAVE del Ministerio de Salud de Argentina para el período de 1994-1998, la cual fue provista por la Dirección de Epidemiología de dicho ministerio. Para el cálculo de incidencias se usaron estimaciones poblacionales para los años 1994-1998 realizadas por el Instituto Nacional de Estadística y Censos (INDEC sobre la base del censo de 1991. El estudio de frecuencias se realizó mediante el análisis de tablas de contingencia de doble entrada, según el método de ji cuadrado con la corrección de Yates. Se consideró significativo el resultado cuando P < 0,05. RESULTADOS: Se confirmó la presencia de un brote de 189 casos entre el 11 de febrero y el 18 de mayo de 1996. La incidencia de casos en la provincia mostró un aumento entre 1995 y 1996 (de 0,5 a 19,3 casos por 100000 años-persona y dicha incidencia fue significativamenrte mayor que la observada en el resto del país (19,3 frente a 2,8 casos por 100000 años-persona. El 75,1% de los casos ocurrió en niños menores de 9 años (142/189. Se detectó la presencia de Enterovirus (EV en 65 de las 111 muestras estudiadas (58,6%. Mediante la reacción en cadena de la polimerasa (RCP anidada con transcripción inversa se logró detectar EV en 66,3% (53/80 de los casos estudiados por este método, en comparación con solo 29,6% (24/81 de los estudiados mediante aislamiento viral. Se identificó echovirus tipo 4 en 15 (68% en las 22 muestras tipificadas (5 por aislamiento, 3 por secuenciación y 7 por ambos métodos. Este brote demuestra la capacidad de los EV para diseminarse y producir enfermedad en la población. Durante el brote, por lo menos 56% de los casos fueron hospitalizados. CONCLUSIONES: El uso de métodos moleculares

Tres brotes de ictiosarcotoxicosis por ingestión de Sphyraena barracuda (Walbaum y Seriola zonata (Mitchill en el Caribe de Colombia

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Ricardo Alvarez

1999-03-01

Full Text Available Se comentan los tres brotes de ictiosarcotoxicosis (ciguatera conocidos en las costas colombianas sobre el Mar Caribe, causados por la ingestión de la carne de los peces Sphyraena barracuda (Walbaum y Seriola dumerili (Mitchiil.

Diagnóstico temprano en un brote epidémico del virus Dengue en Piura usando RT-PCR y nested-PCR

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Oscar Nolasco

1997-07-01

Full Text Available Un test de diagnóstico temprano (RT-PCR y Nested-PCR fue evaluado y comparado con métodos convencionales (cultivo in vitro, IFI y MAC-ELISA. Treinta y cuatro sueros de pacientes correspondientes de un brote epidémico de la costa norte peruana (Mancora, Piura en mayo de 1997 fueron incluidos en este estudio. Todos los sueros fueron obtenidos de pacientes que presentaron en los primeros cinco días manifestaciones clínicas siendo diagnosticados luego como dengue serotipo 1. Asimismo, RT-PCR permitió diagnosticar 82% de los sueros (28/34, sin embargo Mac-ELISA y cultivo in vitro reconocieron unicamente 41% de los sueros (14/34 y 38% de los sueros (13/34 respectivamente. Por lo tanto, el uso de esta herramienta molecular (RT-PCR y Nested-PCR permitiró dar un diagnóstico temprano a estos pacientes y actuar inmediatamente ante la presencia de un brote epidémico.

Manifestaciones sistémicas del brote dentario

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Juana María Abreu Correa

1997-12-01

Full Text Available Se realizó un estudio para comprobar la presencia de manifestaciones sistémicas asociadas con el brote dentario, aspecto que ha sido motivo de discrepancias entre médicos y estomatólogos durante mucho tiempo. Para la obtención de los datos se entrevistaron a las madres de 121 infantes, cuyas edades oscilaron entre 6 y 12 meses, por considerarse las edades más propensas a estas manifestaciones. Se aplicó el método estadístico de prueba de contraste de hipótesis. No hubo diferencias en relación con el sexo. Las madres refirieron los síntomas y signos que se presentan durante la erupción dentaria y que se expresan en por cientos; otro grupo planteó que la erupción fue asintomática. Entre las manifestaciones o patologías asociadas, las diarreas tuvieron una mayor incidencia, seguidas de la fiebre, el estado catarral y los vómitos. También estuvieron presentes, aunque con menos incidencia, la irritabilidad y la dermatitis. Según las pruebas estadísticas los resultados fueron altamente significativos, lo que demuestra la relación existente entre manifestaciones sistémicas y el brote dentario.It was conducted a study to prove the presence of systemic manifestations associated with tooth eruption, an aspect that has been the cause of differences between doctors and stomatologists for a long time. In order to obtain information the mothers of 121 infants aged 6-12 months were interviewed as they had more possibilities to present these manifestations. The statistical method of hypothesis contrast test was applied. There were no differences in connection with sex. Mothers explained the symptoms and signs appearing during tooth eruption that are expressed in percents. The other group said that the eruption was asymptomatic. Among the associated manifestations or pathologies, diarrheas had the greatest incidence, followed by fever, cold, and vomits. Irritability and dermatitis were also present but with less incidence. According to the

Descripción de los tres primeros brotes de gripe A (H1N1 2009 notificados en prisiones de España Description of the first three notified outbreaks of influenza A (H1N1 2009 in Spanish prisons

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P. Gómez-Pintado

2010-06-01

Full Text Available Objetivos: describir los tres primeros brotes de gripe A (H1N1 2009 notificados entre julio y septiembre de 2009 en las prisiones españolas. Metodología: Se definió brote como la aparición de tres o más casos con síntomas gripales y con vínculo epidemiológico en el mismo módulo de una prisión. Los brotes son notificados mediante cuestionario específico. El análisis realizado por las variables sexo, edad, fecha de notificación, duración de los brotes, factores de riesgo y características clínicas se presenta en forma de números absolutos, porcentajes y tasas de ataque y el estudio de la difusión de la enfermedad a través de las curvas epidémicas. Resultados: Se notifican tres brotes desde las prisiones de Alcalá-Meco con 85 varones afectados, Pamplona (18 varones afectados y Jaén (12 mujeres afectadas con una tasa de ataque global que varía entre el 7,1% y el 17,9%. La duración de los brotes varía entre 8 y 35 días, y la mediana de duración de la enfermedad es de 3 días. Sólo ingresaron 4 internos que fueron dados de alta por mejoría. Los hombres son mas jóvenes (pAim: This study describes three reported outbreaks of influenza H1N1 2009 in Spanish prisons between july and september 2009. Methods: An outbreak was defined as the appearance of three or more cases with influenza symptoms and with an epidemiological link in the same module of a prison. The outbreaks were reported using a specific questionnaire. The analysis, which used variables of gender, age, date of notification, duration of outbreak, risk factors and clinical features are presented as absolute numbers, percentages and attack rates, while study of the diffusion of the illness is expressed as epidemic curves. Results: Three outbreaks were reported at the prisons of Alcala-Meco (85 affected males, Pamplona (18 affected males and Jaen (12 affected females with an overall attack rate that ranged from 7.1% to 17.9%. Duration of the outbreaks was between 8

Inducción y enraizamiento de brotes epicórmicos de Cordia alliodora (Ruiz Et Pavon, Oken

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Mercedes Susana Carranza Patiño

2016-10-01

Full Text Available La atractiva apariencia de la madera de Cordia alliodora (laurel, sus características físico-mecánicas, su abundante regeneración natural, captura de carbono y protección al suelo, la hacen ideal para la reforestación. No obstante, la falta de material de siembra de buena calidad para suplir la demanda media anual, convierten la propagación vegetativa en una herramienta esencial para el mejoramiento genético, y la conservación de genotipos en bancos clonales. En este sentido, se propuso establecer una metodología para la inducción y enraizamiento de brotes epicórmicos de árboles de laurel utilizando reguladores de crecimiento vegetal. Las concentraciones de citoquininas empleadas para la inducción de brotes a partir de árboles adultos fueron de: 0, 3000, 6000, 9000 mg L-1 de BAP sola y combinadas con 1000, 2000, 3000 mg L-1 de AIA, y se determinaron utilizando un Diseño Completo Aleatorizado (DCA. Las concentraciones de auxinas para el enraizamiento de los brotes fueron de 0, 1000, y 1500 mg kg-1 de ANA y AIB, mediante un DCA con arreglo factorial 3 x 3 (hormona ANA x hormona AIB. Se evaluó la inducción de brotes epicórmicos y se obtuvieron 2.67 brotes de 16.42 cm de longitud, con 6000 mg kg-1 de BAP + 2000 mg kg-1 de AIA. El porcentaje de enraizamiento fue 54%, número de raíces 1.78, longitud 2.59 con 1500 mg kg-1 de ANA + 1500 mg kg-1 de AIB. El uso de citoquininas y auxinas fue efectivo para provocar la diferenciación celular tanto en la inducción y rizogénesis de brotes epicórmicos de laurel.

Floral scents and their interaction with insect pollinators

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Grajales-Conesa, Julieta; Meléndez-Ramírez, Virginia; Cruz-López, Leopoldo

2011-01-01

Las plantas emplean diversas señales visuales y olfativas con la finalidad de atraer a los polinizadores que en su mayoría son insectos. Algunas plantas han desarrollado mecanismos, basándose en mensajes olfativos que los hacen únicos para sus polinizadores específicos. Estos mecanismos, así como las variaciones intra- e interespecíficas en el perfil de los aromas florales han evolucionado para determinadas especies. Los aromas florales son un conjunto de compuestos volátiles orgánicos y para...

BROTE DE GASTROENTERITIS POR VIRUS NORWALK EN UNA RESIDENCIA DE ANCIANOS DE GRANADA

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Diego Almagro Nievas

2003-01-01

Full Text Available vírico son actualmente uno de los problemas de salud que más están afectando a las personas residentes en instituciones de la tercera edad. El objetivo del estudio es investigar las causas del origen y transmisión de un brote de gastroenteritis aguda por virus Norwal- Like. Método: En una residencia de ancianos con 141 residentes y 71 trabajadores expuestos, se investigó la relación entre un brote de gastroenteritis aguda y distintas variables: características personales, de lugar, fecha de inicio de los síntomas, clínica de la enfermedad y factores causales (alimentos y agua de consumo. Se realizó un estudio descriptivo, tabla de contingencia y test de hipótesis 2, diseño de casos y controles con el calculo de Odds Ratio cruda y posteriormente ajustada (IC al 95% utilizando regresión logística. Resultados: No se observaron diferencias significativas en las variables de características personales y de lugar. La tasa de ataque en los residentes fue del 30,1% y en trabajadores fue del 21,12%. En el calculo de la Odds Ratio ajustada sólo tuvo valores de relación causal la mousse de nata (Odds Ratio ajustada=4,66; IC-95% 1,15- 18,91; p=0,031. Se remitieron 10 muestras de heces de enfermos para su análisis, no detectándose ninguna bacteria patógena, pero si se aisló en 3 de ellas virus Norwal-Like. Conclusiones: El hallazgo de la mousse de nata como posible responsable del brote supone una primicia en la presencia de virus Norwalk, pero este resultado está sujeto a limitaciones, como el posible sesgo de clasificación por no recuerdo de consumo de alimentos. Aún así, supone un elemento a tener en cuenta en el control de gastroenteritis agudas por virus.

Brote de fiebre amarilla selvática en Colombia 2004

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Pilar Bernal M.

2004-03-01

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Antecedentes: el 9 de enero se confirma un caso de fiebre amarilla en la sierra nevada de Santa Marta cuya circulación viral es la continuación de la presentada en el 2003 en la región del Catatumbo. En la región no se confirmaban casos desde el año 1979 y el comportamiento del brote es similar al presentado en dicho año.

Metodología: estudio descriptivo longitudinal de casos captados mediante vigilancia activa comunitaria, estudio de casos y vigilancia pasiva. Los casos son confirmados por IgM, inmunohistoquímica y patología. Se realizaron acciones del fortalecimiento de la vigilancia de febriles icterohemorrágicos, entomológica, vectorial y de epizootias. Igualmente acciones de intensificación de la inmunización de susceptibles y educación a la comunidad.

Resultados: se confirmó la circulación del virus en epizootias ocurridas en tres zonas de la región (Municipios de Valledupar, La Paz y Santa Marta. Por fecha de inicio de síntomas los casos comenzaron en la semana 51 de 2003 y el pico epidémico fue en la semana 1 de 2004; el último caso se confirmó el 22 de enero de 2004. Se confirmaron 29 casos de 787 notificados (15 del distrito de Santa Marta, 8 del departamento del Cesar y 6 de La Guajira; 20% de los casos fueron captados por vigilancia activa. El 28% fue confirmado por patología e inmunohistoquímica y el restante por IgM. El grupo de edad con mayor incidencia fue 15 a 44 años (75%, hombres (72% y agricultores (45%. La letalidad fue 28%.

La vigilancia entomológica reportó la presencia de Sabethes s.p en Valledupar y los índice médicos, excepto en esta última ciudad, fueron mayores del 10%. Las coberturas de

Brote por virus de la parotiditis G1 en la provincia de Almería en el año 2005

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Pilar Barroso García; Ma Ángeles Lucerna Méndez; Amparo Navarro Monzón

2007-01-01

Fundamento:A pesar de que en España se registran coberturas elevadas de la vacuna de parotiditis siguen notificándose brotes epidémicos de parotiditis. El objetivo de este trabajo es describir un brote notificado en la provincia de Almería en el año 2005 y valorar la afectación en población vacunada. Métodos: Estudio descriptivo de los casos notificados. Variables estudiadas: Zona Básica de Salud, municipio, edad, sexo, tipo de población (autóctona y extranjera), fecha in...

Brote de faringoamigdalitis de origen alimentario por estreptococo betahemolítico A

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Juan Nieto Vera

2011-01-01

Full Text Available Fundamento: Aunque no son frecuentes, algunos autores han comunicado brotes de faringoamigdalitis de origen alimentario. El 11 de mayo de 2010 se notificó a la Red de Vigilancia Epidemiológica de Andalucía (SVEA que había personas con cuadro de faringoamigdalitis que tenían en común haber asistido a una comunión celebrada el día 8. El objetivo de este trabajo es la caracterización epidemiológica del brote. Método: Estudio observacional descriptivo de casos notificados y análisis de casos control por exposición a los alimentos implicados. Se analizaron las variables edad, sexo, sintomatología y fecha de inicio de síntomas. Fuentes de información fueron los registros del SVEA e historia digital individual (DIRAYA. Se calcularon frecuencias, tasas de ataque, y análisis bayesiano de comparación de diferencia de proporciones de enfermar para un intervalo de probabilidad o credibilidad (IP del 95%. Resultados: De 130 asistentes a una celebración se detectaron 41 casos de faringoamigdalitis (tasa ataque 31,5% y se aisló en frotis Estreptococo betahemolítico A. El grupo de edad más afectado fue el de 25-44 años: 16 (39,0%;hubo más afectación de las mujeres 24 (68,6% mujeres. La ensaladilla de huevo presentó una probabilidad mayor del 80% P(Δ>0,10 y Δ>0,15 para un IP del 95% de enfermar tras su consumo y la probabilidad de tener menos riesgo de no enfermar. Conclusiones: Se trató de un brote por estreptococo betahemolítico A. El análisis epidemiológico evidenció exposición a fuente única y común, siendo plausible la hipótesis del origen alimentario, posiblemente por la ensaladilla de huevo contaminada por algún manipulador de alimentos. Como factores contribuyentes se identificaron inadecuadas medidas higiénico-sanitarias en la manipulación y conservación de los alimentos.

Brote de rabia urbana transmitida por perros en el distrito de Santa Marta, Colombia, 2006-2008

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Andrés Páez

2009-09-01

El control del brote se logró 20 meses después del primer caso en perros y 14 meses después de haberse iniciado la primera vacunación masiva en animales. Es necesario implementar y mantener acciones para el control de la rabia urbana y evitar su impacto en los humanos.

Brotes de babesiosis y anaplasmosis bovina diagnosticados en el INTA Salta, Argentina: período 2006-2016

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ARAOZ V

2017-12-01

Full Text Available Se realizó un estudio retrospectivo de brotes de babesiosis y anaplasmosis (tristeza parasitaria bovina, TPB ocurridos entre 2006 y 2016 en el Noroeste argentino (NOA para evaluar algunos aspectos epidemiológicos y clínicos de estas enfermedades. De 4.398 muestras para diagnóstico, 238 (5,4% tuvieron sospechas de TPB, las cuales se confirmaron en 106 (44,3% casos por observación microscópica de los agentes causales. Cuarenta y siete (44,3% brotes se debieron a Anaplasma marginale, 40 (37,7% a Babesia bovis y 14 (13,2% a Babesia bigemina. En cinco (4,7% focos de babesiosis no se determinó la especie causal de Babesia. Los brotes se diagnosticaron en 62 establecimientos ganaderos de cuatro provincias (Salta, Jujuy, Santiago del Estero y Chaco. La mayoría ocurrieron en verano y otoño, con máxima incidencia en abril y nula en setiembre para ambas noxas. Las vacas adultas fueron la categoría de ganado más afectada. En 58% (61/106 de los brotes murió al menos un bovino, con un número promedio de cuatro muertes por brote. Se concluye que la TPB continúa incidiendo negativamente en la producción bovina del NOA. SUMMARY. Bovine babesiosis and anaplasmosis outbreaks diagnosed at INTA Salta, Argentina: 2006-2016. A retrospective study of babesiosis and anaplasmosis outbreaks (tick fever, TF was made, which occurred from 2006 to 2016 in Northwest Argentina (NWA, to evaluate clinical and epidemiological aspects of these diseases. From 4,398 specimens, 238 (5.4% were associated with suspicions of TF and 106 of these cases (44.3% were confirmed as TF outbreaks by microscopic observation of causal agents. Forty seven (44.3% were due to Anaplasma marginale, 40 (37.7% to Babesia bovis and 14 (13.2% to Babesia bigemina. In five (4.7% outbreaks of babesiosis, Babesia species were not determined. Outbreaks were diagnosed at 62 different cattle ranches in four provinces (Salta, Jujuy, Santiago del Estero and Chaco. The outbreaks occurred mostly during

Clostridium difficile outbreak in Costa Rica: control actions and associated factors Brote de infección por Clostridium difficile en Costa Rica: medidas de control y factores asociados

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Roy A. Wong-McClure

2012-12-01

Full Text Available OBJECTIVE: To describe interventions implemented during a nosocomial outbreak of Clostridium difficile in a general hospital in Costa Rica from December 2009 to April 2010 in order to achieve outbreak control and the factors determined to be associated with C. difficile infection. METHODS: Laboratory-confirmed cases of C. difficile were analyzed to describe the outbreak pattern and intervention measures implemented. Cases were selected and recruited in a case-control study. Controls were selected from the same services and time period as the cases. Evaluated exposures included underlying medical conditions and treatments administered before the onset of symptoms. RESULTS: The mean ages in case and control groups were 62.3 and 55.3 years, respectively. Control measures included a hand-hygiene campaign, deep disinfection of hospital surfaces, strict isolation of cases, use of personal protection equipment, and restriction of antibiotic use. The adjusted attributable risks associated with the outbreak were diabetes [odds ratio (OR 3.4, 95% confidence interval (CI 1.5-7.7], chronic renal failure (OR 9.0, 95% CI 1.5-53.0, and prescribing ceftazidime (OR 33.3, 95% CI 2.9-385.5 and cefotaxime (OR 20.4, 95% CI 6.9-60.3. CONCLUSIONS: Timely implementation of control measures resulted in reduced infection transmission and successful control of the outbreak. Conditions associated with C. difficile infection were similar to those found in previously described outbreaks of this bacterium.OBJETIVO: Describir las intervenciones ejecutadas durante un brote intrahospitalario de infección por Clostridium difficile en un hospital general de Costa Rica desde diciembre del 2009 hasta abril del 2010 para lograr el control del brote y de los factores asociados a la infección por C. difficile. MÉTODOS: Se analizaron los casos de infección por C. difficile que se habían confirmado mediante pruebas de laboratorio a fin de describir las características del brote y

Tipificación molecular del virus dengue 3 durante el brote epidémico de dengue clásico en Lima, Perú, 2005

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Enrique Mamani Z

2005-07-01

Full Text Available Objetivos: Identificar mediante trascripción reversa-reacción en cadena de la polimerasa (RT-PCR y sitios específicos de restricción - reacción en cadena de la polimerasa (RSS-PCR al agente causal del brote epidémico presentado en el distrito de Comas, Lima en abril del año 2005. Materiales y métodos: veinte muestras de suero colectadas durante el brote de dengue fueron procesados por RT-PCR para determinar el serotipo, esta técnica se realizó en un solo paso. Luego se aplicó la técnica RSS-PCR para la identificación del genotipo circulante y se corroboraron los resultados posteriormente con aislamiento viral y secuenciamiento. Resultados: El análisis del RTPCR del ARN extraído de las muestras presentó un producto amplificado de 290pb que corresponden al dengue serotipo 3 (DEN 3. El análisis de los productos de RSS-PCR del ARN extraído a partir de aislamientos de DEN 3 correspondió al patrón C, incluido en el genotipo III. Los aislamientos de los virus dengue 3 en líneas celulares C6/36, tipificadas por IFI y el secuenciamiento genético confirmaron los resultados obtenidos por las pruebas previamente descritas. Conclusión: Durante el brote epidémico de dengue clásico en Lima, circuló el genotipo III del virus DEN 3.

Brotes de rabia humana transmitida por vampiros en los municipios de Bajo y Alto Baudó, departamento del Chocó, Colombia 2004-2005

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Jessika Valderrama

2006-09-01

Conclusiones. El brote de rabia humana en Bajo Baudó 2004 ha sido el de mayor magnitud reportado en Colombia. Este fue causado por vampiros, demostrando la amenaza que representa la rabia de especies silvestres para la salud pública, y la necesidad de implementar acciones para evitar su impacto en humanos. Se desconoce si existen vínculos entre este brote y el reportado en Alto Baudó seis meses después.

Análisis espacial de un brote de leishmaniasis en el sur del Área metropolitana de la Comunidad de Madrid. 2009-2013

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Emiliano Aránguez Ruiz

2014-06-01

Full Text Available La leishmaniasis es una enfermedad zoonótica endémica en España. El objetivo de este estudio es realizar un análisis espacial de los elementos claves del ciclo de la enfermedad, vectores, reservorios y casos humanos, en un brote comunitario declarado en cuatro municipios del sur del Área metropolitana de Madrid: Fuenlabrada, Getafe, Humanes de Madrid y Leganés.Se analizaron 485 casos de leishmaniasis, declarados en el Sistema de Vigilancia Epidemiológica de la Comunidad de Madrid, con fecha de inicio de síntomas entre el 1 de julio de 2009 y el 30 de junio de 2013.La mayor parte de los casos se localizaron en el norte de Fuenlabrada. Los resultados del análisis espacial pusieron de manifiesto que, durante el periodo de estudio, la zona con mayor concentración de casos coincidió espacialmente con áreas residenciales periféricas inmediatas a espacios verdes con alta densidad de flebotomos y prevalencia relativamente elevada de leishmaniasis en lagomorfos. Esto informa de que la exposición principal ocurre en su entorno domiciliario o peridomiciliario.El estudio parece indicar que las infraestructuras viarias podrían haber tenido un papel decisivo en la distribución espacial del brote comportándose de diferentes maneras: barreras territoriales que aíslan en cierta medida a varios núcleos urbanos de la exposición al patógeno, vías de penetración del vector en el interior de otros núcleos o generadores de un entorno de hábitats idóneos para reservorios y vectores.El análisis espacial ha permitido orientar las actuaciones de prevención y control del brote y continúa siendo de gran utilidad en la evolución del mismo. Los sistemas de información geográfica son herramientas que ayudan a la comprensión de la génesis y evolución de los brotes de enfermedades infecciosas, así como al diseño de las intervenciones ambientales.

EL ÁCIDO ABSCÍSICO ACELERA EL DESARROLLO FLORAL DE SOLIDAGO EN DÍAS CORTOS ABSCISIC ACID SPEED UP FLORAL DEVELOPMENT OF SOLIDAGO UNDER SHORT DAYS

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Víctor Julio Flórez Roncancio

2009-06-01

Full Text Available Solidago x luteus (M. L. Greene Broulliet y Semple (= x Solidaster hybridus, x S. luteus es una planta que responde a días cortos (DC para el desarrollo floral. En este proceso se ha establecido la participación de varias fitohormonas, entre éstas, la presencia del ácido abscísico (ABA en zonas y periodos específicos durante el desarrollo de la flor lo cual sugiere su acción promotora en la velocidad de antesis floral de esta especie en DC. En este trabajo se buscaron nuevos indicios de la participación de fitohormonas presentes en la fracción ácida con el proceso de floración. En una primera etapa, extractos foliares provenientes de hojas de plantas en días largos (caracterizadas por menor velocidad de antesis floral se aplicaron en botones florales de plantas en días cortos (caracterizadas por una mayor velocidad de antesis floral. Se realizaron ocho aplicaciones con diferentes frecuencias totalizando un periodo de tratamiento de 25 días. Los resultados mostraron que las sustancias presentes en los extractos de la fracción ácida, no alteran la velocidad promedio de antesis floral en los botones florales de plantas en DC. En la segunda etapa del experimento, la cuantificación de los extractos por ELISA, permitió establecer una mayor concentración de ABA en los extractos de hojas y de botones florales de plantas en DC y de botones florales en el inicio del tratamiento. Estos resultados confirman la relación del ABA con la mayor velocidad de antesis floral en plantas de Solidago x luteus en condiciones de DC.Solidago x luteus (M.L. Greene Broulliet & Semple (= x Solidaster hybridus, x S. luteus is a plant that respond to short days (SD for flower development. In this process, there has been established the involvement of many phytohormones, between these, the presence of the abscisic acid (ABA in zones and specific periods during flower development, suggests its promoter roll on the floral anthesis period of this species under

Brote de shigelosis en la ciudad de Luján, Argentina

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Anabella Della Gaspera

2015-06-01

Full Text Available El objetivo del estudio fue describir un brote por Shigella sonnei ocurrido en julio de 2012 en Luján, Buenos Aires, Argentina. Estuvieron afectadas 5 personas que asistieron a una reunión familiar, donde consumieron una rosca vienesa de elaboración artesanal adquirida en un comercio. Todos presentaron fiebre, dolores articulares, escalofríos y diarrea no sanguinolenta con mucus. Se realizaron coprocultivos en los afectados y análisis microbiológicos de los ingredientes. Se aisló y caracterizó S. sonnei de todos los pacientes y de la crema de almendras empleada en la preparación de la rosca vienesa. A los aislamientos se les determinó el perfil de sensibilidad a los antimicrobianos y el genético por electroforesis en campo pulsado. Los resultados demostraron la relación genética de los aislamientos, y esto confirmó la ocurrencia de los casos por exposición a una misma fuente de infección, la crema de almendras. Al ser un ingrediente industrial, de improbable contaminación inicial, la crema de almendras podría haber sufrido una contaminación durante la manipulación en la panadería.

Brote de faringo-amigdalítis por estreptococo ?-hemolítico grupo A

OpenAIRE

Culqui,Dante R; Manzanares-Laya,Sandra; Van Der Sluis,Sarah Lafuente; Fanlo,Albert Anton; Comas,Rosa Bartolomé; Rossi,Marcello; Caylá,Joán A

2014-01-01

El objetivo fue describir un brote de faringo-amigdalitis causado por estreptococos β-hemolíticos del grupo A (EGA) en profesionales de la salud. El estudio que se transmite de persona-persona o por vía alimentaria. El estudio transversal descriptivo se realizó en 17 clientes, localizados en la misma mesa, que participaron de una cena en restaurante de Barcelona, España, en julio de 2012. Se analizaron, la frecuencia de síntomas de los afectados, el tiempo y la s...

Biología floral de Passiflora foetida (Passifloraceae

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María T. Amela García

1998-06-01

Full Text Available Un experimento reproductivo muestra que Passiflora foetida es autocompatible. Observaciones de las características florales y de los visitantes durante la antesis, más el análisis del polen transportado, permitieron identificar el síndrome floral (melitofilia y las funciones de cada visitante. La antesis ocurre desde las 6 hasta las 11 hs. Se identificaron 3 fases florales: 1 estigmas por encima de las anteras, 2 estigmas a la altura de las anteras, 3 estigmas por encima de las anteras; los radii, los pétalos y los sépalos se incurvan. Los estigmas están receptivos durante toda la antesis. La concentración de azúcares del néctar es 34 %. El color predominante en el espectro visible es el blanco. En el espectro UV, los estambres y el gineceo contrastan con el limen y el androginóforo; pueden ser una guía de néctar. Tres especies de himenópteros fueron los visitantes más frecuentes y constantes: Ptiloglossa tarsata (Colletidae siempre contactan las anteras y los estigmas cuando liban, transportan un alto porcentaje de polen de P. foetida y visitan flores en fase 1 y 2; pueden ser considerados los principales polinizadores. Pseudaugochloropsis sp. (Halictidae raramente contactan las anteras o los estigmas cuando perforan el limen para acceder al néctar y visitan flores en fase 2 y 3; son ladrones de néctar que raramente polinizan. Augochlorella sp. (Halictidae recolectan polen sin tocar los estigmas y visitan flores en fase 2 y 3; son hurtadores de polen.A reproductive experiment shows that Passiflora foetida is autocompatible. Observations of floral characteristics and visitors during anthesis, plus the analysis of pollen allowed identification of floral syndrome (melittophily and functions for each visitor. Anthesis occurs from 6 to 11 AM. Three floral phases were identified: 1 stigmas above anthers, 2 stigmas at anther level, 3 stigmas above anthers; radii, petals and sepals become incurved. The stigmas are receptive during the

Brote de faringo-amigdalítis por estreptococo ?-hemolítico grupo A

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Dante R Culqui

2014-04-01

Full Text Available El objetivo fue describir un brote de faringo-amigdalitis causado por estreptococos β-hemolíticos del grupo A (EGA en profesionales de la salud. El estudio que se transmite de persona-persona o por vía alimentaria. El estudio transversal descriptivo se realizó en 17 clientes, localizados en la misma mesa, que participaron de una cena en restaurante de Barcelona, España, en julio de 2012. Se analizaron, la frecuencia de síntomas de los afectados, el tiempo y la severidad de los síntomas, variables demográficas y alimentos ingeridos, entre otros factores. La tasa de ataque (TA en los comensales fue del 58,8% (10/17. El 60,0% (6/10 de los comensales fueron positivos para EGA. El 46,2% (6/13 de los manipuladores de alimentos suministrados en la cena presentaron síntomas. No se identificó asociación con los alimentos ingeridos. Existen evidencias epidemiológicas de la transmisión alimentaria del EGA, pero no podría descartarse la transmisión respiratoria.

The modular structure of the floral phenotype in Mimulus luteus var. luteus (Phrymaceae Estructura modular del fenotipo floral en Mimulus luteus var. luteus (Phrymaceae

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GASTÓN CARVALLO

2005-12-01

Full Text Available Most studies of multivariate evolution on the floral phenotype assume that traits evolve independently one from each other, ignoring the modular structure that results from genetic correlations or developmental constraints. In this paper we describe the interdependence of nine floral traits in the herb Mimulus luteus var. luteus (Phrymaceae, as an attempt to characterize functional modules on which natural selection can potentially act upon. Using edge exclusion deviance analysis, we detected four modules: (a an attractiveness module, (b a stigma behavior module, (c a stigma surface module, and (d a herkogamy module. Consequences of these findings for future studies of natural selection in this species are discussedLa mayor parte de los estudios de evolución multivariada sobre el fenotipo floral suponen que los rasgos evolucionan independientemente unos de otros, ignorando la estructura modular que resulta de correlaciones genéticas o restricciones impuestas por el desarrollo. En este trabajo describimos la interdependencia de nueve rasgos florales en Mimulus luteus var. luteus (Phrymaceae, en un intento por caracterizar los módulos funcionales sobre los cuales la selección natural pudiera eventualmente actuar. Mediante análisis de desviación límite-excluyente detectamos cuatro módulos: (a un módulo de atractividad floral, (b un módulo de comportamiento estigmático, (c un módulo de superficie estigmática, y (d un módulo de hercogamia. Se discuten las consecuencias de estos hallazgos para futuros estudios de selección natural en esta especie

Anatomía floral comparativa del género Polianthes (Agavaceae Comparative floral anatomy of the genus Polianthes (Agavaceae

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Héctor Serrano-Casas

2011-03-01

Full Text Available Se realizó un estudio anatómico de las flores de algunas especies en los subgéneros Polianthes y Bravoa del género Polianthes L. (Agavaceae, con el propósito de investigar si la actual clasificación subgenérica es adecuada. Los taxa analizados del subgénero Polianthes fueron P. densiflora, P. nelsonii y P. platyphylla, y del subgénero Bravoa, P. geminiflora var. geminiflora, P. howardii y P. multicolor. Las características anatómicas florales entre las especies son similares y comparten con otros miembros de la familia Agavaceae los nectarios septales y los óvulos anátropos, bitégmicos y crasinucelados. En los taxa del subgénero Bravoa, los filamentos se originan en la base del tubo floral, mientras que en el subgénero Polianthes se originan por debajo de los tépalos internos del perianto. Anteriormente, sin considerar la anatomía de las flores, se planteaba que los filamentos se originaban en ambos subgéneros desde la base del tubo del perianto y que éstos permanecían adnados al mismo, separándose a diferentes niveles. En el nivel interespecífico, P. howardii presenta nectarios de mayor longitud que los lóculos, en relación con los de las otras especies estudiadas.An anatomical floral study of some species of the genus Polianthes (Agavaceae, of both subgenus Polianthes and subgenus Bravoa (Agavaceae was carried out, with the aim of testing the adequacy of the present subgeneric classification. The taxa studied of subgenus Polianthes were P. densiflora, P. nelsonii and P. platyphylla; and P. geminiflora var. geminiflora, P. howardii and P. multicolor of subgenus Bravoa. The anatomical characters between these species are similar, sharing with other members of the Agavaceae family the septal nectaries and the anatropous, bitegmic, and crassinucellated ovules. In the taxa of subgenus Bravoa, the filaments originate from the floral tube base, while in subgenus Polianthes they originate near the base of the internal tepals

Identificación de una nueva área de infección por Rickettsias del grupo typhi: estudio de un brote de tifus en Huánuco

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Rosa Mostorino E

2003-03-01

Full Text Available Objetivos: Investigar un brote de síndrome febril en el distrito de Punchao mediante una evaluación clínica, laboratorial y entomológica para conocer los factores asociados a la aparición de dicho brote. Materiales y métodos: Debido al reporte de tres pacientes con cuadro clínico febril asociado a cefalea, mialgias y postración en la semana epidemiológica Nº41 del año 2000, procedentes del distrito de Punchao, Humalíes, Huánuco y ante la información de presentación inusual de pacientes febriles en la última semana en dicho lugar, se decidió investigar la naturaleza y características del brote. Se definió como caso a todo paciente con cuadro febril agudo y uno de estos síntomas: cefalea, mialgias o postración; procediéndose a la búsqueda activa de éstos y a la evaluación de presencia de anticuerpos para rickettsias en suero mediante inmunofluorescencia indirecta (IFI. Se capturaron roedores y se colectaron ectoparásitos en las viviendas (roedores, animales domésticos y humanos, a fin de identificar la presencia de Rickettsias en ellos mediante IFI, aislamiento o PCR. Resultados: No se logró el aislamiento del agente causal. Se evidenció circulación de la Rickettsia sp. (serología positiva tanto en humanos (en casos y en no casos como en roedores. Se evidenció mayor presencia de malos hábitos de aseo y condiciones inadecuadas de saneamiento básico en los casos (respecto a los no casos y una disminución de los casos luego del inicio de las medidas de control. Conclusiones: Las evidencias encontradas permitieron identificar un brote de tifus en Punchao, no pudiéndose determinar la especie involucrada debido a que no se aisló el agente causal.

Brote de histoplasmosis aguda en un grupo familiar: identificación de la fuente de infección

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Roberto Alonso Jiménez

2002-06-01

Full Text Available Se informa un brote de histoplasmosis ocurrido en los integrantes de una familia y que comprometió a cuatro personas, dos mujeres, una niña y un hombre. El caso índice consultó por sintomatología respiratoria grave, de comienzo súbito, que requirió hospitalización. En los otros casos, la infección cursó de manera asintomática pero se puso en evidencia por la reactividad en las pruebas serológicas con histoplasmina. La búsqueda de una fuente común de contagio llevó a sospechar que era la tierra de un vivero que se había utilizado como fertilizante de las plantas caseras. Las suspensiones de las tierras de las macetas sirvieron para inocular ratones BALB/c, de cuyos órganos fue posible aislar el agente etiológico, Histoplasma capsulatum var. capsulatum. Si bien la histoplasmosis es más frecuente en ciertas ocupaciones y es propia de áreas rurales, las epidemias y los brotes son ahora comunes en áreas urbanas debido a actividades como la urbanización masiva, la tala de árboles, las demoliciones y el uso de tierras enriquecidas con abonos orgánicos (gallinaza, guano. Se llama la atención sobre el peligro que representa esta última actividad.

BROTE DE SARAMPIÓN EN CAMPO DE GIBRALTAR, CÁDIZ, DURANTE EL PERÍODO FEBRERO-JULIO 2008

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Juan Nieto Vera

2010-01-01

Full Text Available Fundamento: El 4 de febrero de 2008 se notificó a la Red de Vigilancia Epidemiológica de Andalucía (SVEA, 2 casos de sarampión vinculados epidemiológicamente, 2 tripulantes del Fast-Ferry Jaime I de la Compañía Balearia, que realiza la línea de Algeciras - Tánger. El objetivo de este trabajo es caracterizar epidemiológicamente el brote de ámbito poblacional detectado en la Comarca Campo de Gibraltar, las medidas de control implementadas y la efectividad vacunal. Método: Estudio observacional descriptivo de casos notificados. Se analizan las variables edad, sexo, municipio de residencia, sintomatología, fecha de inicio, colectivos implicados, estado vacunal previo, intervenciones realizadas, genotipo del virus, y efectividad vacunal. Fuentes de información los registros del SVEA, programa de vacunas e historia digital individual (Diraya. Se calcularon tasas x 105 por grupo de edad y medidas de frecuencia. Para comparación de efectividad vacunal se utilizó test Chi2. Resultados: Se confirmaron 155 casos de sarampión, 88.4% por laboratorio. Grupos de edad mas afectados menores de 2 años (19% y de 21 a 40 (51%. El 54.2% varones. El 72,14% no estaban vacunados. Se aisló virus sarampión Genotipo D4 importado. La efectividad vacunal era superior al 99%. Conclusiones: Se confirma un brote por virus del sarampión importado. Mas de la mitad de los casos no estaban vacunados. La disminución de la incidencia en vacunados hace necesario recomendar campañas de Cacht - Up que aumenten las coberturas para evitar la aparición de estos brotes vacunales.

Brote de gastroenteritis por agua potable de suministro público Waterborne outbreak of gastroenteritis transmitted through the public water supply

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P. Godoy

2003-06-01

Full Text Available Introducción: La potabilidad del agua induce a descartar el posible origen hídrico de los brotes. El objetivo fue investigar un brote de gastroenteritis por agua potable de suministro público. Métodos: Después de la notificación de un brote de gastroenteritis en el municipio de Baqueira (Valle de Arán se diseñó un estudio epidemiológico de cohortes retrospectivo. Mediante un muestreo sistemático se eligió a 87 personas hospedadas en los hoteles y a 62 alojadas en diferentes apartamentos. Se recogió información sobre 4 factores (consumo de agua de la red, bocadillos, agua y alimentos en las pistas de esquí y presencia de síntomas. Se determinó la existencia de cloro, se analizó el agua de la red y se realizó un coprocultivo a 4 enfermos. La implicación de cada factor se determinó con el riesgo relativo (RR y su intervalo de confianza (IC del 95%. Resultados: La incidencia de gastroenteritis fue del 51,0% (76/149. Los porcentajes de los síntomas fueron los siguientes: fiebre, 27,0%; diarrea, 87,5%; náuseas, 50,7%; vómitos, 30,3%, y dolor abdominal, 80,0%. El único factor que presentó un riesgo estadísticamente significativo fue el consumo de agua de la red (RR = 11,0; IC del 95%, 1,6-74,7. La calificación sanitaria del agua fue de potabilidad. Se observó un defecto de situación del clorador en el depósito, que fue corregido. Se recomendó incrementar aún más las concentraciones de cloro, lo cual se acompañó de una disminución de los casos. Los coprocultivos de los 4 enfermos fueron negativos para las enterobacterias investigadas. Conclusiones: El estudio demuestra la posibilidad de presentación de brotes hídricos por agua cualificada como potable y sugiere la necesidad de mejorar la investigación microbiológica (determinación de protozoos y virus en este tipo de brotes.Introduction: The chlorination of public water supplies has led researchers to largely discard drinking water as a potential source of

Estudios morfo-anatómicos en nectarios florales y extraflorales de Triumfetta rhomboidea (Malvaceae, Grewioideae Morpho-anatomical studies of the floral and extrafloral nectaries of Triumfetta rhomboidea (Malvaceae, Grewioideae

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Elsa Lattar

2009-07-01

Full Text Available La morfo-anatomía de los nectarios florales y extraflorales tricomáticos de Triumfetta rhomboidea Jacq. se estudió con microscopio óptico y microscopio electrónico de barrido. Las cinco glándulas nectaríferas florales, están localizadas en el androginóforo, mientras que los nectarios extraflorales se hallan en los márgenes de la base de la lámina en la hoja y en los márgenes de la bráctea. Las diferencias observadas entre ellos están dadas por el tamaño y la forma de las células epidérmicas basales, el número de las células del pie y de la cabezuela de los tricomas glandulares, los idioblastos del parénquima secretor y el tejido vascular que inerva los nectarios. El análisis de la varianza mostró diferencias significativas entre los nectarios florales y extraflorales en las siguientes variables: longitud y diámetro de la cabezuela, longitud y ancho del pie, pared periclinal de la célula epidérmica basal. Estos resultados fueron congruentes con el análisis de componentes principales (ACP. La longitud de cabezuela y la pared periclinal de la célula basal permitieron reconocer los tres tipos de nectarios, mientras el diámetro de cabezuela y la longitud y ancho de pie sólo diferenciaron los nectarios florales de los extraflorales. Los resultados de este trabajo se discuten en relación a información previa sobre el género.The morpho-anatomy of the floral and extrafloral trichomatic nectaries of Triumfetta rhomboidea Jacq. was studied by light and scanning electron microscope. Five nectariferous glands are located on the androgynophore, whereas extrafloral nectaries are on the margins at the base of the leaf and on the margins of the bract. The differences observed between them are the size and shape of the epidermal basal cells, the number of the foot and the head cells of the glandular trichomes, the idioblasts of the secretor parenchyma and the vascular tissue which innervates the nectaries. The analysis of variance

CDC Signos Vitales- Los alimentos más seguros salvan vidas (Safer Food Saves Lives)

Centers for Disease Control (CDC) Podcasts

2015-11-03

Este podcast se basa en la edición de noviembre del 2015 del informe Signos Vitales de los CDC. Los alimentos contaminados que se envían a múltiples estados pueden causar brotes de enfermedades y enfermar gravemente a muchas personas. Sepa lo que se puede hacer para prevenir y detener los brotes.  Created: 11/3/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 11/3/2015.

Brote de enfermedad transmitida por alimentos en el distrito de Catache, provincia de Santa Cruz, departamento de Cajamarca. Abril 2007

OpenAIRE

Suarez, Victor

2007-01-01

De acuerdo con la información proporcionada por la Dirección de Epidemiología de la DIRESA Cajamarca, durante la primera semana de abril se ha producido un brote de una enfermedad transmitida por alimentos en el distrito de Catache, provincia de Santa Cruz, departamento de Cajamarca, con 49 casos. Los primeros casos se presentaron el 3 de abril y los últimos seis casos fueron atendidos en el C.S. Catache el día 9 de abril. El 100% de los casos presentaron nauseas, 85,7% vómitos y 75,5% cef...

Aislamiento rápido del virus dengue 3 por el método de shell vial en el brote de dengue en Lima

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Victoria Gutiérrez P

2005-07-01

Full Text Available El aislamiento de virus dengue con los métodos tradicionales demora hasta un mes, en situaciones de emergencia como el brote de dengue clásico en el distrito de Comas-Lima entre abril y mayo de 2005, es necesario un diagnóstico precoz. Se procesaron 117 muestras de sueros de pacientes con diagnóstico clínico de dengue clásico en fase virémica procedentes la zona del brote, mediante el método de shell vial para el aislamiento del virus dengue en la línea celular C6-36, se identificó el serotipo del virus mediante inmunofluorescencia indirecta (IFI empleando anticuerpos monoclonales. Se logró el aislamiento del virus DEN-3 al quinto día de cosecha en el 48,7% (57/117 de los sueros. Los resultados sugieren que el método de shell vial, por el menor tiempo de aislamiento que el método tradicional, puede ser implementado como método de diagnóstico y usado en la vigilancia epidemiológica del virus dengue.

MEMORIA Y APRENDIZAJE EN LA ESCOGENCIA FLORAL DE LAS ABEJAS

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MARISOL AMAYA

2009-05-01

Full Text Available RESUMEN Los polinizadores altamente especializados en su dieta, no hacen escogencias florales, ellos visitan un recurso específico siguiendo el dictado de la información almacenada en sus genes. En contraste, para la abeja social Apis mellifera una escogencia floral implica, la toma de una decisión, usualmente con criterio económico, basada en información aprendida y almacenada en alguna forma de memoria. Aunque existen numerosos estudios y modelos sobre la escogencia floral en abejas, la gran mayoría de éstos, han derivado sus conclusiones a partir de condiciones temporalmente fijas de la interacción. Muy pocos estudios han abordado la dinámica propia del contexto ecológico, en el cual el mercado floral de las abejas cambia con las estaciones del año y con los patrones diarios de antesis floral. Este cambio en la disponibilidad de especies florales enfrenta a los polinizadores, a realizar escogencias secuenciales acerca del alimento a explotar. En este trabajo abordo el tema del forrajeo secuencial en parches florales heterospecíficos, enfocándome en el uso que la abeja melífera hace de la información previamente aprendida en un contexto, cuando se enfrenta a la explotación de alimento en un contexto ecológicamente diferente. He realizado experimentos sobre escogencia floral simulando las condiciones de cambio del paisaje floral, exponiendo abejas individuales de A. mellifera a decidir sobre cuales especies forrajear en cada parche. Los resultados indican que la abeja invierte en procesos de aprendizaje en un muestreo inicial, pero una vez almacenada la información, utiliza una pieza de la información previamente aprendida (color para explotar parches florales heteroespecíficos siguiendo una imagen de búsqueda de color. En esta revisión discuto situaciones biológicas de la interacción planta-abeja, las cuales apoyan la idea que en la naturaleza el uso de imágenes de búsqueda de color por parte de abejas sociales puede

Outbreak of rotavirus gastroenteritis with high mortality, Nicaragua, 2005 Brote de gastroenteritis por rotavirus con alta mortalidad, Nicaragua, 2005

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Juan José Amador

2008-04-01

ños de edad que provocó numerosas consultas, hospitalizaciones y muertes en Nicaragua. Se analizó si la vacunación habría evitado estos casos de enfermedad y fallecimiento, se buscaron factores de riesgo de muerte y se elaboró un perfil clínico de los niños hospitalizados con diarrea. MÉTODOS: Se realizó un estudio de casos y controles para determinar si los niños que murieron tuvieron acceso a programas de vacunación, como medida indirecta del acceso a la vacuna contra rotavirus. Se identificaron los factores de riesgo de muerte en los niños que fallecieron durante el brote en comparación con los controles con diarrea sobrevivientes, emparejados según la edad. Se tomaron muestras de heces fecales, datos clínicos y de vacunación de los niños hospitalizados con diarrea para realizar el diagnóstico de rotavirus, elaborar el perfil clínico y pronosticar el acceso futuro a una vacuna contra rotavirus. RESULTADOS: El brote ocurrido entre febrero y abril de 2005 ocasionó 47 470 consultas y 52 muertes. Aproximadamente 80% de los casos y controles y 60% de los niños hospitalizados con diarrea tuvieron acceso a la vacunación programada y posiblemente tuvieron acceso a una vacuna contra rotavirus. Si en los programas de vacunación se hubiera dispuesto de una vacuna de 85% de eficacia, se hubieran prevenido hasta 51% de los casos graves de rotavirus y hasta 68% de las muertes. El estudio de 35 pares de casos y controles demostró que la enfermedad grave, la desnutrición y la atención por curanderos tradicionales fueron los factores de riesgo de muerte. Se encontró rotavirus en 42% de las muestras de niños hospitalizados, asociado con la enfermedad grave y la deshidratación. CONCLUSIONES: El efecto de los brotes estacionales de la enfermedad por rotavirus podría reducirse mediante la vacunación contra rotavirus, el perfeccionamiento de los programas de rehidratación oral y el entrenamiento de los curanderos tradicionales en el tratamiento correcto de

Factores relacionados con el control exitoso de un brote por Klebsiella pneumoniae productora de KPC-2 en una unidad de cuidado intensivo en Bogotá, Colombia

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Gisell Bustos-Moya

Full Text Available La resistencia a carbapenémicos en Klebsiella pneumoniae ha aumentado de manera considerable, incrementando las tasas de morbimortalidad. El objetivo de este trabajo fue describir las características epidemiológicas, microbiológicas y las medidas de intervención que permitieron el control exitoso de un brote de Klebsiella pneumoniae productora de KPC-2. Métodos: El estudio se realizó en 2 periodos: el primero durante el brote, con instauración de un protocolo de medidas de intervención; y el segundo, de seguimiento posbrote. Se realizaron pruebas de identificación y susceptibilidad por sistema automatizado, tamización de carbapenemasas por test de Hodge modificado, PCR para detección de los genes bla KPC , bla KPC-2 , NDM-1 y estudio de clonalidad por electroforesis de campos pulsados. Resultados: Durante el brote, se identificaron 18 aislamientos de Klebsiella pneumoniae productora de KPC en 11 pacientes. Tres casos fueron confirmados como infección intrahospitalaria. La técnica de PCR reveló la presencia del gen bla KPC en 21 de 22 aislamientos (pacientes y medio ambiente y se identificó la presencia de un clon con una similitud superior al 75%. En el periodo posbrote los cultivos ambientales y de búsqueda de colonizados fueron negativos. Discusión: Se evidenció un control exitoso del brote producido por un clon. La implementación de un protocolo de intervención y la monitorización de su cumplimiento, la comunicación efectiva y el trabajo en equipo fueron indispensables para evitar su propagación y evitar un comportamiento endémico posbrote.

BROTES DE GASTROENTERITIS AGUDA VÍRICA EN RESIDENCIAS DE ANCIANOS. SISTEMA DE DETECCIÓN POR UMBRAL DE PREVALENCIA (SIDUP

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Juan B Bellido-Blasco

2009-01-01

Full Text Available Se describen las intervenciones llevadas a cabo en una unidad de epidemiología local, durante varios años, relacionadas con la epidemiología de la gastroenteritis por norovirus en residencias de ancianos de Castellón. Desde varios brotes acaecidos en un mismo geriátrico, hasta el estudio de los casos esporádicos que determinan la situación endémica en varias residencias. Este trabajo se centra en el análisis de esa situación endémica de síntomas digestivos en periodos de silencio epidémico y la propuesta de un método sencillo para detectar el inicio de brotes de GEA de transmisión progresiva (persona- persona que hemos denominado Sistema de Detección por Umbral de Prevalencia (SiDUP. Se discute el espectro epidemiológico de la gastroenteritis por norovirus en estas instituciones para personas mayores.

Epidemiologia de la fiebre amarilla selvática en Colombia durante los últimos años

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Jorge Boshell Manrique

1944-08-01

Full Text Available La primera manifestación de Fiebre Amarilla Selvática en los Llanos Orientales de Colombia se registro en agosto de 1934 en forma de un brote epidémico en la vecindad de la población de Restrepo, y se prolongó hasta febrero de 1935 (1. En la segunda mitad del mismo año la enfermedad apareció en los alrededores de Villavicencio y Acacías; en los últimos meses de 1936 se registraron casos en las tres regiones. Nuevas manifestaciones se presentaron en 1937 en el curso inferior de los ríos correspondientes a tales regiones, seguidas por un silencio que se prolongó hasta 1940, año en que principió el brote actual. No hubo explicación satisfactoria respecto al origen del brote de 1934. Era evidente que la infección atacaba de preferencia a los peones que trabajaban en el bosque. En ningún sitio de toda esa región, a pesar de larga y cuidadosa búsqueda, fue posible encontrar larvas o adultos de Aedes aegypti.

Brote de legionelosis asociado a un balneario

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I. Santa Marina Rodríguez

2001-06-01

Full Text Available En 1998 el inicio de la temporada de actividad de un balneario en Gipuzkoa coincidió con la detección de un brote de legionelosis asociado al mismo, lo cual condujo al cierre de la instalación y al estudio epidemiológico -casos y controles- y ambiental oportunos. Se definió como caso toda persona que durante su estancia en el balneario o durante los 10 días siguientes presentará neumonía o un cuadro febril compatible con fiebre de Pontiac.El estudio ambiental incluyó la inspección del balneario y entorno y muestreos de los sistemas sanitarios de agua y de los elementos de hidroterapia.De las 287 personas encuestadas de la Comunidad Autónoma Vasca, el 12.5% cumplían con la definición de caso; 9 casos presentaron neumonía y 26 fiebre de Pontiac. La curva epidémica se inició el 7 de mayo, alcanzando un pico los días 14 y 15 de mayo y finalizando el día 20. El riesgo de enfermar ajustado por edad, sexo y consumo de tabaco se asoció con la duración de la estancia en el balneario (OR=118.5, 95% I.C: 18.7-750.2 y con el uso de una piscina (OR=10.5, 95% I.C: 1.3-82.6. Se detecto L. pneumophila serogrupo1 en recuentos superiores a 103 ufc/l en diversos puntos de la red de hidroterapia y en la ducha de la habitación de uno de los enfermos. El análisis por electroforesis en campos pulsados de una muestra biológica y muestras ambientales permitió la confirmación genotípica. El establecimiento se abrió al público tras realizar un tratamiento de choque y comprobar que transcurridos 15 días no se detectó L. pneumophila en las muestras ambientales.

Investigación de vectores y reservorios en brote de Chagas agudo por posible transmisión oral en Aguachica, Cesar, Colombia

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Hugo Soto

2014-04-01

Full Text Available Colombia tiene un registro de 11 casos de Chagas agudo y 80 casos por contaminación oral con Trypanosoma cruzi. Este trabajo analiza los hallazgos entomológicos y parasitológicos del brote de Aguachica, Cesar, en 2010. Un grupo interdisciplinario de profesionales de la salud y de universidades regionales realizó las pruebas de laboratorio a los pacientes y el estudio del foco de transmisión. Se detectaron 11 casos agudos de enfermedad de Chagas en una sola familia con vivienda sin triatominos domiciliados y, Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus y dos Didelphis marsupialis infectados con T. cruzi en palmas de Attalea butyracea y Elaeis oleifera del área urbana de Aguachica. Se analiza la participación del R. pallescens y el rol de las palmas en el ciclo silvestre de T. cruzi y para la transmisión oral de la enfermedad de Chagas. Incursiones esporádicas de R. pallescens, P. geniculatus y E. cuspidatus silvestres desde palmas cercanas al domicilio humano pueden provocar brotes cada vez más frecuentes de Chagas oral.

Regeneración de brotes adventicios en hojas de guayaba (Psidium guajava L. cultivadas in vitro Adventitious shoot regeneration from in vitro cultured leaves of guava (Psidium guava L.

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Trujillo Sánchez Reinaldo

2004-12-01

Full Text Available La regeneración de brotes adventicios es una etapa clave para la aplicación de las técnicas de ingeniería gené­tica. El presente trabajo tuvo como objetivo el desarrollo de un procedimiento para la regeneración de brotes por organogénesis a partir de hojas de microesquejes o brotes de guayaba (Psidium guajava L. cultivados in vi­tro. Para ello se estudiaron algunos de los principales factores que afectan la regeneración de brotes, tales como la concentración de reguladores del crecimiento (citoquinina, el estado fisiológico del explante y la he­rida. En todos los experimentos se utilizaron como explantes hojas de vitroplantas de guayaba de la variedad Enana Roja Cubana EEA18-40 de diferentes subcultivos. El mejor resultado se alcanzó con una concentración de 0,75 mg/L de 6-bencilaminopurina como suplemento hormonal del medio MS. Se comprobó que para las hojas provenientes de microesquejes con mayor número de subcultivo y tomadas de la parte inferior de los brotes, el potencial morfogenético disminuye significativamente (p60% y el mayor número de brotes por explante promedio (>3 se alcanzó al realizar varias heridas en forma de punteaduras en el nervio central de las hojas. Este protocolo de regeneración constituye una importante herramienta que puede ser empleada para futuros estudios de transformación genética en esta especie. Palabras clave: cultivo de tejidos, explantes de hoja, reguladores de crecimiento, organogénesis, guayaba.Adventitious regeneration is a key step in the application of genetic engineering to the breeding programs of plants. In this work a method for adventitious shoot regeneration from leaves of micropropagated guava shoots has been developed and some of main factors to affect the shoot regeneration like, concentration of plant growth regulators (citoquinine, physiological state of explants and the wound are studied. Leaves from guava in vitro cultured of variety Cuban Red Dwarf 18-40 was used

Effects of Hydrogen Cyanamide on the Floral Morphogenesis of Kiwifruit Buds Efectos de la Cianamida de Hidrógeno sobre la Morfogénesis Floral de Kiwi

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Hakan Engin

2010-09-01

Full Text Available The influence of hydrogen cyanamide (HC on the flower bud development of kiwifruit (Actinidia deliciosa (A. Chev. C.F. Liang & A.R. Ferguson. ‘Hayward’ was studied. The bud samples were taken every 5-10 d starting from dormant season (March and fixed in FAA (10% formalin, 50% ethanol, 5% glacial acetic acid. Flower bud development was compared in three HC concentrations and the control. 1%, 2%, and 3% of HC was applied 35 d before the expected natural bud break. During the onset of bud break, only 57.6% of control buds had sepal primordia developed. On the other hand, HC treated buds had almost completed their stamen formation and started stigma primordia. When the control vines were in advanced bud break, gynoecial plateau already began to form in the vines treated with 2 and 3% HC. Vines treated with 1% HC lagged a little behind and had not started developing the gynoecial plateau. As the bud developed from the open cluster to the tight bud stage, the differences between the control and HC treated plants were more distinct. However, there were no differences between HC treatments as the ovule initiation took place in the buds.El presente estudio evalúa la influencia de la aplicación de cianamida de hidrogeno (HC sobre el desarrollo de las yemas florales de kiwi (Actinidia deliciosa (A. Chev. C.F. Liang & A.R. Ferguson cv. Hayward. Las muestras de yemas se tomaron cada 5-10 días comenzando en la época de dormancia en marzo y se fijaron en FAA (10% formaldehido, 50% etanol, 5% ácido acético glacial. Se comparó el desarrollo de las yemas florales en tres concentraciones de HC y el control. Se aplicó HC al 1%, 2% y 3% 35 días antes del brote natural de las yemas. En el momento de la apertura de las yemas, sólo el 57,6% de las yemas de control habían desarrollado los primordios de los sépalos. Por el contrario, las yemas tratadas con HC casi habían completado la formación de estambres y habían empezado el desarrollo de primordios

Brote de bacteriemia por Serratia marcescens en pacientes portadores de catéteres tunelizados en hemodiálisis secundario a colonización de la solución antiséptica. Experiencia en 4 centros

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José L. Merino

2016-11-01

Conclusiones: Las bacteriemias por gérmenes no convencionales deben ponernos sobre aviso para investigar posibles brotes. La aplicación de una solución contaminada por S. marcescens en los catéteres en hemodiálisis fue la vía de bacteriemia. El tratamiento antibiótico intravenoso y el sellado de los catéteres permitió una excelente supervivencia tanto de los pacientes como de los catéteres.

Descripción de un brote de enfisema y edema pulmonar agudo del bovino (EPAB) en Parral (Chile)

OpenAIRE

H. URRUTIA; C. BREVIS; M. QUEZADA; S. DONOSO

1997-01-01

Se describe un brote de enfisema y edema alveolar agudo del bovino (EPAB) ocurrido en la zona centro-sur a fines del verano de 1995. Los animales Frisón negro, de aproximadamente 2 años de edad, fueron afectados después de cambiarse de una pradera fibrosa a una suculenta de alfalfa. La mortalidad por esta causa fue de un 23%. Las principales lesiones encontradas en la necropsia fueron enfisema y edema intersticial intenso del pulmón, lo cual fue corroborado histopatológicamente, encontrándose...

Descripción de un brote de enfisema y edema pulmonar agudo del bovino (EPAB) en Parral (Chile)

OpenAIRE

URRUTIA, H.; BREVIS, C.; QUEZADA, M.; DONOSO, S.

1997-01-01

Se describe un brote de enfisema y edema alveolar agudo del bovino (EPAB) ocurrido en la zona centro-sur a fines del verano de 1995. Los animales Frisón negro, de aproximadamente 2 años de edad, fueron afectados después de cambiarse de una pradera fibrosa a una suculenta de alfalfa. La mortalidad por esta causa fue de un 23%. Las principales lesiones encontradas en la necropsia fueron enfisema y edema intersticial intenso del pulmón, lo cual fue corroborado histopatológicamente, encontrándos...

Brote de encefalitis de San Luis en el Área Metropolitana Buenos Aires

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Alfredo Seijo

2011-06-01

Full Text Available Se describen los hallazgos epidemiológicos y clínicos de 13 enfermos con diagnóstico de infección por virus de la encefalitis de San Luis, con transmisión entre enero y marzo de 2010, en el Area Metropolitana Buenos Aires (AMBA. Los 13 enfermos, promedio de edad 38 años, tuvieron un comienzo agudo caracterizado por hipertermia y cefalea. Entre los días dos y diez de iniciados los síntomas, 7/13 enfermos tuvieron signos y síntomas de compromiso neurológico caracterizado por meningitis sin signos encefálicos en 1/7. En 6/7 los hallazgos más frecuentes fueron: rigidez de nuca, desorientación temporoespacial, fotofobia, confusión y alteración del lenguaje. Dos resonancias magnéticas y un electroencefalograma presentaron signos de afectación de lóbulos temporales. El líquido cefalorraquídeo se caracterizó por pleocitosis con predominio de células mononucleadas, glucorraquia normal y discreto aumento de proteínas. No hubo casos fatales. En 6/13 pacientes la sospecha clínica inicial fue dengue. Por la agrupación espacial y temporal de los casos puede considerarse un brote epidémico, el primero conocido en el AMBA, ya que no se había notificado previamente la circulación epidémica del virus.

Brote por Salmonella enteritidis en trabajadores de un hospital An outbreak of Salmonella gastroenteritis among hospital workers

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Ma. Eugenia Chávez-de la Peña

2001-06-01

Full Text Available Objetivo. Describir y determinar las causas de un brote de enfermedad gastrointestinal por Salmonella enteritidis, ocurrido en junio de 1998, entre el personal trabajador de la salud (TS que labora en un hospital de tercer nivel de atención, en la ciudad de México. Material y métodos. Se incluyó a todo aquel empleado que presentó diarrea o fiebre asociada a síntomas gastrointestinales, a partir del día 8 de junio de ese año, posterior a la ingestión de alimentos en el comedor del hospital (caso, y en aquellos asintomáticos (controles que ingirieron alimentos durante el mismo periodo y en el mismo lugar. Se les aplicó un cuestionario para conocer los alimentos ingeridos, se realizó hemocultivo a sujetos con fiebre mayor de 38 °C y coprocultivo a todos, incluido el personal de la cocina. En el análisis estadístico se utilizó razón de momios (RM, intervalos de confianza al 95% (IC 95%, ji cuadrada y valor de p= 0.05 para conocer la significancia estadística. Resultados: Desarrollaron síntomas 155 TS, y de éstos 129 completaron la encuesta; se encuestaron además 150 TS asintomáticos. Los síntomas más comunes fueron diarrea (85%, dolor abdominal (84%, cefalea (81.4%, náusea (78.3% y escalofríos (74.4%. Ocho hemocultivos fueron negativos; 59 casos (46% y seis controles (4% tuvieron coprocultivos positivos a Salmonella enteritidis. De los alimentos ingeridos, las tortas de carne capeadas con huevo (RM 19.39, IC 95% 9.09-41.4, la crema de mamey, así como el yogur fueron significativamente más frecuentes en casos que en controles. Los cultivos de los alimentos resultaron negativos. Conclusión. Muy probablemente este brote se debió a la ingestión de alimentos contaminados (tortas preparadas con huevo, papa y carne con insuficiente cocción. Este brote enfatiza la necesidad de mantener un programa de evaluación de la calidad de los alimentos en hospitales. El texto completo en inglés de este artículo está disponible en

Floral induction, floral hormones and flowering

NARCIS (Netherlands)

Pol, van de P.A.

1972-01-01

The factors, influencing the synthesis and action of floral hormones, and possible differences between floral hormones in different plants were studied. The experimental results are summarized in the conclusions 1-20, on pages 35-36 (Crassulaceae'); 21-39 on pages

Propagación in vitro de Heliconia bihai (L. cv. Lobster Salmón a partir de meristemos florales

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Marta Leonor Marulanda-ángel

2011-04-01

Full Text Available Se desarrolló un protocolo de propagación in vitro a partir de meristemos florales para Heliconia bihai cv. Lobster Salmón. Para el efecto se establecieron 250 yemas florales en diferentes tiempos utilizando NaClO al 1% durante 20 min. El medio de establecimiento Murashige y Skoog con mejores resultados fue BAP (2 mg/lt, AIA (1 mg/lt y 0.1 g/lt de L-cisteína. La mayor produccion de brotes en multiplicación se obtuvo con 6 mg/lt de BAP y con un subcultivo posterior en medio con 2 mg/lt de BAP y 0.5 mg/lt de AIA, alcanzando una tasa de multiplicación de tres nuevas yemas. El enraizamiento de las plántulas in vitro se logró con 1.3 mg/lt de AIA. La aclimatación en vivero fue 92% de supervivencia. Se realizó un análisis de varianza (Anova y un test de Tukey para las variables evaluadas las cuales mostraron diferencias estadísticas en cada fase. La propagación in vitro de heliconias a partir de yemas florales requiere mayor tiempo en la fase de establecimiento y multiplicación, no obstante permite mayores porcentajes de supervivencia y una menor contaminación, ofreciendo material de siembra de diferentes especies de esta planta de interés comercial.

Estudio de un brote poblacional de hepatitis A: Efectividad de la vacunación como medida de control Study of a population outbreak of hepatitis A: Effectiveness of vaccination as a control measure

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María José Díaz Villaescusa

2010-08-01

Full Text Available Objetivo: Describir un brote de hepatitis A en la ciudad de Albacete y valorar la efectividad de las medidas de control adoptadas. Métodos: Constatada la existencia del brote, se establecieron las definiciones de caso. Se recogieron los datos clínicos y epidemiológicos de los casos mediante encuesta. Se describió la distribución temporoespacial, mediante la localización de los casos y la curva epidémica. Se pusieron en marcha, como medidas de control y prevención inmediatas, la administración de inmunoglobulina (IG y educación sanitaria a la población en riesgo. Resultados: Desde enero de 2005 a enero de 2006 se declararon 62 casos. Los grupos de edad más afectados fueron los escolares y los adultos jóvenes. El mecanismo de transmisión fue de persona a persona. La curva epidémica presenta dos periodos. Las medidas de control iniciales fueron higiénicas y administración de IG a los contactos; en el segundo periodo se complementaron con la vacunación contra la hepatitis A, administrada a los alumnos de los centros de enseñanza de los dos barrios inicialmente implicados. La extensión del brote a los barrios colindantes y la alarma social que ocasionó hicieron que se ampliara la vacunación a los centros de enseñanza próximos a aquellos en que se habían detectado casos. Después de la última vacunación, en enero de 2006, no se notificó ningún caso. Conclusiones: El uso de la vacuna postexposición frente al virus de la hepatitis A en la población escolar y los adultos jóvenes parece ser una medida efectiva para el control de un brote.Objective: To describe an outbreak of hepatitis A in the city of Albacete (Spain and to assess the effectiveness of the control measures implemented. Methods: When the outbreak was noted, definitions of a case were established. Clinical and epidemiological data were collected through a survey. The temporal-spatial distribution was identified through mapping and the epidemic curve. Health

Análisis de un brote epidémico de brucelosis en trabajadores de un matadero

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Luna Sánchez Antonio

1998-01-01

Full Text Available FUNDAMENTO: La notificación mediante el Sistema de Vigilancia Epidemiológica de un número inusual de casos de Brucelosis en trabajadores de un matadero a finales de 1996 hizo sospechar la existencia de un brote epidémico entre dicho colectivo profesional. MÉTODOS: Se recopiló la información disponible respecto a: 1 animales sacrificados en el matadero diagnosticados de brucelosis; 2 bajas laborales producidas y 3 datos de la mutualidad laboral relativos a los empleados del matadero con la enfermedad. Se realizó una encuesta epidemiológica a los trabajadores sobre los antecedentes de enfermedad, actividad laboral y riesgos no laborales (ingesta de leche o derivados sin higienizar. Las dependencias y actividades del matadero fueron inspeccionadas. Se diseñó un estudio de casos y controles. Se estudió cada puesto de trabajo tomando como controles a los restantes empleados del matadero. Para su verificación se realizó un estudio retrospectivo de cohortes. RESULTADOS: El brote epidémico de la enfermedad entre los trabajadores comenzó durante el mes de septiembre y duró hasta febrero del siguiente año. Las encuestas epidemiológicas descubrieron 28 trabajadores con síntomas sugestivos de la enfermedad, siendo los operarios del área de sacrificio del matadero quienes presentan la tasa de ataque más alta: 56%. En el estudio de casos y controles el riesgo más elevado se observó en dicho colectivo de trabajadores con una OR de 4,27 (IC 95%: 1,6-15 y p<0.01. Del mismo modo en el estudio de cohortes apreciamos que estos trabajadores presentan un RR de 2,5 (IC 95%: 1,5-4,3 cuando son comparados con el resto de trabajadores de la cohorte y de 8 (IC 95%: 2-30 si los comparamos con el colectivo de menor exposición. Los RR de los operarios de la limpieza y de la sala de despiece fueron de 6,56 (IC 95%: 1,6-27 para los primeros y de 4,77 (IC 95%: 1,1-21 para los segundos. Las fracciones etiológicas fueron del 87% para los de la zona de

Response of first attack of inflammatory bowel disease requiring hospital admission to steroid therapy Respuesta al tratamiento esteroideo del primer brote de enfermedad inflamatoria intestinal que requiere ingreso hospitalario

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M. Abu-Suboh Abadía

2004-08-01

Full Text Available Introduction: corticoid administration is the usual treatment of Crohn' disease (CD and ulcerative colitis (UC attacks. How-ever, information available on response rates and their predictive factors is scarce. Objective: to establish response to steroidal treatment in an homogeneous group of patients with CD or UC during their first admission to hospital. Methods: restrospective analysis of 86 patients who received systemic steroidal treatment for a severe flare-up during their first hospital admission between 1995 and 2000. Patients were treated per protocol with fluid therapy, absolute diet, IV 6-methyl-prednisolone 1 mg/kg/day, and enoxaparin at prophylactic doses. Clinical response at 30 days was considered good in case of complete remission, and poor in case of partial or absent remission. Univariate and multivariate analyses according to non-parametric statistics were performed for sociodemographic and biologic variables. Results: 45 patients with CD and 41 with UC were included. Good response rates were 64.4% for CD and 60.9% for UC. The univariate analysis showed that patients with good response have shorter evolution times and fewer previous flare-ups (p Introducción: la administración de corticoides constituye el tratamiento habitual de los brotes de enfermedad de Crohn (EC y colitis ulcerosa (CU. Sin embargo, existe poca información sobre las tasas de respuesta y los factores que puedan predecirla. Objetivo: determinar la respuesta al tratamiento esteroideo en un grupo homogéneo de pacientes de EC y CU que ingresan por primera vez en el hospital. Métodos: análisis retrospectivo de 86 pacientes que en su primer ingreso hospitalario recibieron tratamiento esteroideo sistémico por brote grave de EC o CU entre 1995 y 2000. Fueron tratados de forma protocolizada con sueroterapia, dieta absoluta, 6-metil-prednisolona 1 mg/kg/día IV y enoxaparina a dosis profilácticas. Se ha considerado la respuesta clínica a los 30 días como

Efectividad de la terapia floral para el tratamiento de la depresión en pacientes adultos mayores con cáncer

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Arely Díaz Cifuentes

2014-08-01

Full Text Available Se realizó un estudio experimental con el objetivo de determinar la efectividad de la terapia floral en el tratamiento de la depresión leve y moderada, en adultos mayores con cáncer, en el Hospital Provincial Docente de Oncología María Curie, de la provincia de Camagüey, Cuba; el período de estudio comprendió desde enero de 2011 hasta enero de 2012. El universo contempló los pacientes neoplásicos de la tercera edad con síntomas de depresión, remitidos a la consulta de Medicina Tradicional y Natural de la institución y la muestra quedó integrada por 100 pacientes que cumplían los criterios de inclusión y exclusión, los cuales se dividieron en dos grupos de 50 cada uno: el A con tratamiento floral y el B con tratamiento convencional. Se evaluó la persistencia de los síntomas depresivos a los tres y a los seis meses después de aplicado el tratamiento. La terapia floral fue efectiva en el 94% de los casos. Se evidenció la existencia de situaciones intensas antes de ser diagnosticados con cáncer, la más relevante fue la separación familiar, en el 70% de la muestra. Los pacientes del grupo A evolucionaron mejor que los del B. En los primeros, se redujeron notablemente los síntomas depresivos a los tres meses, situación más notable a los seis meses de tratamiento, avalando como efectiva la terapia floral empleada. No se reportaron efectos adversos

Fenología, crecimiento y sincronía floral de los progenitores del híbrido de maíz QPM H-374C Phenology, plant growth and floral synchrony of the parental lines of H-374C QPM maize hybrid

OpenAIRE

Luis Alberto Noriega González; Ricardo Ernesto Preciado Ortiz; Enrique Andrio Enríquez; Arturo Daniel Terrón Ibarra; Jorge Covarrubias Prieto

2011-01-01

La temperatura es uno de los parámetros climáticos que mayor influencia ejercen sobre la fisiología de las plantas; por otro lado, en la producción de semilla de maíz (Zea mays L.), la caracterización fenológica de progenitores con base en unidades calor, permite definir con exactitud la fecha de siembra para lograr sincronía floral en la formación de híbridos. El objetivo de esta investigación fue estudiar el efecto de la temperatura en el crecimiento y las etapas de desarrollo de los progen...

Determinación de tamaño de muestra de características del xilema de brote de aguacate mediante remuestreo

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Elizabeth Meza-Castillo

2010-12-01

Full Text Available El propósito de este trabajo fue determinar el tamaño de muestra adecuado, para detectar diferencias estadísticas en análisis de varianza de los caracteres de xilema, en brotes anuales de aguacate. Para esto, fueron registradas en tres árboles con altura contrastante las variables frecuencia, área, perímetro y diámetro de los vasos del xilema. A partir de 50 observaciones de cada árbol, se realizaron 5.000 remuestreos no paramétricos, para cada repetición de 2 a 50 campos microscópicos. A partir del tamaño de muestra de 15 repeticiones, las desviaciones en los cinco estadísticos son mínimas, por lo que se propone como el mínimo para el muestreo de dichas variables.

Descripción de un brote epidémico de malaria en una comunidad indígena asentada en la zona urbana de Armenia, Colombia, 2012

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Liliana Quintero

2015-03-01

Conclusiones. Se reportó el primer brote autóctono de malaria por P.vivax en Armenia, asociado con un asentamiento subnormal en una comunidad indígena y se constató cómo en los márgenes del río Quindío se presentan las condiciones eco-epidemiológicas que permiten el ciclo de reproducción del mosquito vector de la malaria.

Estandarización de una técnica para la micropropagación de los helechos Platycerium bifurcatum Y Asplenium nidus (Polipodiaceae

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Viviana Becerra

2005-07-01

(MS3, en concentraciones entre 2,5 a 7,5 mg/L. La aparición de los primeros brotes para P. bifurcatum y A. nidus se observó en los tres y cuatro meses después de la siembra, los mejores resultados en brotación para P. bifurcatum corresponden a los medios: MS1 (2,5 y 5,0 mg/L, MS2 (5,0 y 7,5 mg/L y MS3 (2,5, 5,0 y 7,5 y mg/L. Para A. nidus, los medios MS1 (2,5 y 7,5 mg/L y MS3 (7,5 mg/L, mostraron los mejores resultados. Los brotes obtenidos fueron transferidos a medios MS líquido, sólido y semisólido, con resultados óptimos en medio líquido y MS con 1,0% de agar.

Propagación in vitro de Heliconia bihai (L. cv. Lobster Salmón a partir de meristemos florales

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Londoño-Giraldo Lina María

2011-06-01

Full Text Available

Se desarrolló un protocolo de propagación in vitro a partir de meristemos florales para Heliconia bihai cv. Lobster Salmón. Para el efecto se establecieron 250 yemas florales en diferentes tiempos utilizando NaClO al 1% durante 20 min. El medio de establecimiento Murashige y Skoog con mejores resultados fue BAP (2 mg/lt, AIA (1 mg/lt y 0.1 g/lt de L-cisteína. La mayor produccion de brotes en multiplicación se obtuvo con 6 mg/lt de BAP y con un subcultivo posterior en medio con 2 mg/lt de BAP y 0.5 mg/lt de AIA, alcanzando una tasa de multiplicación de tres nuevas yemas. El enraizamiento de las plántulas in vitro se logró con 1.3 mg/lt de AIA. La aclimatación en vivero fue 92% de supervivencia. Se realizó un análisis de varianza (Anova y un test de Tukey para las variables evaluadas las cuales mostraron diferencias estadísticas en cada fase. La propagación in vitro de heliconias a partir de yemas florales requiere mayor tiempo en la fase de establecimiento y multiplicación, no obstante permite mayores porcentajes de supervivencia y una menor contaminación, ofreciendo material de siembra de diferentes especies de esta planta de interés comercial.

Evaluación de la definición de caso probable de dengue clásico durante el brote de dengue en Lima, 2005

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José Juárez S

2005-07-01

Full Text Available Objetivos: Evaluar la utilidad diagnóstica de la definición de caso probable de dengue clásico (DCPDC para la identificación de casos definitivos, durante el brote en el distrito de Comas, abril - mayo 2005. Materiales y métodos: Estudio observacional, analítico, no controlado de corte transversal. Se incluyeron pacientes procedentes de Comas que en el periodo de estudio presentaron sospecha de dengue y con resultados de aislamiento viral o ELISA IgM, según el tiempo de enfermedad (4 ó e5 días respectivamente realizados en el Instituto Nacional de Salud. Se determinó la sensibilidad (S, especificidad (E, valor predictivo positivo (VPP y negativo (VPN de la DCPDC y de los síntomas que la conforman, tomando como prueba de oro al aislamiento viral o ELISA IgM. Resultados:Se incluyeron 316 pacientes, de los cuales se confirmaron 137 (43,4% casos de dengue. Se detectaron 60 pacientes mediante aislamiento viral, la DCPDC en pacientes con cuatro o menos días de enfermedad presentó una S=85%, E=13,40%, VPP=13,18%, VPN= 74,29%. Se detectaron 77 pacientes con cinco o más días de enfermedad con IgM ELISA, la DCPDC en este grupo presentó S= 68,42, E= 16,28, VPP= 68,42, VPN= 46,67. Conclusiones: La DCPDC aplicada en el brote de dengue en Comas, al igual que los síntomas individuales que la conforman es sensible, pero poco específico.

Evaluación de preservantes florales en la poscosecha de tres variedades de clavel estándar

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López Paola

2008-04-01

Full Text Available

En clavel es imprescindible el tratamiento poscosecha a base de tiosulfato de plata (STS, para garantizar una mayor longevidad floral; sin embargo, los tratamientos antietilénicos a base del ión plata implican contaminación ambiental. El objetivo de este estudio fue realizar la evaluación de diferentes compuestos en la poscosecha de clavel estándar variedades Nelson, Dream y Delphi, como posibles sustitutos del STS. Para este fin, se utilizaron tratamientos a base de STS, SR-AOA (ácido aminooxacético de liberación lenta y quitosan. En seguida a la cosecha de los tallos florales se realizó una simulación de viaje con una duración aproximada de 21 días; posteriormente, las flores fueron sometidas a evaluaciones de longevidad, velocidad de apertura, color y consumo de agua. En la evolución de la vida en florero, se observó la misma tendencia para las tres variedades: un primer grupo de mayor longevidad floral, conformado por los tratamientos a base de SR-AOA y STS, con un promedio de durabilidad de 14 a 20 días; y el segundo grupo, de menor longevidad floral, conformado por los tratamientos a base de quitosan, quitosan más ácido cítrico, quitosan más AOA y testigo absoluto, con una duración promedio de 6 a 8 días.

Floral structure in the neotropical palm genus Chamaedorea (Arecoideae, Arecaceae

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Stauffer, Fred W.

2008-12-01

Full Text Available Male and female floral structure has been studied in 28 species of Chamaedorea, the largest palm genus present in the Neotropics. The taxa investigated represent all subgenera according to the most recent taxonomic revision of the group. Morphological, histological and cytological features that are known to be of importance for interactions with visiting insects were studied and their putative role in protecting the flowering parts assessed. The taxonomic distribution of selected characters is in some cases congruent with relationships inferred by recently published molecular studies within the group.Se ha estudiado la estructura de las flores masculinas y femeninas en 28 especies de Chamaedorea, el género de palmas con mayor número de especies en la región neotropical. Los táxones investigados representan a todos los subgéneros contemplados en la más reciente revisión taxonómica del grupo. Se han estudiado los caracteres morfológicos, histológicos y citológicos de mayor importancia en cuanto a la visita de insectos y se ha examinado su rol dentro de la protección de los órganos florales. La distribución taxonómica de caracteres seleccionados ha demostrado, en algunos casos, ser congruente con las relaciones inferidas por los más recientes estudios moleculares que incluyen al grupo.

A mortality study of the last outbreak of yellow fever in Barcelona City (Spain in 1870 Estudio de la mortalidad del último brote de fiebre amarilla en la ciudad de Barcelona (España en 1870

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Jaume Canela Soler

2009-08-01

Full Text Available Background: The last outbreak of yellow fever in the city of Barcelona, Spain, was caused by a ship arriving from Cuba. The objective of this study was to describe and analyze the epidemic of 1870 by using the available mortality data. Methods: The information on 1,235 deaths identified in the parochial registries was analyzed, using statistical and epidemiological procedures for epidemic outbreaks. Results: Mortality due to yellow fever was 549.7 per 100,000 inhabitants. The temporal distribution of the deaths showed two peaks at the end of September and October with the last fatalities occurring in December 1870. The distribution of the fatalities in the city's neighborhoods was unequal. In La Barceloneta, in particular, more fatalities were found in the streets adjacent to the port than in the most remote streets (r=0.83; pObjetivo: El último brote de fiebre amarilla en la ciudad de Barcelona, España, se originó a partir de un barco que venía de Cuba. El objetivo de este estudio es describir y analizar esa epidemia ocurrida en 1870, utilizando los datos disponibles de mortalidad. Métodos: La información de las 1235 defunciones identificadas en los registros parroquiales se ha analizado utilizando los procedimientos estadísticos y epidemiológicos para brotes epidémicos. Resultados: La tasa de mortalidad por fiebre amarilla fue de 549.7 por 100,000 habitantes. La distribución temporal de las muertes tenía dos modas en el final de septiembre y octubre, y los últimos muertos ocurrieron en diciembre de 1870. La distribución de las defunciones según los barrios de la ciudad fue desigual. En La Barceloneta, en particular, hubo mas muertos en las calles adyacentes al puerto que en las más lejanas (r=0,83; p<0,0001. Conclusiones: Este estudio muestra una distribución bimodal de la mortalidad por fiebre amarilla durante el brote, con un impacto alto en hombres adultos, y en el barrio de La Barceloneta.

Brote epidémico de neumonías por Legionella pneumophila en niños cubanos

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Roberto Razón Behar

2002-09-01

Full Text Available La Legionella pneumophila es uno de los patógenos responsable de neumonías atípicas, a través de la inhalación de aerosoles o aspiración de líquidos infectados. Se detectó un brote epidémico de neumonías por Legionella, originado por la aspiración de agua contaminada de una piscina en un grupo de niños cubanos. El agente causal se identificó en 5 de 9 pacientes, por la técnica de inmunofluorescencia indirecta en muestras de sueros pareados. Los síntomas y signos más frecuentes fueron malestar general, anorexia, astenia, fiebre persistente de 39 °C a 40 °C (103 °F a 105 °F, mialgias, cefaleas, náuseas, vómitos, dolor abdominal, diarreas, tos húmeda, dolor torácico y polipnea. Durante el desarrollo de la enfermedad, el tratamiento antibiótico fue empírico (incluyendo los macrólidos, por no tener confirmado el diagnóstico. Todos los pacientes evolucionaron satisfactoriamente. Se reportó un brote epidémico de neumonías por Legionella en niños por primera vez en Cuba, lo cual tiene importancia clínica y epidemiológica.The legionella pneumophila is one of the pathogens responsible for atypic pneumonias by the inhalation of aerosols or aspiration of infected liquids. An epidemic outbreak of pneumonias caused by Legionella was detected among a group of Cuban children. It was originated by the aspiration of contaminated water in a swimming pool. The causal agent was identified in 5 of 9 patients by using the indirect immunofluorescence technique in samples of matched sera. The most frequent symptoms and signs were malaise, anorexia, asthenia, persistent fever from 39°C to 40°C (103° F to 105° F, myalgias, headache, nauseas, vomits, abdominal pain, diarrheas, moist cough, thoracic pain and polypnoea. The antibiotic treatment was empiric (including the macrolides during the development of the disease, since the diagnosis was not confirmed. The patients’ evolution was satisfactory. An epidemic outbreak of pneumonias

Influencia del fotoperiodo en el desarrollo floral de plantas de Solidago chilensis, Aster ericoides ev. 'Monteeasino' y Solidago x luteus Influenee of photoperiod on floral development in plants of Solidago chilensis, Aster ericoides ev. 'Monteeasino' and Solidago x tuteus

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Flórez Roncancio Victor J.

1998-06-01

Full Text Available Solidago x luteus es un híbrido interespecífico entre Solidago ptarmicoides y Solidago canadensis. Este híbrido, Solidago chilensis y Aster ericoides cv. 'Montecasino' son las especies objeto del presente estudio. Son plantas típicas de días largos, las cuales crecen como rosetas en días cortos y son explotadas para flor de corte. Se observaron características vegetativas y reproductivas de estas especies en condiciones fotoperiódicas de 8h y 20h y, en Solidago x luteus, por su mejor performance en cuanto a la inducción floral, se realizaron estudios de comportamiento fotoperiódico del desarrollo desde el botón floral hasta antesis. En forma general, en las tres especies estudiadas, los fotoperíodos largos promueven inducción floral y aumento en el número de ramificaciones laterales y de hojas. En días cortos, las
plantas de Solidago chilensis permanecieron en roseta, en las de Solidago x luteus hubo inducción y antesis floral, en tanto que, en Aster ericoides, había plantas en roseta y plantas inducidas. La evidencia de que los días cortos aceleraban la antesis floral en plantas de Solidago x luteus, inducidas en
días largos, se fortaleció con el experimento de diferente duración en días cortos (5; 10 y 15 días; lo cual se confirmó en experimentos subsecuentes, en donde se comprobó que la planta responde a los fotoperíodos cortos (8h; 10h y 12h, acelerando la antesis y a los fotoperíodos largos (16h y 20h, retardándola y los fotoperiódos entre 12h y 16h (14h  estarían en una situación de transición entre días cortos y días largos, caracterizando, así, una respuesta cuantitativa con el aumento del fotoperíodo.
Solidago x luteus is a hybrid between Solidago ptarmicoides and Solidago canadensis. This hybrid, Solidago chilensis and Aster ericoides cv. 'Montecasino' are the subject of the present work. They are typically long-day plants which grow as rosettes in short days and are exploited as cut

UFO: an Arabidopsis gene involved in both floral meristem and floral organ development.

Science.gov (United States)

Levin, J Z; Meyerowitz, E M

1995-05-01

We describe the role of the UNUSUAL FLORAL ORGANS (UFO) gene in Arabidopsis floral development based on a genetic and molecular characterization of the phenotypes of nine ufo alleles. UFO is required for the proper identity of the floral meristem and acts in three different aspects of the process that distinguishes flowers from shoots. UFO is involved in establishing the whorled pattern of floral organs, controlling the determinacy of the floral meristem, and activating the APETALA3 and PISTILLATA genes required for petal and stamen identity. In many respects, UFO acts in a manner similar to LEAFY, but the ufo mutant phenotype also suggests an additional role for UFO in defining boundaries within the floral primordia or controlling cell proliferation during floral organ growth. Finally, genetic interactions that prevent flower formation and lead to the generation of filamentous structures implicate UFO as a member of a new, large, and diverse class of genes in Arabidopsis necessary for flower formation.

BROTE DE LEGIONELOSIS EN UN RESTAURANTE DE LA COMUNIDAD DE MADRID

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Isabel Abad Sanz

2014-01-01

Full Text Available Fundamentos: el 27 de Junio de 2012 se detectó en el Servicio de Salud Pública del Área 8 de la Comunidad de Madrid un brote de legio- nelosis con 46 personas afectadas. Todas habían estado en el mismo restaurante del municipio de Móstoles dentro del periodo de incubación de la enfermedad. El objetivo de este trabajo es describir la evolución del brote y las medidas sanitarias adoptadas durante el mismo. Métodos: se trata de un estudio descriptivo. Se estudiaron las variables demográficas de los enfermos , antecedentes patológicos, síntomas, evolución clínica y pruebas diagnósticas. Para las variables cualitativas se calcularon frecuencias y porcentajes. Para las variables cuantitativas la media, el valor mínimo y máximo. En las muestras de agua tomadas en las instalaciones de riesgo se estudió concentración de cloro, pH, temperatura y presencia de Legionella. Resultados: en el cultivo del agua del filtro de arena de la depuradora de la fuente exterior creció Legionella pneumophila Serogrupo 1, Sub-grupo Pontiac Allentown/France. Este resultado coincidió con la cepa aislada en las muestras respiratorias de 4 pacientes. Por otro lado, en las muestras de biopelícula obtenidas en la champanera se detectó por PCR la presencia de Legionella pneumophila cuya secuenciación de genes fue idéntica a la encontrada en la muestra respiratoria de un paciente. Conclusiones: se consiguió aislar Legionella pneumophila serogrupo 1 Subgrupo Pontiac Allentown/France serotipo 448 en muestras ambientales, coincidente con la Legionella aislada en muestras respiratorias de algunos pacientes, por lo que se pudo demostrar la vinculación entre el factor de riesgo ambiental y la enfermedad. Este vínculo se confirmó además por secuenciación genética realizada por PCR.

Micropropagación de chayote (sechium edule jacq. Sw. a partir de brotes vegetativos

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Ana Abdelnour

2002-01-01

Full Text Available El chayote (Sechium edule es una importante fuente de divisas para los países exportadores, entre los que Costa Rica mantiene el liderazgo mundial. Entre los factores más limitantes para su producci ón se encuentra el material de siembra, tradicionalmente la semilla, que por su naturaleza no permite la obtención de una producción morfológicamente homogénea de frutos (color, forma y textura de la epidermis motivo de los altos porcentajes de rechazo en las plantas empacadoras. El establecimiento de una metodología de propagación vegetativa de la especie ayudaría a resolver los problemas de heterogeneidad. Por lo anterior, la presente investigación se dirigió a desarrollar un método de micropropagación a partir de brotes vegetativos. Se evaluó el efecto de varios desinfectantes y concentraciones de reguladores de crecimiento en las etapas de establecimiento, multiplicación y enraizamiento de dos cultivares comerciales. Se observó que una desinfección con hipoclorito de calcio al 4% permitió el mayor porcentaje de explantes establecidos asépticamente bajo condiciones in vitro (49%. También se observó que durante las etapas posteriores de la micropropagación, los requerimientos de reguladores de crecimiento fueron muy bajos (0,1 mgL-1 de BA en la etapa de brotación de yemas y de 0,1 a 0,2 mgL-1 de AIB durante el enraizamiento o no se requirieron (etapa de multiplicaci ón de microestacas.

Brote de norovirus en Mallorca asociado al consumo de ostras Norovirus outbreak in Majorca (Spain associated with oyster consumption

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Antònia Galmés Truyols

2011-04-01

Full Text Available Se describe la investigación de un brote de gastroenteritis por norovirus asociado al consumo de ostras. Se encuestaron 346 expuestos (266 afectados. Solamente se enviaron 14 muestras de heces de pacientes al Centro Nacional de Microbiología. Se mandaron ostras recogidas en el lugar de producción al Centro Nacional de Alimentación. Las ostras cumplían los parámetros microbiológicos de calidad aplicables antes de la comercialización, que no incluyen investigación de virus. El análisis epidemiológico asoció la aparición de la enfermedad al consumo de ostras (odds ratio [OR]=60,4; intervalo de confianza del 95% [IC95%]: 26,2-139,3 y de navajas (OR=3,13; IC95%: 1,4-6,9. Los análisis microbiológicos identificaron norovirus en los afectados, pero no en las ostras que habían estado sometidas a un tiempo mayor de depuración que las consumidas. Es necesario un control riguroso de los alimentos de especial riesgo para la transmisión de norovirus y disponer de recursos de laboratorio para investigar brotes alimentarios por norovirus.We describe investigation into an outbreak of norovirus gastroenteritis associated with oyster consumption. A survey was conducted in 346 exposed persons, 266 of whom were cases. Only 14 feces samples from patients were sent to the National Microbiology Laboratory. Oysters collected at the production site were sent to the National Food Center. The oysters met the microbiological quality standard required before sale, which did not include virus investigation. Epidemiological analysis showed an association between gastroenteritis and consumption of oysters (OR=60.4; 95% CI: 26.2-139.3 and razor shells (OR=3.13; 95% CI: 1.4-6.9. Microbiological analysis confirmed norovirus in affected individuals but not in the oysters that had been tested after a longer purification period than those consumed. Food with a special risk of norovirus transmission should be strictly monitored. Investigators should dispose of the

Floral development and floral phyllotaxis in Anaxagorea (Annonaceae).

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Endress, Peter K; Armstrong, Joseph E

2011-10-01

Background and Aims Anaxagorea is the phylogenetically basalmost genus in the large tropical Annonaceae (custard apple family) of Magnoliales, but its floral structure is unknown in many respects. The aim of this study is to analyse evolutionarily interesting floral features in comparison with other genera of the Annonaceae and the sister family Eupomatiaceae. Methods Live flowers of Anaxagorea crassipetala were examined in the field with vital staining, liquid-fixed material was studied with scanning electron microscopy, and microtome section series were studied with light microscopy. In addition, herbarium material of two other Anaxagorea species was cursorily studied with the dissecting microscope. Key Results Floral phyllotaxis in Anaxagorea is regularly whorled (with complex whorls) as in all other Annonaceae with a low or medium number of floral organs studied so far (in those with numerous stamens and carpels, phyllotaxis becoming irregular in the androecium and gynoecium). The carpels are completely plicate as in almost all other Annonaceae. In these features Anaxagorea differs sharply from the sister family Eupomatiaceae, which has spiral floral phyllotaxis and ascidiate carpels. Flat stamens and the presence of inner staminodes differ from most other Annonaceae and may be plesiomorphic in Anaxagorea. However, the inner staminodes appear to be non-secretory in most Anaxagorea species, which differs from inner staminodes in other families of Magnoliales (Eupomatiaceae, Degeneriacae, Himantandraceae), which are secretory. Conclusions Floral phyllotaxis in Anaxagorea shows that there is no signature of a basal spiral pattern in Annonaceae and that complex whorls are an apomorphy not just for a part of the family but for the family in its entirety, and irregular phyllotaxis is derived. This and the presence of completely plicate carpels in Anaxagorea makes the family homogeneous and distinguishes it from the closest relatives in Magnoliales.

Brote de rabia urbana transmitida por perros en el distrito de Santa Marta, Colombia, 2006-2008

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Páez, Andrés; Rey, Gloria; Agudelo, Carlos; Dulce, Álvaro; Parra, Edgar; Díaz-Granados, Hernando; Heredia, Damaris; Polo, Luis

2009-01-01

Introducción. En el distrito de Santa Marta ocurrió un brote de rabia urbana entre abril de 2006 y enero de 2008, con cuatro casos fatales en humanos y 28 en perros. Objetivos. Describir el brote, las técnicas de diagnóstico de laboratorio y las acciones de control de foco empleadas. Medir el impacto de la vacunación antirrábica canina en términos de seroconversión de anticuerpos neutralizantes. Discutir el significado epidemiológico y las implicaciones en salud pública. Materiales y métodos....

Brote de rabia urbana transmitida por perros en el distrito de Santa Marta, Colombia, 2006-2008

OpenAIRE

Andrés Páez; Gloria Rey; Carlos Agudelo; Alvaro Dulce; Edgar Parra; Hernando Díaz-Granados; Damaris Heredia; Luis Polo

2009-01-01

Introducción. En el distrito de Santa Marta ocurrió un brote de rabia urbana entre abril de 2006 y enero de 2008, con cuatro casos fatales en humanos y 28 en perros. Objetivos. Describir el brote, las técnicas de diagnóstico de laboratorio y las acciones de control de foco empleadas. Medir el impacto de la vacunación antirrábica canina en términos de seroconversión de anticuerpos neutralizantes. Discutir el significado epidemiológico y las implicaciones en salud pública. Materiales y mé...

Floral development and floral phyllotaxis in Anaxagorea (Annonaceae)

OpenAIRE

Endress, Peter K.; Armstrong, Joseph E.

2011-01-01

Background and Aims Anaxagorea is the phylogenetically basalmost genus in the large tropical Annonaceae (custard apple family) of Magnoliales, but its floral structure is unknown in many respects. The aim of this study is to analyse evolutionarily interesting floral features in comparison with other genera of the Annonaceae and the sister family Eupomatiaceae. Methods Live flowers of Anaxagorea crassipetala were examined in the field with vital staining, liquid-fixed material was studied with...

Dependency on floral resources determines the animals' responses to floral scents.

Science.gov (United States)

Junker, Robert R; Blüthgen, Nico

2010-08-01

Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination - the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including mechanisms to bypass or tolerate floral defences such as morphological barriers and repellent / deterrent secondary metabolites. Facultative flower visitors, in contrast, are supposed to lack these adaptations and are often prevented to consume floral resources by defence mechanisms. In cases where obligate flower visitors are mutualists and facultative ones are antagonists, this dichotomy provides a solution for the plants' dilemma to attract pollinators and simultaneously repel exploiters. In a meta-analysis, we recently supported this hypothesis: obligate flower visitors are attracted to floral scents, while facultative ones are repelled. Here, we add empirical evidence to these results: bumblebees and ants, obligate and facultative flower visitors, respectively, responded as predicted by the results of the meta-analysis to synthetic floral scent compounds.

Estudio de un brote de bacteremia secundaria asociada con nutrición parenteral en una unidad de recién nacidos de tercer nivel.

OpenAIRE

Jaime A. del Río; Carmen M. Jurado; Fernando Arango

2009-01-01

Ante la evidencia de un brote de bacteremia secundaria neonatal, en la Unidad de Recién Nacidos, Hospital de Caldas, Manizales, se realizó un estudio de casos y controles 1:4, para determinar la asociación de factores de riesgo importantes para los pediatras como nutrición parenteral, terapia respiratoria, tubo orotraqueal, cámara cefálica, parto vaginal, la aplicación de hemoderivado, remisión de otra unidad, leche materna por sonda, peso y edad. Como definición de caso se adoptó la clínica ...

Estudio de un brote epidémico de tos ferina en Castellón

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González Morán Francisco

2002-01-01

Full Text Available Fundamento: A partir de la declaración de varios casos en un centro escolar se inicia el estudio de brote con el objetivo de caracterizar éste desde el punto de vista de persona, lugar y tiempo; se calcula la efectividad de la vacuna, y se estudia la concordancia entre los casos y el resultado positivo del estudio serológico. Métodos: Se define caso a la persona que presenta tos persistente de dos semanas de duración. Se realiza estudio de la difusión de la enfermedad a través de la curva epidémica, y de la efectividad de la dosis de refuerzo de la vacuna antipertussis. La concordancia entre los casos y la serología positiva se evalúa por el índice Kappa. Resultados: Entre los alumnos de varios centros escolares y sus convivientes se encuesta a 130 personas, de los que 94 entran en la definición de caso. La media de edad de los casos es 10,5 años, un 42,6% son varones, el 84% escolares, el 71,3% muestra signos de infección reciente (IgM positiva, y el tiempo medio desde la última dosis de vacuna antipertussis es de 8,25 años. La efectividad de la dosis de refuerzo de la vacuna es del 66%. La concordancia entre los casos y el resultado positivo de la serología muestra un Kappa igual a 0,45. No se aisló B. Pertussis en las 25 muestras de frotis faríngeo. Conclusiones: Las aulas y el medio familiar son un factor de difusión de la enfermedad. La inclusión de una dosis de refuerzo a los 18 meses mejora la efectividad de la vacuna antipertussis. El aislamiento de la B. Pertussis es poco frecuente, y la serología, puede ser una alternativa ante la sospecha clínica de la enfermedad.

Aplicación del teorema del umbral estocástico de Whittle a un brote de varicela Application of Whittle's stochastic threshold theorem to a chickenpox outbreak

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Doracelly Hincapié Palacio

2006-08-01

Full Text Available OBJETIVO: Estimar el ritmo reproductivo básico en un brote de varicela, aplicar el teorema umbral estocástico para estimar la probabilidad de la ocurrencia del brote e identificar medidas preventivas. MÉTODOS: El estudio fue realizado en una guardería de 16 niños, con 13 susceptibles, un infectado inicial y dos niños inmunes por antecedente de enfermedad. Se partió de un modelo estocástico: susceptible - infectado - removido. Se estimó el ritmo de reproducción básico de la enfermedad R0, usando un método de máxima verosimilitud basado en el conocimiento de la distribución de probabilidades para el tamaño total de la epidemia y haciendo una aproximación de epidemia casi-completa. Con el R0 obtenido se aplicó el teorema de umbral estocástico para obtener algunas medidas preventivas que podrían impedir la irrupción del brote de varicela. RESULTADOS: Cada infectado inicial produjo tres casos nuevos de infección, requiriendo para impedir el brote, una cobertura mínima de vacunación del 62%, o disminuir en 62% el contacto entre miembros del grupo o aumentar en 170% la remoción de infectados. CONCLUSIONES: El teorema del umbral estocástico permite identificar medidas que se podrían implementar para prevenir y controlar brotes de varicela. Aunque la distribución del tamaño de la epidemia en forma bimodal con similar probabilidad de ocurrencia de brotes grandes y pequeños, señala la incertidumbre del proceso epidémico en grupos pequeños, requiriéndose un estrecho seguimiento de los brotes en tales grupos.OBJECTIVE: To estimate the basic reproductive rate of a chickenpox outbreak, to apply the stochastic threshold theorem to estimate the probability of an outbreak occurrence and to identify preventive measures. METHODS: The study was carried out in a daycare center comprising 16 children, 13 susceptible, one infected and two children with acquired immunity by previous disease. A stochastic susceptible - infected - removed

Estudio comparativo del crecimiento y la ramificación de brotes anuales en dos especies de Nothofagus (Nothofagaceae y en híbridos inter-específicos Comparative study of annual shoot growth and branching in two species of Nothofagus (Nothofagaceae and inter-specific hybrids

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Cristian Torres

2009-12-01

Full Text Available Las ramas principales y secundarias se diferencian en mayor o menor medida según las especies, lo cual puede observarse en base al crecimiento primario de los brotes que las originan. En ejemplares de vivero juveniles-adultos de Nothofagus obliqua, N. nervosa e híbridos entre ambas especies, se compararon la dinámica de alargamiento, el tamaño y la morfología de dos brotes distales de ramas principales: uno que continúa el alargamiento de la rama principal y el otro que inicia una rama secundaria. En N. alpina y en híbridos, los dos brotes más distales se diferencian más que en N. obliqua. A pesar de la homogeneidad ambiental en el vivero y el origen geográfico común para los ejemplares de N. nervosa y los híbridos, hubieron diferencias fenológicas y morfológicas entre estas entidades. La duración y tasa de alargamiento y la longitud final de los brotes fueron altamente variables en cada entidad. Las variaciones entre entidades en la diferenciación de ejes podrían indicar diferencias en sus capacidades de uso del espacio circundante. La diferenciación entre ramas principales y secundarias se iniciaría en el estado de yema. La variación intra-específica fenológica y morfológica es útil para programas de selección artificial de individuos.Main and secondary branches are more or less differentiated according to the species and this could be observed during the primary growth of the shoots that produce them. In young-adult trees of Nothofagus obliqua, N. nervosa and hybrids between them growing in a common garden, growth dynamics, size and morphology were compared between two distal shoots produced by main branches: one of these shoots continued the extension of the main branch whereas the other initiated a secondary branch. The two distal shoots differed from each other more notably in N. nervosa and in the hybrids than in N. obliqua. Despite the environmental homogeneities at the nursery and the common geographic origin of

Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid

Science.gov (United States)

Gross, Karin; Sun, Mimi; Schiestl, Florian P.

2016-01-01

Geographically structured phenotypic selection can lead to adaptive divergence. However, in flowering plants, such divergent selection has rarely been shown, and selection on floral signals is generally little understood. In this study, we measured phenotypic selection on display size, floral color, and floral scent in four lowland and four mountain populations of the nectar-rewarding terrestrial orchid Gymnadenia odoratissima in two years. We also quantified population differences in these traits and pollinator community composition. Our results show positive selection on display size and positive, negative, or absence of selection on different scent compounds and floral color. Selection on the main scent compounds was consistently stronger in the lowlands than in the mountains, and lowland plants emitted higher amounts of most of these compounds. Pollinator community composition also differed between regions, suggesting different pollinators select for differences in floral volatiles. Overall, our study is the first to document consistent regional differences in selection on floral scent, suggesting this pattern of selection is one of the evolutionary forces contributing to regional divergence in floral chemical signaling. PMID:26886766

Las citoquininas están asociadas al desarrollo floral de plantas de Solidago x luteus en días cortos

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Flórez Víctor Julio

2008-08-01

Full Text Available

En Solidago × luteus (M.L. Greene Brouillet y Semple (= × Solidaster hybridus,× S. luteus, planta comercializada principalmente para flor de corte, el proceso de inducción floral es dependiente de las condiciones fotoperiódicas ambientales. Con el objetivo de determinar la acción de las citoquininas en este proceso, se analizó su presencia en condiciones fotoperiódicas opuestas: días largos (DL de 18 h y días cortos (DC de 8 h. En la primera fase del ensayo, con el fin de analizar la respuesta de las plantas a fitohormonas con frecuencia semanal de aplicación, se realizaron los siguientes tratamientos: 1 ácido giberélico (GA₃ 10^-4M, 6-benzilaminopurina (6-BA 4x10^-4 M y GA₃ 10^-4 M más 6-BA 4x10^-4 M; 2 GA₃ 10^-4M, kinetina (KI 4x10^-4 M y GA₃ 10^-4 M más KI 4x10^-4 M y 3 KI 4x10^-4 M. Con el objeto de conocer la concentración endógena de hormonas, en la segunda fase los extractos vegetales se analizaron a través de cromatografía en capa fina y cuantificados por el ensayo inmunoenzimático de Elisa, previa separación por cromatografía líquida de alta eficiencia. Los resultados permitieron determinar la actividad citoquinínica en extractos provenientes de hojas y de botones florales de plantas en el inicio de los tratamientos, en DL y en DC. Se demostró que la aplicación de KI acelera la antesis floral, evidenciando la relación de citoquininas endógenas con el proceso de desarrollo floral. Por último, de los resultados obtenidos de los extractos sometidos a Elisa se sugiere la participación de las citoquininas en el proceso de antesis floral de S.× luteus, donde la iPA (isopentenil adenosina tendría una acción importante al ser transportada rápidamente de la hoja al botón floral en DC, posibilitando tal vez la mayor

Outbreak of Paratyphoid Fever Among Naval Personnel in Peru (Brote de Fiebre Paratifoidea Entre Personal de la Marina Del Peru.)

Science.gov (United States)

1992-01-01

son menosde 2Okniquecaiusania nvar comun Cs la tifoidea cldsica producida por S parte de las infecciones hunanas La fiebre Isv’lht la parat-foidea. par...TITLE (Include Secunty Clasifi4tin) Brote de Fiebre Parutifoidea Entre Personal de la Marina del Peru 1.PERSON4AL AUTHORCS) Pazzagllia G; Wgnall FS...CLASSIFIATIO F THIS PAGE All othe~redmtons areobolete. ZINCLASSIITIED Best Avai~lable Copy BROTE Dl FIEBRE PARATIFOIDEA ENTRE PERSONAL DE1 LA MARINA DEL PERU G

Descripción de un brote de intoxicación alimentaria estafilocócica ocurrido en Las Rosas, Provincia de Santa Fe, Argentina

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Aníbal A. Brizzio

2011-03-01

Full Text Available En febrero de 2008 se denunció en la localidad santafecina de Las Rosas un presunto brote de una enfermedad transmitida por alimentos. En los procedimientos oficiales no fue posible determinar la cantidad de personas afectadas luego de consumir canelones de verdura adquiridos en un local comercial. Se auditó el establecimiento elaborador y se tomaron muestras del citado producto, muestras ambientales e hisopados de los manipuladores de alimentos. Se entrevistó a los afectados y se recuperaron restos del alimento ingerido. Mediante análisis microbiológicos de rutina se determinó la presencia de S. aureus subespecie aureus coagulasa positivo en muestras del producto consumido, del producto crudo y de los manipuladores del alimento. Los microorganismos indicadores no mostraron niveles significativos y no se aisló otro patógeno de transmisión alimentaria. Se investigó la presencia de genes productores de enterotoxinas estafilocócicas, con resultado positivo para la enterotoxina B en las cepas aisladas de un manipulador y en el alimento vinculado con el brote. Al analizar los aislamientos por SmaI-PFGE se demostró un 100% de similitud entre ellos. La notificación oportuna, las acciones sanitarias coordinadas y la disponibilidad de las herramientas de laboratorio apropiadas permitieron identificar los factores de protección y de riesgo, y cortar la cadena de transmisión de la enfermedad.On February 2008, a suspected foodborne outbreak was reported in Las Rosas (Santa Fe Province, Argentina. The formal procedures indicated that an undetermined number of individuals had experienced food poisoning following consumption of vegetable cannelloni bought at a local shop. The manufacturer establishment was audited. Samples from the suspected food, as well as environmental samples and swabs from food handlers were obtained and involved subjects were interviewed. Remnants of ingested food were also obtained. Routine microbiological procedures of

Situación epidemiológica y de los factores de riesgo de transmisión de Leishmania infantum en España

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Berta Suárez Rodríguez

2012-01-01

Full Text Available En España la leishmaniasis es una zoonosis endémica presente en la mayor parte del territorio peninsular e Islas Baleares. El parásito que se detecta es la Leishmania infantum y el principal reservorio es el perro. Los vectores competentes para transmitir el parásito son los flebotomos, de los que existen dos especies distribuidas por todo el territorio peninsular e Islas Baleares. En este artículo se revisa la situación actual y el comportamiento de la leishmaniasis en España. Se analiza y compara la información sobre la enfermedad procedente de las altas hospitalarias y de la Red Nacional de Vigilancia Epidemiológica así como los factores de riesgo identificados en estudios anteriores que facilitan la transmisión. Desde 2009 está teniendo lugar un brote en el suroeste de la Comunidad de Madrid, destacando el elevado número de casos, cerca de 400 y la detección de un nuevo reservorio, la liebre. Las condiciones que pueden incrementar la incidencia de la leishmaniasis están asociadas al aumento del número de vectores infectados, al de la densidad del flebotomo, al de hospedadores o la aparición de nuevos reservorios en un área geográfica. Esta infección tiene una dinámica de transmisión compleja y para responder oportunamente a los brotes debe estar previamente desarrollado un plan de acción integral y multisectorial en el que participen todas las instituciones involucradas. Ante un brote, es importante estudiar los factores que condicionan la transmisión del lugar y adaptar el plan de acción a sus características específicas.

Biología floral, sistema reproductivo y éxito reproductivo de Macroptilium fraternum (Fabaceae

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Patricia S. Hoc

2003-06-01

Full Text Available Se realizaron observaciones de la biología floral y el sistema reproductivo de Macroptilium fraternum en dos poblaciones de la Argentina, con diferentes condiciones edáficas, localizadas en el extremo Sur del área de distribución de esta especie. En ambas poblaciones y en material de herbario de distintas procedencias se determinó la coexistencia en una misma planta de dos tipos florales: a flores cleistógamas preantesis y b flores pseudocleistógamas. Las flores cleistógamas preantesis con alas mayores de 5 mm, dispuestas en racimos pubescentes, erectos, expuestos sobre el nivel del follaje. La antesis duraba aproximadamente 5 horas en los días soleados y 9 horas en los días lluviosos, el ala derecha cubría al ala izquierda, adquiriendo la corola aspecto bilabiado, ofreciendo el ala izquierda como plataforma de aterrizaje; producían escasa cantidad de néctar (0.18 ± 0.13 µl y no recibieron visitas de polinizadores; aproximadamente cuatro horas después del inicio de la antesis en días soleados el ovario comenzaba a crecer; en el capullo, el estigma receptivo se encontraba cubierto con granos de polen de la misma unidad floral germinando. Las flores pseudocleistógamas con alas menores de 5 mm, dispuestas en racimos breves, hirsutos y postrados, no subterráneos como en otras especies de Macroptilium. El estandarte comenzaba a desplegarse exponiendo parcialmente las alas, el limbo del ala izquierda rodeaba la quilla y nunca se desplegaba; el ala derecha comenzaba a desplegarse y a los 2 segundos se replegaba y marchitaba, inmediatamente el ovario comenzaba a crecer; la flor no ofrecía ninguna superficie donde algún visitante pudiera posarse; en los capullos el estigma estaba receptivo y con los granos de polen de la misma unidad floral emitiendo sus tubos polínicos. El éxito reproductivo relativo fue bajo (polinización natural = 8%, autopolinización espontánea = 3%, debido probablemente a la baja viabilidad polínica, el

CARACTERIZACIÓN DE LA MORFOLOGÍA FLORAL DE DOS CULTIVARES DE BERENJENA (Solanum melongena L. (Solanaceae FLORAL MORPHOLOGY CHARACTERIZATION OF TWO CULTIVARS OF EGGPLANT (Solanum melongena L. (Solanaceae

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Hermes Araméndiz Tatis

2009-12-01

Full Text Available La berenjena es una especie perteneciente al género Solanum, de gran importancia en la horticultura del Caribe colombiano. El estudio tuvo como objetivo describir la morfología floral de dos cultivares de berenjena “Long Purple” y “Criolla Lila”, que tienen origen geográfico diferente, utilizando para ello, una muestra aleatoria de 100 cojines florales por cultivar. Se estimaron la media, rango, varianza, desviación estándar, coeficiente de variación y se aplicó la prueba t, para determinar diferencias entre los dos cultivares. Los resultados indicaron que el cultivar “Long Purple”, presenta flores distílicas, en tanto que en el “Criollo Lila” se observó la presencia de tristilia. El potencial de producción de frutos, fue del 76,5% y 57,52%, para el “Criollo Lila” y “Long Purple”, respectivamente. Las flores brevistílicas en ambos cultivares, incrementan la aptitud masculina y por ende un desbalance entre las flores con funcionamiento masculino y hermafrodita.The eggplant is a specie of genus Solanum, of great importance in horticulture of colombian Caribbean region. The objective of study was to describe the floral morphology of two cultivars of eggplant “Long Purple” and “Lilac land race”, which have different geographic origin. We used a random sample of 100 floral cushions for cultivar. The mean, range, variance, standard deviation, variation coefficient were estimated. The t-test was applied to determine differences between two cultivars. The results indicated that genotype ‘Long Purple’, showed distylics flowers, while in the “Lilac land race” was observed the presence of tristylics flowers. The potential for production of fruit was 76.50% and 57.52% for the “Lilac land race” and “Long Purple”, respectively. Brevistylics flowers in the two cultivars, increased male fitness and thus produced a nonbalance on functioning between male and hermaphrodite flowers.

Brote causado por Escherichia coli en Chalco, México Outbreak caused by Escherichia coli in Chalco, México

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Iliana Alejandra Cortés-Ortiz

2002-07-01

Full Text Available Objetivo. Identificar el agente causal del brote de diarrea asociado con el desbordamiento del canal de aguas negras en Chalco. Material y métodos. Estudio retrospectivo y transversal, efectuado en el Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, de la Secretaría de Salud, con 1 550 hisopos rectales para el aislamiento e identificación bioquímica de V. cholerae y enterobacterias, obtenidos de la población del Valle de Chalco, que presentó diarrea y vómito durante el desastre natural acontecido el 31 de mayo de 2000. El análisis de los resultados se efectuó por la diferencia entre las proporciones de dos poblaciones (prueba de Ji cuadrada. Las cepas de E. coli se hibridaron por "colony blot" para los grupos ETEC, EIEC, EPEC y EHEC. Resultados. El 0.45% correspondió a Salmonella: S. agona, S. infantis, S. enteritidis, S. muenchen, S. typhimurium; 0.06% a Shigella flexneri 3a, y 76.6% a E. coli: 62.2% a ETEC (44.6 % con LT, 11.2% con ST, y 44.1% con ambas sondas, 0.84% a EIEC (sonda ial, 0.84% a EPEC (sonda bundle-forming pilus BFP, 0.08% a E. coli enterohemorrágica no-O157:H7 (sonda pCVD419, y 36.02% no hibridó. No se encontró asociación entre E. coli patógena con la edad y género. Conclusiones. Escherichia coli podría ser responsable del brote de diarrea. Es importante conocer el agente etiológico del brote para encaminar las estrategias en el estudio y control sanitario del mismo.Objective. To identify the etiologic agent responsible for a disease outbreak following an overflow of sewage water in Valle de Chalco, Mexico. Material and Methods. A retrospective cross-sectional study was carried out. Rectal samples were collected from the population of Chalco valley, who suffered from diarrhea and vomiting during a natural disaster that took place on May 31, 2000. The Instituto de Diagnóstico y Referencia Epidemiológicos (Epidemic Reference and Diagnosis Institute, InDRE, Ministry of Health, received 1521 rectal

Brote de leptospirosis en terneros en recría en la provincia de Corrientes, Argentina Leptospirosis outbreak in calves from Corrientes Province, Argentina

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María G. Draghi

2011-03-01

Full Text Available La leptospirosis es una enfermedad infecciosa que produce importantes pérdidas económicas en la producción ganadera. Los signos característicos de la enfermedad son aborto, muerte embrionaria, muerte de terneros de pocos días de vida y mastitis. Se describe un brote de leptospirosis en terneros en actividad de recría. Se realizaron estudios histopatológicos, de hemoparásitos, inmunofluorescencia y cultivos bacterianos. Se aisló Leptospira interrogans serovar Pomona a partir de muestras de los terneros muertos.Leptospirosis is an infectious disease resulting in significant economic losses in livestock production. This disease causes abortion, embryo death, death of calves within the first few days of life and mastitis. We report a leptospirosis outbreak in calf growing and fattening. Histopathological and hemoparasite studies, immunofluorescence, and bacterial cultures were performed. A strain of Leptospira interrogans serovar Pomona was isolated from samples collected from dead calves.

Brote por Salmonella enteritidis en trabajadores de un hospital

OpenAIRE

Chávez-de la Peña Ma. Eugenia; Higuera-Iglesias Anjarath L.; Huertas-Jiménez Martha A.; Báez-Martínez Rosa; Morales-de León Josefina; Arteaga-Cabello Fernando; Rangel-Frausto Sigfrido; Ponce de León-Rosales Samuel

2001-01-01

Objetivo. Describir y determinar las causas de un brote de enfermedad gastrointestinal por Salmonella enteritidis, ocurrido en junio de 1998, entre el personal trabajador de la salud (TS) que labora en un hospital de tercer nivel de atención, en la ciudad de México. Material y métodos. Se incluyó a todo aquel empleado que presentó diarrea o fiebre asociada a síntomas gastrointestinales, a partir del día 8 de junio de ese año, posterior a la ingestión de alimentos en el comedor del hospital (c...

Determinación de la composición fenólica y actividad antioxidante en brotes de clones de Pinus pinaster procedentes de tres orígenes contrastantes

OpenAIRE

Baizán González, Silvia

2013-01-01

Pinus pinaster es una especie de gran importancia económica y ecológica y que presenta una gran diversidad genética. En nuestro grupo de trabajo disponemos de una colección clonal representativa de toda el área de distribución natural de la especie. En una parcela que alberga un ensayo anidado de 10 procedencias x 5 familias x 5 clones x 8 copias y con distribución de bloques aleatorizados, se evaluó la variabilidad del color en base al Espacio de Color CIELAB de los brotes que emergen en pri...

Probable brote de transmisión oral de enfermedad de Chagas en Turbo, Antioquia

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Juan Fernando Ríos

2011-03-01

Conclusión. Se identificó un probable brote agudo de enfermedad de Chagas en Antioquia y se plantea como hipótesis la transmisión por vía oral, mediante la ingestión de T. cruzi en alimentos contaminados con restos de triatominos o excrementos de marsupiales.

Herramientas para afrontar las situaciones de crisis en un brote de gastroenteritis aguda en un colegio público Practical lessons from the risk management of an outbreak of acute gastroenteritis in a public school

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Áurea Morillo-García

2005-08-01

Full Text Available En este trabajo describimos las reflexiones y conclusiones extraídas del análisis de un brote de gastroenteritis en un centro escolar, que ocasionó una crisis de salud pública. El análisis realizado tuvo como base la metodología de las matrices de "debilidades, amenazas, fortalezas y oportunidades" (DAFO. Se describe la epidemiología de los sucesos y decisiones tomadas, basadas en aspectos operativos durante una situación de crisis. Incluye la experiencia del equipo responsable del brote, las relaciones con otras entidades y la gestión de la información. Las dificultades encontradas por el equipo coordinador consistieron en el retraso de la declaración, la falta de formación de algunas entidades implicadas y el mal uso de los circuitos establecidos. Es necesario un entrenamiento específico en los actuales protocolos de manejo de crisis y fomentar la mejora continua de los circuitos de coordinación mediante la autoevaluación y actualización de conocimientos y recursos.We present our reflections on the management of an acute gastroenteritis outbreak in a public school, which caused a public health crisis, and the conclusions drawn from this experience. The methodology of strengths, weaknesses, opportunities, and threats (SWOT analysis was used. This article describes the epidemiology of the incident and the policy decisions made, but focuses on operational aspects of outbreak management. The experience of the outbreak control team, liaison with other organizations, and data management are discussed. The difficulties encountered by the outbreak team related to delay in declaring in the outbreak, lack of training in some of the entities involved, and incorrect use of the surveillance circuits. Current protocols and specific action plans for the management of outbreaks should be improved through self-evaluation and updating of resources and knowledge.

Brote epidémico por consumo de pez mantequilla: keriorrea e intoxicación histamínica

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Mª Azucena Fariñas Cabrero

2015-01-01

Full Text Available Fundamentos: El consumo de pez mantequilla se está extendiendo en nuestro país. Si no se cumplen unas adecuadas normas de conservación y preparación de este tipo de alimento puede producir intoxicaciones. El objetivo del trabajo fue describir un brote de doble intoxicación por histamina y ésteres cerosos tras el consumo de pez mantequilla. Métodos: Estudio descriptivo de la doble intoxicación producida en un banquete celebrado en julio de 2013 en Valladolid. Se estudió mediante la cumplimentación de una encuesta específica telefónica o desde los centros asistenciales que atendieron a los comensales. La base de datos y posterior análisis estadístico descriptivo se realizaron con el programa Microsoft Excel Professional Plus 2010. Resultados. De los 27 casos declarados,en 24 se obtuvo información sobre los síntomas. La tasa de ataque fue 22,5%, con un cuadro clínico en el que predominó la diarrea (75%, la cefalea (46%, el dolor abdominal (38% y la sudoración (38%, destacando por su especificidad el picor/ardor de boca (29%. Cuatro pacientes presentaron heces anaranjadas y oleosas (keriorrhea. El tiempo medio transcurrido, desde el inicio de la cena hasta la aparición de los síntomas, fue de dos horas. La duración media de la sintomatología fue de 14 horas. La analítica del pescado servido mostró niveles de histamina superiores a 2.000 mg/kg. Conclusiones. Se produjo una doble intoxicación (histamina y ésteres cerosos por consumo de pez mantequilla. El cuadro fue leve y autolimitado.

Regulation of Floral Stem Cell Termination in Arabidopsis

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Toshiro eIto

2015-02-01

Full Text Available In Arabidopsis, floral stem cells are maintained only at the initial stages of flower development, and they are terminated at a specific time to ensure proper development of the reproductive organs. Floral stem cell termination is a dynamic and multi-step process involving many transcription factors, chromatin remodeling factors and signaling pathways. In this review, we discuss the mechanisms involved in floral stem cell maintenance and termination, highlighting the interplay between transcriptional regulation and epigenetic machinery in the control of specific floral developmental genes. In addition, we discuss additional factors involved in floral stem cell regulation, with the goal of untangling the complexity of the floral stem cell regulatory network.

Caracterización genética del virus de la fiebre amarilla proveniente de un brote icterohemorrágico en una comunidad nativa del distrito de Imaza, Amazonas, 2005

OpenAIRE

Yábar, Carlos; Mamani, Enrique

2006-01-01

La fiebre amarilla (FA) sigue siendo una enfermedad de importancia en salud pública en el mundo a pesar de la existencia de una vacuna eficaz (WHO, 2005). En Sudamérica, el Perú fue uno de los países que registró el mayor número de casos de FA durante el 2004 (WHO, 2005), contando con zonas endémicas que se extienden desde la selva norte hacia la selva central. Recientemente, en diciembre de 2005 la Dirección de Salud (DISA) de Bagua tomó conocimiento de un brote icterohemorrágico en la co...

Variaciones Intra-Específicas en el crecimiento primario de Nothofagus dombeyi (Nothofagaceae Intra-specific variations in the primary growth of Nothofagus dombeyi (Nothofagaceae

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Javier Puntieri

2005-07-01

Full Text Available Se evaluó el patrón de crecimiento bajo condiciones controladas de los ejes foliados de 16 plántulas de Nothofagus dombeyi. Los individuos fueron ubicados en una cámara de crecimiento y se evaluó el crecimiento del tronco en dos eventos de crecimiento sucesivos (julio 2002 - marzo 2004. Se identificaron tres patrones de crecimiento del primer brote medido: (1 crecimiento ininterrumpido por unos 8 meses, (2 crecimiento interrumpido por un período de reposo no menor de 7 semanas, con rebrote posterior y (3 crecimiento ininterrumpido por 6 a 7 meses. En los individuos con los patrones de crecimiento 1 y 2, la tasa máxima de producción de hojas del primer brote producido fue mayor que en los individuos con el tercer patrón de crecimiento. La tasa media de crecimiento fue mayor para los brotes del primer grupo que para los de los otros dos grupos. El segundo de los brotes medidos se alargó en un único pulso y alcanzó menor tamaño que el primero de los brotes. Se discute el posible rol de gradientes ontogenéticos o de variaciones genéticas entre individuos de coihue como explicación de los diferentes patrones de crecimiento registrados.

El hospital ante un brote prolongado de legionelosis The hospital faced with a prolonged Legionella outbreak

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Juan Antonio Fernández

2004-08-01

Full Text Available Objetivo: Describir los recursos asistenciales utilizados en pacientes hospitalizados por neumonía por Legionella durante un brote ocurrido en Alcoy y compararlos con los empleados en otras neumonías. Métodos y resultados: Mediante un protocolo, se analiza y compara a 177 pacientes con neumonía por Legionella con 180 pacientes ingresados por otras neumonías, y se describe su tratamiento y los recursos empleados. La claritromicina fue el antibiótico más utilizado en ambos grupos. La estancia hospitalaria fue similar, pero los requerimientos de ventilación mecánica y cuidados intensivos fueron superiores para Legionella. La hospitalización domiciliaria se utilizó con éxito en un 15,6% de los pacientes con Legionella y en un 11,3% de los demás. El uso de oxigenoterapia domiciliaria al alta fue menor para Legionella (7,8% que para el resto de neumonías (16,7%. Conclusiones: Se destaca la mayor necesidad de ventilación mecánica en la neumonía por Legionella y los buenos resultados de la hospitalización domiciliaria dentro de los nuevos sistemas de gestión.Objective: To describe the health resources used in patients hospitalized with Legionella pneumonia during an outbreak of Legionnaire's disease in Alcoy (Spain, and to compare them with those used in other forms of pneumonia. Methods and results: Using a clinical protocol, 177 Legionella pneumonia patients were compared with 180 patients hospitalized for other types of pneumonia. Data on therapy and the resources used were collected. The most common antibiotic treatment in both groups was clarithromycin, but intensive care and mechanical ventilation requirements were greater in Legionella pneumonia. Home-based hospital care was successfully used in 15.6% of patients with Legionella pneumonia and in 11.3% of those with other types of pneumonia. Home oxygen therapy after discharge was less frequent in the Legionella pneumonia group (7.8% than in the group with non

Floral biology of candeia (Eremanthus erythropappus, Asteraceae Biologia floral da candeia (Eremanthus erythropappus, Asteraceae

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Fábio de Almeida Vieira

2012-12-01

Full Text Available Floral biology and pollinators of candeia (Eremanthus erythropappus were analyzed in a natural population. We studied anthesis, flower morphology, stigmatic receptivity, pollen viability and floral visitors. The small flowers (10.17 mm in length are pink, hermaphrodites and organized in dense capitula (mean = 29 flowers. We observed a large percentage of viable pollen (77.25% and relatively scarce nectar availability for floral visitors (0.63 μL. The bees Apis mellifera and Trigona sp. were the most frequent visitors. The length of the bud, style and flowers varied significantly among plants. O objetivo deste trabalho foi examinar e documentar a biologia floral e os polinizadores da candeia (Eremanthus erythropappus em uma população natural, sendo estudados a antese, a morfologia floral, a receptividade estigmática, a viabilidade de pólen e os visitantes florais. As flores pequenas (10,17 mm de comprimento são cor de rosa, hermafroditas e organizadas em densos capítulos (média = 29 flores. Foi observada alta porcentagem de pólen viável (77,25% e relativamente pouca disponibilidade de néctar para os visitantes florais (0,63 μL. As abelhas Apis mellifera e Trigona sp. foram os visitantes mais frequentes. Os comprimentos dos botões, estiletes e flores variaram significativamente entre plantas.

Signos Vitales de los CDC Cómo prevenir los brotes de norovirus (Vital Signs-Preventing Norovirus Outbreaks)

Centers for Disease Control (CDC) Podcasts

2014-06-03

Este podcast se basa en la edición de junio del 2014 del informe Signos Vitales de los CDC. Los norovirus infectan cada año a cerca de 20 millones de personas en los Estados Unidos. Sepa cómo protegerse y proteger a su familia de esta enfermedad que es muy contagiosa y potencialmente grave.  Created: 6/3/2014 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 6/3/2014.

Estructura floral de dos especies de Trachycarpeae (Arecaceae

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Lorena I. Guevara

2014-09-01

Full Text Available Copernicia y Washingtonia son dos de los géneros de Trachycarpeae para los cuales no ha sido propuesta una clasificación subtribal debido a la carencia de resolución en los estudios filogenéticos. La morfología y anatomía floral dentro de Coryphoideae han sido útiles para la delimitación de taxones y apoyo de relaciones. En este trabajo se presenta una descripción de la estructura morfo-anatómica de las flores de C. tectorum y W. filifera, con la finalidad de explorar caracteres reproductivos que puedan aclarar su ubicación dentro de la subfamilia y contribuir con estudios de biología floral. Se fijaron flores de especimenes cultivados de ambos taxones y frutos en desarrollo de C. tectorum, se realizaron disecciones para las descripciones morfológicas y cortes anatómicos seriados para la obtención de láminas permanentes utilizando técnicas convencionales con parafina. Todos los procedimientos fueron llevados a cabo en el Laboratorio de Morfo-Anatomía, Facultad de Agronomía de la Universidad Central de Venezuela (UCV. Ambas especies tienen flores hermafroditas. Las flores de C. tectorum tienen perianto engrosado y pubescente. Las flores de W. filifera presentan un cáliz irregularmente dentado y corola corto-acuminada. Se reportan células con drusas en el tubo estaminal de C. tectorum. Uno solo de los carpelos de C. tectorum se desarrolla en fruto y se encontró una capa de células con rafidios que podrían formar el endocarpo crustáceo en los frutos maduros. W. filifera presenta pocas capas de células de paredes engrosadas y tejido esclerenquimático en el mesofilo del perianto, gineceo con carpelos fusionados en el ápice del ovario (en su porción ventral, libres en la base y en el ápice del estilo, donde presenta suturas ventrales abiertas. Los pétalos de C. tectorum poseen una hipodermis ventral de células con paredes muy engrosadas, gineceo con carpelos fusionados en el ápice del ovario, libres y adpresos en su

The floral transcriptome of Eucalyptus grandis

CSIR Research Space (South Africa)

Vining, KJ

2015-10-01

Full Text Available As a step toward functional annotation of genes required for floral initiation and development within the Eucalyptus genome, we used short read sequencing to analyze transcriptomes of floral buds from early and late developmental stages...

Descripción de un brote de leptospirosis en la ciudad de Santa Fe, Argentina, marzo-abril de 1998 Description of a leptospirosis outbreak in the city of Santa Fe, Argentina, March-April 1998

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Norma B. Vanasco

2000-01-01

Full Text Available En marzo-abril de 1998 se identificó en un barrio de la ciudad de Santa Fe (Argentina un brote de una enfermedad aguda caracterizada por fiebre, cefaleas y mialgias intensas. Se presentan los estudios realizados en relación con este brote y los intentos de identificación de la fuente y del modo de transmisión. Los hallazgos epidemiológicos, serológicos y clínicos indicaron que el agente causal fue Leptospira interrogans. Como prueba de tamizaje se aplicó la técnica de aglutinación macroscópica con antígeno termorresistente, seguida de la prueba de ELISA y, como prueba de confirmación, la aglutinación microscópica frente a 10 serovariedades de L. interrogans. Se estudiaron 32 individuos, 8 perros y 8 muestras de agua. Se registraron 12 casos confirmados, 2 probables y 18 negativos. En seis perros se demostró la existencia de infección y en las muestras de agua se detectó la presencia de espiroquetas móviles. Los sueros humanos reaccionaron con las serovariedades ballum, canicola, icterohaemorrhagiae y pyrogenes, y los caninos con ballum, canicola y pomona. La coaglutinación observada en todos los casos confirmados indica que se trató de casos agudos de leptospirosis, pero no permite identificar la serovariedad causal. Salvo en el caso índice, no se reconoció clínicamente la enfermedad. Varios hechos sugieren que la causa del brote fue la inundación pluvial de la zona estudiada. Los resultados de este estudio resaltan la necesidad de una vigilancia activa de la leptospirosis ante desastres naturales como las inundaciones.In March-April 1998 in a neighborhood in the city of Santa Fe, Argentina, there was an outbreak of an acute disease characterized by fever, headaches, and intense myalgias. This article presents the studies surrounding this outbreak and the attempts to identify the source and the mode of transmission. The epidemiological, serological, and clinical findings indicated that the causative agent was Leptospira

Possible role of jasmonic acid in the regulation of floral induction, evocation and floral differentiation in Lemna minor L.

Science.gov (United States)

Krajncic, B; Kristl, J; Janzekovic, I

2006-01-01

Jasmonic acid (JA) is implicated in a wide variety of developmental and physiological processes in plants. Here, we studied the effects of JA and the combination of JA and ethylenediamine-dio-hydroxyphenyl-acetic acid (EDDHA) on flowering in Lemna minor in axenical cultures. JA (0.475-47.5 nmol l(-1)) enhanced floral induction in L. minor under long-day (LD) conditions. Under the same conditions, at a concentration of 237.5 nmol l(-1), JA inhibited floral induction, and at a concentration of 475 nmol l(-1) it prevented floral induction. Under LD conditions with LD preculture, a combination of EDDHA (20,500 nmol l(-1)) and JA (47.5 nmol l(-1)) had a synergistic effect on the promotion of floral induction. Floral induction was enhanced to the greatest extent in experiments with LD precultures. Microscopic examination of microphotographs of histological sections showed that JA and, to an even greater extent, JA+EDDHA at optimal concentrations promote apical floral induction (evocation). Furthermore, JA, and to an even greater extent JA in combination with EDDHA in an optimal concentration, also promote flower differentiation, especially the development of stamens, as is evident from the microphotographs. The experimental results show that JA promotes floral induction in other species of Lemnaceae from various groups according to their photoperiodic response. The results support our hypothesis that, in addition to previously ascribed functions, JA may regulate floral induction, evocation and floral differentiation. Our hypothesis is supported also by the results obtained by quantitative determination of endogenous JA levels in L. minor at three growth stages. The levels of endogenous JA decreased from 389 ng JA g(-1) (fresh weight) of L. minor during the vegetative stage to 217 ng JA g(-1) during the evocation stage, and to 37.5 ng JA g(-1) during the flowering stage, which proves that JA is used for flowering.

Diversity, distribution and floral specificity of tangle-veined flies (Diptera: Nemestrinidae in north west Patagonia, Argentina Diversidad, distribución y especificidad floral de nemestrínidos (Diptera en el noroeste de la Patagonia, Argentina

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MARIANO DEVOTO

2006-03-01

Full Text Available Tangle-veined flies (Nemestrinidae constitute a primitive and rather widespread family among Diptera. The genus Trichophthalma occurs in Australia and South America and is the only one in the family with a typically Gondwanian, disjoint distribution. The ecology and distribution of most southern South American species of this genus remains virtually unknown. We studied the diversity, distribution and flower specificity of flower-visiting species of the genus Trichophthalma in the temperate forests of southern South America in ten sites along an east-west rainfall gradient (37-40°S on the eastern slope of the Andes. We recorded nine species of Trichophthalma, which showed an overlapped distribution along the gradient and different degrees of floral specificity. Three species are reported for Argentina for the first time and three are first recorded as flower visitors to the local flora. Our results show that while in southern Africa tangle-veined flies are engaged in highly specialized pollination interactions with long-tubed species, the Trichophthalma spp. of Patagonia share their flowers with a diverse and rather unspecialized visitor fauna among which several species of flies, bees and birds are presentLos nemestrínidos constituyen una familia de Dípteros primitiva y de amplia distribución. El género Trichophthalma se encuentra en Australia y Sudamérica y es el único en la familia con una distribución disjunta típicamente gondwánica. La ecología y distribución de la mayoría de las especies sudamericanas permanecen virtualmente desconocidas. Estudiamos la diversidad, distribución y especificidad floral de las especies del género Trichophthalma de los bosques templados del sur de Sudamérica en diez sitios ubicados a lo largo de un gradiente de precipitación este-oeste (37-40°S sobre la vertiente occidental de los Andes. Registramos nueve especies de Trichophthalma, las cuales mostraron una distribución superpuesta a lo largo

Floral colour versus phylogeny in structuring subalpine flowering communities.

Science.gov (United States)

McEwen, Jamie R; Vamosi, Jana C

2010-10-07

The relative number of seeds produced by competing species can influence the community structure; yet, traits that influence seed production, such as pollinator attraction and floral colour, have received little attention in community ecology. Here, we analyse floral colour using reflectance spectra that include near-UV and examined the phylogenetic signal of floral colour. We found that coflowering species within communities tended to be more divergent in floral colour than expected by chance. However, coflowering species were not phylogenetically dispersed, in part due to our finding that floral colour is a labile trait with a weak phylogenetic signal. Furthermore, while we found that locally rare and common species exhibited equivalent floral colour distances from their coflowering neighbours, frequent species (those found in more communities) exhibited higher colour distances from their coflowering neighbours. Our findings support recent studies, which have found that (i) plant lineages exhibit frequent floral colour transitions; and (ii) traits that influence local population dynamics contribute to community structure.

Mejoramiento de la germinación, control de la hiperhidricidad y formación de brotes en Vasconcellea stipulata Badillo

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Diego Paúl Vélez-Mora

2015-07-01

Full Text Available Vasconcellea stipulata posee una gran importancia comercial debido a su actividad enzimática y como fuente para el mejoramiento genético de papaya, debido a su resistencia al virus de la mancha anular de esta especie. Sin embargo, debido a su baja regeneración por semillas y al limitado conocimiento de sus propiedades genéticas y farmacéuticas, esta especie no es cultivada ampliamente. La propagación a través del cultivo in vitro de semillas se ha usado para contrarrestar este tipo de problema, pero la hiperhidricidad, un trastorno fisiológico, expresado principalmente en los ejes embrionarios en desarrollo y asociado específicamente a esta especie, es una restricción significativa. Con el fin de obtener material de élite para el cultivo de V. stipulata, el objetivo de este trabajo fue incrementar la germinación, controlar la hiperhidricidad en embriones y evaluar el potencial para inducir respuestas morfogénicas, es decir, la formación de brotes. Nuestros resultados mostraron que es posible aumentar la germinación hasta un 53% en condiciones in vitro, dentro de un período más corto en presencia de peróxido de hidrógeno. Además, la hiperhidricidad se redujo significativamente (50% en condiciones in vitro cuando se incluyó ácido giberélico en bajas concentraciones en el medio 1/2 Nitsch y Nitsch. Esto permitió recuperar hasta aproximadamente el 80% de plántulas viables. Finalmente, otros reguladores de crecimiento vegetal evaluados, indujeron la formación de brotes en yemas axilares y la formación de callos en secciones de hoja derivadas de plántulas.

Caracterización de dos brotes de fiebre tifoidea en Apartadó, Antioquia, 2005

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Nora María Cardona-Castro

2007-06-01

Conclusiones. La electroforesis en campo pulsado estableció la presencia de dos brotes, que inicialmente, por epidemiología y pruebas fenotípicas del patógeno, habían sido descritos como uno solo. Además, permitió diferenciar dos aislamientos de origen clonal diferente, que indicaron casos aislados. No se pudo corroborar la fuente de infección en el agua.

Visitantes florales diurnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina Diurnal floral visitors of sunflower (Helianthus annuus, Asterales: Asteraceae in Argentina

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Juan P. Torretta

2010-06-01

Full Text Available El girasol (Helianthus annuus L. es un importante cultivo oleaginoso en la Argentina. Durante tres campañas agrícolas, se determinaron la diversidad y la abundancia del elenco de los visitantes florales diurnos de capítulos de girasol, en ocho sitios que cubren gran parte del área cultivada en Argentina. Setenta y seis morfo-especies de visitantes florales, pertenecientes a ocho órdenes, fueron capturados sobre capítulos de este cultivo. El principal orden fue Hymenoptera, con 37 especies o morfoespecies, de las cuales 32 fueron abejas (Apoidea. Las familias de abejas más representadas fueron Apidae (13, Megachilidae (11 y Halictidae (7. La abeja doméstica (Apis mellifera L. realizó el 93% de las visitas. La composición del elenco de visitantes no mostró un patrón de variación identificable a lo largo del día, ni con respecto a la distancia al borde del cultivo, pero varió entre sitios de muestreo. Se concluye que la abeja doméstica es el principal polinizador del girasol en la Argentina, aunque varias especies nativas de abejas (Melissodes tintinnans (Holmberg, M. rufithorax Brèthes, Melissoptila tandilensis Holmberg, y Megachile spp. podrían ser consideradas como potenciales polinizadores del cultivo.Sunflower (Helianthus annuus L. is an important oilseed crop in Argentina. During three agricultural years, the diversity and abundance of diurnal floral visitors of sunflower heads were determined in eight sites spanning much of this crop's cultivation area in Argentina. Seventysix morpho-species of floral visitors, belonging to eight orders, were captured on sunflower. The principal order was Hymenoptera, with 37 species or morpho-species, of which 32 were bees (Apoidea. The most represented bee families were Apidae (13, Megachilidae (11 and Halictidae (7. The domestic bee (Apis mellifera L. accounted for 93% of the visits. Floral visitor composition did not show an identifiable variation pattern either throughout the day or

Floral colour versus phylogeny in structuring subalpine flowering communities

OpenAIRE

McEwen, Jamie R.; Vamosi, Jana C.

2010-01-01

The relative number of seeds produced by competing species can influence the community structure; yet, traits that influence seed production, such as pollinator attraction and floral colour, have received little attention in community ecology. Here, we analyse floral colour using reflectance spectra that include near-UV and examined the phylogenetic signal of floral colour. We found that coflowering species within communities tended to be more divergent in floral colour than expected by chanc...

Biología floral, sistema reproductivo y éxito reproductivo de Macroptilium fraternum (Fabaceae

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Patricia S. Hoc

2003-06-01

Full Text Available Se realizaron observaciones de la biología floral y el sistema reproductivo de Macroptilium fraternum en dos poblaciones de la Argentina, con diferentes condiciones edáficas, localizadas en el extremo Sur del área de distribución de esta especie. En ambas poblaciones y en material de herbario de distintas procedencias se determinó la coexistencia en una misma planta de dos tipos florales: a flores cleistógamas preantesis y b flores pseudocleistógamas. Las flores cleistógamas preantesis con alas mayores de 5 mm, dispuestas en racimos pubescentes, erectos, expuestos sobre el nivel del follaje. La antesis duraba aproximadamente 5 horas en los días soleados y 9 horas en los días lluviosos, el ala derecha cubría al ala izquierda, adquiriendo la corola aspecto bilabiado, ofreciendo el ala izquierda como plataforma de aterrizaje; producían escasa cantidad de néctar (0.18 ± 0.13 µl y no recibieron visitas de polinizadores; aproximadamente cuatro horas después del inicio de la antesis en días soleados el ovario comenzaba a crecer; en el capullo, el estigma receptivo se encontraba cubierto con granos de polen de la misma unidad floral germinando. Las flores pseudocleistógamas con alas menores de 5 mm, dispuestas en racimos breves, hirsutos y postrados, no subterráneos como en otras especies de Macroptilium. El estandarte comenzaba a desplegarse exponiendo parcialmente las alas, el limbo del ala izquierda rodeaba la quilla y nunca se desplegaba; el ala derecha comenzaba a desplegarse y a los 2 segundos se replegaba y marchitaba, inmediatamente el ovario comenzaba a crecer; la flor no ofrecía ninguna superficie donde algún visitante pudiera posarse; en los capullos el estigma estaba receptivo y con los granos de polen de la misma unidad floral emitiendo sus tubos polínicos. El éxito reproductivo relativo fue bajo (polinización natural = 8%, autopolinización espontánea = 3%, debido probablemente a la baja viabilidad polínica, el

CULTIVO in vitro DE PITAYO (Stenocereus stellatus [Pfeiffer] Riccobono

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Ylvi María Martínez Villegas

2011-01-01

Full Text Available El pitayo (Stenocereus stellatus es una cactacea nativa de Mexico, apreciada por sus frutos, los cuales tienen caracteristicas organolepticas unicas. Su propagacion es por esquejes tomados de plantas adultas, generalmente silvestres, causando deforestacion de zonas naturales. El objetivo fue definir el tipo y la dosis de citocininas asi como la concentracion de sacarosa que permita obtener mayor numero de plantas de pitayo in vitro. Se usaron semillas de frutos maduros de las cuales se obtuvieron plantulas para iniciar el incremento de plantas. Para la multiplicacion de brotes se utilizaron plantulas de 2 a 3 cm de altura divididas en secciones de 1 cm, el medio fue MS con 3 % de sacarosa; se evaluaron tres citocininas (kinetina, 6-benciladenina, y 2-isopentiladenina en cinco concentraciones (2.2, 4.4, 8.8, 17.6 y 35.2 ¿ÊM. Para el crecimiento de brotes se uso medio MS con sacarosa (1, 2, 3, 4 y 5 %. En la aclimatacion se evaluo el efecto de la concentracion de sacarosa usada para el crecimiento de los brotes in vitro. Se observo que la concentracion de 17.6 ¿ÊM de 6-benciladenina ocasiono formacion de brotes en todos los explantes, los cuales tuvieron ocho brotes por explante. Los brotes desarrollaron la mayor altura cuando fueron cultivados en 3 y 4 % de sacarosa. En aclimatacion sobrevivieron mas del 92 % de las plantas trasplantadas a sustrato.

Efecto de la aplicación de Chlorpro p ham en el brotamiento de tubérculos de olluco (Ullucus tuberosus L. en condiciones de almacén

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Isaac Aliaga

2011-01-01

Full Text Available Se evaluó el efecto de Chlorpropham sobre el brotamiento de tubérculos de olluco ( U llucus tuberosum L. Variedad Tarmeño durante el almacenamiento a 15 °C y HR de 85 %; los tratamientos fueron 0, 5, 10, 20 y 30 mg de Chlorproph am por kg de tubérculo, e n un diseño completamente al azar con 4 rep eticiones. A los 60 días de almacenamiento l a longitud de brotes para el testigo sin Chlorpropham fue de 9.63 cm y para los tratamientos con Chlorpropham desde 0. 22 hasta 0 .71 cm. A los 90 días la longitud de los brotes se mantuvieron iguales y algunos bro tes empezaron a secarse, a excepción del testigo donde se incrementaron de tamaño de 15 a 20 cm. A los 90 días de almacenamiento la pérdida de peso para los tratamientos con Chlorpropham fue en promedio de 21 % y para el testigo de 37.35 %. Todos los trata mientos de Chlorpropham mostraron un menor número de brotes por tubérculo, menor longitud de brotes, menor número de tubérculos con brotes y menor pérdida de peso; con un p<0 . 05, la prueba de Duncan mostró que no existe diferencias significativa entre l os tratamientos con Chlorpropham para las variables evaluadas, pero si diferencias significativas con el tratamiento testigo.

Floral nectary, nectar production dynamics and chemical composition in five nocturnal Oenothera species (Onagraceae) in relation to floral visitors.

Science.gov (United States)

Antoń, Sebastian; Komoń-Janczara, Elwira; Denisow, Bożena

2017-12-01

Main conclusion The floral nectars were sucrose-dominant; however, nectar protein and amino acid contents differed, indicating that composition of nitrogenous compounds may vary considerably even between closely related plant species, irrespectively of nectary structure. Numerous zoophilous plants attract their pollinators by offering floral nectar; an aqueous solution produced by specialized secretory tissues, known as floral nectaries. Although many papers on nectaries and nectar already exist, there has been a little research into the structure of nectaries and/or nectar production and composition in species belonging to the same genus. To redress this imbalance, we sought, in the present paper, to describe the floral nectary, nectar production, and nectar composition in five nocturnal Oenothera species with respect to their floral visitors. The structure of nectaries was similar for all the species investigated, and comprised the epidermis (with nectarostomata), numerous layers of nectary parenchyma, and subsecretory parenchyma. Anthesis for a single flower was short (ca. 10-12 h), and flowers lasted only one night. The release of floral nectar commenced at the bud stage (approx. 4 h before anthesis) and nectar was available to pollinators until petal closure. Nectar concentration was relatively low (ca. 27%) and the nectar was sucrose-dominant, and composed mainly of sucrose, glucose and fructose. The protein content of the nectar was also relatively low (on average, 0.31 µg ml -1 ). Nevertheless, a great variety of amino acids, including both protein and non-protein types, was detected in the nectar profile of the investigated taxa. We noted both diurnal and nocturnal generalist, opportunistic floral insect visitors.

Nocturnal bees are attracted by widespread floral scents.

Science.gov (United States)

Carvalho, Airton Torres; Maia, Artur Campos Dalia; Ojima, Poliana Yumi; dos Santos, Adauto A; Schlindwein, Clemens

2012-03-01

Flower localization in darkness is a challenging task for nocturnal pollinators. Floral scents often play a crucial role in guiding them towards their hosts. Using common volatile compounds of floral scents, we trapped female nocturnal Megalopta-bees (Halictidae), thus uncovering olfactory cues involved in their search for floral resources. Applying a new sampling method hereby described, we offer novel perspectives on the investigation of nocturnal bees.

The role of jasmonates in floral nectar secretion.

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Venkatesan Radhika

Full Text Available Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants.

Estudio de las torres de refrigeración asociadas a brotes comunitarios de legionelosis Study of refrigeration towers associated with community outbreaks of legionellosis

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Albert Pérez Lleonart

2007-08-01

Full Text Available Objetivo: Evaluar los factores de riesgo de las torres de refrigeración asociadas a un brote comunitario de legionelosis según sus características de mantenimiento y la calidad del agua. Método: Comparar los datos recogidos entre los 4 tipos de torres de refrigeración: control 1, control 2, probable y confirmada. Se han estudiado un total de 184 torres de refrigeración asociadas a 17 brotes comunitarios de legionelosis de la provincia de Barcelona durante el año 2004, de las cuales 112 son control 1, 54 control 2, 8 probables y 10 confirmadas. Resultados: Las torres confirmadas se caracterizan por: niveles elevados de conductividad, aerobios totales, dureza cálcica, sólidos totales en disolución, temperatura y turbidez; concentraciones de cloro deficientes (Objetive: To evaluate the factors of risk of the risk cooling towers associated to a community outbreak of legionellosis according to its characteristics of maintenance and the quality of the water with the purpose of improving the systems of prevention of this one disease. Method: To compare the piece of information gathered between the 4 types of cooling towers: control 1, control 2, probable and confirmed. A total of 184 cooling towers have been studied associated to 17 community outbreak of legionellosis of the province of Barcelona (Spain during the year 2004, of which 112 are control 1, 54 control 2, 8 probable and 10 confirmed. Results: The confirmed towers are characterized by: high levels of conductivity, total aerobes, calcic hardness, total solids in dissolution, temperature and turbidity; low levels of chlorine (< 2 ppm; of use hypochlorite as disinfectant in a 10%; greater degree of breach of the revision program and cleaning of the internal elements of the tower (tray, stuffed and separating of drops; degree of performance of the periodic disinfections and the cleaning of deposits of the 100%. A 47% of the investigated towers do not use the previous treatments of the

Spectrum of induced floral mutants in Petunia

International Nuclear Information System (INIS)

Padmaja, V.; Sudhakar, P.

1987-01-01

A total of six floral mutants of garden Petunia isolated from the populations raised from the seed treatment with γ-rays, 2, 4-D and sodium azide are described. Five of the mutants viz. stellata, Campyloflora, Rubriflora mixed, Grandiflora and Albiflora mixed originated as segregants in M 2 generation while the chimeral floral phenotype was expressed in M 1 generation itself. Breeding behaviour of these horticulturally interesting altered floral phenotypes were studied in subsequent generations and appropriate conclusions were drawn regarding mode of inheritance of the mutant traits. 15 refs., 4 figures, 1 table. (author)

Brote de varicela en Herrera del Duque (Badajoz Chickenpox outbreak in Herrera del Duque, Badajoz, Spain

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F.J. Valadés

2003-06-01

Full Text Available Introducción: La varicela es una enfermedad de distribución mundial con una elevada morbilidad y pocas complicaciones, aunque puede presentar cuadros clínicos graves en inmunodeprimidos y adultos sanos. El objeto de este estudio es identificar y describir las características y los costes de un brote epidémico en Extremadura, cuya tasa anual de casos declarados al sistema de Enfermedades de Declaración Obligatoria (EDO oscila en alrededor de 5 por 1.000 habitantes. Métodos: Estudio descriptivo con búsqueda activa de casos entre los meses de noviembre del año 2000 y marzo de 2001, y de la susceptibilidad de la cohorte escolarizada del colegio de Herrera del Duque (Badajoz. Las definiciones de casos fueron recogidas de los protocolos de la Red de Vigilancia de la comunidad extremeña. La confirmación microbiológica se realizó por aislamiento del virus y por presencia de marcadores IgM e IgG en el suero del enfermo. Se analizaron los costes tangibles directos e indirectos y los no tangibles del brote. Resultados: De los 75 casos identificados, 71 (94,7% eran niños de entre uno y 9 años, predominando el sexo masculino. La tasa de ataque fue de 18,5 casos por 1.000 habitantes, y del 68,2% en convivientes menores de 10 años. La evolución fue benigna, sin ingresos hospitalarios ni complicaciones. Se encontró un 71,6% de niños susceptibles en los de entre 3 y 8 años. Se analizó una posible agregación temporal de casos en el colegio, obteniéndose un riesgo relativo (RR de 5,01 (p Introduction: Chickenpox is a worldwide disease with high morbidity but few complications, although complications can be sevre in immunocompromised individuals and healthy adults. The annual chickenpox rate declared to the National Notification Disease Surveillance System is approximately 5 cases per 1,000 inhabitants in Extremadura (Spain. The aim of this study was to identify and describe the characteristics and cost of an epidemic outbreak of chickenpox

Factores de riesgo que influyen en el retardo del brote de la dentición temporal.: Policlínico "Turcios Lima", 2000-2003 Risk factors influencing the primary dentition eruption retardation. "Turcios Lima" polyclinics, 2000-2003

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Zoila Rosa Podadera Valdés

2004-04-01

Full Text Available Se realizó un estudio analítico de casos y controles en el área de salud del Policlínico "Turcios Lima" en el período comprendido entre julio de 2000 y julio de 2003, con el objetivo de identificar los factores de riesgo que influyen en el retardo del brote de la dentición temporal. El universo estuvo constituido por 1454 niños, de los cuales se obtuvo una muestra aleatoria de 93 niños. El análisis estadístico se realizó mediante porcentajes, la prueba Chi cuadrado y el cálculo de los odds ratio con sus intervalos de confianza. Se observó que el estado nutricional anormal al inicio del embarazo, las enfermedades asociadas con este, la inadecuada ganancia de peso de la madre y el desarrollo físico del niño, constituyeron los factores que más influyeron en la problemática estudiada. Se concluye que existe una significativa influencia del estado nutricional de la madre y del niño en el retardo del brote de su dentición temporal.An analytical case-control study was carried out in "Turcios Lima" polyclinics from July, 2000 to July, 2003, to identify the risk factors influencing primary dentition eruption retardation. The universe was formed by 1 454 children from whom a random sample of 93 children was taken. The statistical analysis was based on Chi-square test and calculation of percentages and odds ratios with confidence intervals. It was observed that poor nutritional status at the beginning of pregnancy, pregnancy-related diseases, inadequate weight gain by the mother and the physical development of the infant were the most influential factors. It was concluded that there is significant influence of the nutritional status of the child and the mother on primary dentition eruption retardation.

Disentangling the role of floral sensory stimuli in pollination networks

DEFF Research Database (Denmark)

Kantsa, Aphrodite; Raguso, Robert A.; Dyer, Adrian G.

2018-01-01

Despite progress in understanding pollination network structure, the functional roles of floral sensory stimuli (visual, olfactory) have never been addressed comprehensively in a community context, even though such traits are known to mediate plant-pollinator interactions. Here, we use...... a comprehensive dataset of floral traits and a novel dynamic data-pooling methodology to explore the impacts of floral sensory diversity on the structure of a pollination network in a Mediterranean scrubland. Our approach tracks transitions in the network behaviour of each plant species throughout its flowering...... period and, despite dynamism in visitor composition, reveals significant links to floral scent, and/or colour as perceived by pollinators. Having accounted for floral phenology, abundance and phylogeny, the persistent association between floral sensory traits and visitor guilds supports a deeper role...

Virus sincicial respiratorio: presentación, manejo y prevención de un brote intrahospitalario en una unidad de cuidados intensivos neonatales de Lima

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T Paredes

2012-01-01

Full Text Available El virus sincicial respiratorio (VSR es el principal patógeno causante de infecciones del tracto respiratorio bajo durante el primer año de vida y ocasiona un elevado índice de hospitalización en niños menores de 12 meses; la presentación clínica severa y su aparición como brotes epidemiológicos en las unidades con recién nacidos prematuros representa un riesgo elevado de morbimortalidad. Se realiza la presentación de dos casos y el análisis sobre la importancia del diagnóstico precoz, el manejo individualizado y las medidas de control de infecciones como factores que reducen la morbimortalidad en estas situaciones y previenen la diseminación de los casos en una unidad de cuidados intensivos neonatales (UCIN.

floral bud distortion

Indian Academy of Sciences (India)

PRASHANT B. KALE

logical behaviour of floral reproductive organs and in silico characterization of differentially ... also prone to be attacked by various biotic and abiotic factors. ... environment. ..... play contributory role and also reported for synergistic effect.

Herbivory by a Phloem-feeding insect inhibits floral volatile production.

Science.gov (United States)

Pareja, Martin; Qvarfordt, Erika; Webster, Ben; Mayon, Patrick; Pickett, John; Birkett, Michael; Glinwood, Robert

2012-01-01

There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry.

Evolution and developmental genetics of floral display-A review of progress

Institute of Scientific and Technical Information of China (English)

Qing Ma; Wenheng Zhang; Qiu-Yun (Jenny) Xiang

2017-01-01

Angiosperms evolved a great diversity of ways to display their flowers for reproductive success by variation in floral color,size,shape,scent,arrangements,and flowering time.The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences can drive new ecological adaptations,speciation,and angiosperm diversification.Evolutionary developmental biology (evo-devo) seeks to uncover the developmental and genetic basis underlying morphological diversification.Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution.A number of regulatory genes controlling floral and inflorescence development have been identified in model plants (e.g.,Arabidopsis thaliana,Antirrhinum majus) using forward genetics and conserved functions of many of these genes across diverse non-model species have been revealed by reverse genetics.Gene-regulatory networks that mediated the developmental progresses of floral and inflorescence development have also been established in some plant species.Meanwhile,phylogeny-based comparative analysis of morphological and genetic character has enabled the identification of key evolutionary events that lead to morphological complexity and diversification.Here we review the recent progress on evo-devo studies of floral display including floral symmetry,petal fusion,floral color,floral scent,and inflorescences.We also review the molecular genetic approaches applied to plant evo-devo studies and highlight the future directions of evo-devo.

Identification of Genes Associated with Lemon Floral Transition and Flower Development during Floral Inductive Water Deficits: A Hypothetical Model.

Science.gov (United States)

Li, Jin-Xue; Hou, Xiao-Jin; Zhu, Jiao; Zhou, Jing-Jing; Huang, Hua-Bin; Yue, Jian-Qiang; Gao, Jun-Yan; Du, Yu-Xia; Hu, Cheng-Xiao; Hu, Chun-Gen; Zhang, Jin-Zhi

2017-01-01

Water deficit is a key factor to induce flowering in many woody plants, but reports on the molecular mechanisms of floral induction and flowering by water deficit are scarce. Here, we analyzed the morphology, cytology, and different hormone levels of lemon buds during floral inductive water deficits. Higher levels of ABA were observed, and the initiation of floral bud differentiation was examined by paraffin sections analysis. A total of 1638 differentially expressed genes (DEGs) were identified by RNA sequencing. DEGs were related to flowering, hormone biosynthesis, or metabolism. The expression of some DEGs was associated with floral induction by real-time PCR analysis. However, some DEGs may not have anything to do with flowering induction/flower development; they may be involved in general stress/drought response. Four genes from the phosphatidylethanolamine-binding protein family were further investigated. Ectopic expression of these genes in Arabidopsis changed the flowering time of transgenic plants. Furthermore, the 5' flanking region of these genes was also isolated and sequence analysis revealed the presence of several putative cis -regulatory elements, including basic elements and hormone regulation elements. The spatial and temporal expression patterns of these promoters were investigated under water deficit treatment. Based on these findings, we propose a model for citrus flowering under water deficit conditions, which will enable us to further understand the molecular mechanism of water deficit-regulated flowering in citrus. Based on gene activity during floral inductive water deficits identified by RNA sequencing and genes associated with lemon floral transition, a model for citrus flowering under water deficit conditions is proposed.

Floral ontogeny in legume genera Petalostylis, Labichea, and Dialium (Caesalpinioideae: Cassieae), a series in floral reduction.

Science.gov (United States)

Tucker, S

1998-02-01

Floral ontogeny of taxa of two subtribes (Labicheinae, Dialiinae) of caesalpinioid tribe Cassieae, characterized by reduced number of floral organs, was compared. All three taxa studied are distichous; Petalostylis labicheoides flowers are solitary in leaf axils, Labichea lanceolata has few-flowered racemes, and Dialium guineense has numerous-flowered cymes. The first sepal primordium in each is initiated abaxially and nonmedianly. Order of organogenesis in Petalostylis is: five sepals bidirectionally, five petals and carpel simultaneously, then five stamens bidirectionally, starting abaxially. The order in Labichea is: five sepals helically (one lagging in time), five petals unidirectionally starting abaxially, the carpel and petals concurrently, then two stamens successively, starting laterally. Order in Dialium is: five sepals bidirectionally, the single petal adaxially, and lastly the carpel and two stamens concurrently. Specializations include (1) reduction of the five sepals to four by fusion in Petalostylis and Labichea; (2) reduction of petal number to one in Dialium; (3) reduction of stamen number to two in Labichea and Dialium, and reduction of functional stamens to three in Petalostylis; and (4) an elaborate, late-developing style in Petalostylis. Floral asymmetry, another specialization, characterizes Labichea, expressed by dissimilar stamens, while the other genera have zygomorphic flowers. Floral ontogenies are compared with other taxa of Cassieae.

Floral Nectar Guide Patterns Discourage Nectar Robbing by Bumble Bees

OpenAIRE

Leonard, Anne S.; Brent, Joshua; Papaj, Daniel R.; Dornhaus, Anna

2013-01-01

Floral displays are under selection to both attract pollinators and deter antagonists. Here we show that a common floral trait, a nectar guide pattern, alters the behavior of bees that can act opportunistically as both pollinators and as antagonists. Generally, bees access nectar via the floral limb, transporting pollen through contact with the plant's reproductive structures; however bees sometimes extract nectar from a hole in the side of the flower that they or other floral visitors create...

Circadian Rhythms in Floral Scent Emission.

Science.gov (United States)

Fenske, Myles P; Imaizumi, Takato

2016-01-01

To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the floral volatile benzenoid/phenylpropanoid (FVBP) pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT 1 (ODO1), EMISSION OF BENZENOIDS I (EOBI), and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY) have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success.

EFECTO DE BIOFERTILIZANTES SOBRE LA TOLERANCIA DE BANANO A LA DESINFECCIÓN E INDUCCIÓN DE ORGANOGÉNESIS

Directory of Open Access Journals (Sweden)

Gabriela Sandoval-Cancino

2013-01-01

Full Text Available El objetivo de este estudio fue evaluar el efecto de biofertilizantes y medios de cultivo sobre la tolerancia al establecimiento aséptico y la inducción de la organogénesis en banano. Se utilizaron explantes de hijuelos de dos genotipos de Musa cavendish AAA, cultivares ‘Clon Francés’ y ‘Clon Oaxaqueño’. Se evaluaron tres aplicaciones de biofertilizante (1 g de Glomus intraradices, 1 ml de la bacteria diazotrófica 11B y la interacción de ambos microorganismos y una sin biofertilizantes. Se sembraron los ápices en tres medios de cultivo: MS sin reguladores de crecimiento, MS adicionado con 22.2 μM de bencilaminopurina (BAP y MS adicionado con 11.4 μM de ácido indolacético (AIA y 22.2 μM de BAP. Se midieron las relaciones hídricas, el contenido de catalasa y peroxidasa, los explantes con brotes y los brotes por explante. En ambos clones se elevó la inducción de la organogénesis con la adición de BAP y por la biofertilización previa de los hijuelos. En el ‘Clon Oaxaqueño’ los tratamientos 6, 8 y 11 indujeron mayor organogénesis, con promedios entre 66 y 71 % de explantes con brotes y entre 3.16 y 2.28 brotes por explante. Para el ‘Clon Francés’ los tratamientos 8 y 9 elevaron la inducción de la organogénesis con promedios de 66 hasta 83 % de explantes con brotes y 1.83 a 2.16 brotes por explante. En ambos genotipos, los biofertilizantes propiciaron mayor porcentaje de supervivencia, mayor tolerancia a la oxidación y menor contaminación. En los dos genotipos, los tratamientos 1 (Glomus intraradices y 4 (Testigo produjeron menos estrés en las plantas.

Biología floral y sistema reproductivo dePhaseolus vulgaris var. aborigineus (Fabaceae

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Patricia S. Hoc

1999-06-01

Full Text Available Las observaciones realizadas sobre la biología floral y los experimentos realizados para conocer el sistema reproductivo permiten concluir que: 1. la antesis dura de 9-13 horas y pueden reconocerse dos fases florales, en la segunda el estigma no está receptivo; 2. el estigma se encuentra receptivo en los capullos, cuando las anteras no están dehiscentes, por lo tanto las flores son protóginas; 3. el néctar es secretado durante la fase 1; 4. la composición del néctar reúne las características de las plantas melitófilas; 5. ni la lluvia ni la llovizna afectan la composición del néctar o la viabilidad polínica debido a que se encuentran protegidos, pero afectan el trabajo de los polinizadores; 6. las flores son papilionadas, están adaptadas a himenópteros medianos y la transferencia polínica es nototriba; ell polen es presentado en los tricomas estilares, 7. los valores obtenidos del ISI y del RRS muestran que la variedad es parcialmente autocompatible, por lo tanto su éxito reperoductivo aumenta si trabajan los polinizadores; 8. individuos de Centris sp. y una casta de Bombus atratus son los visitantes legítimos más importantes, porque trabajan en todas las plantas conespecíficas y liban néctar en pocas flores (en fase 1 por planta durante cada visita, mientras que individuos de Bombus opifex, otra casta de Bombus atratus y Megachile spp., aunque son visitantes legítimos, trabajan con menor frecuencia y constancia; 9. algunos lepidópteros son ladrones de néctar porque liban pero no desencadenan el mecanismo de transferencia polínica.Observations made in Salta, northern Argentina, for a complete flowering season of five plants from several patches, allowed the authors to conclude: 1. anthesis lasts 9-13 hours and consists of two floral phases, in the last of which the stigma is not receptive; 2. stigma is receptive in the bud when anthers are not dehiscent, hence the flowers are protogynous; 3. nectar is secreted during

Herbivory by a Phloem-feeding insect inhibits floral volatile production.

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Martin Pareja

Full Text Available There is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. We show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard Sinapis alba measured by gas chromatographic analysis of headspace volatiles. The effect of the Brassica specialist aphid Lipaphis erysimi was stronger than the generalist aphid Myzus persicae and feeding by chewing larvae of the moth Plutella xylostella caused no reduction in floral volatile emission. Field observations showed no effect of L. erysimi-mediated floral volatile emission on the total number of flower visits by pollinators. Olfactory bioassays suggested that although two aphid natural enemies could detect aphid inhibition of floral volatiles, their olfactory orientation to infested plants was not disrupted. This is the first demonstration that phloem-feeding herbivory can affect floral volatile emission, and that the outcome of interaction between herbivory and floral chemistry may differ depending on the herbivore's feeding mode and degree of specialisation. The findings provide new insights into interactions between insect herbivores and plant chemistry.

Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

Science.gov (United States)

James H. Cane

2011-01-01

Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar...

Encefalitis por virus San Luis en la Ciudad de Buenos Aires durante el brote de dengue 2009

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Horacio López

2011-06-01

Full Text Available Se presenta un paciente de 80 años de edad, residente en la Ciudad de Buenos Aires, con diagnóstico serológico para el virus de la encefalitis de San Luis (SLE durante el brote de dengue ocurrido entre enero y mayo de 2009. Presentaba leucemia linfoide crónica en tratamiento con clorambucilo, cáncer de próstata tratado con hormonoterapia y radioterapia, e imágenes óseas compatibles con metástasis. El estudio del líquido cefalorraquídeo demostró pleocitosis con predominio de mononucleares y proteinorraquia elevada. El resultado de los cultivos para bacterias, hongos y micobacterias, así como el PCR en LCR para herpes virus, HSV, CMV y EBV, fue negativo. Se detectaron anticuerpos IgM para virus SLE tanto en LCR como en muestra de suero, con seroconversión IgG por neutralización en cultivos celulares y resultados negativos para los demás Flavivirus con circulación en Argentina. Se revisan evidencias sobre la presencia de virus de San Luis en nuestro país, y se señala la importancia de la confirmación diagnóstica y el estudio de otros Flavivirus en casos sospechosos de dengue con presentación grave o atípica. Este trabajo remarca la necesidad de fortalecer tanto la vigilancia epidemiológica del virus SLE, como el control vectorial para prevenir las diferentes infecciones transmitidas por mosquitos y conocer su efecto en Salud Pública en la Argentina.

Floral abundance, richness, and spatial distribution drive urban garden bee communities.

Science.gov (United States)

Plascencia, M; Philpott, S M

2017-10-01

In urban landscapes, gardens provide refuges for bee diversity, but conservation potential may depend on local and landscape features. Foraging and population persistence of bee species, as well as overall pollinator community structure, may be supported by the abundance, richness, and spatial distribution of floral resources. Floral resources strongly differ in urban gardens. Using hand netting and pan traps to survey bees, we examined whether abundance, richness, and spatial distribution of floral resources, as well as ground cover and garden landscape surroundings influence bee abundance, species richness, and diversity on the central coast of California. Differences in floral abundance and spatial distribution, as well as urban cover in the landscape, predicted different bee community variables. Abundance of all bees and of honeybees (Apis mellifera) was lower in sites with more urban land cover surrounding the gardens. Honeybee abundance was higher in sites with patchy floral resources, whereas bee species richness and bee diversity was higher in sites with more clustered floral resources. Surprisingly, bee species richness and bee diversity was lower in sites with very high floral abundance, possibly due to interactions with honeybees. Other studies have documented the importance of floral abundance and landscape surroundings for bees in urban gardens, but this study is the first to document that the spatial arrangement of flowers strongly predicts bee abundance and richness. Based on these findings, it is likely that garden managers may promote bee conservation by managing for floral connectivity and abundance within these ubiquitous urban habitats.

Building beauty: the genetic control of floral patterning

Energy Technology Data Exchange (ETDEWEB)

Lohmann, J. U., and Weigel, D.

2002-02-01

OAK-B135 Floral organ identity is controlled by combinatorial action of homeotic genes expressed in different territories within the emerging flower. This review discusses recent progress in our understanding of floral homeotic genes, with an emphasis on how their region-specific expression is regulated.

chemical profiles of honeys originating from different floral sources

African Journals Online (AJOL)

2015-02-05

Feb 5, 2015 ... FLORAL SOURCES AND GEOGRAPHIC LOCATIONS EXAMINED BY A ... quality honeys retail for premium prices, but these honeys are increasingly being counterfeited ... distinguish between two floral sources in Malaysia.

LOS ESTUDIOS EPIDEMIOLÓGICOS SOBRE LA POLIOMIELITIS EN ESPAÑA ANTES DE LA VACUNACIÓN

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J Ferran Martínez Navarro

2013-01-01

Full Text Available a erradicación de la poliomielitis en España es uno de los hitos sanitarios más importantes del siglo XX, no solo para la salud pública sino también por el efecto que su conocimiento científico tuvo en en el ámbito médico de nuestro país. El conocimiento de la literatura internacional por nuestros epidemiólogos y virólogos fue importante, como reflejan los estudios de los brotes epidémicos, los estudios virológicos y, lógicamente, los estudios clínicos. Para la salud pública representó, a lo largo de todo el siglo XX, un esfuerzo orientado a tomar decisiones basadas en el conocimiento científico. Para la epidemiología representó la aplicación de nuevas formas de trabajo y, por tanto, su modernización.

Variations on a theme: changes in the floral ABCs in angiosperms.

NARCIS (Netherlands)

Rijpkema, A.S.; Vandenbussche, M.; Koes, R.E.; Heijmans, K.; Gerats, T.

2010-01-01

Angiosperms display a huge variety of floral forms. The development of the ABC-model for floral organ identity, almost 20 years ago, has created an excellent basis for comparative floral development (evo-devo) studies. These have resulted in an increasingly more detailed understanding of the

Variations on a theme: changes in the floral ABCs in angiosperms.

NARCIS (Netherlands)

Rijpkema, A.S.; Vandenbussche, M.; Koes, R.E.; Heijmans, K.; Gerats, T.

2009-01-01

Angiosperms display a huge variety of floral forms. The development of the ABC-model for floral organ identity, almost 20 years ago, has created an excellent basis for comparative floral development (evo-devo) studies. These have resulted in an increasingly more detailed understanding of the

A developmental basis for stochasticity in floral organ numbers

Science.gov (United States)

Kitazawa, Miho S.; Fujimoto, Koichi

2014-01-01

Stochasticity ubiquitously inevitably appears at all levels from molecular traits to multicellular, morphological traits. Intrinsic stochasticity in biochemical reactions underlies the typical intercellular distributions of chemical concentrations, e.g., morphogen gradients, which can give rise to stochastic morphogenesis. While the universal statistics and mechanisms underlying the stochasticity at the biochemical level have been widely analyzed, those at the morphological level have not. Such morphological stochasticity is found in foral organ numbers. Although the floral organ number is a hallmark of floral species, it can distribute stochastically even within an individual plant. The probability distribution of the floral organ number within a population is usually asymmetric, i.e., it is more likely to increase rather than decrease from the modal value, or vice versa. We combined field observations, statistical analysis, and mathematical modeling to study the developmental basis of the variation in floral organ numbers among 50 species mainly from Ranunculaceae and several other families from core eudicots. We compared six hypothetical mechanisms and found that a modified error function reproduced much of the asymmetric variation found in eudicot floral organ numbers. The error function is derived from mathematical modeling of floral organ positioning, and its parameters represent measurable distances in the floral bud morphologies. The model predicts two developmental sources of the organ-number distributions: stochastic shifts in the expression boundaries of homeotic genes and a semi-concentric (whorled-type) organ arrangement. Other models species- or organ-specifically reproduced different types of distributions that reflect different developmental processes. The organ-number variation could be an indicator of stochasticity in organ fate determination and organ positioning. PMID:25404932

Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides.

Science.gov (United States)

Horth, Lisa; Campbell, Laura; Bray, Rebecca

2014-03-15

Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent floral guides affect

Wild bees preferentially visit Rudbeckia flower heads with exaggerated ultraviolet absorbing floral guides

Directory of Open Access Journals (Sweden)

Lisa Horth

2014-07-01

Full Text Available Here, we report on the results of an experimental study that assessed the visitation frequency of wild bees to conspecific flowers with different sized floral guides. UV absorbent floral guides are ubiquitous in Angiosperms, yet surprisingly little is known about conspecific variation in these guides and very few studies have evaluated pollinator response to UV guide manipulation. This is true despite our rich understanding about learning and color preferences in bees. Historical dogma indicates that flower color serves as an important long-range visual signal allowing pollinators to detect the flowers, while floral guides function as close-range signals that direct pollinators to a reward. We initiated the work presented here by first assessing the population level variation in UV absorbent floral guides for conspecific flowers. We assessed two species, Rudbeckia hirta and R. fulgida. We then used several petal cut-and-paste experiments to test whether UV floral guides can also function to attract visitors. We manipulated floral guide size and evaluated visitation frequency. In all experiments, pollinator visitation rates were clearly associated with floral guide size. Diminished floral guides recruited relatively few insect visitors. Exaggerated floral guides recruited more visitors than smaller or average sized guides. Thus, UV floral guides play an important role in pollinator recruitment and in determining the relative attractiveness of conspecific flower heads. Consideration of floral guides is therefore important when evaluating the overall conspicuousness of flower heads relative to background coloration. This work raises the issue of whether floral guides serve as honest indicators of reward, since guide size varies in nature for conspecific flowers at the same developmental stage and since preferences for larger guides were found. To our knowledge, these are the first cut-and-paste experiments conducted to examine whether UV absorbent

Morphological Observation on Floral Variations of the Genus Cuscuta in Taiwan

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Gwo-Ing Liao

2005-06-01

Full Text Available The variations in floral structure of Cuscuta in Taiwan were studied with special reference to C. campestris. The variations of the floral structure were described and illustrated by using light and scanning electron microscopy. The variations including the following: (1 the absence of floral organs; (2 the abnormal fusion of floral organs; (3 petaloid stamens; (4 the lack of distinctive anther lobes; (5 the unusual protrusions on ovaries; and (6 the extrusion of ovule on ovary surfaces. The variations occur in early developmental stages when the primordia of floral organ were initiated. The findings that the abnormal position of the ovule and the lateral fusion of the scale with the filament or the petal in the species of Cuscuta are first time reported here.

Non-volatile floral oils of Diascia spp. (Scrophulariaceae).

Science.gov (United States)

Dumri, Kanchana; Seipold, Lars; Schmidt, Jürgen; Gerlach, Günter; Dötterl, Stefan; Ellis, Allan G; Wessjohann, Ludger A

2008-04-01

The floral oils of Diascia purpurea, Diascia vigilis, Diascia cordata, Diascia megathura, Diascia integerrima and Diascia barberae (Scrophulariaceae) were selectively collected from trichome elaiophores. The derivatized floral oils were analyzed by gas chromatography-mass spectrometry (GC-MS), whilst the underivatized samples were analysed by electrospray ionization mass spectrometry (ESI-MS) and Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS). The most common constituents of the floral oils investigated are partially acetylated acylglycerols of (3R)-acetoxy fatty acids (C(14), C(16), and C(18)), as was proven with non-racemic synthetic reference samples. The importance of these oils for Rediviva bees is discussed in a co-evolutionary context.

Visitantes florales nocturnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina Nocturnal floral visitors of sunflower (Helianthus annuus, Asterales: Asteraceae in Argentina

Directory of Open Access Journals (Sweden)

Juan P Torretta

2009-12-01

Full Text Available El girasol (Helianthus annuus es un cultivo oleaginoso, polinizado por Apis mellifera L. y otras abejas en distintas regiones del mundo. Sin embargo, sus flores también son visitadas por insectos de actividad nocturna. Durante tres campañas agrícolas, se determinó la diversidad de los visitantes nocturnos de capítulos de girasol, en cinco sitios de Argentina. También se estudió el comportamiento de forrajeo de los principales visitantes y la variación de la receptividad estigmática a lo largo del día, con el fin de establecer si estos visitantes contribuyen a la polinización. Al menos 67 especies o morfoespecies pertenecientes a cuatro órdenes de visitantes nocturnos fueron colectadas. El orden más rico y abundante fue Lepidoptera (44 especies o morfoespecies, cinco familias, seguido por Coleoptera (18 especies o morfoespecies, nueve familias, Orthoptera (tres morfoespecies, una familia y Blattaria (dos especies, una familia. Los lepidópteros forrajearon exclusivamente por néctar, mientras que los individuos de los demás órdenes consumieron polen y/o partes florales. El estigma se encontró receptivo durante las horas de luz, con una receptividad máxima al mediodía (12:00 - 14:00. Llamativamente, las flores del girasol son visitadas por mayor número de polillas que de abejas. Debido a que las polillas consumen néctar y potencialmente transportan polen entre flores, en un momento del día en que los estigmas se encuentran menos receptivos, es improbable que polinicen efectivamente el cultivo.Sunflower (Helianthus annuus is an oilseed crop pollinated by Apis mellifera L. and other diurnal bees in different regions of the world. However, their flowers are also visited by insects active at night. During three agricultural years, the diversity of nocturnal visitors to sunflower heads was assessed in five different sites in Argentina. The foraging behavior of the main visitors as well as the stigmatic receptivity variations along

Overhead irrigation increased winter chilling and floral bud ...

African Journals Online (AJOL)

Eucalyptus nitens requires a sufficiently cold winter to produce flower buds. In areas in South Africa where E. nitens commercial plantations as well as breeding and production seed orchards are located, winter chilling is often insufficient for floral bud initiation. Hence, under such conditions, E. nitens floral bud and seed ...

Do Plants Eavesdrop on Floral Scent Signals?

Science.gov (United States)

Caruso, Christina M; Parachnowitsch, Amy L

2016-01-01

Plants emit a diverse array of volatile organic compounds that can function as cues to other plants. Plants can use volatiles emitted by neighbors to gain information about their environment, and respond by adjusting their phenotype. Less is known about whether the many different volatile signals that plants emit are all equally likely to function as cues to other plants. We review evidence for the function of floral volatile signals and conclude that plants are as likely to perceive and respond to floral volatiles as to other, better-studied volatiles. We propose that eavesdropping on floral volatile cues is particularly likely to be adaptive because plants can respond to these cues by adjusting traits that directly affect pollination and mating. Copyright © 2015 Elsevier Ltd. All rights reserved.

Floral reward in Ranunculaceae species

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Bożena Denisow

2016-04-01

Full Text Available Floral reward is important in ecological and evolutionary perspectives and essential in pollination biology. For example, floral traits, nectar and pollen features are essential for understanding the functional ecology, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant–pollinator interactions. We believe to present a synthetic description in the field of floral reward in Ranunculaceae family important in pollination biology and indicating connections between ecological and evolutionary approaches. The links between insect visitors’ behaviour and floral reward type and characteristics exist. Ranunculaceae is a family of aboot 1700 species (aboot 60 genera, distributed worldwide, however the most abundant representatives are in temperate and cool regions of the northern and southern hemispheres. The flowers are usually radially symmetric (zygomorphic and bisexual, but in Aconitum, Aquilegia are bilaterally symmetric (zygomorphic. Most Ranunculaceae flowers offer no nectar, only pollen (e.g., Ranunculus, Adonis vernalis, Thalictrum, but numerous species create trophic niches for different wild pollinators (e.g. Osmia, Megachile, Bombus, Andrena (Denisow et al. 2008. Pollen is a source of protein, vitamins, mineral salts, organic acids and hormones, but the nutritional value varies greatly between different plant species. The pollen production can differ significantly between Ranunculacea species. The mass of pollen produced in anthers differ due to variations in the number of developed anthers. For example, interspecies differences are considerable, 49 anthers are noted in Aquilegia vulgaris, 70 anthers in Ranunculus lanuginosus, 120 in Adonis vernalis. A significant intra-species differences’ in the number of anthers are also noted (e.g. 41 to 61 in Aquilegia vulgaris, 23-45 in Ranunculus cassubicus. Pollen production can be up to 62 kg per ha for Ranunculus acer

COMPORTAMIENTO FISIOLÓGICO POSTCOSECHA DE TALLOS FLORALES DE ROSA (Rosa hybrida L. EN RESPUESTA AL FÓSFORO APLICADO EN PRECOSECHA

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Colinas-León MT

2011-01-01

Full Text Available Durante el crecimiento y desarro- llo de las flores, la nutrición fosforada es un factor que puede influir en la vida en flore- ro. El objetivo de este trabajo fue evaluar el efecto de cinco niveles de fósforo (P: 0, 0.5, 1.0, 1.5 y 2.0 me·L-1 de P aplicados en precosecha, mediante un sistema hidropóni- co abierto, en el comportamiento fisiológico postcosecha de tallos florales de rosa (Rosa hybrida L. ‘Classy’ y ‘Vega’. Las variables evaluadas durante la vida de florero de los tallos florales fueron: transpiración foliar y floral, potencial de turgencia foliar y de pétalos. Además, se evaluó la concentración de antocianinas en pétalos al momento de la cosecha. Las aplicaciones de P en precose- cha tuvieron efecto significativo únicamente en la transpiración foliar; sin embargo, se demostró que la mayor vida en florero (15.8 días de ‘Classy’ en comparación con ‘Vega’ (11.7 días estuvo directamente asociada con mayores potenciales de turgencia foliar y de pétalos, mayor tasa transpiratoria floral y menor tasa transpiratoria foliar en ‘Classy’.

Dental care associated with an outbreak of HIV infection among dialysis patients Atención dental asociada con un brote de infección por VIH en pacientes sometidos a diálisis

Directory of Open Access Journals (Sweden)

Leonelo E. Bautista

1997-09-01

Full Text Available An outbreak of 14 cases of human immunodeficiency virus (HIV infection was discovered by chance in May 1993 among hemodialysis patients at a university hospital in Bucaramanga, Colombia. The outbreak occurred in 1992. Stored sera were used to establish the probable period of infection (PPI for 10 of the 14 cases. A nested case-control study was carried out to evaluate possible transmission mechanisms. The health care experience of each HIV-positive patient during that patient’s PPI was compared to the experience of time-matched controls. Only invasive dental procedures were significantly associated with the risk of infection. Patients upon whom invasive dental procedures were performed during their PPIs had an average risk of HIV infection 8.15 times greater than comparable controls (P = 0.006, and seven out of nine cases of HIV infection with known PPIs in 1992 had an invasive dental procedure performed one to six months before seroconversion. None of the dental care personnel were found to be infected. Based on the available evidence, it seems most likely that the infection was transmitted from patient to patient by contaminated dental instruments.En mayo de 1993 se descubrió fortuitamente un brote de 14 casos de infección por virus de la inmunodeficiencia humana (VIH en pacientes sometidos a hemodiálisis en un hospital universitario de Bucaramanga, Colombia. El brote tuvo lugar en 1992. Se usaron sueros almacenados para determinar el período de infección probable (PI de 10 de los 14 casos y se llevó a cabo un estudio de casos y controles anidado a fin de evaluar los posibles mecanismos de transmisión. La atención de salud recibida por cada paciente positivo a VIH durante su PIP se comparó con la atención recibida por controles apareados con los casos en tiempo. Solamente los procedimientos odontológicos invasores mostraron una asociación significativa con el riesgo de infección. Los pacientes sometidos a procedimientos dentales

promisorios de Myrciaria dubia (H.B.K. “camu camu” para propagación vegetativa por acodo aéreo

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Jiang Oliver Liao Torres

2012-01-01

Full Text Available El objetivo del presente trabajo fue evaluar el efecto de la ubicación y diámetro de la rama en tres genotipospromisorios de camu camu utilizando la técnica del acodo aéreo sobre el enraizamiento y brotación. Lasplantas madres fueron acodadas, posteriormente las ramas enraizadas se trasplantaron siguiendo el diseño deBloques Completos al Azar, con tres repeticiones. A los 3 meses del trasplante se realizó la evaluación de lasvariables, encontrando los mejores promedios para el Número de raíces al Tercio medio, Diámetro grueso,Genotipo MD-015 y al Tercio superior, Diámetro grueso, Genotipo MD-015 con 28.67 y 28.33 raíces,respectivamente; en la variable Longitud de raíces el Tercio superior, Diámetro grueso, Genotipo MD-015mostró los mejores resultados con 15.27 cm. Con respecto al Número de brotes el Tercio Superior, DiámetroGrueso, Genotipo MD-014 y el Tercio superior, Diámetro grueso, Genotipo MD-015 alcanzaron los mejoresresultados con 13.00 y 12.67 brotes, respectivamente; en la Longitud de brotes, el mejor tratamiento fue elTercio superior, Diámetro grueso, Genotipo MD-015 con 30.73 cm; finalmente en la variable Número dehojas/brote sobresalieron el Tercio superior, Diámetro grueso, Genotipo MD-014 y Tercio superior, Diámetrogrueso, Genotipo MD-015 con 15.10 y 14.83 hojas por brote, respectivamente. Los resultados permitieronidentificar al Tercio superior, Diámetro grueso, Genotipo MD-015 como los mejores en cuanto a la capacidadde enraizamiento y brotación.

Éxito reproductivo y calidad de los frutos en poblaciones del extremo sur de la distribución de Ipomoea purpurea (Convolvulaceae

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Leonardo Galetto

2002-01-01

Full Text Available Se evaluó la producción de frutos y semillas en Ipomea purpurea en relación con diferentes tratamientos de polinización (autopolinización espontánea, autopolinización manual y polinización cruzada, durante dos temporadas reproductivas. La masa de los frutos, de las semillas y el número de semillas por fruto, se compararon entre tratamientos y entre años, a fin de detectar diferencias en la calidad de los frutos. Los resultados para las poblaciones estudiadas en el centro de Argentina confirman que se trata de una especie autocompatible y con la capacidad de producir frutos por autogamia espontánea. Los valores de éxito reproductivo mediados por polinización natural fueron altos (> 50%. Un fruto maduro pesa 0,1 g y contiene 4-6 semillas; la masa del total de semillas producidas por un fruto representa alrededor del 60% de la masa total del fruto. Los caracteres de los frutos y las semillas no presentaron diferencias significativas entre años o tratamientos. Asimismo, se compararon los frutos provenientes de polinización natural entre los individuos con distinto color de flor. En general, tampoco se encontraron diferencias significativas. Sólo los frutos provenientes de flores rosa presentaron un número significativamente menor de semillas que los frutos de los otros morfotipos florales (blanco o púrpura. El grupo principal de visitantes florales fue el de los Himenópteros, que pueden ser considerados polinizadores. Se registraron otros grupos de visitantes florales que no tendrían un papel preponderante en la transferencia de polen

Microbial diversity in the floral nectar of seven Epipactis (Orchidaceae) species

Science.gov (United States)

Jacquemyn, Hans; Lenaerts, Marijke; Tyteca, Daniel; Lievens, Bart

2013-01-01

Abstract Floral nectar of animal-pollinated plants is commonly infested with microorganisms, yet little is known about the microorganisms inhabiting the floral nectar of orchids. In this study, we investigated microbial communities occurring in the floral nectar of seven Epipactis (Orchidaceae) species. Culturable bacteria and yeasts were isolated and identified by partially sequencing the small subunit (SSU) ribosomal RNA (rRNA) gene and the D1/D2 domains of the large subunit (LSU) rRNA gene, respectively. Using three different culture media, we found that bacteria were common inhabitants of the floral nectar of Epipactis. The most widely distributed bacterial operational taxonomic units (OTUs) in nectar of Epipactis were representatives of the family of Enterobacteriaceae, with an unspecified Enterobacteriaceae bacterium as the most common. In contrast to previous studies investigating microbial communities in floral nectar, very few yeast species (mainly of the genus Cryptococcus) were observed, and most of them occurred in very low densities. Total OTU richness (i.e., the number of bacterial and yeast OTUs per orchid species) varied between 4 and 20. Cluster analysis revealed that microbial communities of allogamous species differed from those of autogamous and facultatively autogamous species. This study extends previous efforts to identify microbial communities in floral nectar and indicates that the floral nectar of the orchids investigated mainly contained bacterial communities with moderate phylogenetic diversity. PMID:23836678

MICROPROPAGACIÓN DE CUATRO CULTIVARES DE ARÁNDANO (Vaccinium spp. A PARTIR DE SEGMENTOS FOLIARES DE DOS PROCEDENCIAS

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Arturo Brenes Angulo

2015-01-01

Full Text Available Los cultivares de arándano Sharpblue, Woodard, Bonita y Delite se propagaron a partir de secciones de hoja procedentes de explantes uninodales establecidos in vitro y de secciones de hoja directamente del campo. Los explantes se colocaron en medio WPM suplementado con 1, 5 mg.l -1 de TDZ para promover la brotación; luego se subcultivaron a medio fresco WPM suplementado con 0,5 ó 1,0 mg.l -1 de Zeatina, para promover el crecimiento de los brotes. Se determinó la longitud de la micromacolla y el número de brotes >2mm y >1cm por microma - colla. Brotes de 8-10 cm se cosecharon a las 8 semanas y se subcultivaron en WPM suple - mentado con 0, 1, 2, 4 u 8 mg.l -1 de AIB, para promover su enraizamiento; a las 10 semanas se trasplantaron a invernadero para aclimatización. Al cultivar los segmentos foliares en WPM con 1, 5 mg.l -1 de TDZ se formaron micromacollas en todas las variedades, independientemente de la procedencia de la hoja, con un efecto significati - vo del cultivar, la procedencia, del explante y la interacción cultivar x procedencia, para el núme - ro de brotes >2 mm obtenidos. El tamaño de la micromacolla varió significativamente según cultivares, procedencia del explante e interacción cultivares x procedencia x concentración de zea - tina, al trasferirse a un medio con 2 concentracio - nes del regulador de crecimiento, pero no hubo diferencias con respecto a éstas. El número de brotes > 2mm y la longitud del más largo variaron significativamente con el cultivar, y la interacción cultivar x procedencia del explante en WPM con 0,5 mg.l -1 de Zeatina. Explantes de Woodard a partir de vitrohoja produjeron el mayor número de brotes (44,70±13,34 y Delite de vitrohoja el menor (21,50±4,99. Los brotes subcultivados en WPM con diferentes concentraciones de AIB mostraron enraizamiento menor al 10% en todos los tratamientos. Sin embargo, al trasplantarse a invernadero se obtuvo 100% de enraizamiento, independientemente del

Transcriptional signatures of ancient floral developmental genetics in avocado (Persea americana; Lauraceae).

Science.gov (United States)

Chanderbali, André S; Albert, Victor A; Leebens-Mack, Jim; Altman, Naomi S; Soltis, Douglas E; Soltis, Pamela S

2009-06-02

The debate on the origin and evolution of flowers has recently entered the field of developmental genetics, with focus on the design of the ancestral floral regulatory program. Flowers can differ dramatically among angiosperm lineages, but in general, male and female reproductive organs surrounded by a sterile perianth of sepals and petals constitute the basic floral structure. However, the basal angiosperm lineages exhibit spectacular diversity in the number, arrangement, and structure of floral organs, whereas the evolutionarily derived monocot and eudicot lineages share a far more uniform floral ground plan. Here we show that broadly overlapping transcriptional programs characterize the floral transcriptome of the basal angiosperm Persea americana (avocado), whereas floral gene expression domains are considerably more organ specific in the model eudicot Arabidopsis thaliana. Our findings therefore support the "fading borders" model for organ identity determination in basal angiosperm flowers and extend it from the action of regulatory genes to downstream transcriptional programs. Furthermore, the declining expression of components of the staminal transcriptome in central and peripheral regions of Persea flowers concurs with elements of a previous hypothesis for developmental regulation in a gymnosperm "floral progenitor." Accordingly, in contrast to the canalized organ-specific regulatory apparatus of Arabidopsis, floral development may have been originally regulated by overlapping transcriptional cascades with fading gradients of influence from focal to bordering organs.

Efecto de la densidad de explantes y el volumen de medio de cultivo sobre la multiplicación in vitro de arándano (Vaccinium corymbosum L. variedades Brigitta y Legacy

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Mario Rodríguez Beraud

2015-01-01

Full Text Available El objetivo fue evaluar la multiplicación in vitro de dos variedades de arándano (Vaccinium corymbosum L., “Brigitta” y “Legacy”, en respuesta a cinco densidades de explantes (5, 10, 15, 20 y 25 y cuatro volúmenes de medio (10, 20, 30 y 40 mL utilizando para ambas variedades el medio WPM (Woody Plant Medium en un diseño completamente al azar con 20 tratamientos y 12 repeticiones por tratamiento. Transcurrido 45 días se evaluó: altura de brote, número de brotes/explante, número de nudos/brote y número de brotes/frasco. Brigitta obtuvo la mayor altura del brote en tratamientos con densidades y volúmenes elevados, mientras que Legacy obtuvo el mayor promedio de altura del brote con densidades intermedias y volúmenes elevados. En cuanto al número de brotes/explante, el volumen de medio no influyó en la variedad Brigitta, en cambio, altas densidades la afectaron significativamente, mientras que en Legacy el máximo número de brotes se alcanzó con densidades bajas y volúmenes intermedios. En relación al número de nudos por explante Brigitta obtuvo los valores más bajos comparados con Legacy, pero en ambas variedades se produjo una disminución del número de nudos con menores volúmenes de medio. Para el número de brotes por frasco Brigitta obtuvo las mayores respuestas con densidades elevadas, superando los 40 brotes por frasco. En cambio, en Legacy el resultado máximo se obtuvo con la densidad 25 explantes en 30 mL de medio. Por lo tanto, se concluye que ambas variedades fueron influenciadas tanto por el volumen del medio como la densidad de explantes.

Floral nectar guide patterns discourage nectar robbing by bumble bees.

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Anne S Leonard

Full Text Available Floral displays are under selection to both attract pollinators and deter antagonists. Here we show that a common floral trait, a nectar guide pattern, alters the behavior of bees that can act opportunistically as both pollinators and as antagonists. Generally, bees access nectar via the floral limb, transporting pollen through contact with the plant's reproductive structures; however bees sometimes extract nectar from a hole in the side of the flower that they or other floral visitors create. This behavior is called "nectar robbing" because bees may acquire the nectar without transporting pollen. We asked whether the presence of a symmetric floral nectar guide pattern on artificial flowers affected bumble bees' (Bombus impatiens propensity to rob or access nectar "legitimately." We discovered that nectar guides made legitimate visits more efficient for bees than robbing, and increased the relative frequency of legitimate visits, compared to flowers lacking nectar guides. This study is the first to show that beyond speeding nectar discovery, a nectar guide pattern can influence bees' flower handling in a way that could benefit the plant.

Floral Nectar Guide Patterns Discourage Nectar Robbing by Bumble Bees

Science.gov (United States)

Leonard, Anne S.; Brent, Joshua; Papaj, Daniel R.; Dornhaus, Anna

2013-01-01

Floral displays are under selection to both attract pollinators and deter antagonists. Here we show that a common floral trait, a nectar guide pattern, alters the behavior of bees that can act opportunistically as both pollinators and as antagonists. Generally, bees access nectar via the floral limb, transporting pollen through contact with the plant’s reproductive structures; however bees sometimes extract nectar from a hole in the side of the flower that they or other floral visitors create. This behavior is called “nectar robbing” because bees may acquire the nectar without transporting pollen. We asked whether the presence of a symmetric floral nectar guide pattern on artificial flowers affected bumble bees’ (Bombus impatiens) propensity to rob or access nectar “legitimately.” We discovered that nectar guides made legitimate visits more efficient for bees than robbing, and increased the relative frequency of legitimate visits, compared to flowers lacking nectar guides. This study is the first to show that beyond speeding nectar discovery, a nectar guide pattern can influence bees’ flower handling in a way that could benefit the plant. PMID:23418475

Circadian rhythms in floral scent emission

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Myles eFenske

2016-04-01

Full Text Available To successfully recruit pollinators, plants often release attractive floral scents at specific times of day to coincide with pollinator foraging. This timing of scent emission is thought to be evolutionarily beneficial to maximize resource efficiency while attracting only useful pollinators. Temporal regulation of scent emission is tied to the activity of the specific metabolic pathways responsible for scent production. Although floral volatile profiling in various plants indicated a contribution by the circadian clock, the mechanisms by which the circadian clock regulates timing of floral scent emission remained elusive. Recent studies using two species in the Solanaceae family provided initial insight into molecular clock regulation of scent emission timing. In Petunia hybrida, the benzenoid/phenylpropanoid (FVBP pathway is the major metabolic pathway that produces floral volatiles. Three MYB-type transcription factors, ODORANT1 (ODO1, EMISSION OF BENZENOIDS I (EOBI, and EOBII, all of which show diurnal rhythms in mRNA expression, act as positive regulators for several enzyme genes in the FVBP pathway. Recently, in P. hybrida and Nicotiana attenuata, homologs of the Arabidopsis clock gene LATE ELONGATED HYPOCOTYL (LHY have been shown to have a similar role in the circadian clock in these plants, and to also determine the timing of scent emission. In addition, in P. hybrida, PhLHY directly represses ODO1 and several enzyme genes in the FVBP pathway during the morning as an important negative regulator of scent emission. These findings facilitate our understanding of the relationship between a molecular timekeeper and the timing of scent emission, which may influence reproductive success.

Floral nectary, nectar production dynamics, and floral reproductive isolation among closely related species of Pedicularis.

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Liu, Ya-Nan; Li, Yan; Yang, Fu-Sheng; Wang, Xiao-Quan

2016-02-01

Floral nectar is thought to be one of the most important rewards that attract pollinators in Pedicularis; however, few studies have examined variation of nectary structure and/or nectar secretion in the genus, particularly among closely related species. Here we investigated nectary morphology, nectar quality, and nectar production dynamics in flowers of Pedicularis section Cyathophora. We found a conical floral nectary at the base of the ovary in species of the rex-thamnophila clade. Stomata were found on the surface of the nectary, and copious starch grains were detected in the nectary tissues. In contrast, a semi-annular nectary was found in flowers of the species of the superba clade. Only a few starch grains were observed in tissues of the semi-annular nectary, and the nectar sugar concentration in these flowers was much lower than that in the flowers of the rex-thamnophila clade. Our results indicate that the floral nectary has experienced considerable morphological, structural, and functional differentiation among closely related species of Pedicularis. This could have affected nectar production, leading to a shift of the pollination mode. Our results also imply that variation of the nectary morphology and nectar production may have played an important role in the speciation of sect. Cyathophora. © 2015 Institute of Botany, Chinese Academy of Sciences.

Floral structure and ontogeny of Syndiclis (Lauraceae.

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Gang Zeng

Full Text Available Generic delimitation in the Beilschmiedia group of the Lauraceae remains ambiguous because flowering specimens of a few genera with confined distribution are poorly represented in herbaria, and a few floral characters important for taxonomy are still poorly known. Syndiclis is sporadically distributed in southwestern China, and is represented in the herbaria by only a few flowering specimens. We conducted field investigations to collect floral materials of four species and observed structures and ontogeny of the tiny flowers using both light microscopy (LM and scanning electron microscopy (SEM. The results show that the genus Syndiclis possesses flowers with huge variation in both merosity and organ number. Flowers of the genus are dimerous, trimerous, or tetramerous, or have mixed merosity with monomerous and dimerous, or dimerous and trimerous, or trimerous and tetramerous whorls. The number of staminodes ranges from two to eight, depending on floral merosity, and on how many stamens of the third androecial whorl are reduced to staminodes. The staminodes of the fourth androecial whorl are comparable to the staminodes in Potameia, but the staminodes of the third androecial whorl of Syndiclis are relatively larger than the staminodes in Potameia. They are erect or curved inwards, covering the ovary. The anthers are usually two-locular, but rarely one-locular or three-locular. Each stamen of the third androecial whorl bears two conspicuous and enlarged glands at the base. The lability of floral merosity and organ number of Syndiclis may have been caused by changes of pollination system and loss of special selective pressures that are present in most Lauraceous plants with fixed floral organ number. This study furthers our understanding of variation and evolution of a few important characters of the Beilschmiedia group and provides essential data for a revised generic classification of the group.

How scent and nectar influence floral antagonists and mutualists.

Science.gov (United States)

Kessler, Danny; Kallenbach, Mario; Diezel, Celia; Rothe, Eva; Murdock, Mark; Baldwin, Ian T

2015-07-01

Many plants attract and reward pollinators with floral scents and nectar, respectively, but these traits can also incur fitness costs as they also attract herbivores. This dilemma, common to most flowering plants, could be solved by not producing nectar and/or scent, thereby cheating pollinators. Both nectar and scent are highly variable in native populations of coyote tobacco, Nicotiana attenuata, with some producing no nectar at all, uncorrelated with the tobacco's main floral attractant, benzylacetone. By silencing benzylacetone biosynthesis and nectar production in all combinations by RNAi, we experimentally uncouple these floral rewards/attractrants and measure their costs/benefits in the plant's native habitat and experimental tents. Both scent and nectar increase outcrossing rates for three, separately tested, pollinators and both traits increase oviposition by a hawkmoth herbivore, with nectar being more influential than scent. These results underscore that it makes little sense to study floral traits as if they only mediated pollination services.

Pollen diversity, viability and floral structure of some Musa genotypes

African Journals Online (AJOL)

Pollen diversity, viability and floral structure of some Musa genotypes. ... This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained ... HOW TO USE AJOL.

Galler-induced reduction of shoot growth and fruit production in the shrub Colliguaja integerrima (Euphorbiaceae Insectos cecidómidos reducen el crecimiento de brotes y la producción de frutos en el arbusto Colliguaja integerrima (Euphorbiaceae

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WILFREDO L. GONZÁLES

2005-09-01

huevos depositados por el cecidómido y el número de cecidias entre arbustos. La producción de frutos se relacionó inversamente con el número de cecidias, pero no presentó asociación significativa con la altura del arbusto, su cobertura ni con el número de brotes. Brotes sin cecidias fueron más largos que los con cecidias. El tratamiento químico produjo un efecto positivo retrasado sobre la reproducción de la planta. Una vez transcurridos 24 meses de iniciado el experimento químico, el número de frutos fue mayor en las ramas experimentales que en las ramas control (con cecidias. De igual manera, la remoción mecánica de cecidias aumentó la producción de frutos en comparación a las ramas control en la siguiente estación reproductiva del arbusto. Estos resultados indican que el cecidómido reduce el crecimiento de los brotes y tiene un efecto negativo retardado sobre la producción de frutos de C. integerrima. Como la probabilidad de detectar cecidias nuevas fue mayor en los arbustos previamente infectados, es posible que el proceso de reinfección de cuenta de los efectos negativos acumulativos del insecto sobre el desempeño de la planta

Floral visitors of Ananas comosus in Ghana: A preliminary assessment

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Peter Kwapong

2010-11-01

Full Text Available Ananas comosus var comosus (L. Merr. is the third most important tropical fruit in the world production and the leading foreign exchange earner among fresh fruits exported from Ghana. A survey was conducted in pineapple farms in the Central region of Ghana to identify floral visitors and their activities on the flowers. Nectar concentration and energetics and effect of floral visitors on fruit production were determined. Fourteen species of butterflies and one ant species were the main insect floral visitors as well as four species of sunbirds. The mean nectar concentration was 23.3% (± 0.39, SE and pollination limitation did not significantly affect fruit yield (weight: p = 0.285; length: p = 0.056; width: p= 0.268. The study showed that butterflies, ants and sunbirds are the main floral visitors on A. comosus. However their visits did not results in pollination and fruit production was not affected in any way by floral visitation. Still, it was found that A. comosus provides an important nectar resource for its foragers. Even if pollination is not crucial in pineapple cultivation, it is still essential in pineapple breeding programs to promote genetic diversity and conservation.

PROPAGACIÓN IN VITRO DE Acacia mangium Willd

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LUZ ANGELA TORRES

Full Text Available Acacia Acacia mangium Willd es una de las especies forestales más plantadas por la calidad de su madera y rápido crecimiento; sin embargo, los estudios de propagación clonal son pocos. El presente trabajo tuvo como objetivo desarrollar un protocolo de micropropagacion a partir de explantes con meristemos preexistentes. Los explantes consistieron de brotes de plantas de tres meses de edad mantenidas en invernadero. La desinfección se realizó con diferentes concentraciones de hipoclorito de sodio y antibióticos, y fueron establecidos en medio MS con diferentes concentraciones (0; 0,44; 0,88 y 2,22 µM de BAP. Los brotes micropropagados fueron enraizados con diferentes dosis de ANA y AIB, finalmente los brotes, con o sin raíces, fueron transferidos a condiciones ex vitro para evaluar el porcentaje de supervivencia. Los datos mostraron que 1,0% NaOCl y cefalexina (2 mg L-1 permitieron obtener el mayor porcentaje de explantes libres de contaminación (67%. El mayor número promedio de brotes ocurrió con 2,22 µM de BAP y el mayor número promedio de raíces se observo al utilizar 2,69 µM de ANA. La adaptación de las plantas en condiciones ex vitro fue exitoso lográndose obtener un 87% de supervivencia

PROPAGACIÓN IN VITRO DE BAMBÚ CHINO (Dracaena sanderiana L.

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Marcos Daquinta

2010-06-01

Full Text Available Con el objetivo de establecer un protocolo para la propagación in vitro de Bambú chino (Dracaena sanderiana L., se evaluaron diferentes tiempos de desinfección de las yemas con bicloruro de mercurio (HgCl2 a 0.2% (m/v, distintas condiciones de cultivo para el establecimiento de las yemas, tanto en condiciones de luz y oscuridad, así como diferentes formas de cultivo y manejo de los explantes para la proliferación de los brotes y distintos niveles de AIB para el enraizamiento de los brotes. Se logró realizar el establecimiento in vitro de la Dracaena sanderiana a partir de yemas laterales de estacas de plantas adultas, en medio de cultivo MS (1962 con 1 mg L-1 de BAP en estado semisólido y bajo condiciones de oscuridad. Para la proliferación de brotes, el seccionamiento longitudinal de estos y los sistemas de inmersión permanente, en el medio de cultivo MS (1962 enriquecido con BAP (2 mg L-1 combinado con ANA resulto ser el mejor tratamiento. La aclimatización de los brotes de Dracaena sanderiana se realizó en un sustrato compuesto de zeolita cachaza (1:1 en condiciones de casa de cultivo, con un sistema de riego por microjet.

Brote de enfermedad alimentaria en la localidad de El Huecú, provincia de Neuquén Foodborne disease outbreak in El Huecú community, province of Neuquén

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C. López

2008-12-01

Full Text Available En febrero de 2006 ocurrió un brote epidémico de gastroenteritis aguda de origen alimentario, en ocasión de un festejo popular en una pequeña localidad de la provincia de Neuquén, Argentina. Aproximadamente 800 personas participaron de un almuerzo en las instalaciones del Gimnasio Municipal, y unas tres horas después de finalizado, cerca de 150 asistentes consultaron al hospital local, afectados por síndrome gastroentérico agudo. Se realizó una investigación epidemiológica caso-control a través de un muestreo representativo no probabilístico. Los resultados epidemiológicos establecieron un brote de ETA a fuente común, con una relación caso-control de 1:1,8. Los principales síntomas fueron cólicos abdominales (88%, vómitos (73,5% y diarrea (60%. La torta que se sirvió en ese evento fue identificada como el alimento causal (OR 9,79; IC 95%; 2,66-36,00; valor p = 0,0001, sujeto a condiciones higiénico-sanitarias insatisfactorias en los diferentes procesos de elaboración, conservación y manipulación. De una porción de la torta se aisló una cepa de Staphylococcus aureus subespecie aureus, coagulasa positiva, enterotoxigénica, con un recuento de 2,4x10(6 UFC/g, y también se aisló este microorganismo de tres muestras de manos y narinas de personas involucradas en la preparación y el servicio. Las cepas aisladas de un operador y de la torta portaron el gen sea y presentaron el mismo patrón de SmaI-PFGE. Se atribuyó el brote de ETA a la contaminación durante el proceso de preparación de la torta consumida durante ese almuerzo popular, lo que podría estar relacionado con deficiencias en aspectos higiénicos y con la falta de refrigeración y de mantenimiento de la cadena de frío.In the summer of 2006, an epidemic outbreak of acute gastrointestinal illness related to food consumption occurred in a small town in the province of Neuquén, Argentina. During a popular feast, approximately 800 local residents attended lunch

Efectividad de la terapia floral de Bach en pacientes con alcoholismo crónico

OpenAIRE

Contrera Vega, Noraima; Cedeño Rodríguez, Enriqueta; Vázquez Sánchez, Monserrat

2012-01-01

Se realizó una intervención terapéutica en 15 pacientes con alcoholismo crónico, pertenecientes al Grupo Básico de Trabajo No. 3 del Policlínico Docente "Armando García Aspurú", de Santiago de Cuba, desde junio de 2008 hasta febrero de 2009, a fin de evaluar la efectividad de la terapia floral de Bach en el tratamiento de dichos pacientes, para lo cual se aplicó primero un esquema terapéutico general y luego individual. Se emplearon la media aritmética para cuantificar los datos, la desviació...

Disruption of a belowground mutualism alters interactions between plants and their floral visitors.

Science.gov (United States)

Cahill, James F; Elle, Elizabeth; Smith, Glen R; Shore, Bryon H

2008-07-01

Plants engage in diverse and intimate interactions with unrelated taxa. For example, aboveground floral visitors provide pollination services, while belowground arbuscular mycorrhizal fungi (AMF) enhance nutrient capture. Traditionally in ecology, these processes were studied in isolation, reinforcing the prevailing assumption that these above- and belowground processes were also functionally distinct. More recently, there has been a growing realization that the soil surface is not a barrier to many ecological interactions, particularly those involving plants (who live simultaneously above and below ground). Because of the potentially large impact that mycorrhizae and floral visitors can have on plant performance and community dynamics, we designed an experiment to test whether these multi-species mutualisms were interdependent under field conditions. Using benomyl, a widely used fungicide, we suppressed AMF in a native grassland, measuring plant, fungal, and floral-visitor responses after three years of fungal suppression. AMF suppression caused a shift in the community of floral visitors from large-bodied bees to small-bodied bees and flies, and reduced the total number of floral visits per flowering stem 67% across the 23 flowering species found in the plots. Fungal suppression has species-specific effects on floral visits for the six most common flowering plants in this experiment. Exploratory analyses suggest these results were due to changes in floral-visitor behavior due to altered patch-level floral display, rather than through direct effects of AMF suppression on floral morphology. Our findings indicate that AMF are an important, and overlooked, driver of floral-visitor community structure with the potential to affect pollination services. These results support the growing body of research indicating that interactions among ecological interactions can be of meaningful effect size under natural field conditions and may influence individual performance

Floral scent and pollinators of the holoparasite Pilostyles thurberi (Apodanthaceae

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Sedonia D Sipes

2014-02-01

Full Text Available Floral scent is likely important to the pollination of parasitic plants, despite that it has not been well-studied. We studied the pollination ecology of the North American stem holoparasite Pilostyles thurberi (Apodanthaceae at two field sites in Texas. To identify effective pollinators, we collected floral visitors to P. thurberi flowers, observed their foraging behavior, and looked for P. thurberi pollen on their bodies. Augochloropsis metallica bees (Halictidae and eumenine potter wasps (Vespidae were pollinators. P. thurberi flowers are visually inconspicuous but produce a strong fruity fragrance. GC/MS analysis of whole floral extracts and dynamic headspace samples revealed the fragrance to be an unusually simple bouquet of raspberry ketone and several eugenols. Comparison of scent profiles to those from uninfected host plants (Dalea formosa allowed putative separation of parasite and host volatiles. This is the first report of the constituents of floral fragrance in Apodanthaceae.

UFO in the Arabidopsis inflorescence apex is required for floral-meristem identity and bract suppression.

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Hepworth, Shelley R; Klenz, Jennifer E; Haughn, George W

2006-03-01

The UNUSUAL FLORAL ORGANS (UFO) gene of Arabidopsis encodes an F-box protein required for the determination of floral-organ and floral-meristem identity. Mutation of UFO leads to dramatic changes in floral-organ type which are well-characterized whereas inflorescence defects are more subtle and less understood. These defects include an increase in the number of secondary inflorescences, nodes that alternate between forming flowers and secondary inflorescences, and nodes in which a single flower is subtended by a bract. Here, we show how inflorescence defects correlate with the abnormal development of floral primordia and establish a temporal requirement for UFO in this process. At the inflorescence apex of ufo mutants, newly formed primordia are initially bract-like. Expression of the floral-meristem identity genes LFY and AP1 are confined to a relatively small adaxial region of these primordia with expression of the bract-identity marker FIL observed in cells that comprise the balance of the primordia. Proliferation of cells in the adaxial region of these early primordia is delayed by several nodes such that primordia appear "chimeric" at several nodes, having visible floral and bract components. However, by late stage 2 of floral development, growth of the bract generally ceases and is overtaken by development of the floral primordium. This abnormal pattern of floral meristem development is not rescued by expression of UFO from the AP1 promoter, indicating that UFO is required prior to AP1 activation for normal development of floral primordia. We propose that UFO and LFY are jointly required in the inflorescence meristem to both promote floral meristem development and inhibit, in a non-cell autonomous manner, growth of the bract.

Características clínicas y moleculares de un brote de influenza en dos bases militares, Tumbes- Perú, 2007

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Tatiana Saldarriaga

2008-01-01

Full Text Available Objetivo. Describir un brote de Influenza en dos bases militares en Tumbes, Perú. Material y métodos. Se utilizó la definición de caso de síndrome gripal del Ministerio de Salud en casos con menos de cinco días de inicio de síntomas. Se tomó hisopado nasal para la prueba rápida de Influenza (PRI e hisopado faríngeo para aislamiento viral en tres líneas celulares (MDCK, VERO, LLCMK2. Para la genotipificación de Influenza B se usó un secuenciamiento parcial de la región de hemaglutinina de 898 pares de bases teniendo como base la cepa de la vacuna del 2007 (B/Florida/4/2006 y para el tipo A se analizó 958 pares de bases teniendo como referencia la cepa vacunal del 2007 (A/Brisbane/10/2007 (H3N2. Resultados. Se tomó 124 hisopados, 20 de la base militar (BM # 1 y 104 de la BM # 2. La PRI identificó a 41 casos positivos: Flu B: 27, Flu A: 02, Flu: 12, con 62% de sensibilidad y 100% de especificidad. Finalmente, 66 casos fueron confirmados por cultivo celular, 54 Flu B y 12 Flu A. Los aislamientos de Tumbes fueron genéticamente similares con la cepa B/Texas/4/ 2006 (n=34 y A/Texas/91/2007 (H3N2/ (n=7. Los síntomas más comunes fueron fiebre, cefalea, malestar general, tos, dolor de garganta, mialgias y rinorrea. Las medidas de control consistieron en el aislamiento de los casos identificados y el uso de mascarillas. Conclusiones. Se confirmó 66 casos de Influenza por cultivo celular. Los aislamientos tuvieron la mayor similitud genética con las cepas denominadas B/Texas/4/2006 y A/Texas/91/2007 (H3N2.

Floral biology of Stachytarpheta maximiliani Scham. (Verbenaceae and its floral visitors Biologia floral de Stachytarpheta maximiliani Scham. (Verbenaceae e seus visitantes florais

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Ivana de Freitas Barbola

2006-12-01

Full Text Available This study describes the reproductive system of Stachytarpheta maximiliani (Verbenaceae, including its floral biology, nectar and pollen availability and insect foraging patterns, identifying whose species act as pollinators. It was carried out in a Brazilian Atlantic rain forest site. Observations on the pollination biology of the Verbenaceae S. maximiliani indicate that their flowering period extends from September through May. Anthesis occurs from 5:30 a.m. to 5:00 p.m. and nectar and pollen are available during all the anthesis. Many species of beetles, hemipterans, flies, wasps, bees and butterflies visit their flowers, but bees and butterflies are the most frequent visitors. The flowers are generally small, gathered in dense showy inflorescences. A complex of floral characteristcs, such as violet-blue color of flowers, long floral tubes, without scents, nectar not exposed, high concentration of sugar in nectar (about 32%, allowed identification of floral syndromes (melittophily and psicophily and function for each visitor. The bees, Bombus morio, B. atratus, Trigonopedia ferruginea, Xylocopa brasilianorum and Apis mellifera and the butterflies Corticea mendica mendica, Corticea sp., Vehilius clavicula, Urbanus simplicius, U. teleus and Heraclides thoas brasiliensis, are the most important pollinators.Este estudo descreve alguns aspectos do sistema reprodutivo de Stachytarpheta maximiliani (Verbenaceae, incluindo características da flor, disponibilidade de néctar e pólen e o padrão de forrageio dos insetos visitantes florais, em uma área de Floresta Atlântica, no sul do Brasil. Observações sobre sua biologia floral indicam que esta espécie tem um período de floração que se estende de setembro a maio, antese diurna (das 5:30h às 17:00h e oferta de néctar e pólen praticamente durante todo o período de antese. Suas flores são visitadas por diferentes espécies de coleópteros, dípteros, hemípteros, himenópteros e lepid

Ontogeny of floral organs in flax (Linum usitatissimum; Linaceae).

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Schewe, Lauren C; Sawhney, Vipen K; Davis, Arthur R

2011-07-01

Flax (Linum usitatissimum) is an important crop worldwide; however, a detailed study on flower development of this species is lacking. Here we describe the pattern of initiation and a program of key developmental events in flax flower ontogeny. This study provides important fundamental information for future research in various aspects of flax biology and biotechnology. Floral buds and organs were measured throughout development and examined using scanning electron microscopy. Floral organs were initiated in the following sequence: sepals, stamens and petals, gynoecium, and nectaries. The five sepals originated in a helical pattern, followed evidently by simultaneous initiation of five stamens and five petals, the former opposite of the sepals and the latter alternate to them. The gynoecium, with five carpels, was produced from the remaining, central region of the floral apex. Stamens at early stages were dominated by anther growth but filaments elongated rapidly shortly before anthesis. Early gynoecium development occurred predominantly in the ovary, and ovule initiation began prior to enclosure of carpels. A characteristic feature was the twisted growth of styles, accompanied by the differentiation of papillate stigmas. Petal growth lagged behind that of other floral organs, but petals eventually grew rapidly to enclose the inner whorls after style elongation. Flask-shaped nectaries bearing stomata developed on the external surface of the filament bases. This is the first detailed study on flax floral organ development and has established a key of 12 developmental stages, which should be useful to flax researchers.

Is floral structure a reliable indicator of breeding system in the Brassicaceae?

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Phillip A Salisbury

Full Text Available This study investigated the usefulness of floral characters as a potential indicator of breeding system in the Brassicaceae. Initially, pod set, seed set and pollen tube growth experiments were carried out to confirm the breeding systems of 53 lines representing 25 different cultivated and weedy species from the Brassicaceae. The results of the pod set tests clearly differentiated between self-compatible and self-incompatible species. Floral characters were then evaluated on one or more lines of each of the 25 species. Fourteen floral characters were evaluated including, flower diameter, Cruden's outcrossing index, timing and direction of dehiscence and pollen-ovule ratio. Significant differences between species were evident in all of the floral characteristics evaluated. Flower diameter was generally larger in self-incompatible species than self-compatible species and pollen/ovule ratio was generally higher in self-incompatible species than self-compatible species. However, none of the floral characteristics was able to clearly differentiate the self-compatible and self-incompatible species and allow prediction of the breeding system with absolute confidence. The floral characteristic which was most effective at differentiating the two groups was anther direction at dehiscence.

Floral associations of cyclocephaline scarab beetles.

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Moore, Matthew Robert; Jameson, Mary Liz

2013-01-01

The scarab beetle tribe Cyclocephalini (Coleoptera: Scarabaeidae: Dynastinae) is the second largest tribe of rhinoceros beetles, with nearly 500 described species. This diverse group is most closely associated with early diverging angiosperm groups (the family Nymphaeaceae, magnoliid clade, and monocots), where they feed, mate, and receive the benefit of thermal rewards from the host plant. Cyclocephaline floral association data have never been synthesized, and a comprehensive review of this ecological interaction was necessary to promote research by updating nomenclature, identifying inconsistencies in the data, and reporting previously unpublished data. Based on the most specific data, at least 97 cyclocephaline beetle species have been reported from the flowers of 58 plant genera representing 17 families and 15 orders. Thirteen new cyclocephaline floral associations are reported herein. Six cyclocephaline and 25 plant synonyms were reported in the literature and on beetle voucher specimen labels, and these were updated to reflect current nomenclature. The valid names of three unavailable plant host names were identified. We review the cyclocephaline floral associations with respect to inferred relationships of angiosperm orders. Ten genera of cyclocephaline beetles have been recorded from flowers of early diverging angiosperm groups. In contrast, only one genus, Cyclocephala, has been recorded from dicot flowers. Cyclocephaline visitation of dicot flowers is limited to the New World, and it is unknown whether this is evolutionary meaningful or the result of sampling bias and incomplete data. The most important areas for future research include: (1) elucidating the factors that attract cyclocephalines to flowers including floral scent chemistry and thermogenesis, (2) determining whether cyclocephaline dicot visitation is truly limited to the New World, and (3) inferring evolutionary relationships within the Cyclocephalini to rigorously test vicarance hypotheses

Brote de legionelosis asociado a un balneario Legionella outbreak at a spa

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E. Serrano Ibarbia

2001-06-01

Full Text Available En 1998 el inicio de la temporada de actividad de un balneario en Gipuzkoa coincidió con la detección de un brote de legionelosis asociado al mismo, lo cual condujo al cierre de la instalación y al estudio epidemiológico -casos y controles- y ambiental oportunos. Se definió como caso toda persona que durante su estancia en el balneario o durante los 10 días siguientes presentará neumonía o un cuadro febril compatible con fiebre de Pontiac.El estudio ambiental incluyó la inspección del balneario y entorno y muestreos de los sistemas sanitarios de agua y de los elementos de hidroterapia.De las 287 personas encuestadas de la Comunidad Autónoma Vasca, el 12.5% cumplían con la definición de caso; 9 casos presentaron neumonía y 26 fiebre de Pontiac. La curva epidémica se inició el 7 de mayo, alcanzando un pico los días 14 y 15 de mayo y finalizando el día 20. El riesgo de enfermar ajustado por edad, sexo y consumo de tabaco se asoció con la duración de la estancia en el balneario (OR=118.5, 95% I.C: 18.7-750.2 y con el uso de una piscina (OR=10.5, 95% I.C: 1.3-82.6. Se detecto L. pneumophila serogrupo1 en recuentos superiores a 103 ufc/l en diversos puntos de la red de hidroterapia y en la ducha de la habitación de uno de los enfermos. El análisis por electroforesis en campos pulsados de una muestra biológica y muestras ambientales permitió la confirmación genotípica. El establecimiento se abrió al público tras realizar un tratamiento de choque y comprobar que transcurridos 15 días no se detectó L. pneumophila en las muestras ambientales.The start of seasonal activity at a spa in Guipuzcoa coincided with the detection of an associated legionnaire outbreak in 1998. This led to the closure of the premises and to the carrying out of opportune environmental and epidemiological studies. The latter included case-control study. A case was defined as a person who, either during his stay or in a period of 10 days thereafter

Floral anatomy of Delphinieae (Ranunculaceae: comparing flower organization and vascular patterns

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Andrew V. Novikoff

2014-04-01

Full Text Available Species of the tribe Delphinieae have dorsoventralized flowers; their pentamerous calyx and reduced corolla are dorsally spurred and inner spurs are nectariferous. Based on this common floral scheme, Delphinieae species exhibit a wide diversity of floral structures and morphologies. We present here the first investigation of the floral anatomy in Delphinieae. The organization of the floral vascular system has been studied in species representative of the floral morphological diversity of Delphinieae: Aconitum lasiocarpum, Delphinium elatum, and Consolida regalis. The three species show a similar vascularization of the calyx and of the reproductive organs, but exhibit distinct anatomical features in the corolla where the nectaries are borne. The sepals and the stamens have a trilacunar three-traced and a unilacunar one-traced vascularization, respectively. Three free carpels in D. elatum and A. lasiocarpum are basically supplied by six vascular bundles – three independent dorsal bundles and three fused lateral bundles. In C. regalis the single carpel is supplied by three independent vascular bundles (one dorsal and two ventral. Staminodes are not vascularized. The basic type of petal vascularization is unilacunar one-traced, but in the case of C. regalis the derived bilacunar two-traced type has been observed. This latter state arose as a result of the fusion of the two dorsal petal primordia. The results of this first comparative study of the floral anatomy of Delphinieae are discussed with the recent phylogenetic, morphological, and evo-devo findings concerning the tribe.

Visitantes florales diurnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina

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Juan P. TORRETTA

2010-01-01

Full Text Available El girasol ( Helianthus annuus L. es un importante cultivo oleaginoso en la Argentina. Durante tres campañas agrícolas, se determinaron la diversidad y la abundancia del elenco de los visitantes florales diurnos de capítulos de girasol, en ocho sitios que cubren gran parte del área cultivada en Argentina. Setenta y seis morfo-especies de visitantes florales, pertenecientes a ocho órdenes, fueron capturados sobre capítulos de este cultivo. El principal orden fue Hymenoptera, con 37 especies o morfo- especies, de las cuales 32 fueron abejas (Apoidea. Las familias de abejas más representadas fueron Apidae (13, Megachilidae (11 y Halictidae (7. La abeja doméstica ( Apis mellifera L. realizó el 93% de las visitas. La composición del elenco de visitantes no mostró un patrón de variación identificable a lo largo del día, ni con respecto a la distancia al borde del cultivo, pero varió entre sitios de muestreo. Se concluye que la abeja doméstica es el principal polinizador del girasol en la Argentina, aunque varias especies nativas de abejas ( Melissodes tintinnans (Holmberg, M. rufithorax Brèthes, Melissoptila tandilensis Holmberg, y Megachile spp. podrían ser consideradas como potenciales polinizadores del cultivo.

Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths.

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von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A

2012-06-12

Most research on plant-pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue--transient humidity gradients--using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12-24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator.

Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths

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von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A.

2012-01-01

Most research on plant–pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue—transient humidity gradients—using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12–24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator. PMID:22645365

Reproduction and survival of a solitary bee along native and exotic floral resource gradients.

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Palladini, Jennifer D; Maron, John L

2014-11-01

Native bee abundance has long been assumed to be limited by floral resources. This paradigm has been established in large measure because more bees are often found in areas supporting greater floral abundance. This could result from attraction to resource-rich sites as well as greater local demographic performance in sites supporting high floral abundance; however, demographic performance is usually unknown. Factors other than floral resources such as availability of nest sites, pressure from natural enemies, or whether floral resources are from a mixed native or mostly monodominant exotic assemblage might influence survival or fecundity and hence abundance. We examined how the survival and fecundity of the native solitary bee Osmia lignaria varied along a gradient in floral resource abundance. We released bees alongside a nest block at 27 grassland sites in Montana (USA) that varied in floral abundance and the extent of invasion by exotic forbs. We monitored nest construction and the fate of offspring within each nest. The number of nests established was positively related to native forb abundance and was negatively related to exotic forb species richness. Fecundity was positively related to native forb species richness; however, offspring mortality caused by the brood parasite Tricrania stansburyi was significantly greater in native-dominated sites. These results suggest that native floral resources can positively influence bee populations, but that the relationship between native floral resources and bee population performance is not straightforward. Rather, bees may face a trade-off between high offspring production and low offspring survival in native-dominated sites.

Biologia floral de Virola surinamensis (Rol. Warb. (Myristicaceae Virola surinamensis (Rol. Warb. (Myristicaceae floral biology

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Mario Augusto Gonçalves Jardim

2007-12-01

Full Text Available Neste artigo são apresentadas informações sobre a biologia floral de Virola surinamensis (Rol. Warb. (Myristicaceae, espécie florestal dióica de relevante importância econômica na região amazônica. O estudo foi realizado em uma área de várzea próximo à bacia do igarapé Murutucum, lado direito do rio Guamá, localizada no Campus da Faculdade de Ciências Agrárias do Pará, na cidade de Belém, Estado do Pará, no período de janeiro a dezembro de 2001. Avaliou-se a biologia floral desde o aparecimento dos botões florais até a senescência das flores estaminadas, bem como a formação de frutos nas flores pistiladas. Testes bioquímicos foram aplicados para verificação de odor, pigmentos, osmóforos e receptividade do estigma. A observação no comportamento dos visitantes florais foi realizada durante o período diurno, registrando-se os horários de visitas, tempo de permanência na flor e freqüência; alguns indivíduos foram coletados com rede entomológica e identificados no Departamento de Zoologia do Museu Paraense Emílio Goeldi. A antese ocorreu entre 6 e 16 h nas flores estaminadas e entre 8 e 16 h nas flores pistiladas; a presença de odor foi constatada apenas nas flores estaminadas, enquanto os pigmentos e osmóforos foram encontrados em ambas as flores; o estigma mostrou-se receptivo no período entre 12 e 14 h. Os insetos da ordem diptera foram os visitantes mais freqüentes nas flores estaminadas e pistiladas e as espécies Copestylum sp. e Erystalys sp., as responsáveis pela polinização.Information was obtained on the floral biology of Virola surinamensis (Rol. Warb. (Myristicaceae, a dioecious arboreal species of great importance for the Amazon region economy. The study was carried out in the floodplain area near the Murucutu stream, on the right side of the Guamá River, at the Universidade Federal Rural da Amazônia-UFRA, Belém-Pará , from January to December 2001. Floral biology was assessed from

Potencial de regeneración de Psychotria ipecacuanha (Rubiaceae a partir de capas delgadas de células

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Catalina Botero Giraldo

2015-09-01

Full Text Available Conociendo las propiedades medicinales de la especie vegetal Psychotria ipecacuanha (Brot. Stokes, su crítico estado de conservación, así como las dificultades que presenta para la propagación efectiva, el presente estudio tuvo como objetivo evaluar su potencial de propagación por los sistemas de regeneración in vitro, organogénesis y embriogénesis somática. Para este propósito, capas delgadas de células (CDCs de tallos y de hojas, así como segmentos foliares fueron sometidos a diferentes tratamientos con reguladores de crecimiento y condiciones de luz. Además se estableció el efecto de diferentes longitudes de onda vía diodos emisores de luz (LEDs, sobre la regeneración en estos explantes y nudos provenientes de plantas in vitro. Los resultados obtenidos mostraron que los segmentos de hoja y las CDCs de tallo sembrados en el medio de cultivo MS suplementado con las combinaciones de los reguladores de crecimiento IBA + BAP e IBA + TDZ formaron embriones somáticos y brotes. Los cortes histológicos realizados corroboraron estos dos tipos de origen. Se encontró que bajo la condición lumínica 16/8, se alcanzaron los mejores resultados de inducción de brotes y embriones. En cuanto al efecto de las diferentes longitudes de onda de luz, se encontró que las correspondientes al rojo, verde y blanca, favorecieron el crecimiento y desarrollo de brotes y la inducción de embriones somáticos. El desarrollo de los brotes a partir de los nudos no presentó diferencias estadísticas entre los tratamientos con LEDs, por lo que se recomienda el uso de la luz blanca continua y con fotoperiodo durante el proceso de multiplicación y desarrollo de estos.

Visitantes florales nocturnos del girasol (Helianthus annuus, Asterales: Asteraceae en la Argentina

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Juan P TORRETTA

2009-01-01

Full Text Available El girasol (Helianthus annuus es un cultivo oleaginoso, polinizado por Apis mellifera L. y otras abejas en distintas regiones del mundo. Sin embargo, sus flores también son visitadas por insectos de actividad nocturna. Durante tres campañas agrícolas, se determinó la diversidad de los visitantes nocturnos de capítulos de girasol, en cinco sitios de Argentina. También se estudió el comportamiento de forrajeo de los principales visitantes y la variación de la receptividad estigmática a lo largo del día, con el fin de establecer si estos visitantes contribuyen a la polinización. Al menos 67 especies o morfoespecies pertenecientes a cuatro órdenes de visitantes nocturnos fueron colectadas. El orden más rico y abundante fue Lepidoptera (44 especies o morfoespecies, cinco familias, seguido por Coleoptera (18 especies o morfoespecies, nueve familias, Orthoptera (tres morfoespecies, una familia y Blattaria (dos especies, una familia. Los lepidópteros forrajearon exclusivamente por néctar, mientras que los individuos de los demás órdenes consumieron polen y/o partes florales. El estigma se encontró receptivo durante las horas de luz, con una receptividad máxima al mediodía (12:00 - 14:00. Llamativamente, las flores del girasol son visitadas por mayor número de polillas que de abejas. Debido a que las polillas consumen néctar y potencialmente transportan polen entre flores, en un momento del día en que los estigmas se encuentran menos receptivos, es improbable que polinicen efectivamente el cultivo.

Predicción de la epidemia del virus sincitial respiratorio en Bogotá, D.C., utilizando variables climatológicas

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Gilberto González-Parra

2016-09-01

Full Text Available Introducción. El virus sincitial respiratorio es uno de los principales causantes de mortalidad de niños y adultos mayores en el mundo. Objetivo. Predecir las semanas de inicio de los brotes de infección por el virus sincitial respiratorio en Bogotá entre 2005 y 2010, utilizando variables climatológicas como variables de predicción. Materiales y métodos. Se establecieron las fechas de inicio de los brotes en niños menores de cinco años ocurridas entre 2005 y 2010, en Bogotá D.C., Colombia. Se seleccionaron las variables climatológicas utilizando una matriz de correlación y, posteriormente, se construyeron 1.020 modelos resultado de la combinación de las distintas variables climatológicas y las semanas de antelación al inicio del brote. Se seleccionaron los modelos utilizando los datos correspondientes a periodos de seis (2005-2010, cuatro (2005-2008 y dos años (2009-2010. Se determinaron los mejores modelos y las variables climatológicas más relevantes, utilizando clasificadores bayesanos ingenuos y curvas características de operación del receptor (Receiver Operating Characteristic, ROC. Resultados. Los mejores resultados se obtuvieron con los modelos que utilizaron el periodo de dos años (2009-2010 y la semana 0, con 52 y 60 % de aciertos, respectivamente. La humedad mínima fue la variable que más apareció en los mejores modelos (62 %. Los clasificadores bayesanos ingenuos permitieron establecer cuáles eran los mejores modelos para predecir la semana de inicio del brote. Conclusiones. Los resultados sugieren que los modelos en que se utilizaron la humedad mínima, la velocidad del viento y la temperatura mínima serían los modelos de predicción más eficaces.

Dependency on floral resources determines the animals' responses to floral scents

OpenAIRE

Junker, Robert R; Blüthgen, Nico

2010-01-01

Animal-pollinated angiosperms either depend on cross-pollination or may also reproduce after self-pollination—the former are thus obligately, the latter facultatively dependent on the service of animal-pollinators. Analogously, flower visitors either solely feed on floral resources or complement their diet with these, and are hence dependent or not on the flowers they visit. We assume that obligate flower visitors evolved abilities that enable them to effectively forage on flowers including m...

Sensibilidad antimicrobiana y caracterización de cepas de Streptococcus pyogenes aisladas de un brote de escarlatina

Directory of Open Access Journals (Sweden)

Pedraza-Avilés Alberto González

2002-01-01

Full Text Available Objetivo. Evaluar la actividad in vitro de 13 antibióticos contra 47 Streptococcus pyogenes grupo A (SGA. Determinar la presencia de genes que codifican para exotoxina pirogénica estreptocóccica A (SpeA y serotipos con base en proteína M. Material y métodos. Estudio transversal hecho en el Centro de Salud Dr. José Castro Villagrana sobre un brote de escarlatina en el Colegio Espíritu de América, entre diciembre de 1999 y enero de 2000. El número de niños estudiados fue 137. Se extrajeron porcentajes de sensibilidad. La concentración inhibitoria mínima (CIM se obtuvo por microdilución semiautomatizada. Se utilizó un secuenciador automatizado de DNA para el análisis de variación de secuencias en los genes que codifican para proteína M y SpeA. Resultados. Todas las cepas fueron sensibles a beta-lactámicos y clindamicina; 12.7% fueron resistentes a eritromicina. El serotipo M2 fue el más frecuente, 27 del total. Prácticamente todas las bacterias (96% con el gen SpeA tienen el gen que codifica para el serotipo M2. Conclusiones. Debido a la reciente reaparición de infecciones por SGA se sugiere realizar estudios tanto de sensibilidad a macrólidos y beta-lactámicos, como de epidemiología molecular.

Self-pollination rate and floral-display size in Asclepias syriaca (Common Milkweed) with regard to floral-visitor taxa.

Science.gov (United States)

Howard, Aaron F; Barrows, Edward M

2014-06-23

Animals fertilize thousands of angiosperm species whose floral-display sizes can significantly influence pollinator behavior and plant reproductive success. Many studies have measured the interactions among pollinator behavior, floral-display size, and plant reproductive success, but few studies have been able to separate the effects of pollinator behavior and post-pollination processes on angiosperm sexual reproduction. In this study, we utilized the highly self-incompatible pollinium-pollination system of Asclepias syriaca (Common Milkweed) to quantify how insect visitors influenced male reproductive success measured as pollen removal, female reproductive success measured as pollen deposition, and self-pollination rate. We also determined how floral-display size impacts both visitor behavior and self-pollination rate. Four insect taxonomic orders visited A. syriaca: Coleoptera, Diptera, Hymenoptera, and Lepidoptera. We focused on three groups of visitor taxa within two orders (Hymenoptera and Lepidoptera) with sample sizes large enough for quantitative analysis: Apis mellifera (Western Honey Bee), Bombus spp. (bumble bees) and lepidopterans (butterflies and moths). Qualitatively, lepidopterans had the highest pollinator importance values, but the large variability in the lepidopteran data precluded meaningful interpretation of much of their behavior. The introduced A. mellifera was the most effective and most important diurnal pollinator with regard to both pollen removal and pollen deposition. However, when considering the self-incompatibility of A. syriaca, A. mellifera was not the most important pollinator because of its high self-pollination rate as compared to Bombus spp. Additionally, the rate of self-pollination increased more rapidly with the number of flowers per inflorescence in A. mellifera than in the native Bombus spp. Apis mellifera's high rate of self-pollination may have significant negative effects on both male and female reproductive successes

Enantiostyly in Chamaecrista ramosa (Fabaceae-Caesalpinioideae): floral morphology, pollen transfer dynamics and breeding system.

Science.gov (United States)

Almeida, N M de; Castro, C C de; Leite, A V de Lima; Novo, R R; Machado, I C

2013-03-01

Enantiostyly is a form of reciprocal herkogamy, in which floral morphs present reciprocal differences in the position of sexual elements, and occurs in monomorphic and dimorphic forms. This polymorphism maximises cross-pollination and reduces self-pollination, being very common within the subtribe Cassiinae (Fabaceae). Nevertheless, few studies have investigated the functionality of enantiostyly, particularly in this plant group. The present study aimed to investigate enantiostyly and its functionality in Chamaecrista ramosa, a monomorphic enantiostylous shrub, in an area of coastal vegetation in northeast Brazil. Pollen deposition and capture on the body of floral visitors, the relationship of these data with floral biology and breeding system, and morph ratio were evaluated. Pollen deposition and capture occurred in specific sites of the floral visitor body, showing the functionality of enantiostyly. The floral architecture, associated with the floral visitor behaviour, resulted in indirect pollen deposition on the floral visitor body. This occurred through a loop made by the pollen upon the inner petal surface, similar that generally reported for other Cassiinae. Chamaecrista ramosa is self-compatible, although no fruit set was observed through spontaneous self-pollination. The occurrence and number of floral morphs was similar within clumps. Enantiostyly seems to be advantageous for this species, as it results in efficient pollen capture and deposition, reduces the chances of autogamy and maximises intermorph pollen flow. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

Floral scent composition predicts bee pollination system in five butterfly bush (Buddleja, Scrophulariaceae) species.

Science.gov (United States)

Gong, W-C; Chen, G; Vereecken, N J; Dunn, B L; Ma, Y-P; Sun, W-B

2015-01-01

Traditionally, plant-pollinator interactions have been interpreted as pollination syndrome. However, the validity of pollination syndrome has been widely doubted in modern studies of pollination ecology. The pollination ecology of five Asian Buddleja species, B. asiatica, B. crispa, B. forrestii, B. macrostachya and B. myriantha, in the Sino-Himalayan region in Asia, flowering in different local seasons, with scented inflorescences were investigated during 2011 and 2012. These five species exhibited diverse floral traits, with narrow and long corolla tubes and concealed nectar. According to their floral morphology, larger bees and Lepidoptera were expected to be the major pollinators. However, field observations showed that only larger bees (honeybee/bumblebee) were the primary pollinators, ranging from 77.95% to 97.90% of total visits. In this study, floral scents of each species were also analysed using coupled gas chromatography and mass spectrometry (GC-MS). Although the five Buddleja species emitted differentiated floral scent compositions, our results showed that floral scents of the five species are dominated by substances that can serve as attractive signals to bees, including species-specific scent compounds and principal compounds with larger relative amounts. This suggests that floral scent compositions are closely associated with the principal pollinator assemblages in these five species. Therefore, we conclude that floral scent compositions rather than floral morphology traits should be used to interpret plant-pollinator interactions in these Asian Buddleja species. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Brote de rabia humana transmitida por gato en el municipio de Santander de Quilichao, Colombia, 2008

OpenAIRE

Paez, Andrés; Polo, Luis; Heredia, Damaris; Nuñez, Constanza; Rodriguez, Milena; Agudelo, Carlos; Parra, Edgar; Paredes, Andrea; Moreno, Teresa; Rey, Gloria

2009-01-01

Objetivos En marzo de 2008 ocurrió en el municipio de Santander de Quilichao- Cauca, Colombia, un brote de rabia de origen silvestre con 2 víctimas humanas. El presente artículo apunta a describir las técnicas diagnósticas de laboratorio, las acciones de investigación de campo y control de foco empleadas, y su significado epidemiológico e implicaciones en salud pública. Métodos La rabia se diagnosticó por inmunofluorescencia directa, prueba biológica en ratón, histopatología e inmunohistoquím...

Dosage-dependent impacts of a floral volatile compound on pollinators, larcenists, and the potential for floral evolution in the alpine skypilot Polemonium viscosum.

Science.gov (United States)

Galen, Candace; Kaczorowski, Rainee; Todd, Sadie L; Geib, Jennifer; Raguso, Robert A

2011-02-01

All volatile organic compounds (VOCs) vary quantitatively, yet how such variation affects their ecological roles is unknown. Because floral VOCs are cues for both pollinators and floral antagonists, variation in emission may have major consequences for costs and benefits in plant-pollinator interactions. In Polemonium viscosum, the emission rate for the floral VOC 2-phenylethanol (2PE) spans more than two orders of magnitude. We investigated the ecological and evolutionary impacts of this immense phenotypic variation. The emission rate of 2PE varies independently of nectar rewards and thus is uninformative of profitability. Emission is elevated in flowers that are morphologically vulnerable to ant larcenists, suggesting that chemical deterrence may compensate for weak physical barriers. In nature, plants emitting more 2PE than their neighbors escape ant damage. Flower-damaging ants die when exposed to 2PE in the laboratory, and they avoid high 2PE emitters in the field. High 2PE also reduces bumblebee visitation and pollination, suggesting an ecological cost of defense in pollinator service. However, at more moderate emission rates, 2PE enhances the amount of nectar left in flowers, at no pollination cost. In conclusion, repellency of 2PE is highly sensitive to dosage, giving it a key role in shaping ecological interactions between skypilot plants and their floral visitors.

Terrestrial floral change during the ETM2 hyperthermal

Science.gov (United States)

Wing, S. L.; Currano, E. D.

2017-12-01

Hyperthermal events during the Eocene are defined by negative shifts in carbon isotope composition, global temperature increase and carbonate dissolution in marine settings. These features suggest repeated releases of large amounts of carbon followed by increasing concentration of CO2in the atmosphere and ocean, climate change, and biotic responses such as rapid evolution and changes in geographic range and trophic relationships. The Paleocene-Eocene Thermal Maximum (PETM, 56.0 Ma) is the largest Eocene hyperthermal in terms of carbon cycle, climate and biotic effects, including dwarfing of mammalian lineages. Terrestrial floral turnover at the PETM documented in the Bighorn Basin, Wyoming, USA, is very high. Almost all late Paleocene species, most belonging to mesic, warm-temperate lineages, disappeared during the PETM. The PETM flora was composed of species belonging to dry tropical lineages present only during the body of the PETM. Most mesic, warm-temperate species returned to the area immediately after the PETM. Such extreme change in floral composition makes it difficult to assess how much floral turnover is associated with how much change in temperature. The ETM2 hyperthermal event ( 53.7 Ma) is characterized by a carbon isotope excursion and warming about half as great as during the PETM, and by half as much mammalian dwarfing. Here we report on a new fossil flora from ETM2 that demonstrates the magnitude of floral change was also less than during the PETM. Some characteristic PETM plant species reappeared in the Bighorn Basin during ETM2, including species of Fabaceae that dominate PETM assemblages but are less common during ETM2. Many stratigraphically long-ranging plant species that preferred mesic climates remain common in the ETM2 flora. We conclude that warm climate during ETM2 shifted ranges of plant species such that some PETM species returned to northern Wyoming, but was not so severe as to cause local extirpation of species preferring 'background

Mejoramiento genético acelerado de angiospermas perennes vía inducción floral por sobre-expresión del gen FT

Directory of Open Access Journals (Sweden)

Rafael Urrea López

2018-05-01

Full Text Available Los bosques y selvas enfrentan el reto de satisfacer la demanda por recursos de una población en crecimiento, así como la amenaza del rápido cambio climático que exacerba la magnitud y frecuencia de estreses bióticos y abióticos. Para ello, es urgente acelerar el mejoramiento genético de especies forestales. Sin embargo, sus largas etapas juveniles y asincronía floral retrasan peligrosamente este proceso. El presente ensayo explora los adelantos biotecnológicos en inducción floral y su potencial aplicación en especies forestales. Entre los genes identificados y caracterizados que participan en la ruta de señalización de la floración, especial atención se destina al gen FLOWERING LOCUS T, considerado un integrador de rutas de señalización altamente conservado entre las angiospermas, que, al sobre-expresarse por ingeniería genética, es capaz de inducir la floración de forma eficiente. Esta novedosa estrategia biotecnológica se ha utilizado, recientemente, para segregar genes de resistencia a enfermedades, en un menor tiempo, en germoplasma comercial de manzana y ciruela. Permite soslayar barreras naturales que por mucho tiempo han restringido a las especies forestales al mejoramiento por selección, principalmente. Entre sus ventajas está la de poder restringirla al proceso y no al producto, para acelerar las cruzas sexuales sin modificar genéticamente la progenie; se aleja así de la controversia alrededor de la liberación y consumo de organismos genéticamente modificados, y de los costos y trámites obligatorios para los OGM para monitoreo de posibles riesgos. Se proyecta como una tecnología que puede acelerar, significativamente, el mejoramiento de especies forestales.

Factores y mecanismos relacionados con la dormancia en tubérculos de papa. Una revisión

Directory of Open Access Journals (Sweden)

Rodriguez Luis Ernesto

2010-08-01

Full Text Available Los tubérculos de la papa (Solanum tuberosum L., al momento
de la cosecha y por un tiempo determinado, se encuentran en
estado dormante. La dormancia se induce con el inicio de la
tuberización y se define como un período en el cual no ocurre
ningún crecimiento visible de los brotes. Las hormonas vegetales
están involucradas en todas las fases de progresión de
la dormancia. Si bien el ácido abscísico (ABA y el etileno son
necesarios para su inducción, sólo el primero se requiere para
su mantenimiento. Los niveles de ABA se incrementan durante
la formación de los tubérculos, se mantienen constantes durante
la dormancia y disminuyen con el crecimiento activo de los
brotes. Un incremento en los niveles del ácido giberélico (AG
es necesario para inducir la formación del tubérculo, mientras
que una sensibilidad mayor a las citoquininas es determinante
para la pérdida de la dormancia. Cambios en los contenidos de
ácido indol acético (AIA y AG , están relacionados con la regulación
del crecimiento del brote una vez se rompe la dormancia.
Se ha comprobado que un factor importante, que contribuye
tanto a la inducción de la tuberización como a la pérdida de la
dormancia, es el flujo simplástico que controla la asignación de
azúcares, el cual se inicia con un meristemo apical dormante
aislado simplásticamente. La pérdida de dormancia se asocia
con la conexión simplástica del meristemo del brote con la red
de floema del tubérculo, y con una descarga simplástica en la
región de la yema, todo lo cual favorece el crecimiento activo
de los nuevos brotes.

Genetic variation of inbreeding depression among floral and fitness traits in Silene nutans

DEFF Research Database (Denmark)

Thiele, Jan; Hansen, Thomas Møller; Siegismund, Hans Redlef

2010-01-01

The magnitude and variation of inbreeding depression (ID) within populations is important for the evolution and maintenance of mixed mating systems. We studied ID and its genetic variation in a range of floral and fitness traits in a small and large population of the perennial herb Silene nutans......, using controlled pollinations in a fully factorial North Carolina II design. Floral traits and early fitness traits, that is seed mass and germination rate, were not much affected by inbreeding (delta0.4). Lack of genetic correlations indicated that ID in floral, early and late traits is genetically...... was statistically significant in most floral and all seed traits, but not in late fitness traits. However, some paternal families had delta...

Terapia floral como medio de transformación psíquica y orgánica en una paciente con síndrome de Down

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Mercedes Gay Muguercia

2014-07-01

Full Text Available Se describe el caso clínico de una paciente de 23 años de edad, con síndrome de Down, quien presentaba retraimiento, miedo, marcada tartamudez, obesidad, hipertensión arterial e hipercolesterolemia, para lo cual se le indicó terapia floral. Se le realizaron los exámenes físicos y complementarios pertinentes y fue evaluada a los 21, 45 y 90 días. Finalmente, se lograron transformaciones emocionales orgánicas y físicas, de manera que se observó un cambio significativo en su comportamiento

Herbivory as an important selective force in the evolution of floral traits and pollinator shifts

Science.gov (United States)

Overson, Rick P.; Raguso, Robert A.; Skogen, Krissa A.

2017-01-01

Abstract Floral trait evolution is frequently attributed to pollinator-mediated selection but herbivores can play a key role in shaping plant reproductive biology. Here we examine the role of florivores in driving floral trait evolution and pollinator shifts in a recently radiated clade of flowering plants, Oenothera sect. Calylophus. We compare florivory by a specialist, internal feeder, Mompha, on closely related hawkmoth- and bee-pollinated species and document variation in damage based on floral traits within sites, species and among species. Our results show that flowers with longer floral tubes and decreased floral flare have increased Mompha damage. Bee-pollinated flowers, which have substantially smaller floral tubes, experience on average 13% less Mompha florivory than do hawkmoth-pollinated flowers. The positive association between tube length and Mompha damage is evident even within sites of some species, suggesting that Mompha can drive trait differentiation at microevolutionary scales. Given that there are at least two independent shifts from hawkmoth to bee pollination in this clade, florivore-mediated selection on floral traits may have played an important role in facilitating morphological changes associated with transitions from hawkmoth to bee pollination. PMID:28011456

Brote de intoxicación alimentaria asociado al consumo de leche ultrapasteurizada en la República del Paraguay Foodborne outbreak associated with consumption of ultrapasteurized milk in the Republic of Paraguay

Directory of Open Access Journals (Sweden)

Natalie Weiler

2011-03-01

Full Text Available Durante marzo de 2007 ocurrió un brote epidémico asociado al consumo de leche ultrapasteurizada que afectó a las ciudades de San Lorenzo, Ciudad del Este y Asunción, de la República del Paraguay. Las personas afectadas fueron 400, de las cuales 60 requirieron hospitalización. Se aisló S. aureus subespecie aureus de 5 pacientes, 3 operarios y 3 muestras de leche. Todas las cepas fueron productoras de enterotoxinas. Las aislamientos de 3 pacientes, de un operario y de las muestras de leche portaron los genes que codifican las enterotoxinas C (sec y D (sed, y presentaron un patrón único de macrorrestricción (SmaI-PFGE. Se identificó a la leche como fuente de intoxicación y a un operario de la línea de producción como origen de la contaminación. Este es el primer brote de ETA denunciado en Paraguay en el cual se pudo aislar, caracterizar y subtipificar el agente etiológico en la planta de elaboración, en el alimento y en las personas afectadas.During March 2007 there was an epidemic outbreak associated with the consumption of ultrapasteurized milk. Four hundred people were affected and 60 required hospitalization. S. aureus subspecies aureus was isolated from 5 patients, 3 operators and 3 milk samples. All strains produced enterotoxins. Strains isolated from 3 patients, one operator and all the milk samples carried the genes encoding enterotoxins C (sec and D (sed, and showed an indistinguishable macrorestriction pattern (SmaI-PFGE. Milk was identified as the source of intoxication and a production line operator as the source of contamination. This is the first foodborne outbreak reported in Paraguay whose agent was isolated, characterized and subtypified in the production plant, the food and the affected people.

POWERDRESS and diversified expression of the MIR172 gene family bolster the floral stem cell network.

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Rae Eden Yumul

Full Text Available Termination of the stem cells in the floral meristem (also known as floral determinacy is critical for the reproductive success of plants, and the molecular activities regulating floral determinacy are precisely orchestrated during the course of floral development. In Arabidopsis thaliana, regulators of floral determinacy include several transcription factor genes, such as APETALA2 (AP2, AGAMOUS (AG, SUPERMAN (SUP, and CRABSCLAW (CRC, as well as a microRNA (miRNA, miR172, which targets AP2. How the transcription factor and miRNA genes are coordinately regulated to achieve floral determinacy is unknown. A mutation in POWERDRESS (PWR, a previously uncharacterized gene encoding a SANT-domain-containing protein, was isolated in this study as an enhancer of the weakly indeterminate ag-10 allele. PWR was found to promote the transcription of CRC, MIR172a, b, and c and/or enhance Pol II occupancy at their promoters, without affecting MIR172d or e. A mutation in mature miR172d was additionally found to enhance the determinacy defects of ag-10 in an AP2-dependent manner, providing direct evidence that miR172d is functional in repressing AP2 and thereby contributes to floral determinacy. Thus, while PWR promotes floral determinacy by enhancing the expression of three of the five MIR172 members as well as CRC, MIR172d, whose expression is PWR-independent, also functions in floral stem cell termination. Taken together, these findings demonstrate how transcriptional diversification and functional redundancy of a miRNA family along with PWR-mediated co-regulation of miRNA and transcription factor genes contribute to the robustness of the floral determinacy network.

Lessons from Red Data Books: Plant Vulnerability Increases with Floral Complexity.

Science.gov (United States)

Stefanaki, Anastasia; Kantsa, Aphrodite; Tscheulin, Thomas; Charitonidou, Martha; Petanidou, Theodora

2015-01-01

The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant-pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be particularly evident in plants that are currently rare. Using a novel index describing floral complexity we explored whether this aspect of the structure of flowers could be used to predict vulnerability of plant species to extinction. To do this we defined plant vulnerability using the Red Data Book of Rare and Threatened Plants of Greece, a Mediterranean biodiversity hotspot. We also tested whether other intrinsic (e.g. life form, asexual reproduction) or extrinsic (e.g. habitat, altitude, range-restrictedness) factors could affect plant vulnerability. We found that plants with high floral complexity scores were significantly more likely to be vulnerable to extinction. Among all the floral complexity components only floral symmetry was found to have a significant effect, with radial-flower plants appearing to be less vulnerable. Life form was also a predictor of vulnerability, with woody perennial plants having significantly lower risk of extinction. Among the extrinsic factors, both habitat and maximum range were significantly associated with plant vulnerability (coastal plants and narrow-ranged plants are more likely to face higher risk). Although extrinsic and in particular anthropogenic factors determine plant extinction risk, intrinsic traits can indicate a plant's proneness to vulnerability. This raises the potential threat of declining global pollinator diversity interacting with floral complexity to increase the vulnerability of individual plant species. There is potential scope for using plant-pollinator specializations to identify plant species particularly at

Medio de cultivo in vitro para la micropropagación de la planta insectívora Drosera colombiana

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Jarvis Yamith Toscano G.

2005-07-01

en el mayor número de plantas obtenidas y en la gran estabilidad vegetativa de los individuos. En un medio de cultivo Murashige y Skoog (MS, suplementado con 0,01 mg L-1 de AG3, se logró la inducción de múltiples brotes a partir de sus nódulos foliares. El enraizamiento in vitro de los brotes fue de un 100% cuando se utilizó MS/2 sin ningún suplemento hormonal. Es posible que se puedan aclimatar en invernadero con una eficac ia del 80%, instaurando un ambiente muy húmedo, con una temperatura no menor a los 5 ºC.

Estudios sobre Cacao 1.Incidencia de la "Pasmazón de los Pepinos" en Algunos Cacaos Venezolanos

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Ciferri R.

1948-12-01

Full Text Available Se investigó la incidencia de la pudrición de la mazorca del cacao por el Phytophthora palmivora Butler sobre diferentes grupos de variedades de cacao cultivadas en el ambiente subárido de regadío en Ocumare de la Costa, Estado Aragua, Venezuela. Se ha averiguado que la infección sistémica de dichas mazorcas proviene de la infección primaria de los cojines florales, habiéndose estudiado su curso y sus características. Entre otras cosas se notó que, aunque es verdad que el período de mayor susceptibilidad a la infección sistémica es el que corre desde el fin del estado de pepino del fruto (fruto mayor de 9-10 centímetros, o sea de 75 a 90 días de edad y el fin del período de desarrollo del fruto (140 a 150 días a contar desde la fecundación de la flor, puede haber un estado precoz de infección de la mazorca joven, el cual no ocurre nunca antes de los quince días de edad, esto es, en el período de máxima incidencia de la enfermedad fisiológica conocida como "pasmazón de los pepinos". Dicha infección es exclusivamente sistémica y puede afectar hasta las dos quintas partes de los pepinos que cuelgan de cojines infectados. Observóse que el chancro del tallo, que por lo regular sigue a la infección del cojín floral, no es tan dañino como comúnmente se afirma, pero que sus daños económicos se deben a la improductividad producida en el cojín infectado. El Criollo de concha decolorada es más susceptible a la infección por Phytophthora que el de concha morada y el híbrido forastero venezolano el cual, a su vez, parece más susceptible a la infección del cojín floral que los demás grupos de variedades. En un lapso de 10 meses los frutos infectados por medio del cojín floral representan los tres cuartos o cuatro quintos del total. La presencia de pigmento antociánico en la cáscara de la mazorca no madura parece conferir una relativa resistencia a la infección por el Phytophthora; empero, en el Forastero

Study on the Development of Yunnan Floral E-commerce

Institute of Scientific and Technical Information of China (English)

Yulan; KUANG; Qifang; LI; Wangyun; NING

2013-01-01

Cut flower production in Yunnan accounts for 80%nationwide.In order to expand the Yunnan Flower sales channels,the promotion of the development of e-commerce is necessary.In 2012 China’s online shopping users reached 247 million people,but e-commerce of fresh flowers lagged behind due to the constraints of preservation facilities and logistics cost.The analysis of the factors restricting the development of floral e-commerce and the proposition of solutions to this problem can promote faster development of Yunnan floral e-commerce.

Comparative anatomy of floral elaiophores in Vitekorchis Romowicz & Szlach., Cyrtochilum Kunth and a florally dimorphic species of Oncidium Sw. (Orchidaceae: Oncidiinae).

Science.gov (United States)

Davies, Kevin L; Stpiczyńska, Małgorzata; Rawski, Michał

2014-06-01

Recently, molecular approaches have been used to investigate the phylogeny of subtribe Oncidiinae, resulting in the re-alignment of several of its genera. Here, a description is given of the structure of the floral elaiophores (oil glands) of four species formerly assigned to Oncidium Sw. Those of Vitekorchis excavata (Lindl.) Romowicz & Szlach., Cyrtochilum meirax (Rchb.f.) Dalström and a species of Oncidium displaying floral dimorphism, namely O. heteranthum Poepp. & Endl. var. album, are compared with that of Gomesa longipes (Lindl.) M.W. Chase & N.H. Williams, whose epithelial elaiophores are typical of many Oncidiinae, in order to extend our understanding of elaiophore diversity within this subtribe. Floral elaiophore structure was examined and compared at anthesis for all four species using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. In all species investigated, with the exception of C. meirax, the floral elaiophore occurs on the labellar callus and is of the intermediate type, possessing both glabrous and trichomatous regions. By contrast, although all four species produce lipid secretions, C. meirax lacks an obvious elaiophore. In each case, the secretory tissue is represented by a single-layered epidermis of cuboidal cells (trichomatous and/or atrichomatous). Palisade cells are absent. The secretion may be wax- or oil-like and is usually produced by smooth endoplasmic reticulum (SER). However, in C. meirax, where rough endoplasmic reticulum (RER) predominates, oil accumulates as plastoglobuli within elaioplasts. These plastoglobuli are then discharged into the cytoplasm, forming oil bodies. In some species, oil usually accumulates within vesicles at the plasmalemma or in the periplasmic space before traversing the cell wall and accumulating beneath the cuticle, sometimes with distension of the latter. Gomesa longipes is unusual in its production of a heterogeneous secretion, whereas Vitekorchis

Florally rich habitats reduce insect pollination and the reproductive success of isolated plants.

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Evans, Tracie M; Cavers, Stephen; Ennos, Richard; Vanbergen, Adam J; Heard, Matthew S

2017-08-01

Landscape heterogeneity in floral communities has the potential to modify pollinator behavior. Pollinator foraging varies with the diversity, abundance, and spatial configuration of floral resources. However, the implications of this variation for pollen transfer and ultimately the reproductive success of insect pollinated plants remains unclear, especially for species which are rare or isolated in the landscape. We used a landscape-scale experiment, coupled with microsatellite genotyping, to explore how the floral richness of habitats affected pollinator behavior and pollination effectiveness. Small arrays of the partially self-compatible plant Californian poppy ( Eschscholzia californica) were introduced across a landscape gradient to simulate rare, spatially isolated populations. The effects on pollinator activity, outcrossing, and plant reproduction were measured. In florally rich habitats, we found reduced pollen movement between plants, leading to fewer long-distance pollination events, lower plant outcrossing, and a higher incidence of pollen limitation. This pattern indicates a potential reduction in per capita pollinator visitation, as suggested by the lower activity densities and richness of pollinators observed within florally rich habitats. In addition, seed production reduced by a factor of 1.8 in plants within florally rich habitats and progeny germination reduced by a factor of 1.2. We show this to be a consequence of self-fertilization within the partially self-compatible plant, E. californica . These findings indicate that locally rare plants are at a competitive disadvantage within florally rich habitats because neighboring plant species disrupt conspecific mating by co-opting pollinators. Ultimately, this Allee effect may play an important role in determining the long-term persistence of rarer plants in the landscape, both in terms of seed production and viability. Community context therefore requires consideration when designing and

Divergence of the Floral A-Function between an Asterid and a Rosid Species.

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Morel, Patrice; Heijmans, Klaas; Rozier, Frédérique; Zethof, Jan; Chamot, Sophy; Bento, Suzanne Rodrigues; Vialette-Guiraud, Aurélie; Chambrier, Pierre; Trehin, Christophe; Vandenbussche, Michiel

2017-07-01

The ABC model is widely used as a genetic framework for understanding floral development and evolution. In this model, the A-function is required for the development of sepals and petals and to antagonize the C-function in the outer floral whorls. In the rosid species Arabidopsis thaliana , the AP2-type AP2 transcription factor represents a major A-function protein, but how the A-function is encoded in other species is not well understood. Here, we show that in the asterid species petunia ( Petunia hybrida ), AP2B/BLIND ENHANCER ( BEN ) confines the C-function to the inner petunia floral whorls, in parallel with the microRNA BLIND BEN belongs to the TOE-type AP2 gene family, members of which control flowering time in Arabidopsis. In turn, we demonstrate that the petunia AP2-type REPRESSOR OF B-FUNCTION ( ROB ) genes repress the B-function (but not the C-function) in the first floral whorl, together with BEN We propose a combinatorial model for patterning the B- and C-functions, leading to the homeotic conversion of sepals into petals, carpels, or stamens, depending on the genetic context. Combined with earlier results, our findings suggest that the molecular mechanisms controlling the spatial restriction of the floral organ identity genes are more diverse than the well-conserved B and C floral organ identity functions. © 2017 American Society of Plant Biologists. All rights reserved.

More lessons from linalool: insights gained from a ubiquitous floral volatile.

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Raguso, Robert A

2016-08-01

Linalool (3,7-dimethyl-1,6-octadien-3-ol) is a common floral volatile with two distinct enantiomers and related metabolites involved in the full spectrum of plant-pollinator interactions. Recent studies reveal a complex interplay between pollinator attraction and plant defense mediated by linalool and its derivatives, from the smallest (Arabidopsis, Mitella) to the largest (Datura) flowers studied. Accordingly, fig wasps, fungus gnats and moths of all sizes show remarkable electrophysiological, neural and behavioral sensitivity to different enantiomers and quantitative ratios of linalool in floral bouquets. The diverse functions of linalool, ranging from toxin to long distance pollinator attractant are discussed in the broader context of floral volatile ecology and evolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interspecific and Intersexual Differences in the Chemical Composition of Floral Scent in Glochidion Species (Phyllanthaceae in South China

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Daihong Huang

2015-01-01

Full Text Available Plants of the Glochidion (Phyllanthaceae genus are pollinated exclusively by host-specific Epicephala (Gracillariidae moths. Floral scent has been thought to play key role in the obligate pollination mutualism between Glochidion plants and Epicephala moths, but few studies have been reported about chemical variation in floral volatiles of Glochidion species in China. Floral volatiles of male and female flowers of five Glochidion species in south China were collected by dynamic headspace absorption technique and then were chemically analyzed by using gas chromatography-mass spectrometry. A total of 69 compounds were identified from floral scents of five investigated species. Glochidion hirsutum and G. zeylanicum showed no qualitative differences in floral scent, whereas there were clear variations of floral scent among other species (G. eriocarpum, G. daltonii, and G. sphaerogynum and also they distinctly differed from these two species. Male flowers emitted significantly more scent than female flowers. Glochidion plants exhibited qualitative and quantitative differences in floral scent between two sexes of flowers. The findings suggest that the volatile variation of floral scent among Glochidion species reflects adaptations to specific pollinators. Sexual dimorphism in floral scent has evolved to signal alternative rewards provided by each sex to Epicephala moths.

The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant.

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Zhao, Zhi-Gang; Du, Guo-Zhen; Huang, Shuang-Quan

2010-05-20

Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module) in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb Aconitum gymnandrum (Ranunculaceae). We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers), showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position. This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites.

Pollinator Competition as a Driver of Floral Divergence: An Experimental Test.

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Ethan J Temeles

Full Text Available Optimal foraging models of floral divergence predict that competition between two different types of pollinators will result in partitioning, increased assortative mating, and divergence of two floral phenotypes. We tested these predictions in a tropical plant-pollinator system using sexes of purple-throated carib hummingbirds (Anthracothorax jugularis as the pollinators, red and yellow inflorescence morphs of Heliconia caribaea as the plants, and fluorescent dyes as pollen analogs in an enclosed outdoor garden. When foraging alone, males exhibited a significant preference for the yellow morph of H. caribaea, whereas females exhibited no preference. In competition, males maintained their preference for the yellow morph and through aggression caused females to over-visit the red morph, resulting in resource partitioning. Competition significantly increased within-morph dye transfer (assortative mating relative to non-competitive environments. Competition and partitioning of color morphs by sexes of purple-throated caribs also resulted in selection for floral divergence as measured by dye deposition on stigmas. Red and yellow morphs did not differ significantly in dye deposition in the competition trials, but differences in dye deposition and preferences for morphs when sexes of purple-throated caribs foraged alone implied fixation of one or the other color morph in the absence of competition. Competition also resulted in selection for divergence in corolla length, with the red morph experiencing directional selection for longer corollas and the yellow morph experiencing stabilizing selection on corolla length. Our results thus support predictions of foraging models of floral divergence and indicate that pollinator competition is a viable mechanism for divergence in floral traits of plants.

Floral reversion mechanism in longan (Dimocarpus longan Lour.) revealed by proteomic and anatomic analyses.

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You, Xiangrong; Wang, Lingxia; Liang, Wenyu; Gai, Yonghong; Wang, Xiaoyan; Chen, Wei

2012-02-02

Two-dimensional gel electrophoresis (2-DE) was used to analyze the proteins related to floral reversion in Dimocarpus longan Lour. Proteins were extracted from buds undergoing the normal process of flowering and from those undergoing floral reversion in three developing stages in D. longan. Differentially expressed proteins were identified from the gels after 2-DE analysis, which were confirmed using matrix-assisted laser desorption/ionization-time of flying-mass spectroscopy and protein database search. A total of 39 proteins, including 18 up-regulated and 21 down-regulated proteins, were classified into different categories, such as energy and substance metabolism, protein translation, secondary metabolism, phytohormone, cytoskeleton structure, regulation, and stress tolerance. Among these, the largest functional class was associated with primary metabolism. Down-regulated proteins were involved in photosynthesis, transcription, and translation, whereas up-regulated proteins were involved in respiration. Decreased flavonoid synthesis and up-regulated GA20ox might be involved in the floral reversion process. Up-regulated 14-3-3 proteins played a role in the regulation of floral reversion in D. longan by responding to abiotic stress. Observations via transmission electron microscopy revealed the ultrastructure changes in shedding buds undergoing floral reversion. Overall, the results provided insights into the molecular basis for the floral reversion mechanism in D. longan. Copyright © 2011 Elsevier B.V. All rights reserved.

Microbial diversity in the floral nectar of Linaria vulgaris along an urbanization gradient.

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Bartlewicz, Jacek; Lievens, Bart; Honnay, Olivier; Jacquemyn, Hans

2016-03-30

Microbes are common inhabitants of floral nectar and are capable of influencing plant-pollinator interactions. All studies so far investigated microbial communities in floral nectar in plant populations that were located in natural environments, but nothing is known about these communities in nectar of plants inhabiting urban environments. However, at least some microbes are vectored into floral nectar by pollinators, and because urbanization can have a profound impact on pollinator communities and plant-pollinator interactions, it can be expected that it affects nectar microbes as well. To test this hypothesis, we related microbial diversity in floral nectar to the degree of urbanization in the late-flowering plant Linaria vulgaris. Floral nectar was collected from twenty populations along an urbanization gradient and culturable bacteria and yeasts were isolated and identified by partially sequencing the genes coding for small and large ribosome subunits, respectively. A total of seven yeast and 13 bacterial operational taxonomic units (OTUs) were found at 3 and 1% sequence dissimilarity cut-offs, respectively. In agreement with previous studies, Metschnikowia reukaufii and M. gruessi were the main yeast constituents of nectar yeast communities, whereas Acinetobacter nectaris and Rosenbergiella epipactidis were the most frequently found bacterial species. Microbial incidence was high and did not change along the investigated urbanization gradient. However, microbial communities showed a nested subset structure, indicating that species-poor communities were a subset of species-rich communities. The level of urbanization was putatively identified as an important driver of nestedness, suggesting that environmental changes related to urbanization may impact microbial communities in floral nectar of plants growing in urban environments.

The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant

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Du Guo-Zhen

2010-05-01

Full Text Available Abstract Background Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb Aconitum gymnandrum (Ranunculaceae. Results We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers, showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position. Conclusions This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites.

Floral heterochrony promotes flexibility of reproductive strategies in the morphologically homogeneous genus Eugenia (Myrtaceae).

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Vasconcelos, Thais N C; Lucas, Eve J; Faria, Jair E Q; Prenner, Gerhard

2018-01-25

Comparative floral ontogeny represents a valuable tool to understand angiosperm evolution. Such an approach may elucidate subtle changes in development that discretely modify floral architecture and underlie reproductive lability in groups with superficial homogeneous morphology. This study presents a comparative survey of floral development in Eugenia (Myrtaceae), one of the largest genera of angiosperms, and shows how previously undocumented ontogenetic trends help to explain the evolution of its megadiversity in contrast to its apparent flower uniformity. Using scanning electron microscopy, selected steps of the floral ontogeny of a model species (Eugenia punicifolia) are described and compared with 20 further species representing all ten major clades in the Eugenia phylogenetic tree. Additional floral trait data are contrasted for correlation analysis and character reconstructions performed against the Myrtaceae phylogenetic tree. Eugenia flowers show similar organ arrangement patterns: radially symmetrical, (most commonly) tetramerous flowers with variable numbers of stamens and ovules. Despite a similar general organization, heterochrony is evident from size differences between tissues and structures at similar developmental stages. These differences underlie variable levels of investment in protection, subtle modifications to symmetry, herkogamic effects and independent androecium and gynoecium variation, producing a wide spectrum of floral display and contributing to fluctuations in fitness. During Eugenia's bud development, the hypanthium (as defined here) is completely covered by stamen primordia, unusual in other Myrtaceae. This is the likely plesiomorphic state for Myrteae and may have represented a key evolutionary novelty in the tribe. Floral evolution in Eugenia depends on heterochronic patterns rather than changes in complexity to promote flexibility in floral strategies. The successful early establishment of Myrteae, previously mainly linked to the

The relationship between nectaries and floral architecture: a case study in Geraniaceae and Hypseocharitaceae.

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Jeiter, Julius; Hilger, Hartmut H; Smets, Erik F; Weigend, Maximilian

2017-11-10

Flowers of Geraniaceae and Hypseocharitaceae are generally considered as morphologically simple. However, previous studies indicated complex diversity in floral architecture including tendencies towards synorganization. Most of the species have nectar-rewarding flowers which makes the nectaries a key component of floral organization and architecture. Here, the development of the floral nectaries is studied and placed into the context of floral architecture. Seven species from Geraniaceae and one from Hypseocharitaceae were investigated using scanning electron microscopy and light microscopy. Samples were prepared and processed using standard protocols. The development of the nectary glands follows the same trajectory in all species studied. Minor differences occur in the onset of nectarostomata development. The most striking finding is the discovery that a short anthophore develops via intercalary growth at the level of the nectary glands. This anthophore lifts up the entire flower apart from the nectary gland itself and thus plays an important role in floral architecture, especially in the flowers of Pelargonium. Here, the zygomorphic flowers show a particularly extensive receptacular growth, resulting in the formation of a spur-like receptacular cavity ('inner spur'). The nectary gland is hidden at the base of the cavity. Various forms of compartmentalization, culminating in the 'revolver flower' of Geranium maderense, are described. Despite the superficial similarity of the flowers in Geraniaceae and Hypseocharitaceae, there is broad diversity in floral organization and floral architecture. While the receptacular origin of the spur-like cavity in Pelargonium had already been described, anthophore formation via intercalary growth of the receptacle in the other genera had not been previously documented. In the context of the most recent phylogenies of the families, an evolutionary series for the floral architecture is proposed, underscoring the importance of

Comparative GC analyses of ripe fruits, leaves and floral buds essential oils of Tunisian Myrtus communis L.

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Ahmed Snoussi

2014-07-01

Full Text Available The chemical composition of essential oils obtained by hydrodistillation from Tunisian wild growing myrtle ripe fruits, leaves and floral buds was examined by GC and GC-MS. The yields of hydrodistilled oils obtained from different plant parts were: leaves 0.5%, floral buds 0.2% and ripe fruits 0.02%. Significant differences were found in the concentration of main constituents of the oils: α-pinene [48.9% (floral buds, 34.3% (fruits, 23.7% (leaves], 1,8-cineole [15.3% (floral buds, 26.6% (fruits, 61.0% (leaves]. The leaves oil contained less linalool than floral buds and ripe fruits oils. Tunisian myrtle is characterized by the absence of myrtenyl acetate.

Floral Reversion in Arabidopsis suecica Is Correlated with the Onset of Flowering and Meristem Transitioning.

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Amelia Asbe

Full Text Available Angiosperm flowers are usually determinate structures that may produce seeds. In some species, flowers can revert from committed flower development back to an earlier developmental phase in a process called floral reversion. The allopolyploid Arabidopsis suecica displays photoperiod-dependent floral reversion in a subset of its flowers, yet little is known about the environmental conditions enhancing this phenotype, or the morphological processes leading to reversion. We have used light and electron microscopy to further describe this phenomenon. Additionally, we have further studied the phenology of flowering and floral reversion in A. suecica. In this study we confirm and expand upon our previous findings that floral reversion in the allopolyploid A. suecica is photoperiod-dependent, and show that its frequency is correlated with the timing for the onset of flowering. Our results also suggest that floral reversion in A. suecica displays natural variation in its penetrance between geographic populations of A. suecica.

Brote de encefalitis de San Luis en el Área Metropolitana Buenos Aires Outbreack of St. Luis encephalitis in the Metropolitan Buenos Aires Area

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Alfredo Seijo

2011-06-01

Full Text Available Se describen los hallazgos epidemiológicos y clínicos de 13 enfermos con diagnóstico de infección por virus de la encefalitis de San Luis, con transmisión entre enero y marzo de 2010, en el Area Metropolitana Buenos Aires (AMBA. Los 13 enfermos, promedio de edad 38 años, tuvieron un comienzo agudo caracterizado por hipertermia y cefalea. Entre los días dos y diez de iniciados los síntomas, 7/13 enfermos tuvieron signos y síntomas de compromiso neurológico caracterizado por meningitis sin signos encefálicos en 1/7. En 6/7 los hallazgos más frecuentes fueron: rigidez de nuca, desorientación temporoespacial, fotofobia, confusión y alteración del lenguaje. Dos resonancias magnéticas y un electroencefalograma presentaron signos de afectación de lóbulos temporales. El líquido cefalorraquídeo se caracterizó por pleocitosis con predominio de células mononucleadas, glucorraquia normal y discreto aumento de proteínas. No hubo casos fatales. En 6/13 pacientes la sospecha clínica inicial fue dengue. Por la agrupación espacial y temporal de los casos puede considerarse un brote epidémico, el primero conocido en el AMBA, ya que no se había notificado previamente la circulación epidémica del virus.We describe the epidemiological and clinical findings of 13 patients with diagnosis of infection by St. Louis encephalitis virus, transmitted between January and March 2010 in Buenos Aires Metropolitan Area (AMBA. Thirteen patients, average age 38 years, had an acute onset with hyperthermia and headache. Between days two and ten of the onset of symptoms, 7/13 patients had signs and symptoms of neurological involvement. This was characterized by meningitis without encephalic sings in 1/7 and in 6/7 the most frequent findings were: stiff neck, disorientation, photophobia, confusion and language impairment. Two MR and one EEG revealed signs of involvement of temporal lobes. The cerebrospinal fluid showed pleocytosis with predominance of

Fotosíntesis, crecimiento y aceites esenciales en morfotipos florales de caléndula (Calendula officinalis L.).

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Salomé Abarca, Luis Francisco

2014-01-01

La caléndula (Calendula officinalis) es una especie herbácea originaria de Egipto, que se cree fue introducida a Europa en el siglo XII. En México es cultivada como una planta medicinal y de ornato, en lugares con clima semiseco y templado. En la zona de los valles centrales de México, Palma observó amplia diversidad fenotípica en una variedad común de caléndula, y eligió seis variantes en la morfología floral de esa población heterogénea, a las cuales denominó de la S1 a la S6. El objetivo ...

Brote de histoplasmosis en la Escuela de Cadetes de la Base Aérea de Morón, Provincia de Buenos Aires, República Argentina Histoplasmosis outbreak in Morón, Buenos Aires Province, Argentina

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R. Negroni

2010-12-01

Full Text Available Se describe un brote de histoplasmosis que afectó a 6 cadetes de la Fuerza Aérea Argentina, sin antecedentes patológicos previos. Todos consultaron por problemas respiratorios después de haber limpiado un hangar. En ese recinto se encontraron abundantes deyecciones de animales, presuntamente de palomas y murciélagos. Los pacientes sufrieron fiebre, mialgias, taquipnea y tos no productiva. Las radiografías y tomografías de tórax mostraron imágenes pulmonares micronodulares, engrosamiento de los tabiques interalveolares y adenopatías hiliares. Todos tuvieron una evolución favorable y no requirieron tratamiento antifúngico. Las pruebas de inmunodifusión y contrainmunoelectroforesis con antígenos de Histoplasma capsulatum fueron positivas, al igual que las intradermorreacciones con histoplasmina. Se recogieron 5 muestras de tierra del lugar, las que fueron inoculadas por vía intraperitoneal a 20 hámsteres. De los cultivos de hígado y bazo de dichos animales se consiguió aislar la fase micelial de H. capsulatum. La cepa aislada se comparó con las obtenidas de 12 pacientes argentinos utilizando perfiles genéticos y se observó un clado único con más de 96% de similitud, lo que confirma la homogeneidad de las cepas argentinas. Si bien la histoplasmosis es endémica en la Pampa húmeda, este es el primer brote totalmente documentado al sur del paralelo 34°.An histoplasmosis outbreak affecting 6 previously healthy Air Force cadets is herein presented. The patients suffered from fever and respiratory symptoms after having cleaned an abandoned hangar soiled with pigeons and bat droppings. They all presented fever, myalgia, tachypnea, and nonproductive cough. Chest X-ray and CT scan studies showed disseminated reticulonodular images affecting both lungs. Hiliar adenomegalies were also observed. All patients achieved a favourable outcome without antifungal treatment. Both serologic tests searching for specificic antibodies

Discursos de los organismos de inteligencia argentinos sobre el Movimiento Nacionalista Tacuara durante la Guerra Fría (1958-1966

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Maria Valeria Galvan

2009-12-01

Full Text Available En el marco del auge de la primera Guerra Fría y su traslado a la región, por causa de la ruptura de Washington con La Habana, se afi-nan los mecanismos de control de los organis-mos de inteligencia, principalmente, con el objetivo de sofocar posibles brotes comunistas en el país. En este contexto, el objetivo de este artículo es analizar las representaciones de la Dirección de Inteligencia de la Policía de la Provincia de Buenos Aires (DIPBA y la Secre-taría de Inteligencia de Estado (SIDE sobre los grupos derechistas de jóvenes nacionalistas Tacuara, surgidos en la Argentina luego de la caída del peronismo en 1955 y conocidos por sus prácticas de violencia política de corte anticomunista, antiliberal y antisemita, bajo el presupuesto de que esto da cuenta del grado de penetración de los objetivos de la Guerra Fría en las prácticas de control y seguridad y en los informes de estos organismos.

Clave interactiva para los géneros de la familia Asteraceae (Compositae presentes en la reserva municipal de Cogua (Cundinamarca, Colombia

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Juan Carlos Gómez

2005-01-01

Asteraceae presentes en la reserva, utilizando solamente los caracteres de tipo vegetativo, con escaso uso de los caracteres de inflorescencia, y nulo requerimiento de caracteres florales. Esto es un resultado asombroso y no esperado para la familia Asteraceae, cuyas claves tradicionales requieren, desde el comienzo caracteres reproductivos. Es posible apreciar así la alta efectividad de la clave y la gran utilidad del programa DELTA.

Estudio clínico y epidemiológico de un brote de beriberi húmedo en Cartagena de Indias, Colombia, 1992-1993

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M. Martínez

1996-01-01

Full Text Available La presente investigación ha tenido como objetivo primordial aclarar la etiología de un cuadro clínico caracterizado por edema de las piernas, disestesias con déficit motor en miembros inferiores que, en dos casos, incluyó una cardiopatía que llevó a insuficiencia cardiaca irreversible. Este brote ocurrió entre julio de 1991 y junio de 1993; afectó selectivamente infantes de marina de la Escuela Naval Almirante Padilla en Cartagena de Indias. La metodología se centró en un estudio de casos y controles en el cual se sometió a cada grupo a un cuidadoso interrogatorio, examen clínico, medición por el laboratorio de metales pesados en sangre y orina de 24 horas y estudio de niveles de tiamina en muestras de suero; se analizaron cuatro biopsias de nervio sural y en el estudio postmortem de los fallecidos se puso especial atención a las alteraciones de miocardio. En muestras ambientales y biológicas, se analizó mercurio, plomo, arsénico y talio. Los resultados totalizan un grupo de 22 infantes de marina con un cuadro muy uniforme sobre todo por las manifestaciones de una neuropatía periférica nutricional, lo cual sumado a la cardiopatía fatal en dos pacientes, cuyo estudio tanto en microscopia de luz como electrónica, demostró cambios en todo compatibles con lo observado en beriberi, permiten que se considere que el problema de fondo reune las características del beriberi húmedo. Después de concluir que el problema tenía como fondo un origen nutricional basado, en primer lugar, en una falla de tiamina, se hicieron las recomendaciones y ajustes dietéticos indicados para estos casos con una respuesta inmediata y enteramente satisfactoria.

Descripción de un brote epidémico de toxoplasmosis aguda en pacientes inmunocompetentes miembros de las fuerzas militares de Colombia durante operaciones de selva Description of an epidemic outbreak of acute toxoplasmosis in immunocompetent patients from Colombian Armed Forces during jungle operations

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Luis Eduardo Pino

2009-06-01

Full Text Available La toxoplasmosis es una de las infecciones oportunistas más frecuentes en los pacientes infectados con el virus de inmunodeficiencia humana (VIH, mientras que, en los pacientes inmunocompetentes, la infección es sintomática sólo en 10% a 20% de los casos, generalmente con un comportamiento benigno y autolimitado. En la última década se han informado casos graves de compromiso visceral por toxoplasmosis aguda en pacientes inmunocompetentes. En este artículo se presenta un brote epidémico causado por Toxoplasma gondii en personal militar durante el desarrollo de operaciones de selva en el área general de La Macarena, Meta, Colombia. Los 18 casos reportados se confirmaron mediante inmunofluorescencia indirecta (IFI de anticuerpos IgG anti-toxoplasma, al obtener títulos iguales o superiores a 1:1.024 (valor negativo inferior a 1:16. Los síntomas más importantes en estos pacientes fueron fiebre prolongada, adenopatías y compromiso pulmonar y gastrointestinal. Un paciente desarrolló compromiso miopericárdico grave. Todos los pacientes se recuperaron después de tratamiento con pirimetamina/sulfodaxina y clindamicina durante tres semanas. Una hipótesis para la presentación del brote epidémico es el consumo de agua contaminada con ooquistes y, probablemente, la seriedad del compromiso puede atribuirse a una cepa silvestre del parásito, tal como se ha descrito en otros casos reportados en la literatura, aunque en nuestro caso en particular, no se pudo realizar el aislamiento y tipificación de las cepas involucradas.Toxoplasmosis is a common opportunistic infection in patients infected with HIV/AIDS while in immunocompetent patients this infection causes symptoms only in 10% to 20% of the cases, generally with a benign and autoresolutive course. In the last decade some severe cases with visceral involvement has been reported in immunocompetent patients, though they were isolated or recovered during years. We present the first Colombian

Chloride absorption by root, leaf and floral tissues of Petunia

International Nuclear Information System (INIS)

Jooste, J.H.

1980-01-01

Chloride absorption by root, leaf and floral tissues of Petunia was compared at two temperatures (30 and 2 degrees Celcius), employing different absorption periods, and in the presence and absence of a desorption treatment. All treatments revealed highest absorption by floral tissue. This was further confirmed by the absorption of chloride by the various tissues from solutions in the low (0-1 mM) and high (1-50 mM) concentration ranges. The results offer a possible explanation for the observed effects of organic and inorganic solutes on the longevity of cut flowers [af

Floral biology and breeding system of three Ipomoea weeds Biologia floral e sistema reprodutivo de três espécies daninhas de Ipomoea

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R.C.S. Maimoni-Rodella

2007-03-01

Full Text Available The floral biology of three weeds, Ipomoea cairica, I. grandifolia and I. nil (Convolvulaceae, was studied in Botucatu and Jaboticabal, São Paulo, in southeastern Brazil. The three species are melittophilous, with a varied set of floral visitors, but with some overlapping. Cluster analysis using Jacquard similarity index indicated a greater similarity among different plant species in the same locality than among the populations at different places, in relation to floral visitor sets. The promiscuous and opportunistic features of the flowers were shown, with such type of adaptation to pollination being advantageous to weeds since pollinator availability is unpredictable at ruderal environments.A biologia floral de Ipomoea cairica, I. grandifolia e I. nil - plantas daninhas da família Convolvulaceae - foi estudada em Botucatu e Jaboticabal, Estado de São Paulo, Brasil. As três espécies são melitófilas, apresentando conjuntos de visitantes florais bastante diversificados, embora haja alguma sobreposição entre eles. Com relação aos visitantes florais, a análise de agrupamento, empregando-se o índice de similaridade de Jaccard, indicou maior similaridade entre diferentes espécies de Ipomoea ocorrentes no mesmo local do que entre populações da mesma espécie em diferentes localidades. O caráter promíscuo e oportunista da adaptação à polinização, presente nessas espécies, foi demonstrado, sendo essa adaptação vantajosa para plantas daninhas, uma vez que em ambientes ruderais a disponibilidade de polinizadores é imprevisível.

Outbreak of rubella after mass vaccination of children and adult women: challenges for rubella elimination strategies Brote epidémico de rubéola tras la vacunación masiva de niños y mujeres adultas: un reto para las estrategias de eliminación de la rubéola

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Ivone Andreatta Menegolla

2011-04-01

Full Text Available OBJECTIVE: To describe rubella outbreaks and control strategies in the Brazilian state of Rio Grande do Sul before rubella elimination. METHODS: We analyzed rubella and congenital rubella syndrome surveillance data for the state of Rio Grande do Sul and calculated age- and gender-specific incidence of confirmed rubella cases in 2007. We obtained data on measles-rubella doses administered during the outbreak from the state immunization program and reviewed the timing of suspect case notification and implementation of control measures. RESULTS: Of 2 842 confirmed rubella cases reported to the state health department in 2007, 2 145 (75.5% were in males (39.5 cases per 100 000 population and 697 (24.5% were in females (12.3 per 100 000 population. Incidence among 15- to 39-year-olds was 1.8 to 5.5 times higher in males than in females. Rubella genotype 2B was detected in nasopharyngeal specimens from 13 patients from multiple chains of transmission. Eight children were born with congenital rubella syndrome (5.9 cases per 100 000 births in 2008. Delayed notification of initial cases hampered early control efforts, resulting in outbreak spread throughout the state. Rubella transmission was interrupted after mass vaccination of adult men and women as part of a national vaccination campaign. CONCLUSIONS: Routine vaccination strategies and mass vaccination of adolescents and adults for accelerated rubella control and elimination should target men and women.OBJETIVO: Describir los brotes de rubéola y las estrategias para el control de la enfermedad anteriores a la eliminación de la rubéola en el estado brasileño de Rio Grande do Sul. MÉTODOS: Se analizaron los datos de vigilancia epidemiológica sobre la rubéola y el síndrome de rubéola congénita del estado de Rio Grande do Sul y se calculó la incidencia específica por edad y sexo de los casos confirmados de rubéola en el 2007. A partir del programa de vacunación estatal se obtuvieron datos

Floral and mating system divergence in secondary sympatry: testing an alternative hypothesis to reinforcement in Clarkia

Science.gov (United States)

Briscoe Runquist, Ryan D.; Moeller, David A.

2014-01-01

Background and Aims Reproductive character displacement (RCD) is often an important signature of reinforcement when partially cross-compatible taxa meet in secondary sympatry. In this study, floral evolution is examined during the Holocene range expansion of Clarkia xantiana subsp. parviflora from eastern Pleistocene refugia to a western zone of sympatry with its sister taxon, subsp. xantiana. Floral divergence between the two taxa is greater in sympatry than allopatry. The goal was to test an alternative hypothesis to reinforcement – that floral divergence of sympatric genotypes is simply a by-product of adaptation to pollination environments that differ between the allopatric and sympatric portions of the subspecies' range. Methods Floral trait data from two common garden studies were used to examine floral divergence between sympatric and allopatric regions and among phylogeographically defined lineages. In natural populations of C. x. parviflora, the magnitude of pollen limitation and reproductive assurance were quantified across its west-to-east range. Potted sympatric and allopatric genotypes were also reciprocally translocated between geographical regions to distinguish between the effects of floral phenotype versus contrasting pollinator environments on reproductive ecology. Key Results Sympatric populations are considerably smaller flowered with reduced herkogamy. Pollen limitation and the reproductive assurance value of selfing are greater in sympatric than in allopatric populations. Most significantly, reciprocal translocation experiments showed these differences in reproductive ecology cannot be attributed to contrasting pollinator environments between the sympatric and allopatric regions, but instead reflect the effects of flower size on pollinator attraction. Conclusions Floral evolution occurred during the westward range expansion of parviflora, particularly in the zone of sympatry with xantiana. No evidence was found that strongly reduced flower

Floral and mating system divergence in secondary sympatry: testing an alternative hypothesis to reinforcement in Clarkia.

Science.gov (United States)

Briscoe Runquist, Ryan D; Moeller, David A

2014-01-01

Reproductive character displacement (RCD) is often an important signature of reinforcement when partially cross-compatible taxa meet in secondary sympatry. In this study, floral evolution is examined during the Holocene range expansion of Clarkia xantiana subsp. parviflora from eastern Pleistocene refugia to a western zone of sympatry with its sister taxon, subsp. xantiana. Floral divergence between the two taxa is greater in sympatry than allopatry. The goal was to test an alternative hypothesis to reinforcement - that floral divergence of sympatric genotypes is simply a by-product of adaptation to pollination environments that differ between the allopatric and sympatric portions of the subspecies' range. Floral trait data from two common garden studies were used to examine floral divergence between sympatric and allopatric regions and among phylogeographically defined lineages. In natural populations of C. x. parviflora, the magnitude of pollen limitation and reproductive assurance were quantified across its west-to-east range. Potted sympatric and allopatric genotypes were also reciprocally translocated between geographical regions to distinguish between the effects of floral phenotype versus contrasting pollinator environments on reproductive ecology. Sympatric populations are considerably smaller flowered with reduced herkogamy. Pollen limitation and the reproductive assurance value of selfing are greater in sympatric than in allopatric populations. Most significantly, reciprocal translocation experiments showed these differences in reproductive ecology cannot be attributed to contrasting pollinator environments between the sympatric and allopatric regions, but instead reflect the effects of flower size on pollinator attraction. Floral evolution occurred during the westward range expansion of parviflora, particularly in the zone of sympatry with xantiana. No evidence was found that strongly reduced flower size in sympatric parviflora (and RCD between

Orchestration of Floral Initiation by APETALA1

NARCIS (Netherlands)

Kaufmann, K.; Muino Acuna, J.M.

2010-01-01

The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding

Floral vasculature and trichomes of common Indian Scrophulariaceae

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P. C. Datta

2015-01-01

Full Text Available The floral anatomy of 24 species of Scrophulariaceae was studied. The results show that although, clear anatomical bases to differentiate taxa are absent, the Pennell classification of subfamilies is strongly supported.

The application of low frequency longitudinal guided wave mode for the inspection of multi-hole steel floral pipes

International Nuclear Information System (INIS)

Liu, Z H; Xie, X D; Wu, B; Li, Y H; He, C F

2012-01-01

Shed-pipe grouting technology, an effective advanced supporting method, is often used in the excavation of soft strata. Steel floral pipes are one of the key load-carrying components of shed-pipe grouting supporting structures. Guided waves are a very attractive methodology to inspect multi-hole steel floral pipes as they offer long range inspection capability, mode and frequency tuning, and cost effectiveness. In this contribution, preliminary experiments are described for the inspection of steel floral pipes using a low frequency longitudinal guided wave mode, L(0,2). The relation between the number of grouting holes and the peak-to-peak amplitude of the first end-reflected signal was obtained. The effect of the grouting holes in steel floral pipes on the propagation velocity of the L(0,2) mode at 30 kHz was analyzed. Experimental results indicate that the typical grouting holes in steel floral pipe have no significant effect on the propagation of this mode. As a result, low frequency longitudinal guided wave modes have potential for the non-destructive long range inspection of multi-hole steel floral pipes. Furthermore, the propagation velocity of the investigated L(0,2) mode at 30 kHz decreases linearly with the increase of the number of grouting holes in a steel floral pipe. It is also noticeable that the effect of the grouting holes cumulates along with the increase in the number of grouting holes and subsequent increase in reflection times of longitudinal guided waves in the steel floral pipe. The application potential of the low frequency longitudinal guided wave technique for the inspection of embedded steel floral pipes is discussed.

Morphology of floral papillae in Maxillaria Ruiz & Pav. (Orchidaceae).

Science.gov (United States)

Davies, K L; Turner, M P

2004-01-01

The labellar papillae and trichomes of Maxillaria Ruiz & Pav. show great diversity. Although papillae also occur upon other parts of the flower (e.g. column and anther cap), these have not yet been studied. Labellar trichomes of Maxillaria are useful in taxonomy, but hitherto the taxonomic value of floral papillae has not been assessed. The aim of this paper is to describe the range of floral papillae found in Maxillaria and to determine whether papillae are useful as taxonomic characters. Light microscopy, histochemistry, low-vacuum scanning and transmission electron microscopy. A total of 75 taxa were studied. Conical papillae with rounded or pointed tips were the most common. The column and anther cap usually bear conical, obpyriform or villiform papillae, whereas those around the stigmatic surface and at the base of the anther are often larger and swollen. Labellar papillae show greater diversity, and may be conical, obpyriform, villiform, fusiform or clavate. Papillae may also occur on multiseriate trichomes that perhaps function as pseudostamens. Labellar papillae contain protein but most lack lipid. The occurrence of starch, however, is more variable. Many papillae contain pigment or act as osmophores, thereby attracting insects. Rewards such as nectar or a protein-rich, wax-like, lipoidal substance may be secreted by papillae onto the labellar surface. Some papillae may have a protective role in preventing desiccation. Species of diverse vegetative morphology may have identical floral papillae, whereas others of similar vegetative morphology may not. Generally, floral papillae in Maxillaria have little taxonomic value. Nevertheless, the absence of papillae from members of the M. cucullata alliance, the occurrence of clavate papillae with distended apices in the M. rufescens alliance and the presence of papillose trichomes in some species may yet prove to be useful.

Climate effects on phytoplankton floral composition in Chesapeake Bay

Science.gov (United States)

Harding, L. W.; Adolf, J. E.; Mallonee, M. E.; Miller, W. D.; Gallegos, C. L.; Perry, E. S.; Johnson, J. M.; Sellner, K. G.; Paerl, H. W.

2015-09-01

Long-term data on floral composition of phytoplankton are presented to document seasonal and inter-annual variability in Chesapeake Bay related to climate effects on hydrology. Source data consist of the abundances of major taxonomic groups of phytoplankton derived from algal photopigments (1995-2004) and cell counts (1985-2007). Algal photopigments were measured by high-performance liquid chromatography (HPLC) and analyzed using the software CHEMTAX to determine the proportions of chlorophyll-a (chl-a) in major taxonomic groups. Cell counts determined microscopically provided species identifications, enumeration, and dimensions used to obtain proportions of cell volume (CV), plasma volume (PV), and carbon (C) in the same taxonomic groups. We drew upon these two independent data sets to take advantage of the unique strengths of each method, using comparable quantitative measures to express floral composition for the main stem bay. Spatial and temporal variability of floral composition was quantified using data aggregated by season, year, and salinity zone. Both time-series were sufficiently long to encompass the drought-flood cycle with commensurate effects on inputs of freshwater and solutes. Diatoms emerged as the predominant taxonomic group, with significant contributions by dinoflagellates, cryptophytes, and cyanobacteria, depending on salinity zone and season. Our analyses revealed increased abundance of diatoms in wet years compared to long-term average (LTA) or dry years. Results are presented in the context of long-term nutrient over-enrichment of the bay, punctuated by inter-annual variability of freshwater flow that strongly affects nutrient loading, chl-a, and floral composition. Statistical analyses generated flow-adjusted diatom abundance and showed significant trends late in the time series, suggesting current and future decreases of nutrient inputs may lead to a reduction of the proportion of biomass comprised by diatoms in an increasingly diverse

O pessegueiro no sistema de pomar compacto: III. Épocas de poda drástica na diferenciação floral The peach meadow orchards: III. Time of drastic pruning on floral differentiation

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Wilson Barbosa

1990-01-01

Full Text Available Pesquisou-se, na região de Jundiaí, SP (23°8'S, a influência das épocas de poda drástica na diferenciação floral dos pessegueiros Tropical' e 'Aurora-2', conduzidos em alta densidade de plantio (1.667 plantas por hectare. Realizaram-se tais podas em 30 de setembro, 30 de outubro e 30 de novembro de 1986. Coletaram-se as gemas para análise mensalmente, a partir do 30° dia da poda: constatou-se, através de cortes histológicos das gemas, que a poda drástica precoce, de 30 de setembro, não prejudicou a diferenciação floral dos pessegueiros, que se iniciou em fevereiro, a cerca de cinco meses da decepa; em abril, a maioria das gemas de flancos encontrava-se com as sépalas, as pétalas, os estames e o pistilo completamente formados. As demais épocas de poda interferiram no processo de diferenciação floral, reduzindo o número de botões florais e, conseqüentemente, a densidade florífera das plantas. Nos pessegueiros conduzidos com poda normal, a organogênese floral, processada no início do verão (dezembro-janeiro, persistiu até o outono (abril.This paper reports the effect of three different dates of severe pruning on floral differentiation of peach trees of the cultivars Tropical and Aurora-2, conducted on a meadow orchards system. The peach trees were pruned in 1986, at the 30th day of September, October and November. The experimental plots were located at the Experiment Station of Jundiaí, (23º08'S, Instituto Agronômico de Campinas, State of São Paulo, Brazil. The lateral buds of the peach tree branches were first collected for analysis at the 30th day after pruning and on a monthly basis afterwards. Through histological studies made on longitudinal sections of the buds, it was observed that the severe pruning of September 30th, did not change the peach tree reproductive development The floral differentiation began in February, i. e., five months after pruning and produced sequentially: the petals, sepals, stamens and

Determinación de tidiazurón (tdz para la fase de multiplicación in vitro de caimito (chrysophylum cainito l.

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Laura Parismoreno

2017-06-01

Full Text Available El caimito tradicionalmente se propaga de manera vegetativa mediante acodos, ya sea aéreo o terrestre, e injertos. El cultivo in vitro se utiliza para estimular el crecimiento y favorecer la formación de raíces. Se ha demostrado la eficiencia y aumento de la regeneración de brotes mediante el uso de tidiazuron (TDZ. Para lograr los objetivos propuestos, se obtuvieron explantes como yemas axilares y apicales; de los cuales se realizaron cortes de 4-5 cm para la siembra en medio de cultivo estéril. Se esperó que los explantes logren establecerse con varias hojas y observar yemas. Las yemas brotadas se replicaron en el medio de multiplicación MS ½; adicionando reguladores de crecimiento TDZ en dosis de 0, 0.5, 1, 1.5 y 2 mg/L-1, G3 en dosis única de 1 mg/L-1, Phytagel 2 g L, sacarosa 40 g/L; y se mantuvieron a 25 °C y con intensidad de 5.000 lux durante 16 h/día. Las variables que se midieron fueron: número de brotación y longitud de los brotes a los 30 y 90 días después de iniciada la siembra. Los explantes tratados con 0.5 mg/l de TDZ, se logró el mayor número de brotes lo que evidenció la eficiencia de las fitohormonas.

Aspectos de biologia floral de cajueiros anão precoce e comum Floral biology aspects of the early dwarf and common cashew

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Larissa Barbosa de Sousa

2007-06-01

Full Text Available O conhecimento da biologia floral é de suma importância para o desenvolvimento da cultura do cajueiro (Anacardium occidentale L.. Com relação aos aspectos botânicos, as características morfológicas das flores contribuíram efetivamente para a determinação das espécies do gênero Anacarduim conhecidas. No presente trabalho, objetivou-se estudar a biologia floral dos cajueiros anão precoce e comum. A pesquisa foi desenvolvida na área experimental do Departamento de Fitotecnia, Centro de Ciências Agrárias, Universidade Federal do Piauí, em Teresina, PI, avaliando-se nove clones de cajueiro anão ("CAP 14", "Embrapa 09", "Embrapa 50", "Embrapa 51", "Embrapa 76", "Embrapa 183", "Embrapa 189", "FAGA 01", "FAGA 11" e um clone de cajueiro comum ("CCA", utilizando-se quatro panículas por planta, cada uma com orientação norte, sul, leste e oeste. Os tipos varietais, cajueiro comum e anão precoce, apresentam pouca variação para a maioria dos caracteres avaliados. A proporção entre flores hermafroditas e o total de flores, em cajueiro comum, pode levá-lo a uma maior produção de frutos por panícula do que nos clones de cajueiro anão precoce analisados. O número de frutos desenvolvidos é bastante reduzido nos dois tipos varietais. As panículas situadas em diferentes orientações cardeais são semelhantes em todos os clones estudados quanto aos aspectos relacionados à biologia floral do cajueiro.The knowledge of the floral biology is very important for the development of the cashew's culture (Anacardium occidentale L.. In relation to botanical aspects, the morphological characteristics of flowers contributed effective to determination of the well-known species of Anacardium. It was aimed at studing the floral biology of the early dwarf and common cashew. The research was developed in the experimental area of the Department of Fitotecnia, Centro de Ciências Agrárias, Universidade Federal do Piauí, in Teresina, PI, and nine

Small RNA-Sequencing Links Physiological Changes and RdDM Process to Vegetative-to-Floral Transition in Apple

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Xinwei Guo

2017-05-01

Full Text Available Transition from vegetative to floral buds is a critical physiological change during flower induction that determines fruit productivity. Small non-coding RNAs (sRNAs including microRNAs (miRNAs and small interfering RNAs (siRNAs are pivotal regulators of plant growth and development. Although the key role of sRNAs in flowering regulation has been well-described in Arabidopsis and some other annual plants, their relevance to vegetative-to-floral transition (hereafter, referred to floral transition in perennial woody trees remains under defined. Here, we performed Illumina sequencing of sRNA libraries prepared from vegetative and floral bud during flower induction of the apple trees. A large number of sRNAs exemplified by 33 previously annotated miRNAs and six novel members display significant differential expression (DE patterns. Notably, most of these DE-miRNAs in floral transition displayed opposite expression changes in reported phase transition in apple trees. Bioinformatics analysis suggests most of the DE-miRNAs targeted transcripts involved in SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL gene regulation, stress responses, and auxin and gibberellin (GA pathways, with further suggestion that there is an inherent link between physiological stress response and metabolism reprogramming during floral transition. We also observed significant changes in 24 nucleotide (nt sRNAs that are hallmarks for RNA-dependent DNA methylation (RdDM pathway, suggestive of the correlation between epigenetic modifications and the floral transition. The study not only provides new insight into our understanding of fundamental mechanism of poorly studied floral transition in apple and other woody plants, but also presents important sRNA resource for future in-depth research in the apple flowering physiology.

Effect of temperature on the floral scent emission and endogenous volatile profile of Petunia axillaris.

Science.gov (United States)

Sagae, Masanori; Oyama-Okubo, Naomi; Ando, Toshio; Marchesi, Eduardo; Nakayama, Masayoshi

2008-01-01

The floral scent emission and endogenous level of its components in Petunia axillaris under different conditions (20, 25, 30, and 35 degrees C) were investigated under the hypothesis that floral scent emission would be regulated by both metabolic and vaporization processes. The total endogenous amount of scent components decreased as the temperature increased, the total emission showing a peak at 30 degrees C. This decrease in endogenous amount was compensated for by increased vaporization, resulting in an increase of floral scent emission from 20 degrees C to 30 degrees C. The ambient temperature differently and independently influenced the metabolism and vaporization of the scent compounds, and differences in vapor pressure among the scent compounds were reduced as the temperature increased. These characteristics suggest the operation of an unknown regulator to change the vaporization of floral scent.

The biochemistry and genetics of floral scent production as part of the petunia pollination syndrome

NARCIS (Netherlands)

Shaipulah, N.F.M.

2018-01-01

Floral scent plays a major role in flower discrimination by pollinators in the Petunia genus. By providing specific signals to pollinators, floral scent can significantly contribute to the plant pollination efficiency and reproductive success. Fragrant petunias mostly emit volatile benzenoids and

Vigilancia epidemiológica de enfermedades transmitidas por alimentos en la provincia de Río Negro, Argentina, 1993-2001 Surveillance of foodborne diseases in the Province of Rio Negro, Argentina, 1993 - 2001

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Silvana Di Pietro

2004-04-01

Full Text Available Se describen 39 brotes de enfermedades transmitidas por alimentos que afectaron a 958 personas en la provincia de Río Negro, Argentina, en el período 1993- 2001. Se identifican los agentes causales, los alimentos involucrados, los sitios de ocurrencia, los factores de riesgo involucrados y los mecanismos de notificación empleados. Salmonella spp (38%, Trichinella spiralis (15%, Escherichia coli (13% y Staphylococcus aureus (15% resultaron los agentes más frecuentes en los brotes. Salmonella spp. también produjo el mayor número de casos (52%. Los principales alimentos involucrados resultaron cárneos (36%, quesos (10%, fiambres y sándwiches (10%, postres (10% y helados (8%. El mayor número de casos, por su parte, fue causado por la ingestión de helados (37%. Con relación al origen de los alimentos, 41% de los brotes fueron causados por comidas elaboradas en los domicilios, 23% en establecimientos comerciales, 13% en fiestas familiares, 8% en fiestas comunitarias y 8% en restaurantes de hoteles. En el 28% de los brotes fue identificado el agente etiológico por análisis epidemiológico exclusivamente, en el 64% se logró el aislamiento del agente, mientras que en el 8% de los casos no se logró el diagnóstico definitivo. Se analiza el valor de la encuesta epidemiológica en los estudios de enfermedades transmitidas por alimentos, la necesidad de fortalecer el sistema de notificación médica de casos y brotes y la importancia de las buenas prácticas en la manipulación de alimentos.A total of 39 outbreaks of foodborne diseases affecting 958 people in the province of Rio Negro, Argentina between 1993 and 2001 are described and evaluated. The main causal agents were identified involving food, sites of occurrence, risk factors and notification system used. Salmonella spp (38%, Trichinella spiralis (15%, Escherichia coli (13% and Staphylococcus aureus (15% were the most frequent agents present in outbreaks. Salmonella spp produced the

The KNOXI Transcription Factor SHOOT MERISTEMLESS Regulates Floral Fate in Arabidopsis.

Science.gov (United States)

Roth, Ohad; Alvarez, John; Levy, Matan; Bowman, John L; Ori, Naomi; Shani, Eilon

2018-05-09

Plants have evolved a unique and conserved developmental program that enables the conversion of leaves into floral organs. Elegant genetic and molecular work has identified key regulators of flower meristem identity. However, further understanding of flower meristem specification has been hampered by redundancy and by pleiotropic effects. The KNOXI transcription factor SHOOT MERISTEMLESS (STM) is a well-characterized regulator of shoot apical meristem maintenance. Arabidopsis thaliana stm loss-of-function mutants arrest shortly after germination, and therefore the knowledge on later roles of STM in later processes, including flower development, is limited. Here, we uncover a role for STM in the specification of flower meristem identity. Silencing STM in the APETALA1 (AP1) expression domain in the ap1-4 mutant background resulted in a leafy-flower phenotype, and an intermediate stm-2 allele enhanced the flower meristem identity phenotype of ap1-4. Transcriptional profiling of STM perturbation suggested that STM activity affects multiple floral fate genes, among them the F-Box protein-encoding gene UNUSUAL FLORAL ORGANS (UFO). In agreement with this notion, stm-2 enhanced the ufo-2 floral fate phenotype, and ectopic UFO expression rescued the leafy flowers in genetic backgrounds with compromised AP1 and STM activities. This work suggests a genetic mechanism that underlies the activity of STM in the specification of flower meristem identity. © 2018 American Society of Plant Biologists. All rights reserved.

A novel role of BELL1-like homeobox genes, PENNYWISE and POUND-FOOLISH, in floral patterning.

Science.gov (United States)

Yu, Lifeng; Patibanda, Varun; Smith, Harley M S

2009-02-01

Flowers are determinate shoots comprised of perianth and reproductive organs displayed in a whorled phyllotactic pattern. Floral organ identity genes display region-specific expression patterns in the developing flower. In Arabidopsis, floral organ identity genes are activated by LEAFY (LFY), which functions with region-specific co-regulators, UNUSUAL FLORAL ORGANS (UFO) and WUSCHEL (WUS), to up-regulate homeotic genes in specific whorls of the flower. PENNYWISE (PNY) and POUND-FOOLISH (PNF) are redundant functioning BELL1-like homeodomain proteins that are expressed in shoot and floral meristems. During flower development, PNY functions with a co-repressor complex to down-regulate the homeotic gene, AGAMOUS (AG), in the outer whorls of the flower. However, the function of PNY as well as PNF in regulating floral organ identity in the central whorls of the flower is not known. In this report, we show that combining mutations in PNY and PNF enhance the floral patterning phenotypes of weak and strong alleles of lfy, indicating that these BELL1-like homeodomain proteins play a role in the specification of petals, stamens and carpels during flower development. Expression studies show that PNY and PNF positively regulate the homeotic genes, APETALA3 and AG, in the inner whorls of the flower. Moreover, PNY and PNF function in parallel with LFY, UFO and WUS to regulate homeotic gene expression. Since PNY and PNF interact with the KNOTTED1-like homeodomain proteins, SHOOTMERISTEMLESS (STM) and KNOTTED-LIKE from ARABIDOPSIS THALIANA2 (KNAT2) that regulate floral development, we propose that PNY/PNF-STM and PNY/PNF-KNAT2 complexes function in the inner whorls to regulate flower patterning events.

Nectar Sugar Production across Floral Phases in the Gynodioecious Protandrous Plant Geranium sylvaticum

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Varga, Sandra; Nuortila, Carolin; Kytöviita, Minna-Maarit

2013-01-01

Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separation of pollen dispersal and stigma receptivity) has rarely been examined. In this study, sugar production in nectar standing crop and secretion rate were investigated in Geranium sylvaticum, a gynodioecious plant species with protandry (i.e. with hermaphrodite flowers releasing their pollen before the stigma is receptive). We found that flowers from hermaphrodites produced more nectar than female flowers in terms of total nectar sugar content. In addition, differences in nectar production among floral phases were found in hermaphrodite flowers but not in female flowers. In hermaphrodite flowers, maximum sugar content coincided with pollen presentation and declined slightly towards the female phase, indicating nectar reabsorption, whereas in female flowers sugar content did not differ between the floral phases. These differences in floral reward are discussed in relation to visitation patterns by pollinators and seed production in this species. PMID:23614053

Extreme variation in floral characters and its consequences for pollinator attraction among populations of an Andean cactus

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Schlumpberger, Boris O.; Cocucci, Andrea A.; Moré, Marcela; Sérsic, Alicia N.; Raguso, Robert A.

2009-01-01

Background and aims A South American cactus species, Echinopsis ancistrophora (Cactaceae), with dramatic among-population variation in floral traits is presented. Methods Eleven populations of E. ancistrophora were studied in their habitats in northern Argentina, and comparisons were made of relevant floral traits such as depth, stigma position, nectar volume and sugar concentration, and anthesis time. Diurnal and nocturnal pollinator assemblages were evaluated for populations with different floral trait combinations. Key Results Remarkable geographical variations in floral traits were recorded among the 11 populations throughout the distribution range of E. ancistrophora, with flower lengths ranging from 4·5 to 24·1 cm. Other floral traits associated with pollinator attraction also varied in a population-specific manner, in concert with floral depth. Populations with the shortest flowers showed morning anthesis and those with the longest flowers opened at dusk, whereas those with flowers of intermediate length opened at unusual times (2300–0600 h). Nectar production varied non-linearly with floral length; it was absent to low (population means up to 15 µL) in short- to intermediate-length flowers, but was high (population means up to 170 µL) in the longest tubed flowers. Evidence from light-trapping of moths, pollen carriage on their bodies and moth scale deposition on stigmas suggests that sphingid pollination is prevalent only in the four populations with the longest flowers, in which floral morphological traits and nectar volumes match the classic expectations for the hawkmoth pollination syndrome. All other populations, with flowers 4·5–15 cm long, were pollinated exclusively by solitary bees. Conclusions The results suggest incipient differentiation at the population level and local adaptation to either bee or hawkmoth (potentially plus bee) pollination. PMID:19342397

Relative floral density of an invasive plant affects pollinator foraging behaviour on a native plant

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Amy Marie Iler

2014-08-01

Full Text Available Interactions between invasive and native plants for pollinators vary from competition to facilitation of pollination of native plants. Theory predicts that relative floral densities should account for some of this variation in outcomes, with facilitation at low floral densities and competition at high floral densities of the invader. We tested this prediction by quantifying pollination and female reproductive success of a native herb, Geranium maculatum, in three experimental arrays that varied in floral density of the invasive shrub Lonicera maackii: control (no L. maackii, low floral density of L. maackii, and high floral density of L. maackii. A low density of L. maackii flowers was associated with an increase in pollinator visitation rate to G. maculatum flowers and an increase in conspecific pollen deposition compared to controls and high density arrays. Increased visitation rates were not associated with an increase in the number of visitors to low density arrays, suggesting instead that a behavioural switch in visitation within the array accounted for increased pollen deposition. In contrast, the only evidence of competition in high density arrays was a shorter duration of visits to G. maculatum flowers relative to the other treatments. The number of seeds per flower did not vary among treatments, although trends in seeds per flower were consistent with patterns of pollinator foraging behaviour. Given increased pollinator visits and pollen deposition at a low density of the invader, our study indicates that complete eradication of invasives as a management or restoration technique may have unintended negative consequences for pollination of native plants.

Drought and increased CO2 alter floral visual and olfactory traits with context-dependent effects on pollinator visitation.

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Glenny, William R; Runyon, Justin B; Burkle, Laura A

2018-03-25

Climate change can alter species interactions essential for maintaining biodiversity and ecosystem function, such as pollination. Understanding the interactive effects of multiple abiotic conditions on floral traits and pollinator visitation are important to anticipate the implications of climate change on pollinator services. Floral visual and olfactory traits were measured from individuals of four forb species subjected to drought or normal water availability, and elevated or ambient concentrations of CO 2 in a factorial design. Pollinator visitation rates and community composition were observed in single-species and multi-species forb assemblages. Drought decreased floral visual traits and pollinator visitation rates but increased volatile organic compound (VOC) emissions, whereas elevated CO 2 positively affected floral visual traits, VOC emissions and pollinator visitation rates. There was little evidence of interactive effects of drought and CO 2 on floral traits and pollinator visitation. Interestingly, the effects of climate treatments on pollinator visitation depended on whether plants were in single- or multi-species assemblages. Components of climate change altered floral traits and pollinator visitation, but effects were modulated by plant community context. Investigating the response of floral traits, including VOCs, and context-dependency of pollinator attraction provides additional insights and may aid in understanding the overall effects of climate change on plant-pollinator interactions. © No claim to US Government works New Phytologist Trust © 2018 New Phytologist Trust.

Simulation of organ patterning on the floral meristem using a polar auxin transport model.

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Simon van Mourik

Full Text Available An intriguing phenomenon in plant development is the timing and positioning of lateral organ initiation, which is a fundamental aspect of plant architecture. Although important progress has been made in elucidating the role of auxin transport in the vegetative shoot to explain the phyllotaxis of leaf formation in a spiral fashion, a model study of the role of auxin transport in whorled organ patterning in the expanding floral meristem is not available yet. We present an initial simulation approach to study the mechanisms that are expected to play an important role. Starting point is a confocal imaging study of Arabidopsis floral meristems at consecutive time points during flower development. These images reveal auxin accumulation patterns at the positions of the organs, which strongly suggests that the role of auxin in the floral meristem is similar to the role it plays in the shoot apical meristem. This is the basis for a simulation study of auxin transport through a growing floral meristem, which may answer the question whether auxin transport can in itself be responsible for the typical whorled floral pattern. We combined a cellular growth model for the meristem with a polar auxin transport model. The model predicts that sepals are initiated by auxin maxima arising early during meristem outgrowth. These form a pre-pattern relative to which a series of smaller auxin maxima are positioned, which partially overlap with the anlagen of petals, stamens, and carpels. We adjusted the model parameters corresponding to properties of floral mutants and found that the model predictions agree with the observed mutant patterns. The predicted timing of the primordia outgrowth and the timing and positioning of the sepal primordia show remarkable similarities with a developing flower in nature.

Floral traits driving reproductive isolation of two co-flowering taxa that share vertebrate pollinators

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Queiroz, Joel A.; Quirino, Zelma G. M.; Machado, Isabel C.

2015-01-01

Floral attributes evolve in response to frequent and efficient pollinators, which are potentially important drivers of floral diversification and reproductive isolation. In this context, we asked, how do flowers evolve in a bat–hummingbird pollination system? Hence, we investigated the pollination ecology of two co-flowering Ipomoea taxa (I. marcellia and I. aff. marcellia) pollinated by bats and hummingbirds, and factors favouring reproductive isolation and pollinator sharing in these plants. To identify the most important drivers of reproductive isolation, we compared the flowers of the two Ipomoea taxa in terms of morphometry, anthesis and nectar production. Pollinator services were assessed using frequency of visits, fruit set and the number of seeds per fruit after visits. The studied Ipomoea taxa differed in corolla size and width, beginning and duration of anthesis, and nectar attributes. However, they shared the same diurnal and nocturnal visitors. The hummingbird Heliomaster squamosus was more frequent in I. marcellia (1.90 visits h−1) than in I. aff. marcellia (0.57 visits h−1), whereas glossophagine bats showed similar visit rates in both taxa (I. marcellia: 0.57 visits h−1 and I. aff. marcellia: 0.64 visits h−1). Bat pollination was more efficient in I. aff. marcellia, whereas pollination by hummingbirds was more efficient in I. marcellia. Differences in floral attributes between Ipomoea taxa, especially related to the anthesis period, length of floral parts and floral arrangement in the inflorescence, favour reproductive isolation from congeners through differential pollen placement on pollinators. This bat–hummingbird pollination system seems to be advantageous in the study area, where the availability of pollinators and floral resources changes considerably throughout the year, mainly as a result of rainfall seasonality. This interaction is beneficial for both sides, as it maximizes the number of potential pollen vectors for plants and

Lepidosaphes gloverii (Hemiptera: Diaspididae, Estudios Biológicos y Ecológicos en Cítricos de Cuba

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Caridad GONZÁLEZ

2005-01-01

Full Text Available Se estudió la distribución espacial y temporal de Lepidosaphes gloverii (Pack. y sus biorreguladores sobre naranjo Valencia en Cuba. Fueron examinados brotes orientados hacia los cuatro puntos cardinales y en tres estratos de los árboles. Los estados de desarrollo de L. gloverii y la incidencia de los biorreguladores se contabilizaron en el haz y el envés de las hojas. Se estudió la biología del insecto en plantines de lima Persa, limón Eureka y naranjo Valencia. Un complejo de enemigos naturales fue inventariado: parasitoides, depredadores y hongos entomopatógenos, los que difieren por su ubicación en micro hábitats. Se observó la tendencia de la población a la agregación, así como mayores densidades poblacionales hacia el noroeste del campo, el norte del árbol, la zona central del brote y el haz de las hojas.

The co-optimization of floral display and nectar reward

Indian Academy of Sciences (India)

Prakash

2009-12-10

Dec 10, 2009 ... Flowers may lure pollinators by making large floral displays. (Ohashi and ... Pollination biology; plant–animal interaction; co-evolution; cheater; pollinator learning ..... cheater flowers optimized according to the local ecological.

Brote de legionelosis en Murcia en julio de 2001. La óptica de sanidad ambiental

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C. Gutiérrez Molina

2002-06-01

Full Text Available Se exponen las medidas de intervención adoptadas para el estudio y control del brote. Se encontraron 126 instalaciones con riesgo (45 de ellas de alto: 70 torres de refrigeración y similares, 35 fuentes ornamentales, 1 obra con movimiento de tierra y 20 sistemas con circuito cerrado aire-agua, que se distribuyeron por categorías de riesgo.De forma inmediata se clausuraron: las fuentes ornamentales, el baldeo de calles y riegos por aspersión de parques y la obra.Se realizaron un total de 486 inspecciones y 1040 toma de muestras, ordenando la limpieza y desinfección de torres de refrigeración y similares y su clausura en caso necesario. Posteriormente, se cambio de relleno en torres de refrigeración positivas a Lp.Del total de instalaciones investigadas (339, en 57 (16’9% se encontró un cultivo positivo a Lp. Distribución por tipo de instalación con cultivo positivo a Lp: en torres de refrigeración 23 (6’8%, en fuentes ornamentales 3 (7,32% y en agua sanitaria 31 (9’1%.Distribución por serogrupos: LpS1 (62’3%, serogrupos 2-14 (36’68%.LpS1Olda Olda (21’74% fue la mas abundante seguida de LpS1 Pontiac Filadelfia Lugano (18’84% frente a LpS1 Pontiac Filadelfia Glasgow (en 1 ocasión, 1’45%, esta ultima fue la aislada en las 18 muestras de enfermos.En 355 ocasiones se dispone de cultivo y PCR, encontrándose una sensibilidad de 30,8% (Intervalo de confianza al 95%, de 25,1 y una especificidad del 99,4±0,8. Hay que considerar la eventual influencia en los resultados aportada por la posible aparición de dos falsos negativos en el cultivo.Se encuentra un elevado porcentaje de muestras correspondientes a Legionella pneumophilla serogrupo 1, dentro de estas prevalecen las tipo Pontiac Philadelphia, y dentro de estas las tipo Lugano.La primera desinfección no erradicó la contaminación en su totalidad. Abundando en lo anterior, el hallazgo de un número considerable de torres de refrigeración positivas a Lp tras limpieza y

Isolation and characterization of a floral homeotic gene in Fraxinus nigra causing earlier flowering and homeotic alterations in transgenic Arabidopsis

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Jun Hyung Lee; Paula M. Pijut

2017-01-01

Reproductive sterility, which can be obtained by manipulating floral organ identity genes, is an important tool for gene containment of genetically engineered trees. In Arabidopsis, AGAMOUS (AG) is the only C-class gene responsible for both floral meristem determinacy and floral organ identity, and its mutations produce...

Historical nectar assessment reveals the fall and rise of floral resources in Britain.

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Baude, Mathilde; Kunin, William E; Boatman, Nigel D; Conyers, Simon; Davies, Nancy; Gillespie, Mark A K; Morton, R Daniel; Smart, Simon M; Memmott, Jane

2016-02-04

There is considerable concern over declines in insect pollinator communities and potential impacts on the pollination of crops and wildflowers. Among the multiple pressures facing pollinators, decreasing floral resources due to habitat loss and degradation has been suggested as a key contributing factor. However, a lack of quantitative data has hampered testing for historical changes in floral resources. Here we show that overall floral rewards can be estimated at a national scale by combining vegetation surveys and direct nectar measurements. We find evidence for substantial losses in nectar resources in England and Wales between the 1930s and 1970s; however, total nectar provision in Great Britain as a whole had stabilized by 1978, and increased from 1998 to 2007. These findings concur with trends in pollinator diversity, which declined in the mid-twentieth century but stabilized more recently. The diversity of nectar sources declined from 1978 to 1990 and thereafter in some habitats, with four plant species accounting for over 50% of national nectar provision in 2007. Calcareous grassland, broadleaved woodland and neutral grassland are the habitats that produce the greatest amount of nectar per unit area from the most diverse sources, whereas arable land is the poorest with respect to amount of nectar per unit area and diversity of nectar sources. Although agri-environment schemes add resources to arable landscapes, their national contribution is low. Owing to their large area, improved grasslands could add substantially to national nectar provision if they were managed to increase floral resource provision. This national-scale assessment of floral resource provision affords new insights into the links between plant and pollinator declines, and offers considerable opportunities for conservation.

Historical nectar assessment reveals the fall and rise of floral resources in Britain

Science.gov (United States)

Baude, Mathilde; Kunin, William E.; Boatman, Nigel D.; Conyers, Simon; Davies, Nancy; Gillespie, Mark A. K.; Morton, R. Daniel; Smart, Simon M.; Memmott, Jane

2016-02-01

There is considerable concern over declines in insect pollinator communities and potential impacts on the pollination of crops and wildflowers. Among the multiple pressures facing pollinators, decreasing floral resources due to habitat loss and degradation has been suggested as a key contributing factor. However, a lack of quantitative data has hampered testing for historical changes in floral resources. Here we show that overall floral rewards can be estimated at a national scale by combining vegetation surveys and direct nectar measurements. We find evidence for substantial losses in nectar resources in England and Wales between the 1930s and 1970s; however, total nectar provision in Great Britain as a whole had stabilized by 1978, and increased from 1998 to 2007. These findings concur with trends in pollinator diversity, which declined in the mid-twentieth century but stabilized more recently. The diversity of nectar sources declined from 1978 to 1990 and thereafter in some habitats, with four plant species accounting for over 50% of national nectar provision in 2007. Calcareous grassland, broadleaved woodland and neutral grassland are the habitats that produce the greatest amount of nectar per unit area from the most diverse sources, whereas arable land is the poorest with respect to amount of nectar per unit area and diversity of nectar sources. Although agri-environment schemes add resources to arable landscapes, their national contribution is low. Owing to their large area, improved grasslands could add substantially to national nectar provision if they were managed to increase floral resource provision. This national-scale assessment of floral resource provision affords new insights into the links between plant and pollinator declines, and offers considerable opportunities for conservation.

Effects of floral scents and their dietary experiences on the feeding preference in the blowfly, Phormia regina

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Toru eMaeda

2015-12-01

Full Text Available AbstractThe flowers of different plant species have diverse scents with varied chemical compositions. Hence, every floral scent does not uniformly affect insect feeding preferences. The blowfly, Phormia regina, is a nectar feeder, and when a fly feeds on flower nectar, its olfactory organs, antennae, and maxillary palps are exposed to the scent. Generally, feeding preference is influenced by food flavor, which relies on both taste and odor. Therefore, the flies perceive the sweet taste of nectar and the particular scent of the flower simultaneously, and this olfactory information affects their feeding preference. Here, we show that the floral scents of 50 plant species have various effects on their sucrose feeding motivation, which was evaluated using the proboscis extension reflex (PER. Those floral scents were first categorized into three groups, based on their effects on the PER threshold sucrose concentration, which indicates whether a fly innately dislikes, ignores, or likes the target scent. Moreover, memory of olfactory experience with those floral scents during sugar feeding influenced the PER threshold. After feeding on sucrose solutions flavored with floral scents for 5 days, the scents did not consistently show the previously observed effects. Considering such empirical effects of scents on the PER threshold, we categorized the effects of the 50 tested floral scents on feeding preference into 16 of all possible 27 theoretical types. We then conducted the same experiments with flies whose antennae or maxillary palps were ablated prior to PER test in a fly group naïve to floral scents and prior to the olfactory experience during sugar feeding in the other fly group in order to test how these organs were involved in the effect of the floral scent. The results suggested that olfactory inputs through these organs play different roles in forming or modifying feeding preferences. Thus, our study contributes to an understanding of underlying

Effects of Floral Scents and Their Dietary Experiences on the Feeding Preference in the Blowfly, Phormia regina.

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Maeda, Toru; Tamotsu, Miwako; Yamaoka, Ryohei; Ozaki, Mamiko

2015-01-01

The flowers of different plant species have diverse scents with varied chemical compositions. Hence, every floral scent does not uniformly affect insect feeding preferences. The blowfly, Phormia regina, is a nectar feeder, and when a fly feeds on flower nectar, its olfactory organs, antennae, and maxillary palps are exposed to the scent. Generally, feeding preference is influenced by food flavor, which relies on both taste and odor. Therefore, the flies perceive the sweet taste of nectar and the particular scent of the flower simultaneously, and this olfactory information affects their feeding preference. Here, we show that the floral scents of 50 plant species have various effects on their sucrose feeding motivation, which was evaluated using the proboscis extension reflex (PER). Those floral scents were first categorized into three groups, based on their effects on the PER threshold sucrose concentration, which indicates whether a fly innately dislikes, ignores, or likes the target scent. Moreover, memory of olfactory experience with those floral scents during sugar feeding influenced the PER threshold. After feeding on sucrose solutions flavored with floral scents for 5 days, the scents did not consistently show the previously observed effects. Considering such empirical effects of scents on the PER threshold, we categorized the effects of the 50 tested floral scents on feeding preference into 16 of all possible 27 theoretical types. We then conducted the same experiments with flies whose antennae or maxillary palps were ablated prior to PER test in a fly group naïve to floral scents and prior to the olfactory experience during sugar feeding in the other fly group in order to test how these organs were involved in the effect of the floral scent. The results suggested that olfactory inputs through these organs play different roles in forming or modifying feeding preferences. Thus, our study contributes to an understanding of underlying mechanisms associated with

Biologia floral e polinização de Arrabidaea conjugata (Vell. Mart. (Bignoniaceae Floral and pollination biology of Arrabidaea conjugata (Vell. Mart. (Bignoniaceae

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Maria Célia Rodrigues Correia

2005-09-01

Full Text Available O trabalho aborda a biologia floral, a atividade forrageira dos visitantes florais (polinizadores e pilhadores, os eventos fenológicos e o sistema de reprodução de Arrabidaea conjugata (Vell. Mart. (Bignoniaceae, em área de vegetação de restinga, município de Maricá, Rio de Janeiro, no período 1997 a 2000. A espécie estudada tem flores com antese diurna, lilases, tubulosas, hermafroditas, odoríferas e oferecem néctar como recurso floral. O néctar é secretado por um disco localizado na base do gineceu e é acumulado em câmara nectarífera. Os grãos de pólen são liberados gradativamente, prolongando-se a fase de doação de pólen. As abelhas Euglossa cordata Linnaeus, Centris analis Fabricius e C. tarsata Smith são os polinizadores da espécie. Destaca-se pilhagem primária de néctar, por abelhas, e secundária, por borboletas e beija-flor. A espécie é auto-incompatível, apresentando baixos índices de formação de frutos em condições naturais (Frutos/Flores = 12,2%. Foi registrado padrão de floração "cornucópia", entre os meses de dezembro a março (estação quente/chuvosa, com pico em janeiro. As sementes são anemocóricas e liberadas gradativamente na estação fria e seca.This work deals with the floral biology, the foraging activities of floral visitors (pollinators and robbers, phenology and reproductive system of Arrabidaea conjugata (Vell. Mart. (Bignoniaceae in the "restinga" of Maricá, Rio de Janeiro, Brazil, from 1997 to 2000. The flowers display daytime anthesis and last only one day. These attractive pink flowers are tubular, hermaphroditic, odoriferous and produce nectar as the floral reward. The nectar is secreted by a nectariferous disk concealed within a chamber. The pollen grains are gradually released throughout anthesis, extending the pollen presentation phase. The bees Euglossa cordata Linnaeus, Centris analis Fabricius and C. tarsata Smith are the pollinator species. Primary and secondary

Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time.

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van Dijk, Aalt D J; Molenaar, Jaap

2017-01-01

The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

Floral pathway integrator gene expression mediates gradual transmission of environmental and endogenous cues to flowering time

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Aalt D.J. van Dijk

2017-04-01

Full Text Available The appropriate timing of flowering is crucial for the reproductive success of plants. Hence, intricate genetic networks integrate various environmental and endogenous cues such as temperature or hormonal statues. These signals integrate into a network of floral pathway integrator genes. At a quantitative level, it is currently unclear how the impact of genetic variation in signaling pathways on flowering time is mediated by floral pathway integrator genes. Here, using datasets available from literature, we connect Arabidopsis thaliana flowering time in genetic backgrounds varying in upstream signalling components with the expression levels of floral pathway integrator genes in these genetic backgrounds. Our modelling results indicate that flowering time depends in a quite linear way on expression levels of floral pathway integrator genes. This gradual, proportional response of flowering time to upstream changes enables a gradual adaptation to changing environmental factors such as temperature and light.

Nectar sugar production across floral phases in the Gynodioecious Protandrous Plant Geranium sylvaticum [corrected].

Science.gov (United States)

Varga, Sandra; Nuortila, Carolin; Kytöviita, Minna-Maarit

2013-01-01

Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separation of pollen dispersal and stigma receptivity) has rarely been examined. In this study, sugar production in nectar standing crop and secretion rate were investigated in Geranium sylvaticum, a gynodioecious plant species with protandry (i.e. with hermaphrodite flowers releasing their pollen before the stigma is receptive). We found that flowers from hermaphrodites produced more nectar than female flowers in terms of total nectar sugar content. In addition, differences in nectar production among floral phases were found in hermaphrodite flowers but not in female flowers. In hermaphrodite flowers, maximum sugar content coincided with pollen presentation and declined slightly towards the female phase, indicating nectar reabsorption, whereas in female flowers sugar content did not differ between the floral phases. These differences in floral reward are discussed in relation to visitation patterns by pollinators and seed production in this species.

Floral flavonoids and ultraviolet patterns in Viguiera (Compositae)

International Nuclear Information System (INIS)

Rieseberg, L.H.; Schilling, E.E.

1985-01-01

Variation occurs among species of Viguiera series Viguiera for ultraviolet (UV) absorption/reflection patterns of ligules. Floral flavonoids that cause UV absorption occur in epidermal papillae. Flavonoids are further localized to the proximal portion of the ligule in the seven taxa that have only proximal UV absorption. Floral flavonoids involved in UV absorption consist of flavone, flavonol, and anthochlor (chalcone/aurone) glycosides. Quercetin 3-methyl ether glycosides characterize the ligules of 10 taxa occurring in Baja California, Mexico, and nearby areas, and these taxa appear to form one taxonomic group. The anthochlor pair, marein/maritimein, characterizes V. dentata, and the lack of ligule flavonoids distinguishes V. potosina from the remaining taxa. The presence of the anthochlor pair, marein/maritimein, only in V. dentata and the lack of ligule flavonoids in V. potosina concur with other data to indicate that these species are not correctly placed with each other or with the other species currently included in series Viguiera. (author)

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum).

Science.gov (United States)

Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

2016-12-01

Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions.

Pollination systems and floral traits in cerrado woody species of the Upper Taquari region (central Brazil

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F. Q. Martins

Full Text Available Plant species present flowers with varied morphological and functional features, which may be associated to pollination systems, including species pollinated by wind, beetles, moths, bees, small insects, birds, or bats. We calculated the frequencies of the pollination systems among woody species in five cerrado fragments in central-western Brazil and tested whether the pollination systems were indeed related to floral traits. We sampled 2,280 individuals, belonging to 121 species, ninety-nine of which were described in relation to all floral traits. Most species had diurnal anthesis, pale colors, and open flowers. The most frequent groups were those composed by the species pollinated by bees, small insects, and moths. A Principal Component Analysis of the species and floral traits showed that there was a grouping among species with some pollination systems, such as those pollinated mainly by beetles, moths, birds, and bats, for which inferences based on the floral traits are recommended in cerrado sites. For the species pollinated mainly by bees or small insects, inferences based on the floral traits are not recommended, due to the large dispersion of the species scores and overlapping between these two groups, which probably occurred due to the specificity absence in plant-pollinator relationships.

The Role of Abiotic Environmental Conditions and Herbivory in Shaping Bacterial Community Composition in Floral Nectar

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Samuni-Blank, Michal; Izhaki, Ido; Laviad, Sivan; Bar-Massada, Avi; Gerchman, Yoram; Halpern, Malka

2014-01-01

Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that “everything is everywhere, but the environment selects”. Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria) and animals as dispersal vectors, the environmental and geographic factors that shape microbial communities in floral nectar are unknown. We studied culturable bacterial communities in Asphodelus aestivus floral nectar and in its typical herbivorous bug Capsodes infuscatus, along an aridity gradient. Bacteria were sampled from floral nectar and bugs at four sites, spanning a geographical range of 200 km from Mediterranean to semi-arid conditions, under open and bagged flower treatments. In agreement with the niche assembly hypothesis, the differences in bacterial community compositions were explained by differences in abiotic environmental conditions. These results suggest that microbial model systems are useful for addressing macro-ecological questions. In addition, similar bacterial communities were found in the nectar and on the surface of the bugs that were documented visiting the flowers. These similarities imply that floral nectar bacteria dispersal is shaped not only by air borne bacteria and nectar consumers as previously reported, but also by visiting vectors like the mirid bugs. PMID:24922317

Pollinator responses to floral colour change, nectar, and scent promote reproductive fitness in Quisqualis indica (Combretaceae).

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Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling

2016-04-13

Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness.

Separating selection by diurnal and nocturnal pollinators on floral display and spur length in Gymnadenia conopsea.

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Sletvold, Nina; Trunschke, Judith; Wimmergren, Carolina; Agren, Jon

2012-08-01

Most plants attract multiple flower visitors that may vary widely in their effectiveness as pollinators. Floral evolution is expected to reflect interactions with the most important pollinators, but few studies have quantified the contribution of different pollinators to current selection on floral traits. To compare selection mediated by diurnal and nocturnal pollinators on floral display and spur length in the rewarding orchid Gymnadenia conopsea, we manipulated the environment by conducting supplemental hand-pollinations and selective pollinator exclusions in two populations in central Norway. In both populations, the exclusion of diurnal pollinators significantly reduced seed production compared to open pollination, whereas the exclusion of nocturnal pollinators did not. There was significant selection on traits expected to influence pollinator attraction and pollination efficiency in both the diurnal and nocturnal pollination treatment. The relative strength of selection among plants exposed to diurnal and nocturnal visitors varied among traits and populations, but the direction of selection was consistent. The results suggest that diurnal pollinators are more important than nocturnal pollinators for seed production in the study populations, but that both categories contribute to selection on floral morphology. The study illustrates how experimental manipulations can link specific categories of pollinators to observed selection on floral traits, and thus improve our understanding of how species interactions shape patterns of selection.

Separable roles of UFO during floral development revealed by conditional restoration of gene function.

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Laufs, Patrick; Coen, Enrico; Kronenberger, Jocelyne; Traas, Jan; Doonan, John

2003-02-01

The UNUSUAL FLORAL ORGANS (UFO) gene is required for several aspects of floral development in Arabidopsis including specification of organ identity in the second and third whorls and the proper pattern of primordium initiation in the inner three whorls. UFO is expressed in a dynamic pattern during the early phases of flower development. Here we dissect the role of UFO by ubiquitously expressing it in ufo loss-of-function flowers at different developmental stages and for various durations using an ethanol-inducible expression system. The previously known functions of UFO could be separated and related to its expression at specific stages of development. We show that a 24- to 48-hour period of UFO expression from floral stage 2, before any floral organs are visible, is sufficient to restore normal petal and stamen development. The earliest requirement for UFO is during stage 2, when the endogenous UFO gene is transiently expressed in the centre of the wild-type flower and is required to specify the initiation patterns of petal, stamen and carpel primordia. Petal and stamen identity is determined during stages 2 or 3, when UFO is normally expressed in the presumptive second and third whorl. Although endogenous UFO expression is absent from the stamen whorl from stage 4 onwards, stamen identity can be restored by UFO activation up to stage 6. We also observed floral phenotypes not observed in loss-of-function or constitutive gain-of-function backgrounds, revealing additional roles of UFO in outgrowth of petal primordia.

Identificación de infección primaria y secundaria al virus de la rubéola mediante la detección de la avidez de la IgG en muestras de un brote en el 2004 en Cuba

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Yahisel Tejero

2013-12-01

Full Text Available La rubéola es una enfermedad infectocontagiosa que afecta a niños y adultos jóvenes, y cuando esta se produce en el primer trimestre del embarazo ocasiona malformaciones congénitas en el feto. En el Laboratorio Nacional de Referencia de Sarampión, Rubéola y Parotiditis del Instituto de Medicina Tropical "Pedro Kourí", se realizó la detección del índice de avidez relativo (IAR de la IgG en 15 pares de sueros correspondientes a igual número de pacientes adultos que enfermaron durante un brote de rubéola ocurrido en dos provincias de Cuba en el 2004, los cuales fueron positivos a anticuerpos de tipo IgM específicos al virus, y en algunos se encontró seroconversión o un aumento de cuatro veces el título entre los sueros de la fase aguda y convaleciente con la técnica de inhibición de la hemaglutinación. En 13 (86,6% de los pacientes estudiados se detectó infección primaria, mientras que en dos (13,3% de ellos la infección fue secundaria. La detección de la avidez de la IgG constituye un método alternativo útil para distinguir una infección primaria de una secundaria al virus de la rubéola y fortalece el diagnóstico de esta enfermedad en Cuba.

Brote epidémico por Salmonella richmond en Castellón, España Epidemic outbreak caused by Salmonella richmond in Castellón, España

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María Rosario Pac Sa

1998-02-01

Full Text Available Se efectuó un estudio de casos y controles para investigar un brote de gastroenteritis aguda declarado en un destacamento militar situado en una zona rural de Castellón, España. El objetivo del estudio fue conocer las causas del brote y adoptar medidas de control. En total se incluyó a 135 hombres de los 153 que componían dicho destacamento. Entre el 9 y el 11 de agosto de 1993 se notificaron 45 casos, cuya media de edad fue de 19,2 ± 1,5 años. La tasa de ataque fue de 33,3%. En el cuadro clínico predominaron diarreas (76%, vómitos (67%, náuseas (67% y dolor abdominal (28%. La mediana de la duración de los síntomas fue un día y la del período de incubación, 33 horas. Solo se hospitalizó a un paciente y la evolución de todos los afectados fue buena. En cinco de 14 coprocultivos realizados se aisló Salmonella richmond (6,7:y:1,2. También se detectó una asociación entre el consumo de agua de una acequia, que discurría próxima al campamento, y la enfermedad. Mediante un modelo de regresión logística se constató que el consumo del agua de esta fuente permaneció asociado con el estado de caso después de ajustar la asociación según la edad y el consumo de distintos alimentos (razón de posibilidades = 96,5; intervalo de confianza de 95%: 11,4 ­ 814,4. El riesgo de padecer la enfermedad aumentó con la cantidad de agua ingerida (prueba de tendencia X² = 65,4; P A case-control study was carried out to investigate an outbreak of acute gastroenteritis among a military detachment stationed in a rural area of Castellón, España. The purpose of the study was to determine the causes of the outbreak and develop control measures. Of the 153 men in the detachment, 135 were included in the study. Between 9 and 11 August 1993, 45 cases were reported; the patients' average age was 19.2 ± 1.5 years. The attack rate was 33.3%. The clinical picture was dominated by the following symptoms: diarrhea (76%, vomiting (67%, nausea (67%, and

Caffeine in floral nectar enhances a pollinator's memory of reward.

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Wright, G A; Baker, D D; Palmer, M J; Stabler, D; Mustard, J A; Power, E F; Borland, A M; Stevenson, P C

2013-03-08

Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees' bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.

Combined effect of rootstocks and uniconazol-p application via irrigation on the canopy of ‘Hass’ avocado trees

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Catalina Bórquez-Lillo

2015-01-01

Full Text Available En Chile, el cultivo de aguacate ha incorporado el uso de uniconazol-p vía riego en plantaciones donde predominan los portainjertos provenientes de semilla. El presente estudio planteó que la efectividad de la aplicación de uniconazol-p al suelo, en árboles de aguacate ‘Hass’, depende del origen del portainjerto. Se utilizaron árboles ‘Hass’ de nueve meses de edad en el portainjerto clonal Duke 7 y el proveniente de semilla Mexícola, junto con 0, 0.0035, 0.007 y 0.014 g·L-1 de uniconazol-p. Se realizaron mediciones en el dosel de las plantas, a nivel de crecimiento vegetativo, desarrollo de yemas y precocidad en la floración. Se observó que las diferencias entre variables fueron a nivel de portainjerto; Duke 7 presentó mayor vigor y adelanto en la floración que los árboles con Mexícola. Además, Duke 7 no tuvo respuesta a la aplicación de uniconazol-p; caso contrario a lo presentado por Mexícola, donde la concentración de uniconazol-p mayor a 0.007 g·L-1 no mostró efectos en el largo de brotes, ni en la proporción de yemas potencialmente florales con relación al total de yemas.

Soil fungal effects on floral signals, rewards, and aboveground interactions in an alpine pollination web.

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Becklin, Katie M; Gamez, Guadalupe; Uelk, Bryan; Raguso, Robert A; Galen, Candace

2011-08-01

Plants interact with above- and belowground organisms; the combined effects of these interactions determine plant fitness and trait evolution. To better understand the ecological and evolutionary implications of multispecies interactions, we explored linkages between soil fungi, pollinators, and floral larcenists in Polemonium viscosum (Polemoniaceae). Using a fungicide, we experimentally reduced fungal colonization of krummholz and tundra P. viscosum in 2008-2009. We monitored floral signals and rewards, interactions with pollinators and larcenists, and seed set for fungicide-treated and control plants. Fungicide effects varied among traits, between interactions, and with environmental context. Treatment effects were negligible in 2008, but stronger in 2009, especially in the less-fertile krummholz habitat. There, fungicide increased nectar sugar content and damage by larcenist ants, but did not affect pollination. Surprisingly, fungicide also enhanced seed set, suggesting that direct resource costs of soil fungi exceed indirect benefits from reduced larceny. In the tundra, fungicide effects were negligible in both years. However, pooled across treatments, colonization by mycorrhizal fungi in 2009 correlated negatively with the intensity and diversity of floral volatile organic compounds, suggesting integrated above- and belowground signaling pathways. Fungicide effects on floral rewards in P. viscosum link soil fungi to ecological costs of pollinator attraction. Trait-specific linkages to soil fungi should decouple expression of sensitive and buffered floral phenotypes in P. viscosum. Overall, this study demonstrates how multitrophic linkages may lead to shifting selection pressures on interaction traits, restricting the evolution of specialization.

Pollen diversity, viability and floral structure of some Musa genotypes

African Journals Online (AJOL)

Prof. Ogunji

Pollen diversity, viability and floral structure of some Musa genotypes ... at the Faculty of Agriculture & Natural Resources Management farm, Ebonyi State University,. Abakaliki. ..... Roots, tuber, plantains and bananas in human nutrition. Rome,.

Propagación in vitro de Heliconia bihai (L. cv. Lobster Salmón a partir de meristemos florales In vitro propagation of Heliconia bihai (L. cv. Lobster Salmón from flowering buds

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Marta Leonor Marulanda-ángel

2011-04-01

Full Text Available Se desarrolló un protocolo de propagación in vitro a partir de meristemos florales para Heliconia bihai cv. Lobster Salmón. Para el efecto se establecieron 250 yemas florales en diferentes tiempos utilizando NaClO al 1% durante 20 min. El medio de establecimiento Murashige y Skoog con mejores resultados fue BAP (2 mg/lt, AIA (1 mg/lt y 0.1 g/lt de L-cisteína. La mayor produccion de brotes en multiplicación se obtuvo con 6 mg/lt de BAP y con un subcultivo posterior en medio con 2 mg/lt de BAP y 0.5 mg/lt de AIA, alcanzando una tasa de multiplicación de tres nuevas yemas. El enraizamiento de las plántulas in vitro se logró con 1.3 mg/lt de AIA. La aclimatación en vivero fue 92% de supervivencia. Se realizó un análisis de varianza (Anova y un test de Tukey para las variables evaluadas las cuales mostraron diferencias estadísticas en cada fase. La propagación in vitro de heliconias a partir de yemas florales requiere mayor tiempo en la fase de establecimiento y multiplicación, no obstante permite mayores porcentajes de supervivencia y una menor contaminación, ofreciendo material de siembra de diferentes especies de esta planta de interés comercial.A protocol for in vitro propagation of Heliconia bihai cv. Lobster Salmón was developed using flowering buds as initial explants. 250 flowering buds were established in different assays with NaClO at 1% during 20 minutes. The establishment in Murashige & Skoog's medium with BAP (2mg/L, AIA (1 mg/L and L-cystein (0.1 g/L showed the best results. Shoot multiplication was obtained with BAP (6 mg/L with a subsequent subculture in a medium with BAP (2 mg/L and AIA (0.5 mg/L, reaching multiplication rates of 3.0 new shoots. Rooting was achieved with AIA 1.3 mg/L. The survival rate during greenhouse acclimatization was 92%. Analysis of variance (ANOVA and Turkey's test were realized for each of the variables evaluated that showed statistical differences in all stages. The in vitro propagation of

An ortholog of LEAFY in Jatropha curcas regulates flowering time and floral organ development.

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Tang, Mingyong; Tao, Yan-Bin; Fu, Qiantang; Song, Yaling; Niu, Longjian; Xu, Zeng-Fu

2016-11-21

Jatropha curcas seeds are an excellent biofuel feedstock, but seed yields of Jatropha are limited by its poor flowering and fruiting ability. Thus, identifying genes controlling flowering is critical for genetic improvement of seed yield. We isolated the JcLFY, a Jatropha ortholog of Arabidopsis thaliana LEAFY (LFY), and identified JcLFY function by overexpressing it in Arabidopsis and Jatropha. JcLFY is expressed in Jatropha inflorescence buds, flower buds, and carpels, with highest expression in the early developmental stage of flower buds. JcLFY overexpression induced early flowering, solitary flowers, and terminal flowers in Arabidopsis, and also rescued the delayed flowering phenotype of lfy-15, a LFY loss-of-function Arabidopsis mutant. Microarray and qPCR analysis revealed several flower identity and flower organ development genes were upregulated in JcLFY-overexpressing Arabidopsis. JcLFY overexpression in Jatropha also induced early flowering. Significant changes in inflorescence structure, floral organs, and fruit shape occurred in JcLFY co-suppressed plants in which expression of several flower identity and floral organ development genes were changed. This suggests JcLFY is involved in regulating flower identity, floral organ patterns, and fruit shape, although JcLFY function in Jatropha floral meristem determination is not as strong as that of Arabidopsis.

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum)

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Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

2018-01-01

Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions. PMID:29367803

Expression of proteinase inhibitor II proteins during floral development in Solanum americanum.

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Sin, Suk-Fong; Chye, Mee-Len

2004-10-01

The heterologous expression of serine proteinase inhibitor II (PIN2) proteins confers insect resistance in transgenic plants, but little is known of their endogenous roles. We have cloned two cDNAs encoding Solanum americanum PIN2 proteins, SaPIN2a and SaPIN2b. SaPIN2a is highly expressed in stem, particularly in the phloem, suggesting it could possibly regulate proteolysis in the sieve elements. When SaPIN2a was expressed in transgenic lettuce, we observed an inhibition of endogenous trypsin- and chymotrypsin-like activities. Here, we demonstrate that both SaPIN2a and SaPIN2b are expressed in floral tissues that are destined to undergo developmental programmed cell death (PCD), suggesting possible endogenous roles in inhibiting trypsin- and chymotrypsin-like activities during flower development. Northern and western blot analyses revealed that SaPIN2a and SaPIN2b mRNAs and proteins show highest expression early in floral development. In situ hybridization analysis and immunolocalization on floral sections, localized SaPIN2a and SaPIN2b mRNAs and their proteins to tissues that would apparently undergo PCD: the ovules, the stylar transmitting tissue, the stigma and the vascular bundles. Detection of PCD in floral sections was achieved using terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) analysis. Examination of the mid-style before, and 1 day after, pollination revealed that high expression of SaPIN2a and SaPIN2b in the style was inversely correlated with PCD.

36 CFR 12.10 - Floral and commemorative tributes.

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2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Floral and commemorative tributes. 12.10 Section 12.10 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... of fresh cut or artificial flowers in or on a metal or other non-breakable rod or container...

Geographic variation in floral allometry suggests repeated transitions between selfing and outcrossing in a mixed mating plant.

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Summers, Holly E; Hartwick, Sally M; Raguso, Robert A

2015-05-01

Isometric and allometric scaling of a conserved floral plan could provide a parsimonious mechanism for rapid and reversible transitions between breeding systems. This scaling may occur during transitions between predominant autogamy and xenogamy, contributing to the maintenance of a stable mixed mating system. We compared nine disjunct populations of the polytypic, mixed mating species Oenothera flava (Onagraceae) to two parapatric relatives, the obligately xenogamous species O. acutissima and the mixed mating species O. triloba. We compared floral morphology of all taxa using principal component analysis (PCA) and developmental trajectories of floral organs using ANCOVA homogeneity of slopes. The PCA revealed both isometric and allometric scaling of a conserved floral plan. Three principal components (PCs) explained 92.5% of the variation in the three species. PC1 predominantly loaded on measures of floral size and accounts for 36% of the variation. PC2 accounted for 35% of the variation, predominantly in traits that influence pollinator handling. PC3 accounted for 22% of the variation, primarily in anther-stigma distance (herkogamy). During O. flava subsp. taraxacoides development, style elongation was accelerated relative to anthers, resulting in positive herkogamy. During O. flava subsp. flava development, style elongation was decelerated, resulting in zero or negative herkogamy. Of the two populations with intermediate morphology, style elongation was accelerated in one population and decelerated in the other. Isometric and allometric scaling of floral organs in North American Oenothera section Lavauxia drive variation in breeding system. Multiple developmental paths to intermediate phenotypes support the likelihood of multiple mating system transitions. © 2015 Botanical Society of America, Inc.

Floral development and evolution of capitulum structure in Anacyclus (Anthemideae, Asteraceae).

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Bello, M Angélica; Álvarez, Inés; Torices, Rubén; Fuertes-Aguilar, Javier

2013-11-01

Most of the diversity in the pseudanthia of Asteraceae is based on the differential symmetry and sexuality of its flowers. In Anacyclus, where there are (1) homogamous capitula, with bisexual, mainly actinomorphic and pentamerous flowers; and (2) heterogamous capitula, with peripheral zygomorphic, trimerous and long-/short-rayed female flowers, the floral ontogeny was investigated to infer their origin. Floral morphology and ontogeny were studied using scanning electron microscope and light microscope techniques. Disc flowers, subtended by paleae, initiate acropetally. Perianth and androecium initiation is unidirectional/simultaneous. Late zygomorphy occurs by enlargement of the adaxial perianth lobes. In contrast, ray flowers, subtended by involucral bracts, initiate after the proximal disc buds, breaking the inflorescence acropetal pattern. Early zygomorphy is manifested through the fusion of the lateral and abaxial perianth lobes and the arrest of the adaxials. We report atypical phenotypes with peripheral 'trumpet' flowers from natural populations. The peripheral 'trumpet' buds initiate after disc flowers, but maintain an actinomorphic perianth. All phenotypes are compared and interpreted in the context of alternative scenarios for the origin of the capitulum and the perianth identity. Homogamous inflorescences display a uniform floral morphology and development, whereas the peripheral buds in heterogamous capitula display remarkable plasticity. Disc and ray flowers follow different floral developmental pathways. Peripheral zygomorphic flowers initiate after the proximal actinomorphic disc flowers, behaving as lateral independent units of the pseudanthial disc from inception. The perianth and the androecium are the most variable whorls across the different types of flowers, but their changes are not correlated. Lack of homology between hypanthial appendages and a calyx, and the perianth double-sided structure are discussed for Anacyclus together with potential

Geographic variation in floral traits and the capacity of autonomous selfing across allopatric and sympatric populations of two closely related Centaurium species.

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Schouppe, Dorien; Brys, Rein; Vallejo-Marin, Mario; Jacquemyn, Hans

2017-04-21

Floral traits and the relative contribution of autonomous selfing to total seed set varies geographically and is often driven by the availability and abundance of suitable pollinators and/or the presence of co-flowering relatives. In the latter case, competition for pollinator services and costs of hybridization can select for floral traits that reduce interspecific gene flow and contribute to prezygotic isolation, potentially leading to geographic variation in floral divergence between allopatric and sympatric populations. In this study, we investigated variation in floral traits and its implications on the capacity of autonomous selfing in both allopatric and sympatric populations of two closely related Centaurium species(Gentianaceae) across two distinct geographic regions(UK and mainland Europe). Although the magnitude and direction of floral differentiation varied between regions, sympatric populations were always significantly more divergent in floral traits and the capacity to self autonomously than allopatric populations. These results indicate that mating systems can vary substantially within a species and that the joint occurrence of plant species can have a major impact on floral morphology and capacity of autonomous selfing, most likely as a way to reduce the probability of interspecific interference.

Variabilidad anatómica de los sistemas de conducción y estomático de genotipos de Prunus spp. de diferentes orígenes Anatomical variability of water conduction and stomatal systems in genotypes of Prunus spp. of different origins

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Carlos Alberto Núñez-Colín

2006-02-01

Full Text Available El propósito de esta investigación fue estudiar las relaciones ambientales de disponibilidad de humedad, con las características anatómicas del sistema de conducción de agua y estomático, en cinco genotipos de duraznos mexicanos con diferentes orígenes (Jalatzingo y Misantla, Veracruz; Temascaltepec, México; Tulancingo, Oaxaca; Sombrerete, Zacatecas, un almendro y el portainjerto Nemaguard. Fueron caracterizados anatómicamente brotes, hojas y estomas de plántulas de seis meses de edad, mediante 25 caracteres. El almendro y el portainjerto Nemaguard presentaron diferencias con respecto a los duraznos, los cuales tuvieron mayor similitud, aunque mantuvieron una separación acorde con su origen. Los caracteres que diferenciaron los grupos fueron: densidad estomática, grosor de la epidermis superior, número, frecuencia y perímetro de vasos, el índice de vulnerabilidad de la nervadura central, y el porcentaje de médula, xilema y floema del brote. Las condiciones de disponibilidad de humedad del origen presentaron fuerte asociación con las características anatómicas estudiadas, debido a que los ambientes con mayor déficit de humedad (Tulancingo y Sombrerete presentaron mayor tamaño y menor frecuencia de vasos de xilema, así como bajo porcentaje de xilema y floema en brote, lo que puede interpretarse como adaptaciones de resistencia a sequía. La zona donde es rara la ocurrencia de sequía (Jalatzingo presentó características opuestas.The aim of this research was to study the relationships between environmental humidity availability and the anatomical characteristics of water conduction and stomatal systems, in five Mexican peach genotypes with different origins (Jalatzingo and Misantla, Veracruz; Temascaltepec, México; Tulancingo, Oaxaca; Sombrerete, Zacatecas, one almond and Nemaguard rootstock. Shoots, leaves and stomata of six months old plants were anatomically characterized by means of 25 characters. The almond tree and

A genetic screen for modifiers of UFO meristem activity identifies three novel FUSED FLORAL ORGANS genes required for early flower development in Arabidopsis.

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Levin, J Z; Fletcher, J C; Chen, X; Meyerowitz, E M

1998-06-01

In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s) acting between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development.

Covariance and decoupling of floral and vegetative traits in nine Neotropical plants: a re-evaluation of Berg's correlation-pleiades concept.

Science.gov (United States)

Armbruster, W S; Di Stilio, V S; Tuxill, J D; Flores, T C; Velásquez Runk, J L

1999-01-01

Nearly forty years ago R. L. Berg proposed that plants with specialized pollination ecology evolve genetic and developmental systems that decouple floral morphology from phenotypic variation in vegetative traits. These species evolve separate floral and vegetative trait clusters, or as she termed them, "correlation pleiades." The predictions of this hypothesis have been generally supported, but only a small sample of temperate-zone herb and grass species has been tested. To further evaluate this hypothesis, especially its applicability to plants of other growth forms, we examined the patterns of phenotypic variation and covariation of floral and vegetative traits in nine species of Neotropical plants. We recognized seven specific predictions of Berg's hypothesis. Our results supported some predictions but not others. Species with specialized pollination systems usually had floral traits decoupled (weak correlation; Canna and Eichornia) or buffered (relationship with shallow proportional slope; Calathea and Canna) from variation in vegetative traits. However, the same trend was also observed in three species with unspecialized pollination systems (Echinodorus, Muntingia, and Wedelia). One species with unspecialized pollination (Croton) and one wind-pollinated species (Cyperus) showed no decoupling or buffering, as predicted. While species with specialized pollination usually showed lower coefficients of variation for floral traits than vegetative traits (as predicted), the same was also true of species with unspecialized or wind pollination (unlike our prediction). Species with specialized pollination showed less variation in floral traits than did species with unspecialized or wind pollination, as predicted. However, the same was true of the corresponding vegetative traits, which was unexpected. Also in contrast to our prediction, plants with specialized pollination systems did not exhibit tighter phenotypic integration of floral characters than did species with

Floral development and vascularization help to explain merism evolution in Paepalanthus (Eriocaulaceae, Poales

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Arthur de Lima Silva

2016-12-01

Full Text Available Background Flowers in Eriocaulaceae, a monocot family that is highly diversified in Brazil, are generally trimerous, but dimerous flowers occur in Paepalanthus and a few other genera. The floral merism in an evolutionary context, however, is unclear. Paepalanthus encompasses significant morphological variation leading to a still unresolved infrageneric classification. Ontogenetic comparative studies of infrageneric groups in Paepalanthus and in Eriocaulaceae are lacking, albeit necessary to establish evolution of characters such as floral merism and their role as putative synapomorphies. Methods We studied the floral development and vascularization of eight species of Paepalanthus that belong to distinct clades in which dimery occurs, using light and scanning electron microscopies. Results Floral ontogeny in dimerous Paepalanthus shows lateral sepals emerging simultaneously and late-developing petals. The outer whorl of stamens is absent in all flowers examined here. The inner whorl of stamens becomes functional in staminate flowers and is reduced to staminodes in the pistillate ones. In pistillate flowers, vascular bundles reach the staminodes. Ovary vascularization shows ventral bundles in a commissural position reaching the synascidiate portion of the carpels. Three gynoecial patterns are described for the studied species: (1 gynoecium with a short style, two nectariferous branches and two long stigmatic branches, in most species; (2 gynoecium with a long style, two nectariferous branches and two short stigmatic branches, in P. echinoides; and (3 gynoecium with long style, absent nectariferous branches and two short stigmatic branches, in P. scleranthus. Discussion Floral development of the studied species corroborates the hypothesis that the sepals of dimerous flowers of Paepalanthus correspond to the lateral sepals of trimerous flowers. The position and vascularization of floral parts also show that, during dimery evolution in Paepalanthus

Flavonoids patterns of French honeys with different floral origin

NARCIS (Netherlands)

Soler, C.; Gil, M.I.; Garcia-Viguera, C.; Tomás-Barberán, F.A.

1995-01-01

The flavonoid profiles of 12 different unifloral French honey samples were analysed by HPLC to evaluate if these substances could be used as markers of the floral origin of honey. In this analysis, the characteristic flavonoids from propolis and/or beeswax (chrysin, galangin, tectochrysin,

[Floral syndrome and breeding system of Corydalis edulis].

Science.gov (United States)

Xia, Qing; Zhou, Shoubiao; Zhang, Dong; Chao, Tiancai

2012-05-01

A field investigation was conducted on the floral syndrome and breeding system of Corydalis edulis located in natural populations in campus of Anhui Normal University by out-crossing index, pollen-ovule ratio, artificial pollination and bagging experiment. The results showed that the plant was in bloom from March to May and flowering span among populations was 72 days. The flowering span for a raceme was 14-24 days. The life span of one single flower was approximately 5-10 days. Spatial positioning of stigma and anthers were spatially desperation on the day of anthesis. The filaments were shorter than the styles through pollen vitality and stigma receptivity experiments. A self-pollination breeding system was reflected by OCI 3, pollinators were required sometimes; A complex cross bred was indicated by P/O = 857.14, combined with the results of the bagging and artificial pollination experiment, the breeding system of C. edulis was mixed with self-pollination and outcrossing. The special floral structure and pests destroying may have a certain impact on seed-set rate.

Floral Trait Variations Among Wild Tobacco Populations Influence the Foraging Behavior of Hawkmoth Pollinators

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Alexander Haverkamp

2018-02-01

Full Text Available Most pollinators visit flowers in the search of nectar rewards. However, as the floral nectar can often not be directly detected by pollinators, many flower visitors use secondary metabolites such as odor- or taste-proxies to anticipate nectar quantity and quality. Plants might exploit these sensory inferences of the pollinator to increase their pollination rates without increasing their caloric investment into their floral rewards. Here we investigated the effects of natural variation in certain primary and secondary floral metabolites in three populations of the wild tobacco, Nicotiana attenuata, on the pollination behavior of the hawkmoth Manduca sexta. Although offering the same caloric value per flower, the plants of these populations differ in the compositions and concentrations of sugars within the nectar. Moreover, the flowers of these plants emitted highly contrasting levels of attractive floral volatiles (benzyl acetone, but did not differ in the amounts of defensive nectar metabolites (nicotine. In wind tunnel assays with M. sexta moths, plants from those populations that released the largest amount of benzyl acetone as well as those that had a higher ratio of nectar sucrose were more frequently visited and re-visited by the hawkmoth. High emissions of benzyl acetone additionally correlated with a higher time investment of the moths into individual flowers on each visit, leading to the largest foraging success of the moths on those flowers that were most strongly scented. We propose that it is the variation of flower metabolites and their detection by the pollinator rather than the actual caloric value of the nectar, which determines pollinator visitations to a certain flower population. Hence, plants could potentially create a specialist pollinator community by altering their floral signals, either by producing volatiles that pollinators prefer or by providing nectar sugars that pollinators are most sensitive to, while at the same

Perseguir al SRAG: CDC en acción (Stalking SARS: CDC at Work)

Centers for Disease Control (CDC) Podcasts

2013-04-29

En este podcast los niños de Kidtastics hablan sobre el brote del SRAS y cómo trabajaron los CDC para resolver el misterio.  Created: 4/29/2013 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 8/10/2016.

Translocation of heavy metals from soils into floral organs and rewards of Cucurbita pepo: Implications for plant reproductive fitness.

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Xun, Erna; Zhang, Yanwen; Zhao, Jimin; Guo, Jixun

2017-11-01

Metals and metalloids in soil could be transferred into reproductive organs and floral rewards of hyperaccumulator plants and influence their reproductive success, yet little is known whether non-hyperaccumulator plants can translocate heavy metals from soil into their floral organs and rewards (i.e., nectar and pollen) and, if so, whether plant reproduction will be affected. In our studies, summer squash (Cucurbita pepo L. cv. Golden Apple) was exposed to heavy-metal treatments during bud stage to investigate the translocation of soil-supplemented zinc, copper, nickel and lead into its floral organs (pistil, anther and nectary) and rewards (nectar and pollen) as well as floral metal accumulation effects on its reproduction. The results showed that metals taken up by squash did translocate into its floral organs and rewards, although metal accumulation varied depending on different metal types and concentrations as well as floral organ/reward types. Mean foraging time of honey bees to each male and female flower of squash grown in metal-supplemented soils was shorter relative to that of plants grown in control soils, although the visitation rate of honeybees to both male and female flowers was not affected by metal treatments. Pollen viability, pollen removal and deposition as well as mean mass per seed produced by metal-treated squash that received pollen from plants grown in control soils decreased with elevated soil-supplemented metal concentrations. The fact that squash could translocate soil-supplemented heavy metals into floral organs and rewards indicated possible reproductive consequences caused either directly (i.e., decreasing pollen viability or seed mass) or indirectly (i.e., affecting pollinators' visitation behavior to flowers) to plant fitness. Copyright © 2017 Elsevier Inc. All rights reserved.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

Science.gov (United States)

Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

2014-01-01

In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

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Stefan Dötterl

Full Text Available In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues in dioecious sallow, Salix caprea, ii to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Mediator subunit18 controls flowering time and floral organ identity in Arabidopsis.

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Zhengui Zheng

Full Text Available Mediator is a conserved multi-protein complex that plays an important role in regulating transcription by mediating interactions between transcriptional activator proteins and RNA polymerase II. Much evidence exists that Mediator plays a constitutive role in the transcription of all genes transcribed by RNA polymerase II. However, evidence is mounting that specific Mediator subunits may control the developmental regulation of specific subsets of RNA polymerase II-dependent genes. Although the Mediator complex has been extensively studied in yeast and mammals, only a few reports on Mediator function in flowering time control of plants, little is known about Mediator function in floral organ identity. Here we show that in Arabidopsis thaliana, MEDIATOR SUBUNIT 18 (MED18 affects flowering time and floral organ formation through FLOWERING LOCUS C (FLC and AGAMOUS (AG. A MED18 loss-of-function mutant showed a remarkable syndrome of later flowering and altered floral organ number. We show that FLC and AG mRNA levels and AG expression patterns are altered in the mutant. Our results support parallels between the regulation of FLC and AG and demonstrate a developmental role for Mediator in plants.

Polimorfismo floral em Valeriana scandens L. (Valerianaceae Floral polymorphism in Valeriana scandens L. (Valerianaceae

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Erica Duarte-Silva

2010-09-01

Full Text Available Foram encontrados três morfos florais em Valeriana scandens L.: flor perfeita, flor pistilada 1 e flor pistilada 2. A perfeita possui corola maior que a dos demais morfos, com lobos reflexos na antese, giba proeminente e localizada na porção proximal do tubo floral; anteras maiores que as dos demais morfos, com pólen viável; estilete curto e estigma incluso, o menor ovário e saco embrionário estruturalmente normal, semelhante ao dos demais morfos. A pistilada 1 possui a giba menos proeminente, corola de tamanho intermediário em relação aos demais morfos, lobos radiais na antese; anteras pequenas, sem pólen e estilete longo e estigma exserto. A pistilada 2 possui lobos radiais na antese, anteras de comprimento semelhante às da perfeita, mas de menor largura, com pólen inviável; estilete mais curto, tal como o da flor perfeita, e estigma exserto, tal como o da flor pistilada 1. Nos três morfos, o nectário é formado por tricomas secretores unicelulares situados na epiderme da face interna da giba, e suas sementes são viáveis. As flores pistilada 2 e perfeita apresentam um septo que isola a giba do restante do tubo floral, formando uma câmara nectarífera. V. scandens L. é ginomonóica-ginodióica, expressão sexual inédita em Valerianaceae.Three floral morphs were found in Valeriana scandens L.: perfect, pistillate 1, and pistillate 2. In perfect flowers, the corolla is longer than in the other morphs, with reflexed lobes at anthesis and a prominent gibbus at the tube base; anthers are longer and contain viable pollen grains; the pistil has a short included style/stigma and the smallest ovary, but a structurally normal embryo sac similar to that of the other morphs. In pistillate 1 flowers, the corolla is intermediate in size, and has radially displayed lobes at anthesis, and a softly prominent gibbus; anthers are small and devoid of pollen; the pistil shows a long exerted style/stigma. In pistillate 2 flowers, the corolla

Floral ontogeny of two Jatropha species (Euphorbiaceae s.s) and its systematic implications

International Nuclear Information System (INIS)

Liu, H.; Liao, J.

2015-01-01

Floral ontogeny of Jatropha multifida L. and Jatropha integerrima Jacq. (Euphorbiaceae) was studied using scanning electron microscopy (SEM). These two species possess unisexual male flowers and bisexual (with unfunctional staminodes) female flowers. In both male and female flowers, five sepal primordia arise in a 2/5 sequence on the periphery of the floral apex and initiate anticlockwise or clockwise in different floral buds. Five petal primordia initiate simultaneously alternate to sepals. Dicyclic stamens (obdiplostemony) arise in both male and female flowers. In J. multifida, five outer stamen primordia arise first simultaneously and then three inner stamens initiate simultaneously. However, in J. integerrima, ten stamen primordia arranged in two whorls initiate simultaneously. While the ovary is absent in the male flowers, in the female flowers, three carpel primordia appear simultaneously. With further development of the ovary the stamens degenerate in the female flowers, whereas in the male flowers, the stamens grow normally. Ancestral state reconstruction using MacClade indicates that stamen simultaneous vs. non-simultaneous initiation supports the phylogenetic analysis based on nuclear ribosomal DNA ITS sequence. (author)

Cytological behaviour of floral organs and in silico characterization ...

Indian Academy of Sciences (India)

c Indian Academy of Sciences. RESEARCH ... have defects in number, size, shape and function. ... associated with 'floral bud distortion' in soybean. J. Genet. 95, 787–799] ... with different names, namely no podding syndrome in India, .... three independent runs. ... eluted from the agaros gel with sharp surgical blade without.

Pollination of Cypripedium plectrochilum (Orchidaceae) by Lasioglossum spp. (Halictidae): the roles of generalist attractants versus restrictive floral architecture.

Science.gov (United States)

Li, P; Luo, Y; Bernhardt, P; Kou, Y; Perner, H

2008-03-01

The pollination of Cypripedium plectrochilum Franch. was studied in the Huanglong Nature Reserve, Sichuan, China. Although large bees (Bombus, Apis), small bees (Ceratina, Lasioglossum), ants (Formica sp.), true flies (Diptera) and a butterfly were all found to visit the flowers, only small bees, including three Lasioglossum spp. (L. viridiclaucum, L. sichuanense and L. sp.; Halictidae) and one Ceratina sp., carried the flower's pollen and contacted the receptive stigma. Measurements of floral architecture showed that interior floral dimensions best fit the exterior dimensions of Lasioglossum spp., leading to the consistent deposition and stigmatic reception of dorsally-placed, pollen smears. The floral fragrance was dominated by one ketone, 3-methyl-Decen-2-one. The conversion rate of flowers into capsules in open (insect) pollinated flowers at the site was more than 38%. We conclude that, while pigmentation patterns and floral fragrance attracted a wide variety of insect foragers, canalization of interior floral dimensions ultimately determined the spectrum of potential pollinators in this generalist, food-mimic flower. A review of the literature showed that the specialised mode of pollination-by-deceit in C. plectrochilum, limiting pollinators to a narrow and closely related guild of 'dupes' is typical for other members of this genus.

How to be an attractive male: floral dimorphism and attractiveness to pollinators in a dioecious plant

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Waelti Marc O

2009-08-01

Full Text Available Abstract Background Sexual selection theory predicts that males are limited in their reproductive success by access to mates, whereas females are more limited by resources. In animal-pollinated plants, attraction of pollinators and successful pollination is crucial for reproductive success. In dioecious plant species, males should thus be selected to increase their attractiveness to pollinators by investing more than females in floral traits that enhance pollinator visitation. We tested the prediction of higher attractiveness of male flowers in the dioecious, moth-pollinated herb Silene latifolia, by investigating floral signals (floral display and fragrance and conducting behavioral experiments with the pollinator-moth, Hadena bicruris. Results As found in previous studies, male plants produced more but smaller flowers. Male flowers, however, emitted significantly larger amounts of scent than female flowers, especially of the pollinator-attracting compounds. In behavioral tests we showed that naïve pollinator-moths preferred male over female flowers, but this preference was only significant for male moths. Conclusion Our data suggest the evolution of dimorphic floral signals is shaped by sexual selection and pollinator preferences, causing sexual conflict in both plants and pollinators.

Efecto del nitrato de potasio, fosfato de potasio y ethephon en la inducción floral de la feijoa o goiabeira serrana (Acca sellowiana [O. Berg] Burret Effect of potassium nitrate, potassium phosphate and ethephon in floral induction of pineapple guava (Acca sellowiana [O. Berg] Burret

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Oskar Javier Garcia

2008-09-01

Full Text Available El ensayo se llevó a cabo en la finca El Cortijo (La Vega, Cundinamarca, Colombia [04°55'N y 74°18'W], 2350 m altitud, 17°C temperatura media, 1423 mm precipitación anual, 85% humedad relativa, 1377 horas brillo solar/año. Se utilizaron árboles de feijoa o goiabeira serrana de seis años, Clon 41 ('Quimba', evaluando fertilizantes foliares KNO3 (Nitrato de Potasio 13-0-46® 1%, 1,5% y 2% y KH2PO4 (fosfato de potasio; Cosmofoliar 0-32-43®; 0,5%, 0,75% y 1,0% y la fitohormona ethephon (Ethrel® 48 SL; 100, 150 y 200 mg L-1. Se determinaron el número de botones florales inducidos, flores formadas, además, el porcentaje de flores formadas y nivel de eficacia de los productos inductores. El KH2PO4 al 0,5% obtuvo resultados favorables en cada una de las variables evaluadas, comparado con el 0,75% y 1% del mismo producto y, sin embargo hubo un alto número de flores inducidas y formadas, no se presentaron diferencias significativas con el testigo. Ethephon a 150 mg L-1 en la inducción de botones florales y a 100 mg L-1 en la de formación de flores mostró resultados favorables, pero tampoco pudo superar el testigo por falta de significancia. La respuesta generada por KNO3 mostró una baja inducción de botones florales, y una eficacia negativa en la proporción de flores formadas; asimismo fitotoxicidad, cuando se emplearon concentraciones al 2% de este producto.The experiment was carried out in El Cortijo farm (La Vega, Cundinamarca, Colombia [ 04° 55' N and 74° 18' W ], 2350 m above sea level, 17° C average temperature, 1423 mm of annual precipitation, 85% of relative humidity, and 1.377 of sunshine hours/year. In the study, evaluation of foliar fertilizers KNO3 (potassium nitrate 13-0-46® 1%, 1.5%, and 2%, KH2PO4 (potassium phosphate; Cosmofoliar 0-32-43®; 0.5%, 0.75%, and 1.0%, and ethephon phytohormone (Ethrel® 48 SL; 100, 150, and 200 mg L-1 was done on six year old pineapple guava trees of Clone 41 ('Quimba'. The number of

Fenología del aguacate 'hass' en el clima semicálido de Nayarit, México

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L. E. Cossio-Vargas

2008-01-01

Full Text Available Este estudio se desarrolló en varios periodos del 2000 al 2005, en dos huertos comerciales de aguacate 'Hass' en los municipios de Tepic y Xalisco, Nayarit, México. El objetivo fue determinar los ciclos de crecimiento de árboles de 'Hass' cultivados sin riego. El cv. Hass presentó dos flujos de crecimiento vegetativo: invierno (mayor intensidad y verano (menor intensidad. El proceso completo de desarrollo floral, de yema cerrada a antesis, en brotes del flujo vegetativo de invierno y verano fue de 11.5 meses y 7.5 meses, respectivamente. La máxima producción de raíces ocurrió en agosto. La máxima intensidad (45 % de la "caída de fruto de junio" ocurrió durante las primeras lluvias de verano (junio. El crecimiento en longitud del fruto, desde el amarre (marzo hasta cosecha (noviembre, duró ocho meses. Los promedios anuales de temperaturas máximas del aire fluctuaron de 26.8 a 33.4 °C y las mínimas de 9.3 a 20.4 °C. El promedio de las temperaturas máximas mensuales del suelo se mantuvo todo el año entre 20.1 y 24.5 °C, y las mínimas entre 18.5 y 23.4 °C. El nivel de humedad del suelo fue >85 % desde la estación lluviosa (junio a octubre hasta diciembre; posteriormente descendió hasta alcanzar 65 % en mayo.

Dinâmica floral e abortamento de flores em híbridos de canola e mostarda castanha Floral dynamics and flower abortion in hybrids of canola and Indian mustard

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Rafael Battisti

2013-02-01

Full Text Available O objetivo deste trabalho foi avaliar a dinâmica floral e determinar o índice de abortamento de flores de híbridos de canola (Brassica napus e de mostarda castanha (Brassica juncea, bem como determinar suas relações com as condições meteorológicas do Sul do Brasil. Durante a floração, dez híbridos de canola e dois de mostarda foram avaliados a cada três dias quanto ao número de flores abertas, de síliquas e de flores abortadas. O número acumulado e relativo de flores foi usado para avaliação da dinâmica floral. A relação desses números com a soma térmica acumulada durante a floração foi determinada por meio de modelo logístico. A partir dos coeficientes desse modelo, identificaram-se grupos de genótipos com diferentes taxas de emissão de flores. O abortamento de flores entre híbridos variou de 10,53 a 45,96% e correlacionou-se com a temperatura e a demanda evaporativa da atmosfera. Genótipos com maiores tempos térmicos entre o período de máxima emissão de flores e o final da floração geralmente apresentam maiores percentagens de abortamento de flores. O ajuste dos dados de emissão de flores aos de soma térmica do período da floração, por meio de modelo logístico, permite simular a dinâmica floral de híbridos de canola e mostarda castanha.The objective of this work was to evaluate the floral dynamics and to determine the index of flower abortion in canola (Brassica napus and Indian mustard (Brassica juncea hybrids, as well as to determine their relation with meteorological conditions of southern Brazil. During flowering, ten hybrids of canola and two of Indian mustard were evaluated every three days as to the number of open flowers, pods, and aborted flowers. The cumulative and the relative number of flowers were used to evaluate floral dynamics. The relation of these numbers with the accumulated thermal sum during flowering was determined with a logistic model. Groups of genotypes with different

Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

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Liliana M Cano

Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.

Digital Gene Expression Analysis Based on De Novo Transcriptome Assembly Reveals New Genes Associated with Floral Organ Differentiation of the Orchid Plant Cymbidium ensifolium.

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Fengxi Yang

Full Text Available Cymbidium ensifolium belongs to the genus Cymbidium of the orchid family. Owing to its spectacular flower morphology, C. ensifolium has considerable ecological and cultural value. However, limited genetic data is available for this non-model plant, and the molecular mechanism underlying floral organ identity is still poorly understood. In this study, we characterize the floral transcriptome of C. ensifolium and present, for the first time, extensive sequence and transcript abundance data of individual floral organs. After sequencing, over 10 Gb clean sequence data were generated and assembled into 111,892 unigenes with an average length of 932.03 base pairs, including 1,227 clusters and 110,665 singletons. Assembled sequences were annotated with gene descriptions, gene ontology, clusters of orthologous group terms, the Kyoto Encyclopedia of Genes and Genomes, and the plant transcription factor database. From these annotations, 131 flowering-associated unigenes, 61 CONSTANS-LIKE (COL unigenes and 90 floral homeotic genes were identified. In addition, four digital gene expression libraries were constructed for the sepal, petal, labellum and gynostemium, and 1,058 genes corresponding to individual floral organ development were identified. Among them, eight MADS-box genes were further investigated by full-length cDNA sequence analysis and expression validation, which revealed two APETALA1/AGL9-like MADS-box genes preferentially expressed in the sepal and petal, two AGAMOUS-like genes particularly restricted to the gynostemium, and four DEF-like genes distinctively expressed in different floral organs. The spatial expression of these genes varied distinctly in different floral mutant corresponding to different floral morphogenesis, which validated the specialized roles of them in floral patterning and further supported the effectiveness of our in silico analysis. This dataset generated in our study provides new insights into the molecular mechanisms

Direct and indirect effects of land use on floral resources and flower-visiting insects across an urban landscape

Science.gov (United States)

Matteson, K.C.; Grace, James B.; Minor, E.S.

2013-01-01

Although urban areas are often considered to have uniformly negative effects on biodiversity, cities are most accurately characterized as heterogeneous mosaics of buildings, streets, parks, and gardens that include both ‘good’ and ‘bad’ areas for wildlife. However, to date, few studies have evaluated how human impacts vary in direction and magnitude across a heterogeneous urban landscape. In this study, we assessed the distribution of floral resources and flower-visiting insects across a variety of land uses in New York City. We visited both green spaces (e.g. parks, cemeteries) and heavily developed neighborhood blocks (e.g. with high or low density residential zoning) and used structural equation modeling (SEM) to evaluate the direct and indirect effects of median income, vegetation, and development intensity on floral resources and insects in both settings. Abundance and taxonomic richness of flower-visiting insects was significantly greater in green spaces than neighborhood blocks. The SEM results indicated that heavily-developed neighborhoods generally had fewer flower-visiting insects consistent with reductions in floral resources. However, some low-density residential neighborhoods maintained high levels of floral resources and flower-visiting insects. We found that the effects of surrounding vegetation on floral resources, and thus indirect effects on insects, varied considerably between green spaces and neighborhood blocks. Along neighborhood blocks, vegetation consisted of a mosaic of open gardens and sparsely distributed trees and had a positive indirect effect on flower-visiting insects. In contrast, vegetation in urban green spaces was associated with increased canopy cover and thus had a negative indirect effect on flower-visiting insects through reductions in floral resources. In both neighborhood blocks and green spaces, vegetation had a positive direct effect on flower-visiting insects independent of the influence of vegetation on floral

Drought and increased CO2 alter floral visual and olfactory traits with context-dependent effects on pollinator visitation

Science.gov (United States)

William R. Glenny; Justin B. Runyon; Laura A. Burkle

2018-01-01

Climate change can alter species interactions essential for maintaining biodiversity and ecosystem function, such as pollination. Understanding the interactive effects of multiple abiotic conditions on floral traits and pollinator visitation are important to anticipate the implications of climate change on pollinator services. Floral visual and olfactory traits were...

Seasonal distribution and evolving forms of multiple sclerosis patients diagnosed from April 2004 to November 2007 Distribución estacional y formas evolutivas de esclerosis múltiple en pacientes diagnosticados entre Abril del 2004 y Noviembre del 2007

Directory of Open Access Journals (Sweden)

Hermes Fundora-Hernández

2009-09-01

Full Text Available BACKGROUND: Multiple sclerosis (MS was first reported in Cuba in 1965. The most frequent appearance is observed in the first six months of the year. OBJECTIVE: To determine the seasonal distribution and evolving forms of MS patients diagnosed with the disease between April 2004 and November 2007. METHOD: Twenty-one patients with suspected MS and 42 outbreaks were studied. Patients were classified according to Lublin and Revingold's criteria for clinical forms and according to McDonald. RESULTS: Most patients were classified in outbreak and remission and only two patients classified as primary-progressive multiple sclerosis. The higher number of outbreaks occurred in the first two quarters of the year. CONCLUSION: It is recommended to study further weather variables that may be related to the emergence of these outbreaks in our environment.INTRODUCCIÓN: La esclerosis múltiple (EM fue reportada en Cuba por primera vez en 1965. Se ha venido observando la aparición más frecuente en los primeros seis meses del año. OBJETIVO: Determinar la distribución estacional y formas evolutivas de EM en pacientes con diagnóstico de esta enfermedad entre abril 2004 y noviembre 2007. MÉTODO: Se estudiaron 21 pacientes con sospecha de EM y un total de 42 brotes. Los pacientes fueron clasificados según los criterios de Lublin y Revingold para las formas evolutivas y según los criterios de McDonald. RESULTADOS: Solo dos pacientes clasificaron en la forma evolutiva progresiva primaria; los primeros dos trimestres del año fueron los de mayor número de brotes. CONCLUSIÓN: Se recomienda profundizar en las variables climatológicas que pudieran tener vínculo con la aparición de estos brotes en nuestro medio.

Enfermedad del virus del Ébola (Ebola Virus Disease)

Centers for Disease Control (CDC) Podcasts

Este podcast proporciona información general sobre la enfermedad del virus del Ébola y el brote en África Occidental. El programa contiene declaraciones del director de los CDC, Dr. Tom Frieden, así como una breve descripción de las actividades de respuesta de los CDC.

Caffeine in floral nectar enhances a pollinator’s memory of reward

Science.gov (United States)

Wright, G. A.; Baker, D. D.; Palmer, M. J.; Stabler, D.; Mustard, J. A.; Power, E. F.; Borland, A. M.; Stevenson, P. C.

2015-01-01

Plant defence compounds occur in floral nectar, but their ecological role is not well-understood. We provide the first evidence that plant compounds pharmacologically alter pollinator behaviour by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times more likely to remember a learned floral scent than those rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar never exceeded the bees’ bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success. PMID:23471406

Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: implications for flower visitation by bees

Science.gov (United States)

Rodriguez-Saona, Cesar; Parra, Leonardo; Quiroz, Andrés; Isaacs, Rufus

2011-01-01

Background and Aims Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined. Methods Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles. Key Results Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps. Conclusions Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in

Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: implications for flower visitation by bees.

Science.gov (United States)

Rodriguez-Saona, Cesar; Parra, Leonardo; Quiroz, Andrés; Isaacs, Rufus

2011-06-01

Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined. Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles. Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps. Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in increasing pollination of flowers.

Research on floral timing by ambient temperature comes into blossom

NARCIS (Netherlands)

Verhage, D.S.L.; Angenent, G.C.; Immink, R.G.H.

2014-01-01

The floral transition is an essential process in the life cycle of flower-bearing plants, because their reproductive success depends on it. To determine the right moment of flowering, plants respond to many environmental signals, including day length, light quality, and temperature. Small changes in

High floral bud abscission and lack of open flower abscission in Dendrobium cv. Miss Teen: rapid reduction of ethylene sensitivity in the abscission zone

NARCIS (Netherlands)

Bunya-atichart, K.; Ketsa, S.; Doorn, van W.G.

2006-01-01

We studied the abscission of floral buds and open flowers in cut Dendrobium inflorescences. Abscission of floral buds was high and sensitive to ethylene in all cultivars studied. Many open flowers abscised in most cultivars, but cv. Willie exhibited only small amount of floral fall and cv. Miss Teen

Pollinarium morphology and floral rewards in Brazilian Maxillariinae (Orchidaceae).

Science.gov (United States)

Singer, Rodrigo B; Koehler, Samantha

2004-01-01

There is strong support for the monophyly of the orchid subtribe Maxillariinae s.l., yet generic boundaries within it are unsatisfactory and need re-evaluation. In an effort to assemble sets of morphological characters to distinguish major clades within this subtribe, the pollinarium morphology and floral rewards of representative Brazilian species of this subtribe were studied. The study was based on fresh material from 60 species and seven genera obtained from cultivated specimens. Variation of pollinarium structure and floral rewards was assessed using a stereomicroscope and by SEM analysis. Four morphological types of pollinaria are described. Type 1 appears to be the most widespread and is characterized by a well-developed tegula. Type 2 lacks a stipe and the pollinia are attached directly to the viscidium. Type 3 also lacks a stipe, and the viscidium is rigid and dark. In Type 4, the stipe consists of the whole median rostelar portion and, so far, is known only from Maxillaria uncata. Nectar, trichomes, wax-like and resin-like secretions are described as flower rewards for different groups of species within the genus Maxillaria. Data on the biomechanics and pollination biology are also discussed and illustrated. In Maxillariinae flowers with arcuate viscidia, the pollinaria are deposited on the scuttellum of their Hymenopteran pollinators. In contrast, some flowers with rounded to rectangular, pad-like viscidia fix their pollinaria on the face of their pollinators. Pollinarium morphology and floral features related to pollination in Brazilian Maxillariinae are more diverse than previously suggested. It is hoped that the data presented herein, together with other data sources such as vegetative traits and molecular tools, will be helpful in redefining and diagnosing clades within the subtribe Maxillariinae.

The early inflorescence of Arabidopsis thaliana demonstrates positional effects in floral organ growth and meristem patterning.

Science.gov (United States)

Plackett, Andrew R G; Powers, Stephen J; Phillips, Andy L; Wilson, Zoe A; Hedden, Peter; Thomas, Stephen G

2018-06-01

Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradicted by the existence of mutants with phenotypes visible in early flowers only. This phenomenon is demonstrated by mutants partially impaired in the biosynthesis of the phytohormone gibberellin (GA), in which floral organ growth is retarded in the first flowers to be produced but has recovered spontaneously by the 10th flower. We presently lack systematic data from multiple flowers across the Arabidopsis inflorescence to explain such changes. Using mutants of the GA 20-OXIDASE (GA20ox) GA biosynthesis gene family to manipulate endogenous GA levels, we investigated the dynamics of changing floral organ growth across the early Arabidopsis inflorescence (flowers 1-10). Modelling of floral organ lengths identified a significant, GA-independent gradient of increasing stamen length relative to the pistil in the wild-type inflorescence that was separable from other, GA-dependent effects. It was also found that the first flowers exhibited unstable organ patterning in contrast to later flowers and that this instability was prolonged by exogenous GA treatment. These findings indicate that the development of individual flowers is influenced by hitherto unknown factors acting across the inflorescence and also suggest novel functions for GA in floral patterning.

Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops

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LC Rodrigues

Full Text Available Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops.

Science.gov (United States)

Rodrigues, L C; Rodrigues, M

2015-01-01

Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

Effect of floral display on reproductive success in terrestrial orchids

Czech Academy of Sciences Publication Activity Database

Kindlmann, Pavel; Jersáková, Jana

2006-01-01

Roč. 41, - (2006), s. 47-60 ISSN 0015-5551 R&D Projects: GA AV ČR(CZ) KJB6141302; GA ČR(CZ) GA206/00/1124 Keywords : deceptivity * floral display * orchid * reproductive success * reward Subject RIV: EF - Botanics Impact factor: 1.033, year: 2005

Floral biology and the effects of plant-pollinator interaction on ...

African Journals Online (AJOL)

Reproductive biology and patterns of plant-pollinator interaction are fundamental to gene flow, diversity and evolutionary success of plants. Consequently, we examined the magnitude of insect-plant interaction based on the dynamics of breeding systems and floral biology and their effects on pollination intensity, fruit and ...

Evaluación en campo de plantas de ñame (Dioscorea alata L. obtenidas de los microtubérculos formados en Sistema de Inmersión Temporal

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Manuel Cabrera Jova

2010-01-01

Full Text Available Los microtubérculos en algunas especies de plantas constituyen una importante alternativa como material vegetal de plantación. Se definió como objetivo de trabajo evaluar en campo la respuesta morfoagronómica de las plantas obtenidas de los microtubérculos de ñame formados en Sistema de Inmersión Temporal (SIT. Como variantes experimentales se plantaron tres categorías de microtubérculos, clasificados según su masa fresca (I. de 0,5 a 0,9 g; II. de 1,0 a 2,9 g; III. igual o mayor de 3,0 g, plantas in vitro previamente aclimatadas y corona de tubérculo. Se evaluó el efecto de la masa fresca de los microtubérculos sobre su brote, supervivencia y posterior desarrollo de las plantas derivadas de ellos en campo. Con los microtubérculos de ñame, con una masa fresca igual o superior a 3,0 g, se alcanzó el más alto porcentaje de brotación (91,30% y supervivencia de las plantas (96,50%, así como las mejores respuestas en los caracteres cuantitativos que se evaluaron en campo. Estos resultados confirmaron la importancia de la masa fresca de los microtubérculos para ser empleados como material vegetal de plantación directo en campo.

Insect-flower interaction network structure is resilient to a temporary pulse of floral resources from invasive Rhododendron ponticum.

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Erin Jo Tiedeken

Full Text Available Invasive alien plants can compete with native plants for resources, and may ultimately decrease native plant diversity and/or abundance in invaded sites. This could have consequences for native mutualistic interactions, such as pollination. Although invasive plants often become highly connected in plant-pollinator interaction networks, in temperate climates they usually only flower for part of the season. Unless sufficient alternative plants flower outside this period, whole-season floral resources may be reduced by invasion. We hypothesized that the cessation of flowering of a dominant invasive plant would lead to dramatic, seasonal compositional changes in plant-pollinator communities, and subsequent changes in network structure. We investigated variation in floral resources, flower-visiting insect communities, and interaction networks during and after the flowering of invasive Rhododendron ponticum in four invaded Irish woodland sites. Floral resources decreased significantly after R. ponticum flowering, but the magnitude of the decrease varied among sites. Neither insect abundance nor richness varied between the two periods (during and after R. ponticum flowering, yet insect community composition was distinct, mostly due to a significant reduction in Bombus abundance after flowering. During flowering R. ponticum was frequently visited by Bombus; after flowering, these highly mobile pollinators presumably left to find alternative floral resources. Despite compositional changes, however, network structural properties remained stable after R. ponticum flowering ceased: generality increased, but quantitative connectance, interaction evenness, vulnerability, H'2 and network size did not change. This is likely because after R. ponticum flowering, two to three alternative plant species became prominent in networks and insects increased their diet breadth, as indicated by the increase in network-level generality. We conclude that network structure

Self-incompatibility, floral parameters, and pollen characterization in the narrow endemic and threatened species Artemisia granatensis (Asteraceae

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Taisma, María Angélica

2011-06-01

Full Text Available Artemisia granatensis Boiss. is a paradigmatic species for plant conservation in Spain and Europe. It is a critically endangered (CR endemic species growing above 2500 m in the Sierra Nevada (southern Spain. Natural populations have been considerably devastated in the past due to intensive human exploitation for folk medicine. The sparse available data concerning the reproductive biology of this species under natural conditions indicate a low reproductive success. To provide additional information on the reproductive biology of A. granatensis, and consequently information useful for the management and conservation of this species, we studied the breeding system through pollen-tube growth. In addition, some floral and pollen traits were recorded. No differences were found between populations in terms of the morphological traits of flowers and inflorescences. A. granatensis is an anemophilous species, and the data indicate that pollen transfer may be limited between isolated populations, and so contributing to an extremely low fruit-set. Results show A. granatensis is selfincompatible, probably with a sporophytic self-incompatibility system, and with no evidence of partial self-incompatibility. Reproductive traits, related to pollen morphology and settling speed may explain the low rate of recruitment in the small populations separated by geographical barriers.Artemisia granatensis Boiss. es una especie paradigmática en la conservación de flora a nivel español y europeo. Es una especie catalogada como En Peligro Crítico (CR endémica de Sierra Nevada (sur de España, donde habita por encima de los 2500 m. Las poblaciones naturales han sido casi exterminadas en el pasado debido a una recolección masiva de la especie, utilizada en medicina popular. Los escasos datos disponibles acerca de su biología reproductiva en condiciones naturales indican que existe un bajo éxi to reproductivo. Con el objetivo de proporcionar información adicional

Voltammetric sensor for electrochemical determination of the floral origin of honey based on a zinc oxide nanoparticle modified carbon paste electrode

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K. Tiwari

2018-04-01

Full Text Available A new methodology based on cyclic voltammetry using a chemically modified electrode has been developed for the discrimination of the floral origin of honey. This method involves an electronic tongue with an electrochemical sensor made from a carbon paste (CPs electrode where zinc oxide (ZnO nanoparticles are used as an electroactive binder material. The bare CPs electrode is evaluated for comparison. The electrochemical response of the modified electrode in 50 samples of five different floral types of honey has been analysed by the cyclic voltammetric technique. The voltammograms of each floral variety of honey reflect the redox properties of the ZnO nanoparticles present inside the carbon paste matrix and are strongly influenced by the nectar source of honey. Thus, each type of honey provides a characteristic signal which is evaluated by using principal component analysis (PCA and an artificial neural network (ANN. The result of a PCA score plot of the transient responses obtained from the modified carbon paste electrode clearly shows discrimination among the different floral types of honey. The ANN model for floral classification of honey shows more than 90 % accuracy. These results indicate that the ZnO nanoparticles modified carbon paste (ZnO Nps modified CPs electrode can be a useful electrode for discrimination of honey samples from different floral origins.

Comportamiento de casos de Klebsiella pneumoniae productora de carbapenemasas en pacientes con cáncer de un hospital de tercer nivel de Bogotá, D.C.

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Sonia Isabel Cuervo

2014-04-01

Full Text Available Introducción. La presencia en los hospitales de enterobacterias productoras de carbapenemasas es cada vez más frecuente. Los pacientes con cáncer en estado avanzado requieren medios invasivos para el diagnóstico, el tratamiento o los cuidados paliativos, así como el uso de antimicrobianos de amplio espectro para tratar infecciones secundarias, lo cual aumenta su propensión a las infecciones causadas por estas bacterias. Objetivo. Informar el comportamiento de Klebsiella pneumoniae productora de carbapenemasas de tipo KPC en el Instituto Nacional de Cancerología de Bogotá, entre enero de 2010 y diciembre de 2012. Materiales y métodos. Mediante el análisis de la base de datos y de los registros de los pacientes con aislamientos de K. pneumoniae productores de carbapenemasas de tipo KPC, a cargo del comité de infecciones de la institución, se identificaron y describieron las características epidemiológicas de los casos detectados. La determinación de brotes se efectuó con herramientas de control estadístico de calidad. Resultados. Entre enero de 2010 y diciembre de 2012 se identificaron 45 pacientes con aislamiento de K. pneumoniae productor de carbapenemasas de tipo KPC en alguna muestra. Hubo más aislamientos en pacientes de cáncer con tumores sólidos. La identificación se logró más frecuentemente en muestras de orina; el 17,7 % de los casos correspondió a colonización y el 82,3 %, a infección; 35,5 % (16/45 de los pacientes sobrevivió. Durante este periodo se identificaron dos brotes que se controlaron aplicando una estrategia multimodal. Conclusiones. Se encontró que la presencia de KPC fue más frecuente en infecciones que en colonizaciones. Durante estos dos años ocurrieron dos brotes que fueron controlados limitando la transmisión cruzada de bacterias multirresistentes por medio de estrategias de control convencionales.

Selection by pollinators on floral traits in generalized Trollius ranunculoides (Ranunculaceae along altitudinal gradients.

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Zhi-Gang Zhao

Full Text Available Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral differentiation. We investigated the variation of Trollius ranunculoides flowers and its pollinators along an altitudinal gradient on the eastern Qinghai-Tibet Plateau, and measured phenotypic selection by pollinators on floral traits across populations. The results showed significant decline of visitation rate of bees along altitudinal gradients, while flies was unchanged. When fitness is estimated by the visitation rate rather than the seed number per plant, phenotypic selection on the sepal length and width shows a significant correlation between the selection strength and the altitude, with stronger selection at higher altitudes. However, significant decreases in the sepal length and width of T. ranunculoides along the altitudinal gradient did not correspond to stronger selection of pollinators. In contrast to the pollinator visitation, mean annual precipitation negatively affected the sepal length and width, and contributed more to geographical variation in measured floral traits than the visitation rate of pollinators. Therefore, the sepal size may have been influenced by conflicting selection pressures from biotic and abiotic selective agents. This study supports the hypothesis that lower pollinator availability at high altitude can intensify selection on flower attractive traits, but abiotic selection is preventing a response to selection from pollinators.

¿Volverán los tiempos del cólera a Colombia?

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Marco González T.

2013-11-01

Full Text Available “La epidemia de cólera morbo, cuyas primeras víctimas cayeron fulminadas en los charcos del mercado, había causado en once semanas la más grande mortandad de nuestra historia (... En las dos primeras semanas del cólera, el cementerio fue desbordado y no quedó sitio disponible en las iglesias, a pesar de que habían pasado al osario común los restos carcomidos de nuestros próceres sin nombre (... Desde que se proclamó el bando del cólera, en el alcázar de la guarnición local se disparó un cañonazo cada cuarto de hora, de día y de noche, de acuerdo con la superstición cívica de que la pólvora purificaba el ambiente (... Cesó de pronto como había empezado y nunca se conoció el número de sus estragos...” “Así describió Gabriel García Márquez el brote de cólera asiático que azotó a Cartagena en en 1849 y que dio muerte a la cuarta parte de su población. Fue éste seguramente el primer episodio de cólera asiático en nuestro país” (1.

Drought and leaf herbivory influence floral volatiles and pollinator attraction

Science.gov (United States)

Laura A. Burkle; Justin B. Runyon

2016-01-01

The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...

Urban outbreak of acute orally acquired Chagas disease in Táchira, Venezuela

OpenAIRE

Benítez, Jesús A.; Araujo, Benjamín; Contreras, Krisell; Rivas, Marianela; Ramírez, Pedro; Guerra, Watermo; Calderón, Noél; Terren, Carlo Ascaso; Barrera, Reggie; Rodríguez Morales, Alfonso Javier

2013-01-01

Aguda por vía oral adquirió la enfermedad de Chagas (AOACD) se ha convertido en una amenaza importante en algunos países de América del Sur [1,2]. Hasta marzo de 2013, al menos cuatro han reportado brotes de la enfermedad de Chagas aguda adquirida por vía oral, en concreto Brasil [3], Venezuela [4], Colombia [5] y Bolivia [6]. Los brotes también se están produciendo probablemente en Argentina y Ecuador, según algunos informes antiguos [2]. En Venezuela, ha habido por lo menos tres informes ep...

Inducción de yemas Adventicias en Paulownia tomentosa. Estudio anatómico del proceso caulogénico

OpenAIRE

Corredoira, E.; Cernadas, M. J.; San José, M. C.

2010-01-01

Se realizó un estudio histológico del proceso de regeneración de brotes adventicios en hojas de Paulownia tomentosa cultivadas in vitro con el objetivo de determinar el mecanismo morfogénico que da lugar a los brotes regenerados. La formación de yemas adventicias se produce de forma directa a partir de células de la epidermis y subepidermis e indirecta a partir de células de las capas más externas del callo de cicatrización. La activación celular o desdiferenciación tiene lu...

How to be sweet? Extra floral nectar allocation by Gossypium hirsutum fits optimal defense theory predictions

OpenAIRE

Wäckers, F.L.; Bonifay, C.

2004-01-01

Plants employ nectar for two distinct functions. Floral nectar has traditionally been viewed in the context of pollination. Extrafloral nectar on the other hand, can act as an indirect defense, allowing the plant to recruit predators and parasitoids. Whereas this makes for a clear-cut categorization, in reality the functions may not be so discrete. Extrafloral nectar may serve a role in pollination, while floral nectar can be utilized by predators and parasitoids and thus can contribute to pl...

An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

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Eddy Risseeuw

Full Text Available Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems.

Science.gov (United States)

Risseeuw, Eddy; Venglat, Prakash; Xiang, Daoquan; Komendant, Kristina; Daskalchuk, Tim; Babic, Vivijan; Crosby, William; Datla, Raju

2013-01-01

Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.

Arabidopsis BLADE-ON-PETIOLE1 and 2 promote floral meristem fate and determinacy in a previously undefined pathway targeting APETALA1 and AGAMOUS-LIKE24.

Science.gov (United States)

Xu, Mingli; Hu, Tieqiang; McKim, Sarah M; Murmu, Jhadeswar; Haughn, George W; Hepworth, Shelley R

2010-09-01

The transition to flowering is a tightly controlled developmental decision in plants. In Arabidopsis, LEAFY (LFY) and APETALA1 (AP1) are key regulators of this transition and expression of these genes in primordia produced by the inflorescence meristem confers floral fate. Here, we examine the role of architectural regulators BLADE-ON-PETIOLE1 (BOP1) and BOP2 in promotion of floral meristem identity. Loss-of-function bop1 bop2 mutants show subtle defects in inflorescence and floral architecture but in combination with lfy or ap1, synergistic defects in floral meristem fate and determinacy are revealed. The most dramatic changes occur in bop1 bop2 ap1-1 triple mutants where flowers are converted into highly branched inflorescence-like shoots. Our data show that BOP1/2 function distinctly from LFY to upregulate AP1 in floral primordia and that all three activities converge to down-regulate flowering-time regulators including AGAMOUS-LIKE24 in stage 2 floral meristems. Subsequently, BOP1/2 promote A-class floral-organ patterning in parallel with LFY and AP1. Genetic and biochemical evidence support the model that BOP1/2 are recruited to the promoter of AP1 through direct interactions with TGA bZIP transcription factors, including PERIANTHIA. These data reveal an important supporting role for BOP1/2 in remodeling shoot architecture during the floral transition. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

Evolution of floral symmetry Peter K Endress, Current Opinion in ...

Indian Academy of Sciences (India)

First page Back Continue Last page Graphics. Evolution of floral symmetry Peter K Endress, Current Opinion in Plant Biology 2001, 4:86–91. Polysymmetric (more than one plane of symmetry) to monosymmetric in angiosperm (flowering plants) evolution; the other way in Antirrhinaceae. Left and right handed helicity. Bees ...

Floral function: effects of traits on pollinators, male and female pollination success, and female fitness across three species of milkweeds (Asclepias).

Science.gov (United States)

La Rosa, Raffica J; Conner, Jeffrey K

2017-01-01

Central questions in plant reproductive ecology are whether the functions of floral traits in hermaphrodites create conflict between sexes that could slow evolution, and whether individual floral traits function in pollinator attraction, efficiency, or both. We studied how floral traits affect pollinator visitation and efficiency, and how they affect male and female function and female fitness within and across three Asclepias species that differ in floral morphology. Using separate multiple regressions, we regressed pollen removal, deposition, and fruit number onto six floral traits. We also used path analyses integrating these variables with pollinator visitation data for two of the species to further explore floral function and its effects on fruit production. Most traits affected male pollination success only, and these effects often differed between species. The exception was increased slit length, which increased pollinia insertion in two of the species. There were no interspecific differences in the effects of the traits on female pollination success. All traits except horn reach affected pollination efficiency in at least one species, and horn reach and two hood dimensions were the only traits to affect pollinator attraction, but in just one species. Traits tended to function in only one sex, and more traits affected function through pollinator efficiency than through attraction. There was no significant link between female pollination success and female fitness in any of the three species; this pattern is consistent with fruit production not being limited by pollen deposition. © 2017 Botanical Society of America.

Time-Dependent Trapping of Pollinators Driven by the Alignment of Floral Phenology with Insect Circadian Rhythms

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Jenny Y. Y. Lau

2017-06-01

Full Text Available Several evolutionary lineages in the early divergent angiosperm family Annonaceae possess flowers with a distinctive pollinator trapping mechanism, in which floral phenological events are very precisely timed in relation with pollinator activity patterns. This contrasts with previously described angiosperm pollinator traps, which predominantly function as pitfall traps. We assess the circadian rhythms of pollinators independently of their interactions with flowers, and correlate these data with detailed assessments of floral phenology. We reveal a close temporal alignment between patterns of pollinator activity and the floral phenology driving the trapping mechanism (termed ‘circadian trapping’ here. Non-trapping species with anthesis of standard duration (c. 48 h cannot be pollinated effectively by pollinators with a morning-unimodal activity pattern; non-trapping species with abbreviated anthesis (23–27 h face limitations in utilizing pollinators with a bimodal circadian activity; whereas species that trap pollinators (all with short anthesis can utilize a broader range of potential pollinators, including those with both unimodal and bimodal circadian rhythms. In addition to broadening the range of potential pollinators based on their activity patterns, circadian trapping endows other selective advantages, including the possibility of an extended staminate phase to promote pollen deposition, and enhanced interfloral movement of pollinators. The relevance of the alignment of floral phenological changes with peaks in pollinator activity is furthermore evaluated for pitfall trap pollination systems.

Zooming-in on floral nectar: a first exploration of nectar-associated bacteria in wild plant communities.

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Alvarez-Pérez, Sergio; Herrera, Carlos M; de Vega, Clara

2012-06-01

Floral nectar of some animal-pollinated plants usually harbours highly adapted yeast communities which can profoundly alter nectar characteristics and, therefore, potentially have significant impacts on plant reproduction through their effects on insect foraging behaviour. Bacteria have also been occasionally observed in floral nectar, but their prevalence, phylogenetic diversity and ecological role within plant-pollinator-yeast systems remains unclear. Here we present the first reported survey of bacteria in floral nectar from a natural plant community. Culturable bacteria occurring in a total of 71 nectar samples collected from 27 South African plant species were isolated and identified by 16S rRNA gene sequencing. Rarefaction-based analyses were used to assess operational taxonomic units (OTUs) richness at the plant community level using nectar drops as sampling units. Our results showed that bacteria are common inhabitants of floral nectar of South African plants (53.5% of samples yielded growth), and their communities are characterized by low species richness (18 OTUs at a 16S rRNA gene sequence dissimilarity cut-off of 3%) and moderate phylogenetic diversity, with most isolates belonging to the Gammaproteobacteria. Furthermore, isolates showed osmotolerance, catalase activity and the ability to grow under microaerobiosis, three traits that might help bacteria to overcome important factors limiting their survival and/or growth in nectar. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Unique morphological changes in plant pathogenic phytoplasma-infected petunia flowers are related to transcriptional regulation of floral homeotic genes in an organ-specific manner.

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Himeno, Misako; Neriya, Yutaro; Minato, Nami; Miura, Chihiro; Sugawara, Kyoko; Ishii, Yoshiko; Yamaji, Yasuyuki; Kakizawa, Shigeyuki; Oshima, Kenro; Namba, Shigetou

2011-09-01

Abnormal flowers are often induced by infection of certain plant pathogens, e.g. phytoplasma, but the molecular mechanisms underlying these malformations have remained poorly understood. Here, we show that infection with OY-W phytoplasma (Candidatus Phytoplasma asteris, onion yellows phytoplasma strain, line OY-W) affects the expression of the floral homeotic genes of petunia plants in an organ-specific manner. Upon infection with OY-W phytoplasma, floral morphological changes, including conversion to leaf-like structures, were observed in sepals, petals and pistils, but not in stamens. As the expression levels of homeotic genes differ greatly between floral organs, we examined the expression levels of homeotic genes in each floral organ infected by OY-W phytoplasma, compared with healthy plants. The expression levels of several homeotic genes required for organ development, such as PFG, PhGLO1 and FBP7, were significantly downregulated by the phytoplasma infection in floral organs, except the stamens, suggesting that the unique morphological changes caused by the phytoplasma infection might result from the significant decrease in expression of some crucial homeotic genes. Moreover, the expression levels of TER, ALF and DOT genes, which are known to participate in floral meristem identity, were significantly downregulated in the phytoplasma-infected petunia meristems, implying that phytoplasma would affect an upstream signaling pathway of floral meristem identity. Our results suggest that phytoplasma infection may have complex effects on floral development, resulting in the unique phenotypes that were clearly distinct from the mutant flower phenotypes produced by the knock-out or the overexpression of certain homeotic genes. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice.

Directory of Open Access Journals (Sweden)

Takuya Suzaki

2009-10-01

Full Text Available CLAVATA signaling restricts stem cell identity in the shoot apical meristem (SAM in Arabidopsis thaliana. In rice (Oryza sativa, FLORAL ORGAN NUMBER2 (FON2, closely related to CLV3, is involved as a signaling molecule in a similar pathway to negatively regulate stem cell proliferation in the floral meristem (FM. Here we show that the FON2 SPARE1 (FOS1 gene encoding a CLE protein functions along with FON2 in maintenance of the FM. In addition, FOS1 appears to be involved in maintenance of the SAM in the vegetative phase, because constitutive expression of FOS1 caused termination of the vegetative SAM. Genetic analysis revealed that FOS1 does not need FON1, the putative receptor of FON2, for its action, suggesting that FOS1 and FON2 may function in meristem maintenance as signaling molecules in independent pathways. Initially, we identified FOS1 as a suppressor that originates from O. sativa indica and suppresses the fon2 mutation in O. sativa japonica. FOS1 function in japonica appears to be compromised by a functional nucleotide polymorphism (FNP at the putative processing site of the signal peptide. Sequence comparison of FOS1 in about 150 domesticated rice and wild rice species indicates that this FNP is present only in japonica, suggesting that redundant regulation by FOS1 and FON2 is commonplace in species in the Oryza genus. Distribution of the FNP also suggests that this mutation may have occurred during the divergence of japonica from its wild ancestor. Stem cell maintenance may be regulated by at least three negative pathways in rice, and each pathway may contribute differently to this regulation depending on the type of the meristem. This situation contrasts with that in Arabidopsis, where CLV signaling is the major single pathway in all meristems.

Effect of Citrus floral extracts on the foraging behavior of the stingless bee Scaptotrigona pectoralis (Dalla Torre)

OpenAIRE

Grajales-Conesa,Julieta; Meléndez Ramírez,Virginia; Cruz-López,Leopoldo; Sánchez Guillén,Daniel

2012-01-01

Effect of Citrus floral extracts on the foraging behavior of the stingless bee Scaptotrigona pectoralis (Dalla Torre). Stingless bees have an important role as pollinators of many wild and cultivated plant species in tropical regions. Little is known, however, about the interaction between floral fragrances and the foraging behavior of meliponine species. Thus we investigated the chemical composition of the extracts of citric (lemon and orange) flowers and their effects on the foraging behavi...

What shapes amino acid and sugar composition in Mediterranean floral nectars?

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Petanidou, T.; Van Laere, A.; Ellis, W.; Smets, E.

2006-01-01

We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring in a phryganic (East Mediterranean garrigue) community and investigated whether AA and sugar composition is shaped by evolutionary (plant phylogeny), ecological (flowering time as a direct effect of summer

Effects of range-wide variation in climate and isolation on floral traits and reproductive output of Clarkia pulchella.

Science.gov (United States)

Bontrager, Megan; Angert, Amy L

2016-01-01

Plant mating systems and geographic range limits are conceptually linked by shared underlying drivers, including landscape-level heterogeneity in climate and in species' abundance. Studies of how geography and climate interact to affect plant traits that influence mating system and population dynamics can lend insight to ecological and evolutionary processes shaping ranges. Here, we examined how spatiotemporal variation in climate affects reproductive output of a mixed-mating annual, Clarkia pulchella. We also tested the effects of population isolation and climate on mating-system-related floral traits across the range. We measured reproductive output and floral traits on herbarium specimens collected across the range of C. pulchella. We extracted climate data associated with specimens and derived a population isolation metric from a species distribution model. We then examined how predictors of reproductive output and floral traits vary among populations of increasing distance from the range center. Finally, we tested whether reproductive output and floral traits vary with increasing distance from the center of the range. Reproductive output decreased as summer precipitation decreased, and low precipitation may contribute to limiting the southern and western range edges of C. pulchella. High spring and summer temperatures are correlated with low herkogamy, but these climatic factors show contrasting spatial patterns in different quadrants of the range. Limiting factors differ among different parts of the range. Due to the partial decoupling of geography and environment, examining relationships between climate, reproductive output, and mating-system-related floral traits reveals spatial patterns that might be missed when focusing solely on geographic position. © 2016 Botanical Society of America.

Estudios sobre la enfermedad de Carrión en el valle interandino del Mantaro: II. Incidencia de la infección bartonelosica en la población humana

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Arístides Herrer

1960-01-01

Full Text Available Con la finalidad de determinar la zona endémica de la verruga peruana o enfermedad de Carrión en el valle del Mantaro, durante la segunda quincena de abril. 1959, se realizaron 239 hemocultivos y una encuesta informativa en la población del mencionado valle. Para los cultivos se obtuvo 215 muestras de sangre en la población humana y, las 24 restantes, en algunos animales domésticos. En la encuesta se trató de recoger las informaciones que la gente de la región podría ofrecer acerca de la verruga, al mismo tiempo que todas las personas encuestadas fueron revisadas por los autores en busca del brote verrucoso. Los siguientes son los principales resultados obtenidos: 1. En los cultivos con sangre humana se obtuvo 5 positivos, 172 negativos y 38 contaminados y. en la de los animales domésticos, 13 negativos y 11 contaminados. Todos los hemocultivos positivos correspondieron a personas que habitan en localidades que se hallan entre 2.800 y 3,000 metros de altitud. 2. Dos de las cinco personas que ofrecieran hemocultivo positivo, al momento de extraérseles la sangre se encontraban en estado febril y con abundantes bartonelas en los eritrocitos circulantes; ambas murieron pocos días después. Las tres restantes no presentaban síntomas atribuibles a la enfermedad de Carrión, y dos de ellas fueron observadas durante los 15 meses subsiguientes sin que presentasen brote verrucoso. 3. En la encuesta se verificó que, con rarísimas excepciones, la gente del valle del Mantaro no conocía la verruga. Del mismo modo, tan sólo en dos ocasiones los autores observaron nódulos subcutáneos semejantes a verrucomas. 4. Se hace resaltar el que la enfermedad de Carrión sea endémica a considerable altitud en el valle del Mantaro, así como la rareza del brote cutáneo y se cuestiona la extrema gravedad que se atribuye a la verruga en el referido valle del Mantaro.

Natural selection on floral morphology can be influenced by climate.

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Campbell, Diane R; Powers, John M

2015-06-07

Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Analisis de crecimiento de Limonium sinuatum Mill cv. Midnight Blue propagada sexual y asexualmente a partir de yemas vegetativas y florales.

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Pedroza Jaime

1997-06-01

Full Text Available

Se realizo el análisis clásico de crecimiento de plantas de estatice (Limonium sinuatum Mill. cv. Midnight Blue propagadas sexualmente y mediante los sistemas in vitro, a partir de yemas vegetativas y florales bajo condiciones de invernadero en la Sabana de Bogotá, Colombia, mediante el empleo de 10 índices que evalúan el desempeño fisiológico del material vegetal. En este cultivar es característico el comportamiento oscilatorio y simétrico de algunos índices que evidencian una posible actividad fisiológica muy particular en la relación Fuente: Demanda; Así, la exportaci6n de fotoasimilados (RAF esta afectada por su retención en las hojas (AFE, especialmente durante la fase vegetativa. De igual forma. es importante destacar que, en la fase reproductiva, los tallos florales son la principal demanda de fotosintatos. Con respecto a la T.R.C., se nota que detalla muy bien el crecimiento vegetativo y es afectada por la T.A.N., mientras que la T.C.C, el reproductivo.

Aunque se presentaron algunas diferencias cuantitativas en la fase vegetativa, en la reproductiva, presumiblemente, por efectos fisiológicos compensatorios, ocurre total homogeneidad entre los tipos de plantas analizadas.

Isolation and Properties of Floral Defensins from Ornamental Tobacco and Petunia1

Science.gov (United States)

Lay, Fung T.; Brugliera, Filippa; Anderson, Marilyn A.

2003-01-01

The flowers of the solanaceous plants ornamental tobacco (Nicotiana alata) and petunia (Petunia hybrida) produce high levels of defensins during the early stages of development. In contrast to the well-described seed defensins, these floral defensins are produced as precursors with C-terminal prodomains of 27 to 33 amino acids in addition to a typical secretion signal peptide and central defensin domain of 47 or 49 amino acids. Defensins isolated from N. alata and petunia flowers lack the C-terminal domain, suggesting that it is removed during or after transit through the secretory pathway. Immunogold electron microscopy has been used to demonstrate that the N. alata defensin is deposited in the vacuole. In addition to the eight canonical cysteine residues that define the plant defensin family, the two petunia defensins have an extra pair of cysteines that form a fifth disulfide bond and hence define a new subclass of this family of proteins. Expression of the N. alata defensin NaD1 is predominantly flower specific and is most active during the early stages of flower development. NaD1 transcripts accumulate in the outermost cell layers of petals, sepals, anthers, and styles, consistent with a role in protection of the reproductive organs against potential pathogens. The floral defensins inhibit the growth of Botrytis cinerea and Fusarium oxysporum in vitro, providing further support for a role in protection of floral tissues against pathogen invasion. PMID:12644678

Attraction of Plecia nearctica (dipter:bibionidae) to floral lures containing phenylacetaldehyde

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We observed that the floral odorant, phenylacetaldehyde (PAA), was attractive to both sexes of adult lovebugs (Plecia nearctica, Diptera: Bibionidae) in central and southern Florida. The addition of ß-myrcene and methyl salicylate to PAA did not improve the numbers of P. nearctica caught in delta tr...

Pyridine-type alkaloid composition affects bacterial community composition of floral nectar.

Science.gov (United States)

Aizenberg-Gershtein, Yana; Izhaki, Ido; Santhanam, Rakesh; Kumar, Pavan; Baldwin, Ian T; Halpern, Malka

2015-06-30

Pyridine-type alkaloids are most common in Nicotiana species. To study the effect of alkaloid composition on bacterial community composition in floral nectar, we compared the nicotine-rich wild type (WT) N. attenuata, the nicotine biosynthesis-silenced N. attenuata that was rich in anatabine and the anabasine-rich WT N. glauca plants. We found that the composition of these secondary metabolites in the floral nectar drastically affected the bacterial community richness, diversity and composition. Significant differences were found between the bacterial community compositions in the nectar of the three plants with a much greater species richness and diversity in the nectar from the transgenic plant. The highest community composition similarity index was detected between the two wild type plants. The different microbiome composition and diversity, caused by the different pyridine-type alkaloid composition, could modify the nutritional content of the nectar and consequently, may contribute to the change in the nectar consumption and visitation. These may indirectly have an effect on plant fitness.

Differential expressions of putative genes in various floral organs of ...

African Journals Online (AJOL)

STORAGESEVER

2009-06-03

Jun 3, 2009 ... Full Length Research Paper. Differential expressions of putative genes in various floral organs of the Pigeon orchid (Dendrobium crumenatum) using GeneFishing. Faridah, Q. Z.1, 2, Ng, B. Z.3, Raha, A. R.4, Umi, K. A. B.5 and Khosravi, A. R.2*. 1Department of Biology, Faculty Science, University Putra ...

Flowering mechanisms, pollination strategies and floral scent analyses of syntopically co-flowering Homalomena spp. (Araceae) on Borneo.

Science.gov (United States)

Hoe, Y C; Gibernau, M; Maia, A C D; Wong, S Y

2016-07-01

In this study, the flowering mechanisms and pollination strategies of seven species of the highly diverse genus Homalomena (Araceae) were investigated in native populations of West Sarawak, Borneo. The floral scent compositions were also recorded for six of these species. The selected taxa belong to three out of four complexes of the section Cyrtocladon (Hanneae, Giamensis and Borneensis). The species belonging to the Hanneae complex exhibited longer anthesis (53-62 h) than those of the Giamensis and Borneensis complexes (ca. 30 h). Species belonging to the Hanneae complex underwent two floral scent emission events in consecutive days, during the pistillate and staminate phases of anthesis. In species belonging to the Giamensis and Borneensis complexes, floral scent emission was only evident to the human nose during the pistillate phase. A total of 33 volatile organic compounds (VOCs) were detected in floral scent analyses of species belonging to the Hanneae complex, whereas 26 VOCs were found in samples of those belonging to the Giamensis complex. The floral scent blends contained uncommon compounds in high concentration, which could ensure pollinator discrimination. Our observations indicate that scarab beetles (Parastasia gestroi and P. nigripennis; Scarabaeidae, Rutelinae) are the pollinators of the investigated species of Homalomena, with Chaloenus schawalleri (Chrysomelidae, Galeuricinae) acting as a secondary pollinator. The pollinators utilise the inflorescence for food, mating opportunities and safe mating arena as rewards. Flower-breeding flies (Colocasiomyia nigricauda and C. aff. heterodonta; Diptera, Drosophilidae) and terrestrial hydrophilid beetles (Cycreon sp.; Coleoptera, Hydrophilidae) were also frequently recovered from inflorescences belonging to all studied species (except H. velutipedunculata), but they probably do not act as efficient pollinators. Future studies should investigate the post-mating isolating barriers among syntopically co

Nectar sugars and bird visitation define a floral niche for basidiomycetous yeast on the Canary Islands.

Science.gov (United States)

Mittelbach, Moritz; Yurkov, Andrey M; Nocentini, Daniele; Nepi, Massimo; Weigend, Maximilian; Begerow, Dominik

2015-02-01

Studies on the diversity of yeasts in floral nectar were first carried out in the late 19th century. A narrow group of fermenting, osmophilous ascomycetes were regarded as exclusive specialists able to populate this unique and species poor environment. More recently, it became apparent that microorganisms might play an important role in the process of plant pollination. Despite the importance of these nectar dwelling yeasts, knowledge of the factors that drive their diversity and species composition is scarce. In this study, we linked the frequencies of yeast species in floral nectars from various host plants on the Canary Islands to nectar traits and flower visitors. We estimated the structuring impact of pollination syndromes (nectar volume, sugar concentration and sugar composition) on yeast diversity.The observed total yeast diversity was consistent with former studies, however, the present survey yielded additional basidiomycetous yeasts in unexpectedly high numbers. Our results show these basidiomycetes are significantly associated with ornithophilous flowers. Specialized ascomycetes inhabit sucrose-dominant nectars, but are surprisingly rare in nectar dominated by monosaccharides. There are two conclusions from this study: (i) a shift of floral visitors towards ornithophily alters the likelihood of yeast inoculation in flowers, and (ii) low concentrated hexose-dominant nectar promotes colonization of flowers by basidiomycetes. In the studied floral system, basidiomycete yeasts are acknowledged as regular members of nectar. This challenges the current understanding that nectar is an ecological niche solely occupied by ascomycetous yeasts.

Estrategia de PCR múltiple para la caracterización molecular simultánea de Staphylococcus aureus y enterotoxinas estafilocócicas en aislamientos de brotes de origen alimentario

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Aníbal A. Brizzio

2013-03-01

Full Text Available Introducción. La intoxicación alimentaria estafilocócica es la más frecuente de las intoxicaciones alimentarias. La acción de las enterotoxinas de Staphylococcus aureus en la luz intestinal provoca una importante pérdida de agua que origina vómitos y diarrea. Objetivo. Presentar una estrategia rápida, fiable y de bajo costo, basada en una reacción en cadena de la polimerasa (PCR múltiple para, simultáneamente, identificar S. aureus y detectar genes de las cinco enterotoxinas clásicas de S. aureus (sea, seb, sec, sed, see en cepas de Staphylococcus spp. aisladas de alimentos. Materiales y métodos. Se trabajó con aislamientos recuperados de 12 brotes de intoxicación alimentaria estafilocócica ocurridos en la provincia de Santa Fe, Argentina. El aislamiento y la caracterización fenotípica se llevaron a cabo mediante procedimientos estándar. La evaluación genotípica se hizo por una PCR múltiple, utilizando simultáneamente cebadores para los genes nuc, sea-see y 16S rRNA. Resultados. En las cepas analizadas se detectó 58 % de portadoras de genes toxigénicos. Las toxinas sea y seb se encontraron en igual porcentaje (29 %, mientras que las sec, sed y see se encontraron en menor e idéntica proporción (14 %. No encontramos más de un tipo diferente de enterotoxinas de S. aureus en los aislamientos analizados. Conclusiones. La estrategia de PCR múltiple diseñada en este trabajo permitió identificar cepas de S. aureus y confirmar, al mismo tiempo, su enterotoxigenicidad. En estos momentos, nuestros esfuerzos están dirigidos a detectar los genes que codifican enterotoxinas distintas de las clásicas, a fin de conocer su incidencia en las intoxicaciones alimentarias estafilocócicas e investigar su relevancia en la salud pública de nuestro país.   doi: http://dx.doi.org/10.7705/biomedica.v33i1.816

Contribuciones agroecológicas para renovar las fundaciones del manejo de plagas

OpenAIRE

Nicholls, Clara I.

2010-01-01

Las estrategias de manejo integrado de plagas (MIP) han estado dominadas por la idea del producto considerado como “la bala mágica’’ para controlar los brotes de plagas. Los enfoques del MIP no han abordado las causas ecológicas de los problemas de plagas en la agricultura moderna. En este articulo se plantea que los problemas de plagas pueden solucionarse mediante la reestructuración del manejo de los sistemas agrícolas, quebrando el monocultivo vía esquemas de diversificación...

Assessing risks and benefits of floral supplements in conservation biological control

NARCIS (Netherlands)

Winkler, K.; Wackers, F.L.; Termorshuizen, A.J.; Lenteren, van J.C.

2010-01-01

The use of flowering field margins is often proposed as a method to support biological control in agro-ecosystems. In addition to beneficial insects, many herbivores depend on floral food as well. The indiscriminate use of flowering species in field margins can therefore lead to higher pest numbers.

Study of the chemical composition of essential oils and floral waters ...

African Journals Online (AJOL)

This work aimed to study the chemical composition of essential oils and floral waters of Cymbopogon citratus (DC.) Stapf (Poaceae) from Senegal. The plants were collected in two different localities, Dakar and. Kaolack. The extracts were obtained by steam distillation from both fresh and dried plants and analyses carried.

Preferência Floral de Vespas (Hymenoptera, Vespidae no Rio Grande do Sul, Brasil

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Alexandre Somavilla

2012-03-01

Abstract Wasps integrate the floral visitors’ community and they can constitute a representative portion of the pollinators. For this reason, it was aimed to know and to analyze the floral preference of the Vespidae species and to investigate the use of floral resources for these wasps. The collects were performed between 2001 and 2008 in different localities of Rio Grande do Sul state (Estrela Velha, Santa Cruz do Sul, São Francisco de Paula e Sinimbu between 08:00 at 17:00 hours, utilizing entomological nets to catch the flower-visiting wasps. The collected specimens were deposited at the Coleção Entomológica de Santa Cruz do Sul (CESC. 1.483 specimens were captured belonging to 73 wasp species, whose 78.9% were Polistinae (30 species and 21.1% Eumeninae (43 species, visiting the flowers of 33 plant species classified in 16 botanical families; the families with the larger number of plant species were Asteraceae (12, Fabaceae (4 and Apiaceae (3. The plant species with the largest number of wasps collected was Schinus terebinthifolius Raddi (616, followed by Eryngium pandanifolium L. (137 and Eryngium horridum Spreng (122. The analysis of the trophic niche overlap of 26 species with four or more visited plant species, showed an overlap equal or higher than 50% in six cases.

Enhancing resource availability in agro-ecosystems for beneficial arthropods through floral provisioning

Science.gov (United States)

There has been a decline in beneficial arthropods (insects and spiders) including pollinators because of habitat destruction and intense management practices. Enhancing landscapes with additional floral and other non-crop habitats has the potential to attract pollinators, and predatory arthropods wh...

Geometric morphometrics of functionally distinct floral organs in Iris pumila: Analyzing patterns of symmetric and asymmetric shape variations

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Radović Sanja

2017-01-01

Full Text Available The Iris flower is a complex morphological structure composed of two trimerous whorls of functionally distinct petaloid organs (the falls and the standards, one whorl of the stamens and one tricarpellary gynoecium. The petal-like style arms of the carpels are banded over the basal part of the falls, forming three pollination tunnels, each of which is perceived by the Iris pollinators as a single bilaterally symmetrical flower. Apart from the stamens, all petaloid floral organs are preferentially involved in advertising rewards to potential pollinators. Here we used the methods of geometric morphometrics to explore the shape variation in falls, standards and style arms of the Iris pumila flowers and to disentangle the symmetric and the asymmetric component of the total shape variance. Our results show that symmetric variation contributes mostly to the total shape variance in each of the three floral organs. Fluctuating asymmetry (FA was the dominant component of the asymmetric shape variation in the falls and the standards, but appeared to be marginally significant in the style arms. The values of FA indexes for the shape of falls (insects’ landing platforms and for the shape of standards (long-distance reward signals were found to be two orders of magnitude greater compared to that of the style arms. Directional asymmetry appeared to be very low, but highly statistically significant for all analyzed floral organs. Because floral symmetry can reliably indicate the presence of floral rewards, an almost perfect symmetry recorded for the style arm shape might be the outcome of pollinator preferences for symmetrical pollination units. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173007

El Reglamento Sanitario Internacional, la enfermedad por el virus del Ébola y las enfermedades infecciosas emergentes en América Latina y el Caribe

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Marcos Espinal

Full Text Available RESUMEN La determinación por parte de la Organización Mundial de la Salud de que el brote de enfermedad por el virus del Ébola constituía un evento de salud pública de importancia internacional llevó a los países que no estaban afectados a aplicar medidas para prevenir y detectar la introducción del virus en sus territorios y para reaccionar frente a ella. El brote brindó la oportunidad de evaluar la aplicación operativa de las capacidades básicas del Reglamento Sanitario Internacional y la preparación de los sistemas de salud para hacer frente a un caso posible o confirmado de enfermedad por el virus del Ébola. Un marco rector de salud pública aplicado en los países de América Latina y el Caribe, que abarca autoevaluaciones preparatorias, visitas a los propios países y seguimiento, sugiere que esa región debe aumentar sus esfuerzos por consolidar y mantener los progresos en las capacidades básicas y en la preparación del sistema de salud para hacer frente a eventos de salud pública que tengan repercusiones a escala nacional o internacional.

Mapping floral resources for honey bees in New Zealand at the catchment scale.

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Ausseil, Anne-Gaelle E; Dymond, John R; Newstrom, Linda

2018-03-12

Honey bees require nectar and pollen from flowers: nectar for energy and pollen for growth. The demand for nectar and pollen varies during the year, with more pollen needed in spring for colony population growth and more nectar needed in summer to sustain the maximum colony size and collect surplus nectar stores for winter. Sufficient bee forage is therefore necessary to ensure a healthy bee colony. Land-use changes can reduce the availability of floral resources suitable for bees, thereby increasing the susceptibility of bees to other stressors such as disease and pesticides. In contrast, land-based management decisions to protect or plant bee forage can enhance pollen and nectar supply to bees while meeting other goals such as riparian planting for water-quality improvement. Commercial demand for honey can also put pressure on floral resources through over-crowding of hives. To help understand and manage floral resources for bees, we developed a spatial model for mapping monthly nectar and pollen production from maps of land cover. Based on monthly estimated production data we mapped potential monthly supply of nectar and pollen to a given apiary location in the landscape. This is done by summing the total production within the foraging range of the apiary while subtracting the estimated nectar converted to energy for collection. Ratios of estimated supply over theoretical hive demand may then be used to infer a potential landscape carrying capacity to sustain hives. This model framework is quantitative and spatial, utilizing estimated flight energy costs for nectar foraging. It can contribute to management decisions such as where apiaries could be placed in the landscape depending on floral resources and where nectar limited areas may be located. It can contribute to planning areas for bee protection or planting such as in riparian vegetation. This would aid managed bee health, wild pollinator protection, and honey production. We demonstrate the methods in a

Development of TGMS lines with improved floral traits through mutation breeding in rice

International Nuclear Information System (INIS)

Thiyagarajan, K.; Abirami, S.; Robin, S.; Manonmani, S.; Jambhulkar, S.J.

2006-01-01

Mutation breeding is now accepted as an useful means of adding valuable attributes to a variety. Plant breeders have used this tool for the improvement of some cultivated crop varieties. The current investigation is aimed to develop mutants with respect to temperature sensitivity and good floral traits for use in two line breeding. The putative Thermosensitive Genic Male Sterile lines viz,, TS 6 and CBTS 0282 were subjected to induce mutagenesis with gamma rays (300 and 350 Gy) and EMS (0.5 and 0.6%) for developing new TGMS lines with desirable floral traits. The seeds treated with gamma ray and EMS were raised in M1 generation and seeds collected from this population were raised in M2 generation as plant to progeny rows for screening the best TGMS lines with desirable floral traits. In the M2 generation a total of 469 progeny rows of CBTS 0282 and 854 progeny rows of TS 6 were raised. A population of 128, 975 plants in CBTS 0282 and 1,28,100 plants in TS 6 were raised. In M2 generation 361 sterile, uniform stable individual plants with good stigma exertion percentage and wide angle of glume opening were selected and stubble planted at HREC, Gudalur, a low temperature region. At HREC, again the same screening process was carried out and 13 stubbles with excellent stigma exertion percentage were selected and their progenies were raised in M3 generation along with control and check IR 58025 A. A total of 63 sterile and stable M3 plants with good stigma exertion percentage wider angle of glume opening excelling over the check and control were identified and raised in M4 generation along with control and check IR 58025 A. In the M4 generation a total of 16 progeny rows were found to be uniform and homozygous with good floral traits. These lines can be utilized for developing new two line hybrids

Estudio epidemiológico de los casos de triquinelosis registrados en la provincia de Santa Fe, Argentina, 1998-2009 Epidemiological study of recorded trichinosis cases in Santa Fe Province, Argentina, 1998-2009

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Gabriel J. Sequeira

2013-05-01

Full Text Available OBJETIVO: Caracterizar desde los puntos de vista epidemiológico, clínico y de laboratorio los casos y brotes de triquinelosis que se registraron en la provincia de Santa Fe, Argentina, entre 1998 y 2009. MÉTODOS: Se analizaron 1 519 fichas epidemiológicas de personas que presentaron síntomas y signos compatibles con triquinelosis en la provincia de Santa Fe en el período 1998-2009. Se realizó el análisis estadístico descriptivo de la información contenida en las fichas epidemiológicas y los resultados clínicos y de laboratorio; se aplicó el análisis bifactorial para determinar las posibles asociaciones con factores epidemiológicos y ambientales. RESULTADOS: Se encontraron síntomas de triquinelosis en 1 276 casos; 372 cumplían la definición de caso clínico y 224 muestras resultaron positivas por inmunofluorescencia indirecta, independientemente de su clasificación como caso clínico. Se identificaron 27 brotes que involucraron a 1 157 casos en ocho departamentos, con mayor frecuencia en el centro y el sur de la provincia. La distribución anual de los casos asociados epidemiológicamente entre sí fue heterogénea, con una mayor frecuencia en el período 2000-2003 y en los meses de agosto a octubre. Hubo mayor probabilidad de enfermar cuando se consumieron productos de fuentes informales (OR = 3,69; P = 0,014 y en las áreas rurales (OR = 1,799; P = 0,011. El período de incubación de la enfermedad (mediana fue de 12 días. Las personas que consumieron carne de cerdo o sus derivados tuvieron 2,06 veces más riesgo de enfermar que las que no la consumieron. CONCLUSIONES: El mayor número de brotes ocurrió en los departamentos más poblados y con mayor producción porcina. Se deben diseñar acciones específicas de prevención y control de la enfermedad en esos departamentos. Se debe considerar el análisis epidemiológico de riesgos al evaluar, gestionar y comunicar los riesgos sanitarios de triquinelosis.OBJECTIVE: To

Herbivore-Induced DNA Demethylation Changes Floral Signalling and Attractiveness to Pollinators in Brassica rapa.

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Roman T Kellenberger

Full Text Available Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities.

Study of the chemical composition of essential oils and floral waters ...

African Journals Online (AJOL)

This work aimed to study the chemical composition of essential oils and floral waters of Cymbopogon citratus (DC.) Stapf (Poaceae) from Senegal. The plants were collected in two different localities, Dakar and Kaolack. The extracts were obtained by steam distillation from both fresh and dried plants and analyses carried ...

Micropropagación de la planta medicinalPsychotria acuminata

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Alfonso Lara

2003-01-01

Full Text Available Psychotria acuminata es una planta medicinal que produce los alcaloides emetina, cephaelina y psychotrina, usados como expectorantes y eméticos. Hoy día estos alcaloides son extraídos de plantas silvestres pues esta especie no ha sido domesticada. Debido al uso potencial de los principios fitoquímicos, y a la escasa población de esta especie en el país, se desarrolló métodos de cultivo de tejidos para la reproducción clonal y masiva de esta planta. El material vegetal fue recolectado en 4 localidades de Costa Rica. En un medio de cultivo de Murashige y Skoog (MS, 1962, suplementado con 3 mg l-1 de BAP, 0,01 mg l-1 de ANA, 3% de azúcar y 2 g l-1 de phytagel, se logró la inducción de múltiples brotes a partir de las yemas axilares de microestacas (segmentos nodales de 1 cm de largo y de hojas provenientes de plántulas de 5 cm establecidas in vitro para 3 localidades. La formación de los brotes en las hojas ocurrió mediante organogénesis y embriogénesis. El enraizamiento in vitro de los brotes fue de un 100% cuando se utilizó un MS/2 suplementado con 6 mg l-1 de AIA. Debido a que el sistema radical generado in vitro muere una vez que las plántulas son sembradas en el sustrato en el invernadero, se utilizó Agriroot 1 DP® para generar raíces nuevas. Después de 8 semanas fue posible aclimatizar un 80% de las plántulas. La tasa de multiplicación, cuando se utiliza microestacas como explante, así como el tiempo para que ocurrieran los eventos morfogenéticos, fueron diferentes para los materiales de las 3 procedencias, lo que indica que las plantas de cada localidad son genéticamente diferentes.

The dilemma of being a fragrant flower: the major floral volatile attracts pollinators and florivores in the euglossine-pollinated orchid Dichaea pendula.

Science.gov (United States)

Nunes, Carlos E P; Peñaflor, Maria Fernanda G V; Bento, José Maurício S; Salvador, Marcos José; Sazima, Marlies

2016-12-01

Volatile organic compounds (VOCs) mediate both mutualistic and antagonistic plant-animal interactions; thus, the attraction of mutualists and antagonists by floral VOCs constitutes an important trade-off in the evolutionary ecology of angiosperms. Here, we evaluate the role of VOCs in mediating communication between the plant and its mutualist and antagonist floral visitors. To assess the evolutionary consequences of VOC-mediated signalling to distinct floral visitors, we studied the reproductive ecology of Dichaea pendula, assessing the effects of florivores on fruit set, the pollination efficiency of pollinators and florivores, the floral scent composition and the attractiveness of the major VOC to pollinators and florivores. The orchid depends entirely on orchid-bees for sexual reproduction, and the major florivores, the weevils, feed on corollas causing self-pollination, triggering abortion of 26.4 % of the flowers. Floral scent was composed of approximately 99 % 2-methoxy-4-vinylphenol, an unusual floral VOC attractive to pollinators and florivores. The low fruit set from natural pollination (5.6 %) compared to hand cross-pollination (45.5 %) and low level of pollinator visitation [0.02 visits (flower hour) -1 ] represent the limitations to pollination. Our research found that 2-methoxy-4-vinylphenol mediates both mutualistic and antagonistic interactions, which could result in contrary evolutionary pressures on novo-emission. The scarcity of pollinators, not florivory, was the major constraint to fruit set. Our results suggest that, rather than anti-florivory adaptations, adaptations to enhance pollinator attraction and cross-pollination might be the primary drivers of the evolution of VOC emission in euglossine-pollinated flowers.

SENSIBILIDAD DE INMUNOIMPRESIÓN-ELISA Y DAS-ELISA EN EL DIAGNÓSTICO Y MUESTREO DEL VIRUS DE LA TRISTEZA DE LOS CÍTRICOS EN HUERTOS COMERCIALES DE TAMAULIPAS, MEXICO

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N. Ruiz-García

2009-01-01

Full Text Available El Virus de la tristeza de los cítricos (VTC causa una enfermedad de interés regulatorio para la citricultura mexicana. El diagnóstico y un muestreo oportuno y confiable es esencial para aplicar estrategias de manejo ante el avance en territorio nacional del pulgón café, su principal vector. Con el fin de contar con un método eficaz y eficiente para el muestreo y detección del VTC, se evaluó el desempeño del método de inmunoimpresión-ELISA con respecto a DAS-ELISA, el método oficial de diagnóstico, debido a su economía, facilidad y rapidez. Con este propósito se evaluaron 7,421 árboles, considerando la edad del brote y de infección, provenientes de 11 huertos comerciales de Tamaulipas. El método de inmunoimpresión-ELISA superó en sensibilidad y capacidad de pronóstico de positivos a DAS-ELISA en el diagnóstico de árboles con infección reciente o desconocida del VTC (P¿0.028. La disposición de brotes positivos en el dosel fue heterogénea siendo descrita por la función beta binomial (P¿0.16-0.23. Con base en esta función y la reproducción de los resultados de impresiones dobles por pecíolo (93.2 % se sugiere un tamaño óptimo de muestra de 10 pecíolos por árbol en impresiones simples. Este método fue 54.9 % más económico que DAS-ELISA y los diagnósticos se realizaron en una sexta parte del tiempo requerido en esta última prueba. Sin embargo, por el requerimiento de la norma oficial mexicana vigente (NOM- 031-FITO-2000, se recomienda el método de inmunoimpresión-ELISA como un método rápido para discriminar árboles positivos en muestreos de campo que deben posteriormente ser verificados por el método oficial de diagnóstico.

Floral Sources for Stingless Bees (Tetragonula iridipennis in Nellithurai Village, Tamilnadu, India

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K. Vijayakumar

2016-10-01

Full Text Available We documented 45 plant taxa belonging to 29 families and non-floral sources utilized by Tetragonula iridipennis for pollen, nectar and resin. The foragers of T. iridipennis were also found to collect non-floral resources like fruit juice, fruits kept in the market for sales and from falling and damaged mango and jasmine fruits. The mutualistic association between T. iridipennis colonies and Hemipterans was observed and documented. According to pollen analysis, all are appeared to be multifloral honeys. The families Arecaceae and Fabaceae had a significant importance amongst the samples represented by four pollen types. Coconut, Sunflower and Banana pollen types occurred most constantly among the samples. The present palynological analysis of honey samples can provide the accurate depiction of the bee flora in Nellithurai village. The present study to help the beekeepers to know the stingless bee flora and to identify the botanical origins of honey.

Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

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Tóth, Peter; Undas, Anna K.; Verstappen, Francel; Bouwmeester, Harro

2016-01-01

The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

Brote con síntomas respiratorios en la provincia de Almería por una posible exposición a microalgas tóxicas An epidemic outbreak with respiratory symptoms in the province of Almeria (Spain due to toxic microalgae exposure

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Pilar Barroso García

2008-12-01

Full Text Available Objetivos: Describir un brote con clínica de irritación de las vías respiratorias, notificado en una localidad de la costa almeriense en agosto de 2006, así como la investigación etiológica realizada. Métodos: Estudio descriptivo y de casos y controles. Se dividió la localidad en 3 zonas según su mayor o menor cercanía al mar (de 1 a 3. La sintomatología fue valorada subjetivamente de menor a mayor gravedad (1 a 3. Se estimaron las tasas de ataque (TA. Para relacionar la gravedad de los síntomas por zonas y el tipo de exposición se calcularon las odds ratio (OR y sus intervalos de confianza del 95% (IC95%. También se utilizó la prueba de la χ2 y el test exacto de Fisher. Se realizó una investigación ambiental. Resultados: Se encuestó a 57 casos y 26 controles. Se estimó una TA del 69%. El síntoma más frecuente fue el estornudo (87,7%. Los individuos de la zona 1 presentaron mayor riesgo de padecer sintomatología de más gravedad que los de la zona 3 (OR = 46,7; IC95%: 4,7-2.067,4. Los que indicaron una mayor permanencia fuera de la vivienda tuvieron mayor riesgo de enfermar (OR = 12,2; IC95%: 1,1-615,1. En agua de mar se detectaron 1.200 células/l de dinoflagelados Ostreopsis. Conclusiones: Se trata de un brote con sintomatología respiratoria, con distinto grado de afectación según la cercanía al mar de la vivienda. Según la investigación epidemiológica y ambiental, lo más probable es que se haya debido a la presencia de microalgas tóxicas Ostreopsis.Aim: To describe an outbreak with symptoms of respiratory tract irritation reported in a village located on the Almerian coast in August 2006, as well as the etiological research performed. Methods: We performed a descriptive case-control study. The village was divided into three areas (from 1 to 3 according to the distance from the sea. Symptomatology was subjectively assessed on an ascending severity scale (from 1 to 3. Attack rates (AR were estimated. To correlate

Floral-dip transformation of flax (Linum usitatissimum) to generate transgenic progenies with a high transformation rate.

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Bastaki, Nasmah K; Cullis, Christopher A

2014-12-19

Agrobacterium-mediated plant transformation via floral-dip is a widely used technique in the field of plant transformation and has been reported to be successful for many plant species. However, flax (Linum usitatissimum) transformation by floral-dip has not been reported. The goal of this protocol is to establish that Agrobacterium and the floral-dip method can be used to generate transgenic flax. We show that this technique is simple, inexpensive, efficient, and more importantly, gives a higher transformation rate than the current available methods of flax transformation. In summary, inflorescences of flax were dipped in a solution of Agrobacterium carrying a binary vector plasmid (T-DNA fragment plus the Linum Insertion Sequence, LIS-1) for 1 - 2 min. The plants were laid flat on their side for 24 hr. Then, plants were maintained under normal growth conditions until the next treatment. The process of dipping was repeated 2 - 3 times, with approximately 10 - 14 day intervals between dipping. The T1 seeds were collected and germinated on soil. After approximately two weeks, treated progenies were tested by direct PCR; 2 - 3 leaves were used per plant plus the appropriate T-DNA primers. Positive transformants were selected and grown to maturity. The transformation rate was unexpectedly high, with 50 - 60% of the seeds from treated plants being positive transformants. This is a higher transformation rate than those reported for Arabidopsis thaliana and other plant species, using floral-dip transformation. It is also the highest, which has been reported so far, for flax transformation using other methods for transformation.

Circadian clock gene LATE ELONGATED HYPOCOTYL directly regulates the timing of floral scent emission in Petunia.

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Fenske, Myles P; Hewett Hazelton, Kristen D; Hempton, Andrew K; Shim, Jae Sung; Yamamoto, Breanne M; Riffell, Jeffrey A; Imaizumi, Takato

2015-08-04

Flowers present a complex display of signals to attract pollinators, including the emission of floral volatiles. Volatile emission is highly regulated, and many species restrict emissions to specific times of the day. This rhythmic emission of scent is regulated by the circadian clock; however, the mechanisms have remained unknown. In Petunia hybrida, volatile emissions are dominated by products of the floral volatile benzenoid/phenylpropanoid (FVBP) metabolic pathway. Here we demonstrate that the circadian clock gene P. hybrida LATE ELONGATED HYPOCOTYL (LHY; PhLHY) regulates the daily expression patterns of the FVBP pathway genes and floral volatile production. PhLHY expression peaks in the morning, antiphasic to the expression of P. hybrida GIGANTEA (PhGI), the master scent regulator ODORANT1 (ODO1), and many other evening-expressed FVBP genes. Overexpression phenotypes of PhLHY in Arabidopsis caused an arrhythmic clock phenotype, which resembles those of LHY overexpressors. In Petunia, constitutive expression of PhLHY depressed the expression levels of PhGI, ODO1, evening-expressed FVBP pathway genes, and FVBP emission in flowers. Additionally, in the Petunia lines in which PhLHY expression was reduced, the timing of peak expression of PhGI, ODO1, and the FVBP pathway genes advanced to the morning. Moreover, PhLHY protein binds to cis-regulatory elements called evening elements that exist in promoters of ODO1 and other FVBP genes. Thus, our results imply that PhLHY directly sets the timing of floral volatile emission by restricting the expression of ODO1 and other FVBP genes to the evening in Petunia.

The potential role of B-function gene involved in floral development ...

African Journals Online (AJOL)

Camellia changii Ye, a rare and endangered species, has a phenotype that sepals frequently transform into petals. We assumed that this change would cause single C. changii Ye turned double flowers and this was confirmed by the double flowers we found in grafted C. changii Ye. The microstructure of floral organs ...

De flores, brotes y palmitos: alimentos olvidados

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Romano González Arce

2008-01-01

Full Text Available Muchos de los alimentos que aprovecharon nuestros antepasados fueron relegados a alimentos subexplotados por los procesos de conquista o por la desaparición de sus hábitats naturales. Este trabajo exploró las razones de este cambio y el potencial nutricional, agronómico y comercial de un grupo de estos alimentos: las hortalizas subexplotadas. Se realizó a partir de fuentes documentales y entrevistas a personas, generalmente adultos mayores, de diferentes partes del país durante el 2003 y el 2005. Las principales razones que explican el desuso de estos alimentos son: la introducción de hortalizas foráneas, que redujo el estatus de las nativas; la destrucción del hábitat propio de las diferentes especies; la modificación de las técnicas agrícolas que facilitaban su crecimiento; y la urbanización progresiva que redujo el espacio para los solares tradicionales. Estas plantas, por ser nativas, están totalmente adaptadas al clima y suelos del país, por lo que iniciar procesos de domesticación no resulta difícil. Se requiere mayor investigación en biología, etnobotánica, agronomía, química, y nutrición antes de promover su consumo masivo. Pero son fuente de nutrimentos para las poblaciones rurales del país.

Floral to green: mating switches moth olfactory coding and preference.

Science.gov (United States)

Saveer, Ahmed M; Kromann, Sophie H; Birgersson, Göran; Bengtsson, Marie; Lindblom, Tobias; Balkenius, Anna; Hansson, Bill S; Witzgall, Peter; Becher, Paul G; Ignell, Rickard

2012-06-22

Mating induces profound physiological changes in a wide range of insects, leading to behavioural adjustments to match the internal state of the animal. Here, we show for the first time, to our knowledge, that a noctuid moth switches its olfactory response from food to egg-laying cues following mating. Unmated females of the cotton leafworm (Spodoptera littoralis) are strongly attracted to lilac flowers (Syringa vulgaris). After mating, attraction to floral odour is abolished and the females fly instead to green-leaf odour of the larval host plant cotton, Gossypium hirsutum. This behavioural switch is owing to a marked change in the olfactory representation of floral and green odours in the primary olfactory centre, the antennal lobe (AL). Calcium imaging, using authentic and synthetic odours, shows that the ensemble of AL glomeruli dedicated to either lilac or cotton odour is selectively up- and downregulated in response to mating. A clear-cut behavioural modulation as a function of mating is a useful substrate for studies of the neural mechanisms underlying behavioural decisions. Modulation of odour-driven behaviour through concerted regulation of odour maps contributes to our understanding of state-dependent choice and host shifts in insect herbivores.

Identification and cloning of class II and III chitinases from alkaline floral nectar of Rhododendron irroratum, Ericaceae.

Science.gov (United States)

Zha, Hong-Guang; Milne, Richard I; Zhou, Hong-Xia; Chen, Xiang-Yang; Sun, Hang

2016-10-01

Class II and III chitinases belonging to different glycoside hydrolase families were major nectarins in Rhododendron irroratum floral nectar which showed significant chitinolytic activity. Previous studies have demonstrated antimicrobial activity in plant floral nectar, but the molecular basis for the mechanism is still poorly understood. Two chitinases, class II (Rhchi2) and III (Rhchi3), were characterized from alkaline Rhododendron irroratum nectar by both SDS-PAGE and mass spectrometry. Rhchi2 (27 kDa) and Rhchi3 (29 kDa) are glycoside hydrolases (family 19 and 18) with theoretical pI of 8.19 and 7.04. The expression patterns of Rhchi2 and Rhchi3 were analyzed by semi-quantitative RT-PCR. Rhchi2 is expressed in flowers (corolla nectar pouches) and leaves while Rhchi3 is expressed in flowers. Chitinase in concentrated protein and fresh nectar samples was visualised by SDS-PAGE and chitinolytic activity in fresh nectar was determined spectrophotometrically via chitin-azure. Full length gene sequences were cloned with Tail-PCR and RACE. The amino acid sequence deduced from the coding region for these proteins showed high identity with known chitinases and predicted to be located in extracellular space. Fresh R. irroratum floral nectar showed significant chitinolytic activity. Our results demonstrate that class III chitinase (GH 18 family) also exists in floral nectar. The functional relationship between class II and III chitinases and the role of these pathogenesis-related proteins in antimicrobial activity in nectar is suggested.

Identification of QTLs Associated to Plant Architecture in Cassava (Manihot esculenta

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Camilo López

2016-01-01

Full Text Available La yuca (Manihot esculenta es el cuarto cultivo en importancia a nivel mundial como fuente de calorías para la población humana después del arroz, el azúcar y el maíz, posicionándose por esta razón como un cultivo primordial para la seguridad alimentaria. Su arquitectura ha sido considerada como un factor clave que subyace a la fisiología del rendimiento, relacionando características morfológicas con productividad. En este trabajo se evaluaron diferentes características de arquitectura vegetal en yuca. Los caracteres fueron evaluados en una población F1 compuesta por 133 hermanos completos (familia K sembrados en dos lugares biogeográficamente diferentes: La Vega (Cundinamarca y Arauca (Arauca en Colombia. Las características evaluadas relacionadas con la arquitectura vegetal fueron altura de la planta (AT, número de brotes (NB, longitud entrenudos (LE, número de raíces (NR, peso de raíces (PR, pigmentación del peciolo (PP, área de la hoja (AH y tipo de hoja (TH. A partir de los datos obtenidos y empleando un mapa genético de alta densidad basado en SNPs (Single Nucleotide Polymorphisms se llevó a cabo un análisis de QTLs (Quantitative Trait Loci. Se lograron identificar tres QTLs para La Vega asociados con los caracteres altura total, número de brotes y área de la hoja. Para Arauca se detectaron tres QTLs asociados con altura total, longitud de entrenudos y número de brotes. Los QTLs se distribuyeron en cuatro grupos de ligamiento y explicaron entre 18,93 y 41,92 % de la variación genética.

Floral morphology and morphogenesis in Camptotheca (Nyssaceae), and its systematic significance.

Science.gov (United States)

Gong, Jing-Zhi; Li, Qiu-Jie; Wang, Xi; Ma, Yue-Ping; Zhang, Xiao-Hui; Zhao, Liang; Chang, Zhao-Yang; Ronse De Craene, Louis

2018-03-22

Camptotheca is endemic to China and there are limited data about the breeding system and morphogenesis of the flowers. Camptotheca is thought to be related to Nyssa and Davidia in Nyssaceae, which has sometimes been included in Cornaceae. However, molecular phylogenetic studies confirmed the inclusion of Camptotheca in Nyssaceae and its exclusion from Cornaceae. The aim of this study was to reveal developmental features of the inflorescence and flowers in Camptotheca to compare with related taxa in Cornales. Inflorescences and flowers of Camptotheca acuminata at all developmental stages were collected and studied with a scanning electron microscope and stereo microscope. Camptotheca has botryoids which are composed of several capitate floral units (FUs) that are initiated acropetally. On each FU, flowers are grouped in dyads that are initiated acropetally. All floral organs are initiated centripetally. Calyx lobes are restricted to five teeth. The hypanthium, with five toothed calyx lobes, is adnate to the ovary. The five petals are free and valvate. Ten stamens are inserted in two whorls around the central depression, in which the style is immersed. Three carpels are initiated independently but the ovary is syncarpous and unilocular. The ovule is unitegmic and heterotropous. Inflorescences are functionally andromonoecious varying with the position of the FUs on the inflorescence system. Flowers on the upper FU often have robust styles and fully developed ovules. Flowers on the lower FU have undeveloped styles and aborted ovules, and the flowers on the middle FU are transitional. Camptotheca possesses several traits that unify it with Nyssa, Mastixia and Diplopanax. Inflorescence and floral characters support a close relationship with Nyssaceae and Mastixiaceae but a distant relationship with Cornus. Our results corroborate molecular inferences and support a separate family Nyssaceae.

Floral Benzenoid Carboxyl Methyltransferases: From in Vitro to in Planta Function

Energy Technology Data Exchange (ETDEWEB)

Effmert,U.; Saschenbrecker, S.; Ross, J.; Negre, F.; Fraser, C.; Noel, J.; Dudareva, N.; Piechulla, B.

2005-01-01

Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from Clarkia breweri, Stephanotis floribunda, Antirrhinum majus, Hoya carnosa, and Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from A. majus, Arabidopsis thaliana, Arabidopsis lyrata, and Nicotiana suaveolens prefer benzoic acid. The elucidation of C. breweri SAMT's three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in plants depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses

Effect of floral bud reduction on flower longevity in Asiatic hybrids lilies.

NARCIS (Netherlands)

Meulen-Muisers, van der J.J.M.; Oeveren, van J.C.; Sandbrink, J.M.; Tuyl, van J.M.

1995-01-01

Floral bud abortion was found to be an undesirable source of non-genetic variation in breeding trials directed on the improvement of individual flower longevity in Asiatic hybrid lilies. It increased the longevity of the remaining flowers of the inflorescence. A similar response was found after

Molecular evolution and patterns of duplication in the SEP/AGL6-like lineage of the Zingiberales: a proposed mechanism for floral diversification.

Science.gov (United States)

Yockteng, Roxana; Almeida, Ana M R; Morioka, Kelsie; Alvarez-Buylla, Elena R; Specht, Chelsea D

2013-11-01

The diversity of floral forms in the plant order Zingiberales has evolved through alterations in floral organ morphology. One striking alteration is the shift from fertile, filamentous stamens to sterile, laminar (petaloid) organs in the stamen whorls, attributed to specific pollination syndromes. Here, we examine the role of the SEPALLATA (SEP) genes, known to be important in regulatory networks underlying floral development and organ identity, in the evolution of development of the diverse floral organs phenotypes in the Zingiberales. Phylogenetic analyses show that the SEP-like genes have undergone several duplication events giving rise to multiple copies. Selection tests on the SEP-like genes indicate that the two copies of SEP3 have mostly evolved under balancing selection, probably due to strong functional restrictions as a result of their critical role in floral organ specification. In contrast, the two LOFSEP copies have undergone differential positive selection, indicating neofunctionalization. Reverse transcriptase-polymerase chain reaction, gene expression from RNA-seq data, and in situ hybridization analyses show that the recovered genes have differential expression patterns across the various whorls and organ types found in the Zingiberales. Our data also suggest that AGL6, sister to the SEP-like genes, may play an important role in stamen morphology in the Zingiberales. Thus, the SEP-like genes are likely to be involved in some of the unique morphogenetic patterns of floral organ development found among this diverse order of tropical monocots. This work contributes to a growing body of knowledge focused on understanding the role of gene duplications and the evolution of entire gene networks in the evolution of flower development.

Floral thermogenesis of three species of Hydnora (Hydnoraceae) in Africa.

Science.gov (United States)

Seymour, Roger S; Maass, Erika; Bolin, Jay F

2009-10-01

Floral thermogenesis occurs in at least 12 families of ancient seed plants. Some species show very high rates of respiration through the alternative pathway, and some are thermoregulatory, with increasing respiration at decreasing ambient temperature. This study assesses the intensity and regulation of respiration in three species of African Hydnora that represent the Hydnoraceae, an unusual family of holoparasitic plants from arid environments. Long-term respirometry (CO(2) production) and thermometry were carried out on intact flowers of H. africana, H. abyssinica and H. esculenta in the field, and short-term measurements were made on floral parts during the protogynous flowering sequence. For H. africana, there was no temperature elevation in either the osmophores or the gynoecial chamber in any phase, and mass-specific respiration rates of the flower parts were low (maximum 8.3 nmol CO(2) g(-1) s(-1) in osmophore tissue). Respiration tracked ambient and floral temperatures, eliminating the possibility of the inverse relationship expected in thermoregulatory flowers. Hydnora abyssinica flowers had higher respiration (maximum 27.5 nmol g(-1) s(-1) in the osmophores) and a slight elevation of osmophore temperature (maximum 2.8 degrees C) in the female stage. Respiration by gynoecial tissue was similar to that of osmophores in both species, but there was no measurable elevation of gynoecial chamber temperature. Gynoecial chamber temperature of H. esculenta could reach 3.8 degrees C above ambient, but there are no respiration data available. Antheral tissue respiration was maximal in the male phase (4.8 nmol g(-1) s(-1) in H. africana and 10.3 nmol g(-1) s(-1) in H. abyssinica), but it did not raise the antheral ring temperature, which showed that thermogenesis is not a by-product of pollen maturation or release. The exceptionally low thermogenesis in Hydnora appears to be associated with scent production and possibly gynoecial development, but has little direct

Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

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Peter eTóth

2016-03-01

Full Text Available The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae, are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs, consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae.

Study on the Development of Yunnan Floral E-commerce

OpenAIRE

Kuang, Yulan; Li, Qifang; Ning, Wangyun

2013-01-01

Cut flower production in Yunnan accounts for 80% nationwide. In order to expand the Yunnan Flower sales channels, the promotion of the development of e-commerce is necessary. In 2012 China's online shopping users reached 247 million people, but e-commerce of fresh flowers lagged behind due to the constraints of preservation facilities and logistics cost. The analysis of the factors restricting the development of floral e-commerce and the proposition of solutions to this problem can promote fa...

Intoxicación alimentaria por clostridium perfringens en el centro penitenciario cocori, cartago, costa rica, del 4 al 5 de septiembre del 2002

OpenAIRE

Espinoza, A; Arguedas, H; Asenjo, A

2004-01-01

Introducción El 5 de setiembre del 2002 el Centro Penitenciario Cocorí en Cartago, notificó al Sistema de Vigilancia del Ministerio de Salud, la presencia de 133 casos de diarrea. Ante esta situación, las autoridades de salud plantearon la investigación, para identificar los factores asociados a la presencia del brote. Material y métodos Mediante la revisión de los expedientes de los casos atendidos por diarrea en el Centro Penitenciario, se identificaron los que cumplieran con la siguiente d...

Anticuerpos policlonales contra la proteína recombinante NS3 del virus del dengue

OpenAIRE

Liliana Morales; Myriam L. Velandia; María Angélica Calderon; Jaime E. Castellanos; Jacqueline Chaparro-Olaya

2017-01-01

Introducción. El dengue es una enfermedad causada por uno de los cuatro serotipos del virus del dengue (DENV) y es endémica en, aproximadamente, 130 países. Su incidencia ha aumentado notablemente en las últimas décadas, así como la frecuencia y la magnitud de los brotes. A pesar de los esfuerzos, no existen tratamientos profilácticos ni terapéuticos contra la enfermedad y, en ese contexto, el estudio de los procesos que gobiernan el ciclo de infección del DENV es esencial para desarrollar...

Petunia × hybrida floral scent production is negatively affected by high-temperature growth conditions.

Science.gov (United States)

Cna'ani, Alon; Mühlemann, Joelle K; Ravid, Jasmin; Masci, Tania; Klempien, Antje; Nguyen, Thuong T H; Dudareva, Natalia; Pichersky, Eran; Vainstein, Alexander

2015-07-01

Increasing temperatures due to changing global climate are interfering with plant-pollinator mutualism, an interaction facilitated mainly by floral colour and scent. Gas chromatography-mass spectroscopy analyses revealed that increasing ambient temperature leads to a decrease in phenylpropanoid-based floral scent production in two Petunia × hybrida varieties, P720 and Blue Spark, acclimated at 22/16 or 28/22 °C (day/night). This decrease could be attributed to down-regulation of scent-related structural gene expression from both phenylpropanoid and shikimate pathways, and up-regulation of a negative regulator of scent production, emission of benzenoids V (EOBV). To test whether the negative effect of increased temperature on scent production can be reduced in flowers with enhanced metabolic flow in the phenylpropanoid pathway, we analysed floral volatile production by transgenic 'Blue Spark' plants overexpressing CaMV 35S-driven Arabidopsis thaliana production of anthocyanin pigments 1 (PAP1) under elevated versus standard temperature conditions. Flowers of 35S:PAP1 transgenic plants produced the same or even higher levels of volatiles when exposed to a long-term high-temperature regime. This phenotype was also evident when analysing relevant gene expression as inferred from sequencing the transcriptome of 35S:PAP1 transgenic flowers under the two temperature regimes. Thus, up-regulation of transcription might negate the adverse effects of temperature on scent production. © 2014 John Wiley & Sons Ltd.

Teaching Flower Structure & Floral Formulae--A Mix of the Real & Virtual Worlds

Science.gov (United States)

Burrows, Geoff

2010-01-01

The study of flower structure is essential in plant identification and in understanding sexual reproduction in plants, pollination syndromes, plant breeding, and fruit structure. Thus, study of flower structure and construction of floral formulae are standard parts of first-year university botany and biology courses. These activities involve…

A sexually dimorphic corolla appendage affects pollen removal and floral longevity in gynodioecious Cyananthus delavayi (Campanulaceae.

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Yang Niu

Full Text Available The floral traits of bisexual flowers may evolve in response to selection on both male and female functions, but the relative importance of selection associated with each of these two aspects is poorly resolved. Sexually dimorphic traits in plants with unisexual flowers may reflect gender-specific selection, providing opportunities for gaining an increased understanding of the evolution of specific floral traits. We examined sexually dimorphic patterns of floral traits in perfect and female flowers of the gynodioecious species Cyananthus delavayi. A special corolla appendage, the throat hair, was investigated experimentally to examine its influences on male and female function. We found that perfect flowers have larger corollas and much longer throat hairs than female flowers, while female ones have much exerted stigmas. The presence of throat hairs prolonged the duration of pollen presentation by restricting the amount of pollen removed by pollen-collecting bees during each visit. Floral longevity was negatively related to the rate of pollen removal. When pollen removal rate was limited in perfect flowers, the duration of the female phases diminished with the increased male phase duration. There was a weak negative correlation between throat hair length and seed number per fruit in female flowers, but this correlation was not significant in perfect flowers. These results suggest that throat hairs may enhance male function in terms of prolonged pollen presentation. However, throat hairs have no obvious effect on female function in terms of seed number per fruit. The marked sexual dimorphism of this corolla appendage in C. delavayi is likely to have evolved and been maintained by gender-specific selection.

Perspectivas de salud ambiental en la investigación de brotes epidémicos asociados con una zona de abastecimiento de aguas de consumo humano Perspectives of environmental health in outbreaks research associated with a zone of consumption water supply human

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Antonio Lara Villegas

2004-12-01

Full Text Available Introducción. El propósito de este trabajo fue estudiar la magnitud, posibles causas y factores ambientales contribuyentes en la aparición de brotes de origen hídrico, en el ámbito de actuación de la localidad de Benaoján (Serranía de Ronda, Málaga.Material y métodos. Análisis de la potabilidad del agua y controles de desinfección. Evaluación del cumplimiento de la calidad del agua potable y requisitos técnico sanitarios de abastecimientos de aguas, conforme a la normativa española sobre aguas de consumo público.Resultados. Se han realizado 110 análisis de potabilidad, comprobando que el 13,4% de las muestras no cumplen con los criterios de potabilidad del agua. Se practicaron 647 controles de desinfección, de los que el 53% resultaron no conformes. El diseño de la red de abastecimiento es del tipo ramificada y al menos presenta 30 ramales ciegos, puntos donde el agua queda estancada. El servicio municipal de aguas no realiza autocontroles de la calidad del agua ni tiene implantados planes generales de higiene de las instalaciones del abastecimiento.Discusión. La investigación ambiental sugiere que la red pública de abastecimiento de aguas es una fuente de infección, problema relacionado con la aparición de brotes epidémicos. Por ello el consumo de agua no tratada debe ser evitado.Introduction. The purpose of this work was studied the magnitude, possible causes and contributing environmental factors in the waterbourne outbreaks appearance, in the performance area of the locality of Benaoján (Town of Málaga, Spain.Material/Methods. Analysis of the potability of the water and disinfection controls. Evaluation of the fulfillment of the quality of the drinking water and sanitary technical requirements of water supplies, pursuant to the Spanish regulation on public consumption waters.Results. We have been accomplished 110 potability analysis, proving that 13,4% of the samples do not comply with the potability criteria of

Componentes do rendimento de mamona segundo a ordem floral e época de semeadura no Rio Grande do Sul Castor yield components according to floral order and sowing season in the Rio Grande do Sul State

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Jacson Zuchi

2010-09-01

Full Text Available Diversos fatores, como a época de semeadura, afetam a produtividade e a qualidade das sementes. O objetivo deste trabalho foi avaliar quatro componentes do rendimento de mamona em função da época de semeadura e da ordem floral na Embrapa Clima Temperado em Pelotas, Rio Grande do Sul em solo tipo Argissolo Amarelo na latitude de 31º40'53,6" S, longitude de 52º26'23,5" W e altitude de 67,10 metros. O número de cachos emitidos, produtividade de sementes, percentagem de casca e peso de mil sementes foram avaliados para as cultivares Al Guarany 2002, IAC 80, IAC 226 e BRS 188 Paraguaçu. A maior emissão de cachos de mamona não implica, necessariamente, em maior produtividade de sementes, a qual variou entre época de semeadura e ordem floral.Several factors, including sowing time, can affect the productivity and the quality of seeds. The objective of this work was to evaluate four components of the castor oil plant production as function of the sowing time and of the floral order in the "Embrapa Clima Temperado" in Pelotas, Rio Grande do Sul, Brazil in yellow clay soil type at the latitude of 31º40'53.6" S, longitude of 52º26'23.5" W and altitude of 67.10 meters. The number of bunches emitted, productivity of seeds, peel percentage and weight of a thousand seeds were evaluated for the cultivars Al Guarany 2002, IAC 80, IAC 226 and BRS 188 Paraguaçu. The largest emission of bunches on castor oil plant does not lead, necessarily, to higher productivity of seeds, which varied between sowing time and floral order.

T-DNA transfer and T-DNA integration efficiencies upon Arabidopsis thaliana root explant cocultivation and floral dip transformation.

Science.gov (United States)

Ghedira, Rim; De Buck, Sylvie; Van Ex, Frédéric; Angenon, Geert; Depicker, Ann

2013-12-01

T-DNA transfer and integration frequencies during Agrobacterium-mediated root explant cocultivation and floral dip transformations of Arabidopsis thaliana were analyzed with and without selection for transformation-competent cells. Based on the presence or absence of CRE recombinase activity without or with the CRE T-DNA being integrated, transient expression versus stable transformation was differentiated. During root explant cocultivation, continuous light enhanced the number of plant cells competent for interaction with Agrobacterium and thus the number of transient gene expression events. However, in transformation competent plant cells, continuous light did not further enhance cotransfer or cointegration frequencies. Upon selection for root transformants expressing a first T-DNA, 43-69 % of these transformants showed cotransfer of another non-selected T-DNA in two different light regimes. However, integration of the non-selected cotransferred T-DNA occurred only in 19-46 % of these transformants, indicating that T-DNA integration in regenerating root cells limits the transformation frequencies. After floral dip transformation, transient T-DNA expression without integration could not be detected, while stable T-DNA transformation occurred in 0.5-1.3 % of the T1 seedlings. Upon selection for floral dip transformants with a first T-DNA, 8-34 % of the transformants showed cotransfer of the other non-selected T-DNA and in 93-100 % of them, the T-DNA was also integrated. Therefore, a productive interaction between the agrobacteria and the female gametophyte, rather than the T-DNA integration process, restricts the floral dip transformation frequencies.

Pollination ecology and floral function of Brown’s peony (Paeonia brownii in the Blue Mountains of northeastern Oregon

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Nan Vance

2013-03-01

Full Text Available Brown’s peony, Paeonia brownii (Paeoniaceae, is one of only two peony species native to the Western Hemisphere, yet its pollination ecology and breeding system have never been documented. Using flowering individuals of an endemic colony in the Blue Mountains of Oregon, U.S., we investigated the peony’s pollination system and floral function. We also examined pollen/carpel interactions through experimental pollinations aided by fluorescence microscopy. Paeonia brownii appears to be self compatible and mostly protogynous with floral traits of a generalist pollination system. The flowers appear to attract insects by producing abundant floral nectar secreted from lobes of a perigynous disc throughout their 9-15-days of anthesis. The most common pollen vectors were wasp queens (Vespidae, the large flower fly Criorhina caudata (Syrphidae, and females of Lasioglossum spp. (Halictidae, all of which foraged exclusively for nectar. Whether collected from foraging wasps and flies, anthers, or stigmas, about half the pollen grains appeared fertile. The number of ovules per carpel was about 19. Seed set (seeds/ovule of naturally pollinated flowers was about 20% with about 4 viable seeds per follicle. The number of fertile pollen grains transferred to the stigma under natural conditions was highly variable but generally low, which may have contributed in part to the low rate of seed set. This study raises further questions about the role of pollen sterility, floral nectar and vespid wasps in shaping a pollinator system that is unusual in Paeonia.

Duck viral enteritis in domestic muscovy ducks in Pennsylvania

Science.gov (United States)

Davison, S.; Converse, K.A.; Hamir, A.N.; Eckroade, R.J.

1993-01-01

Duck viral enteritis (DVE) outbreaks occurred at two different locations in Pennsylvania in 1991 and 1992. In the first outbreak, four ducks died out of a group of 30 domestic ducks; in the second outbreak, 65 ducks died out of a group of 114 domestic ducks, and 15 domestic geese died as well. A variety of species of ducks were present on both premises, but only muscovy ducks (Cairina moschata) died from the disease. On necropsy, gross lesions included hepatomegaly with petechial hemorrhages, petechial hemorrhages in the abdominal fat, petechial hemorrhages on the epicardial surface of the heart, and multifocal to coalescing areas of fibrinonecrotic material over the mucosal surface of the trachea, esophagus, intestine, and cloaca. Histologically, the liver had random multifocal areas of necrosis and eosinophilic intranuclear inclusion bodies in hepatocytes. DVE virus was isolated and identified using muscovy duck embryo fibroblast inoculation and virus neutralization. /// En dos sitios diferentes se presentaron brotes de enteritis viral de los patos en el estados de Pensilvania en los a??os 1991 y 1992. En el primer brote, cuatro de un lote de 30 patos murieron mientras que en el segundo brote murieron 65 patos de un lote de 114 patos y 15 gansos. En ambas localidades exist?-a una variedad de especies de patos, sin embargo, s??lamente los patos almizcleros (Cairina moschata) murieron. A la necropsia, las lesiones macrosc??picas incluyeron hepatomegalia con hemorragias petequiales, hemorragias petequiales en la grasa abdominal y en la superficie del epicardio, y ?!reas multifocales o coalescentes de material fibrinonecr??tico sobre la superficie de la mucosa de la tr?!quea, es??fago, intestino y cloaca. Histol??gicamente, el h?-gado mostraba ?!reas multifocales de necrosis y cuerpos de inclusi??n intranucleares eosinof?-licos en los hepatocitos. El virus de la enteritis viral de los patos fue aislado e identificado usando fibroblasto de embriones de pato almizclero

Floral evolution of Philodendron subgenus Meconostigma (Araceae.

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Letícia Loss de Oliveira

Full Text Available Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK and two nuclear (ETS and 18S markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

Floral evolution of Philodendron subgenus Meconostigma (Araceae).

Science.gov (United States)

de Oliveira, Letícia Loss; Calazans, Luana Silva Braucks; de Morais, Érica Barroso; Mayo, Simon Joseph; Schrago, Carlos Guerra; Sakuragui, Cassia Mônica

2014-01-01

Elucidating the evolutionary patterns of flower and inflorescence structure is pivotal to understanding the phylogenetic relationships of Angiosperms as a whole. The inflorescence morphology and anatomy of Philodendron subgenus Meconostigma, belonging to the monocot family Araceae, has been widely studied but the evolutionary relationships of subgenus Meconostigma and the evolution of its flower characters have hitherto remained unclear. This study examines gynoecium evolution in subgenus Meconostigma in the context of an estimated molecular phylogeny for all extant species of subgenus Meconostigma and analysis of ancestral character reconstructions of some gynoecial structures. The phylogenetic reconstructions of all extant Meconostigma species were conducted under a maximum likelihood approach based on the sequences of two chloroplast (trnk and matK) and two nuclear (ETS and 18S) markers. This topology was used to reconstruct the ancestral states of seven floral characters and to elucidate their evolutionary pattern in the Meconostigma lineage. Our phylogeny shows that Meconostigma is composed of two major clades, one comprising two Amazonian species and the other all the species from the Atlantic Forest and Cerrado biomes with one Amazonian species. The common ancestor of the species of subgenus Meconostigma probably possessed short stylar lobes, long stylar canals, a stylar body, a vascular plexus in the gynoecium and druses in the stylar parenchyma but it is uncertain whether raphide inclusions were present in the parenchyma. The ancestral lineage also probably possessed up to 10 ovary locules. The evolution of these characters seems to have occurred independently in some lineages. We propose that the morphological and anatomical diversity observed in the gynoecial structures of subgenus Meconostigma is the result of an ongoing process of fusion of floral structures leading to a reduction of energy wastage and increase in stigmatic surface.

Tres casos de odontomas

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Salvador Javier Santos Medina

2015-03-01

Full Text Available Los odontomas son los tumores odontogénicos más comunes, casi siempre se diagnostican accidentalmente, en exámenes radiográficos; pueden sospecharse al retardar el brote dentario o producir maloclusiones. Se clasifican en odontomas compuestos y complejos, ambos constituidos por estructuras dentales como: esmalte, dentina, cemento y tejido pulpar. Su eliminación quirúrgica y la biopsia es el tratamiento de elección. El propósito de este trabajo es reportar tres casos de pacientes atendidos en el Hospital Pediátrico de Las Tunas, todos remitidos previamente por el ortodoncista. El primero, tipo compuesto, en un escolar de 9 años de edad, masculino, asociado a un 31 retenido; el segundo caso se trata de un gran odontoma complejo en una escolar de 11 años de edad, femenina, que produjo interferencia en el brote del 11 y el tercero compuesto; en un escolar de 10 años, masculino, en la línea media entre 11 y 21, con producción de diastema y brote del 12 por palatino. De ellos uno fue descubierto por un examen radiográfico de rutina y los otros dos sospechados por la maloclusión secundaria; todos se trataron quirúrgicamente. Estos casos demuestran la frecuencia de estos tumores en la cavidad bucal y la importancia de la realización de exámenes clínicos y radiográficos para su detección y tratamiento precoz, así como la importancia de la interrelación entre el ortodoncista y el maxilofacial en la resolución satisfactoria de esta entidad

La legionelosis como enfermedad profesional: metodología de valoración

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Dorronsoro Dorronsoro, Marta; Vicente Pardo, José Manuel

2014-01-01

La Legionella es una enfermedad bacteriana producida por la Legionella Pneumofila, patógeno oportunista que para causar una enfermedad debe estar presente en el lugar (reservorio), debe alcanzar un número suficiente para causar la infección (amplificación) y debe pasar al ambiente en estado infectivo (diseminación) los focos de contaminación que con mayor frecuencia han sido relacionados con los brotes epidémicos son instalaciones de suministro de agua y de acondicionamiento del aire de los e...

SEP-class genes in Prunus mume and their likely role in floral organ development.

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Zhou, Yuzhen; Xu, Zongda; Yong, Xue; Ahmad, Sagheer; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

2017-01-13

Flower phylogenetics and genetically controlled development have been revolutionised during the last two decades. However, some of these evolutionary aspects are still debatable. MADS-box genes are known to play essential role in specifying the floral organogenesis and differentiation in numerous model plants like Petunia hybrida, Arabidopsis thaliana and Antirrhinum majus. SEPALLATA (SEP) genes, belonging to the MADS-box gene family, are members of the ABCDE and quartet models of floral organ development and play a vital role in flower development. However, few studies of the genes in Prunus mume have yet been conducted. In this study, we cloned four PmSEPs and investigated their phylogenetic relationship with other species. Expression pattern analyses and yeast two-hybrid assays of these four genes indicated their involvement in the floral organogenesis with PmSEP4 specifically related to specification of the prolificated flowers in P. mume. It was observed that the flower meristem was specified by PmSEP1 and PmSEP4, the sepal by PmSEP1 and PmSEP4, petals by PmSEP2 and PmSEP3, stamens by PmSEP2 and PmSEP3 and pistils by PmSEP2 and PmSEP3. With the above in mind, flower development in P. mume might be due to an expression of SEP genes. Our findings can provide a foundation for further investigations of the transcriptional factors governing flower development, their molecular mechanisms and genetic basis.

Conservación in vitro de chayote (Sechium edule

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Silvana Alvarenga-Venutolo

2007-01-01

Full Text Available Conservación in vitro de chayote (Sechium edule. La técnica de conservación in vitro a mediano plazo fue examinada en chayote. Para ello se determinó la supervivencia de los brotes después de la adición de altas concentraciones de sacarosa (0, 30, 50, 60, 70 y 80 g/l y ácido acetil salicílico (10-9, 10-6 y 10-3 M al medio de cultivo, de disminuciones en la temperatura de crecimiento (16, 18, 20, 22 y 25ºC y combinaciones de estos factores, en Costa Rica, en 1997. Se encontró que los brotes mantuvieron altos porcentajes de viabilidad después de ser conservados durante seis meses en los tratamientos evaluados. Debido a la apariencia más vigorosa y a la coloración más verde que presentaron las plántulas, se consideró que el mejor tratamiento fue la adición de 60 g/l de sacarosa al medio de cultivo combinado con la incubación a 16ºC.

Phenological cycle and floral development of Chloraea crispa (Orchidaceae)

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Steinfort, Ursula; Cisternas, Mauricio A; García, Rolando; Vogel, Hermine; Verdugo, Gabriela

2012-01-01

Chloraea crispa Lindl. is a terrestrial orchid endemic to Chile that has potential to be a novel alternative for the cut flower industry. The objectives of this study were to describe the phenological cycle and floral bud development of C. crispa to determine the timing of initiation and differentiation of the spike. During the summer, plants are dormant. The renewal buds are located at the top of the rhizome, next to the buds from which the shoot of the previous season originated. From the e...

Tres brotes de brucelosis investigados en un año de vigilancia de salud laboral en Ciudad Real Three outbreaks of brucellosis in a one-year period investigated by the occupational health service in Ciudad Real (Spain

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Juan Castell Monsalve

2009-12-01

Full Text Available Presentamos 3 brotes investigados por nuestro servicio de salud laboral en el periodo de 1 año. Dos de ellos, con 2 casos cada uno, en sendas queserías industriales, y el tercero en un laboratorio pecuario perteneciente a la administración autonómica, también con 2 casos. En las 2 queserías se encontraron numerosas oportunidades para que los trabajadores pudieran haberse infectado; se consideró como de mayor riesgo la zona de descarga de leche, y la no utilización de equipos de protección individual por los trabajadores, las deficiencias en los laboratorios y la falta de separación efectiva de las dependencias fueron también potencials factores de riesgo. Respecto al laboratorio pecuario, se hallaron al menos 13 deficiencias importantes que permitían la fácil transmisión del agente infeccioso. En España, el riesgo de adquirir una infección por Brucella en laboratorios o industrias queseras es importante, y las condiciones y medidas para evitarlo que actualmente existen no son efectivas.We describe 3 outbreaks of brucellosis investigated by our Occupational Health Service in a 1-year period. Two of these outbreaks, with 2 cases each, occurred in 2 cheese factories and the third outbreak, also with 2 cases, occurred in a cattle laboratory belonging to the local government. In both cheese factories, numerous opportunities for the workers to become infected were found. The greatest risk was considered to be the area for unloading milk, while failure to use personal protection equipment by workers, deficiencies in the laboratories, and the lack of effective separation between areas were also potential risk factors. In the cattle laboratory, we found at least 13 major risk factors that could allow brucellosis transmission. In Spain, there is a substantial risk of Brucella infection in laboratories or dairy factories and current preventive measures are ineffective.

[Analysis of the components of floral scent in Glochidion puberum using gas chromatography-mass spectrometry with dynamic headspace adsorption].

Science.gov (United States)

Huang, Daihong; Zhang, Zhenguo; Chen, Guoping; Li, Houhun; Shi, Fuchen

2015-03-01

The floral scent plays the important key role in maintaining the obligate pollination mutualism between Glochidion plants and Epicephala moths. In the study, the dynamic headspace adsorption technique was employed to collect the floral scent emitted by Glochidion puberum, gas chromatography coupled with mass spectrometry (GC-MS) was used for the detection and identification of volatile chemical components in headspace samples of flowers from G. puberum. The peak area normalization was used to determine the relative contents of each odour component. The results showed that 45 compounds mainly consisting of monoterpenes and sesquiterpenes were isolated from the floral scent produced by G. puberum. Especially, both linalool (38.06%) and β-elemene (23.84%) were considered as the major scent components of G. puberum. It was speculated that linalool and β-elemene may be the two potential compounds attracting female Epicephala moths. The study provided the basic data for further electroantennographic detection and bioassays to identify the compounds having the actual physiological activity to female Epicephala moths.

Floral scent compounds of Amazonian Annonaceae species pollinated by small beetles and thrips.

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Jürgens, A; Webber, A C; Gottsberger, G

2000-11-01

Chemical analysis (GC-MS) yielded a total of 58 volatile compounds in the floral scents of six species of Annonaceae distributed in four genera (Xylopia, Anaxagorea, Duguetia, and Rollinia), Xylopia aromatica is pollinated principally by Thysanoptera and secondarily by small beetles (Nitidulidae and Staphylinidae), whereas the five other species were pollinated by Nitidulidae and Staphylinidae only. Although the six Annonaceae species attract a similar array of pollinator groups, the major constituents of their floral scents are of different biochemical origin. The fragrances of flowers of Anaxagorea brevipes and Anaxagorea dolichocarpa were dominated by esters of aliphatic acids (ethyl 2-methylbutanoate, ethyl 3-methylbutanoate), which were not detected in the other species. Monoterpenes (limonene, p-cymene, alpha-pinene) were the main scent compounds of Duguetia asterotricha, and naphthalene prevailed in the scent of Rollinia insignis flowers. The odors of X. aromatica and Xylopia benthamii flowers were dominated by high amounts of benzenoids (methylbenzoate, 2-phenylethyl alcohol).

Floral and reproductive biology of Alcantarea nahoumii (Bromeliaceae, a vulnerable endemic species of the Atlantic Forest

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Maria Josirene Souza Moreira Bastos

Full Text Available ABSTRACT Alcantarea nahoumii occurs exclusively in the state of Bahia, Brazil, and is classified as vulnerable due to deforestation and frequent fires in the region. Knowledge of floral and reproductive biology is fundamental to understanding ecological interactions, as well as the reproductive success of plant species. The objective of this study was to evaluate the floral and reproductive biology of A. nahoumii in an Atlantic Forest fragment with regard to phenology, pollen viability, stigma receptivity, pollination ecology and reproductive systems, all of which are important parameters for of the development of conservation strategies for the species. Anthesis is diurnal and heterogeneous, starting at 6:30 a.m. and lasting until 8:00 a.m. Highest germination percentages and greatest pollen tube lengths were obtained in BK culture medium. Histochemical tests revealed high pollen viability (89.71 %. Stigma receptivity occurred during anthesis and lasted for up to 24 hours after floral opening. Alcantarea nahoumii exhibited preferential allogamy and self-compatibility, and required a pollinator to production of viable seeds. Sixteen species of pollinators were observed visiting A. nahoumii, among which were five hummingbird species. Even though its reproductive system is efficient, this bromeliad remains threatened mainly due to habitat fragmentation caused by deforestation, burning and predatory extractivism.

Methylation effect on chalcone synthase gene expression determines anthocyanin pigmentation in floral tissues of two Oncidium orchid cultivars.

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Liu, Xiao-Jing; Chuang, Yao-Nung; Chiou, Chung-Yi; Chin, Dan-Chu; Shen, Fu-Quan; Yeh, Kai-Wun

2012-08-01

The anthocyanin-biosynthetic pathway was studied in flowers of Oncidium Gower Ramsey with yellow floral color and mosaic red anthocyanin in lip crests, sepals and petals, and compared with the anthocyanin biosynthesis in flowers of Oncidium Honey Dollp, a natural somatoclone derived from tissue culture of Gower Ramsey, with a yellow perianth without red anthocyanins in floral tissues. HPLC analysis revealed that the red anthocyanin in lip crests of the Gower Ramsey cultivar comprised peonidin-3-O-glucoside, delphinidin-3-O-glucoside and cyanidin-3-O-glucoside, whereas Honey Dollp was devoid of anthocyanin compounds. Among the five anthocyanin-biosynthetic genes, OgCHS was actively expressed in lip crests of Gower Ramsey flowers, but no transcripts of OgCHS were detected in Honey Dollp floral tissues. Transient expression of OgCHS by bombardment confirmed that recovery of the OgCHS gene expression completed the anthocyanin pathway and produced anthocyanin compounds in lip crests of Honey Dollp flowers. Transcription factor genes regulating anthocyanin biosynthesis showed no distinctive differences in the expression level of OgMYB1, OgbHLH and OgWD40 between the two cultivars. A methylation assay revealed that the promoter of OgCHS was not methylated in Gower Ramsey, while a positive methylation effect was present in the upstream promoter region of OgCHS in Honey Dollp. Overall, our results suggest that the failure of anthocyanin accumulation in Honey Dollp floral tissues may be attributed to inactivation of the OgCHS gene resulting from the epigenetic methylation of 5'-upstream promoter region.

Assessing pollinators’ use of floral resource subsidies in agri-environment schemes: An illustration using Phacelia tanacetifolia and honeybees

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Rowan Sprague

2016-11-01

Full Text Available Background Honeybees (Apis mellifera L. are frequently used in agriculture for pollination services because of their abundance, generalist floral preferences, ease of management and hive transport. However, their populations are declining in many countries. Agri-Environment Schemes (AES are being implemented in agricultural systems to combat the decline in populations of pollinators and other insects. Despite AES being increasingly embedded in policy and budgets, scientific assessments of many of these schemes still are lacking, and only a few studies have examined the extent to which insect pollinators use the floral enhancements that are part of AES and on which floral components they feed (i.e., pollen and/or nectar. Methods In the present work, we used a combination of observations on honeybee foraging for nectar/pollen from the Californian annual plant Phacelia tanacetifolia in the field, collection of pollen pellets from hives, and pollen identification, to assess the value of adding phacelia to an agro-ecosystem to benefit honeybees. Results It was found that phacelia pollen was almost never taken by honeybees. The work here demonstrates that honeybees may not use the floral enhancements added to a landscape as expected and points to the need for more careful assessments of what resources are used by honeybees in AES and understanding the role, if any, which AES play in enhancing pollinator fitness. Discussion We recommend using the methodology in this paper to explore the efficacy of AES before particular flowering species are adopted more widely to give a more complete illustration of the actual efficacy of AES.

Detección de un brote de hepatitis A en Ceuta a través del sistema de información microbiológica Detection of a hepatitis A outbreak in Ceuta [Spain] through a microbiological surveillance system

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María Teresa Ortega-Maján

2008-08-01

Full Text Available Antecedentes: El Servicio de Vigilancia Epidemiológica de Ceuta comunicó al Centro Nacional de Epidemiología un aumento de casos de hepatitis A, detectado por el sistema de información microbiológica (SIM. Se investigó la posible existencia de un brote y se instauraron las medidas de control oportunas. Métodos: Se realizó un estudio descriptivo y otro de casos y controles. La información sociodemográfica, clínica y sobre factores de riesgo se obtuvo mediante un cuestionario cumplimentado por vía telefónica. Resultados: Se identificaron 19 casos. En el estudio univariante se encontró una asociación entre enfermar y el consumo de verduras crudas (odds ratio [OR] = 9,3; intervalo de confianza [IC] del 95%: 1,5-57,6 y de navajas (OR = 55; IC del 95%: 4,3-703,4. En el análisis multivariante sólo se mantuvo la asociación con el consumo de navajas (OR = 36,1; IC del 95%: 2,4-530,4. Ninguno de los 3 restaurantes inspeccionados disponía de control de facturas ni albaranes. Conclusiones: Se confirmó un brote de hepatitis A asociado al consumo de navajas en domicilios y restaurantes. El SIM fue la herramienta fundamental para su detección.Background: The Public Health Department of Ceuta informed the Spanish National Epidemiology Center of an increase in hepatitis A cases detected by the microbiological surveillance system. We conducted a study to confirm the outbreak and to initiate control measures. Methods: A descriptive study and a case-control study were performed. A standardized telephone questionnaire was used to collect information on demographic characteristics, symptoms, and risk factors. Results: Nineteen cases of hepatitis A were identified. Univariate analysis revealed an association between infection and eating raw vegetables (OR = 9.3; 95%CI: 1.5-57.6 or razor-shell (OR = 55; 95%CI: 4.3-703.4. In the logistic regression model, only razor-shell consumption remained a significant risk factor (OR = 36.1; 95%CI: 2

Behavior and diversity of floral visitors to Campomanesia adamantium (Myrtaceae)

OpenAIRE

NUCCI, MATEUS; ALVES-JUNIOR, ALTER VIEIRA

2017-01-01

Abstract Considering the important roles of pollinators in ecosystem services, their identification and studies of their behavior would be extremely important to efforts directed towards their preservation and management. With the aim of examining the diversity and behavior of the floral visitors to Campomanesia adamantium (Cambessédes) O. Berg (“guavira”) and how they act in the pollination process, a total of 31 species belonging to the orders Hymenoptera (79.30 %), Coleoptera (11.34 %), Di...

The Biosynthesis of Unusual Floral Volatiles and Blends Involved in Orchid Pollination by Deception: Current Progress and Future Prospects.

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Wong, Darren C J; Pichersky, Eran; Peakall, Rod

2017-01-01

Flowers have evolved diverse strategies to attract animal pollinators, with visual and olfactory floral cues often crucial for pollinator attraction. While most plants provide reward (e.g., nectar, pollen) in return for the service of pollination, 1000s of plant species, particularly in the orchid family, offer no apparent reward. Instead, they exploit their often specific pollinators (one or few) by mimicking signals of female insects, food source, and oviposition sites, among others. A full understanding of how these deceptive pollination strategies evolve and persist remains an open question. Nonetheless, there is growing evidence that unique blends that often contain unusual compounds in floral volatile constituents are often employed to secure pollination by deception. Thus, the ability of plants to rapidly evolve new pathways for synthesizing floral volatiles may hold the key to the widespread evolution of deceptive pollination. Yet, until now the biosynthesis of these volatile compounds has been largely neglected. While elucidating the biosynthesis in non-model systems is challenging, nonetheless, these cases may also offer untapped potential for biosynthetic breakthroughs given that some of the compounds can be exclusive or dominant components of the floral scent and production is often tissue-specific. In this perspective article, we first highlight the chemical diversity underpinning some of the more widespread deceptive orchid pollination strategies. Next, we explore the potential metabolic pathways and biosynthetic steps that might be involved. Finally, we offer recommendations to accelerate the discovery of the biochemical pathways in these challenging but intriguing systems.

Change of floral orientation within an inflorescence affects pollinator behavior and pollination efficiency in a bee-pollinated plant, Corydalis sheareri.

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Hui Wang

Full Text Available Vertical raceme or spike inflorescences that are bee-pollinated tend to present their flowers horizontally. Horizontal presentation of flowers is hypothesized to enhance pollinator recognition and pollination precision, and it may also ensure greater consistency of pollinator movement on inflorescences. We tested the hypotheses using bee-pollinated Corydalis sheareri which has erect inflorescences consisting of flowers with horizontal orientation. We altered the orientation of individual flowers and prepared three types of inflorescences: (i unmanipulated inflorescences with horizontal-facing flowers, (ii inflorescences with flowers turned upward, and (iii inflorescences with flowers turned downward. We compared number of inflorescences approached and visited, number of successive probes within an inflorescence, the direction percentage of vertical movement on inflorescences, efficiency of pollen removal and seed production per inflorescence. Deviation from horizontal orientation decreased both approaches and visits by leafcutter bees and bumble bees to inflorescences. Changes in floral orientation increased the proportion of downward movements by leafcutter bees and decreased the consistency of pollinator movement on inflorescences. In addition, pollen removal per visit and seed production per inflorescence also declined with changes of floral orientation. In conclusion, floral orientation seems more or less optimal as regards bee behavior and pollen transfer for Corydalis sheareri. A horizontal orientation may be under selection of pollinators and co-adapt with other aspects of the inflorescence and floral traits.

Estudio preliminar de la biología reproductiva Terminalia oblonga (Surá en la región Huetar Norte, Costa Ria

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Elizabeth Arnáez

Full Text Available Para el proceso de domesticación de especies, es necesario la determinación de los ciclos reproductivos de las especies forestales, especialmente de aquellas que se encuentran en peligro de extinción y que se desean utilizar en proyectos de reforestación. El objetivo fue conocer algunos aspectos del comportamiento fenológico y el desarrollo ontogénico de Terminalia oblonga (surá en la Región Huetar Norte. El trabajo de campo se llevó a cabo de enero de 1996 a diciembre de 1998, en la Región Huetar Norte de Costa Rica, en 4 zonas bioclimáticas diferentes de la Región. En cada sitio se seleccionaron 10 árboles, para un total de 40 individuos observados. Los árboles seleccionados se visitaron cada mes, con el fin de determinar épocas de floración (salida de brotes florales, apertura de la flor, salida del fruto, maduración y la caída de este,dispersión de frutos y semillas, brotadura vegetativa y hojas. Mensualmente, se recopiló información climática, donde se tomó en cuenta: precipitación, temperatura, humedad relativa y brillo solar. Estos datos se emplearon para hacer las correlaciones con los resultados de las diferentes expresiones fenológicas. Se hizo una descripción de las piezas reproductivas y vegetativas, con base en material en fresco y con el apoyode microscopía electrónica de barrido. Además, se hicieron estudios químicos y estructurales del suelo en cada uno de los sitios de estudio. Se observó que la brotadura de las hojas de esta especie se mantiene durante todo el año, siendo mayor en julio y diciembre en la mayoría de las zonas y en algunas ocasiones puede llegar a estar casi ausente. El follaje se mantiene relativamente constante casi todo el año, con muy poca defoliación. La brotadura floral generalmente se observa de octubre a enero, e incluso febrero en algunas zonas. La floración se nota de noviembre a febrero y la maduración de los frutos de diciembre a marzo y hasta en abril en algunas

Vigilancia microbiológica del sarampión y la rubéola en España: red de laboratorios

OpenAIRE

Echevarría, Juan Emilio; Fernández García, Aurora; Ory, Fernando de

2015-01-01

El laboratorio es un elemento imprescindible en la vigilancia del sarampión y la rubéola, ya que los casos han de ser adecuadamente confirmados para poder estimar la incidencia de forma precisa, las cepas han de ser caracterizadas genéticamente para conocer el patrón de circulación de los virus y estudiar de forma completa los brotes y las cadenas de transmisión y la susceptibilidad de la población debe de ser determinada mediante encuestas de seroprevalencia. El diagnóstico de laboratorio de...

Inmunidad de grupo. Significado e importancia

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Vaqué Rafart, Josep

2005-01-01

En los últimos veinte años el concepto de “inmunidad de grupo” ha adquirido gran relevancia debido a su utilidad para definir los objetivos y estrategias de los programas de vacunación, pues permite determinar la intensidad de las actuaciones a aplicar para impedir brotes epidémicos y para controlar y eliminar enfermedades infecciosas. Su definición clásica, establecida por Fox en 1971, dice: "Es la resistencia de un grupo a una infección ante la que una amplia proporción de individuos posee ...

Aislamiento de Escherichia coli productor de toxina Shiga durante un brote de gastroenteritis en un Jardín Maternal de la Ciudad de Mar del Plata Isolation of Shiga toxin-producing Escherichia coli strains during a gastrointestinal outbreak at a day care center in Mar del Plata City

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D. Gomez

2005-12-01

Full Text Available Entre el 15 de octubre y el 8 de noviembre de 2003 ocurrió un brote de gastroenteritis en un Jardín Maternal de un Hospital de la ciudad de Mar del Plata. Catorce de un total de 80 niños (17,5%, edad promedio 23,6 ± 13,9 meses, presentaron diarrea, y un caso evolucionó a síndrome urémico hemolítico. La madre de uno de los afectados presentó diarrea simultáneamente. No se pudo establecer el origen del brote, pero probablemente la transmisión haya sido fundamentalmente persona a persona. Las prácticas habituales en el lactario del jardín maternal, y las condiciones inadecuadas de infraestructura y hábitos de higiene de la cocina del Hospital fueron señalados como factores de riesgo. En un caso se detectó Escherichia coli productor de toxina Shiga (STEC O103:H2, y STEC O26:H11 en otro. En el niño infectado por STEC O26:H11, la excreción se extendió por un período de 37 días. La no detección de STEC en aquellos casos en los cuales el intervalo entre el inicio de los síntomas y la toma de muestra fue mayor a 6 días, enfatiza la necesidad de la recolección temprana de especímenes. Las principales conclusiones de este estudio fueron la necesidad de establecer normas óptimas de higiene, informar rápidamente la ocurrencia de casos de gastroenteritis y confirmar la negativización de la excreción del patógeno.From October 15 to November 8, 2003, a gastrointestinal outbreak occurred at a day care center in a Hospital in Mar del Plata City. Fourteen out of 80 (17.5% children, mean age 23.6 ± 13.9 months, and the mother of one of them had diarrhea. One case developed hemolytic uremic syndrome. No conclusive evidence of the origin of the outbreak was found, but the epidemic curve suggested person-to-person spread. The usual practices at the place where infant milk formula was prepared at the day care center, together with the inadequate infrastructure conditions and hygiene practices at the kitchen of the hospital, were

Patterns of nectar production and composition, and morphology of floral nectaries in Helicteres guazumifolia and Helicteres baruensis (Sterculiaceae: two sympatric species from the Costa Rican tropical dry forest

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Loretta Goldberg

2009-11-01

Full Text Available Helicteres guazumifolia Kunth and Helicteres baruensis Jacq. (Sterculiaceae are two sympatric species of shrubs common along the North Western tropical dry forest of Costa Rica. i recorded their nectar production within a 24 hour cycle. i also describe the morphology of extrafloral nectaries with scanning electron microscopy. in H. guazumifolia secretion was restricted to the first day of flower life span, shortly after anthesis (0600 hr - 1800 hr. Flowers secreted on average 15.63 ±8.45 µl (N=409. Nectar is composed of three main sugars: sucrose, fructose and glucose (mainly sucrose. A total of 17 free amino acids were identified: mainly proline, arginine, threonine and tyrosine, with a concentration above 70 Ng/µl. values were different for H. baruensis. Nectar secretion was confined to the second day after anthesis, starting at 1600 hr and ending at 0600 hr the following day. Flowers secreted on average 77.03 ±64.99 µl (N=163 of nectar. Nectar is also composed of three main sugars; however, it showed a tendency to be hexose-rich, having more fructose and glucose than sucrose. There were also 17 free amino acids, mainly proline, alanine, tyrosine, arginine and threonine. Patterns of nectar production are different between the two species for timing, and for amount and composition of nectar secretion. Rev. Biol. Trop. 57 (Suppl. 1: 161-177. Epub 2009 November 30.Helicteres guazumifolia Kunth y Helicteres baruensis Jacq. (Sterculiaceae son dos especies simpátricas de arbustos comunes en el bosque tropical seco de la zona noroeste de Costa Rica. Registré los patrones de producción de néctar de las dos especies según la hora del día o de la noche cuando hubo secreción de néctar. En H. guazumifolia se limitó al primer día del período de vida floral, desde el inicio de la antesis a las 0600 hr hasta las 1800 hr. Las flores secretaron en promedio 15.63 ±8.45 µl (N=409 de néctar. El néctar está compuesto por tres az

The ASK1 gene regulates development and interacts with the UFO gene to control floral organ identity in Arabidopsis.

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Zhao, D; Yang, M; Solava, J; Ma, H

1999-09-01

Normal flower development likely requires both specific and general regulators. We have isolated an Arabidopsis mutant ask1-1 (for -Arabidopsis skp1-like1-1), which exhibits defects in both vegetative and reproductive development. In the ask1-1mutant, rosette leaf growth is reduced, resulting in smaller than normal rosette leaves, and internodes in the floral stem are shorter than normal. Examination of cell sizes in these organs indicates that cell expansion is normal in the mutant, but cell number is reduced. In the mutant, the numbers of petals and stamens are reduced, and many flowers have one or more petals with a reduced size. In addition, all mutant flowers have short stamen filaments. Furthermore, petal/stamen chimeric organs are found in many flowers. These results indicate that the ASK1 gene affects the size of vegetative and floral organs. The ask1 floral phenotype resembles somewhat that of the Arabidopsis ufo mutants in that both genes affect whorls 2 and 3. We therefore tested for possible interactions between ASK1 and UFO by analyzing the phenotypes of ufo-2 ask1-1 double mutant plants. In these plants, vegetative development is similar to that of the ask1-1 single mutant, whereas the floral defects are more severe than those in either single mutant. Interior to the first whorl, the double mutant flowers have more sepals or sepal-like organs than are found in ufo-2, and less petals than ask1-1. Our results suggest that ASK1 interacts with UFO to control floral organ identity in whorls 2 and 3. This is very intriguing because ASK1 is very similar in sequence to the yeast SKP1 protein and UFO contains an F-box, a motif known to interact with SKP1 in yeast. Although the precise mechanism of ASK1 and UFO action is unknown, our results support the hypothesis that these two proteins physically interact in vivo. Copyright 1999 Wiley-Liss, Inc.

Sarampión en Chile 1960-1985

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S. Barja Y.

2017-05-01

Full Text Available El efecto inmediato más destacado del programa de vacunación es la notable caída de la tasa de morbilidad y la virtual eliminación de las muertes causadas por sarampión. Persiste, sin embargo, un remanente de casos y continúan ocurriendo brotes esporádicos de magnitud variable. Ha habido, además, como efecto tardío no esperado, un desplazamiento paulatino de las denuncias hacia edades mayores que vaticinan su importancia relativa creciente en el adulto. Los hechos señalados serían consecuencia de la persistencia de "susceptibles residuales" cuyos incrementos periódicos dan origen a brotes cada vez que alcanzan un cifra crítica.

Floral contrivances and specialised pollination mechanism strongly influence mixed mating in Wrightia tomentosa (Apocynaceae).

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Barman, C; Singh, V K; Das, S; Tandon, R

2018-05-01

Reproductive success of a plant species is largely influenced by the outcome of mating pattern in a population. It is believed that a significantly larger proportion of animal-pollinated plants have evolved a mixed-mating strategy, the extent of which may vary among species. It is thus pertinent to investigate the key contributors to mating success, especially to identify the reproductive constraints in depauperate populations of threatened plant species. We examined the contribution of floral architecture, pollination mechanism and breeding system on the extent of outcrossing rate in a near-threatened tree species, Wrightia tomentosa. The breeding system was ascertained from controlled pollination experiments. In order to determine outcrossing rate, 60 open-pollinated progeny were analysed using an AFLP markers. Although the trees are self-compatible, herkogamy and compartmentalisation of pollen and nectar in different chambers of the floral tube effectively prevent spontaneous autogamy. Pollination is achieved through specialised interaction with moths. Differential foraging behaviour of settling moths and hawkmoths leads to different proportions of geitonogamous and xenogamous pollen on the stigma. However, most open-pollinated progeny were the result of xenogamy (outcrossing rate, tm = 0.68). The study shows that floral contrivances and pollination system have a strong influence on mating pattern. The differential foraging behaviour of the pollinators causes deposition of a mixture of self- and cross-pollen to produce a mixed brood. Inbreeding depression and geitonogamy appear to play a significant role in sustaining mixed mating in this species. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

An ultraviolet floral polymorphism associated with life history drives pollinator discrimination in Mimulus guttatus.

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Peterson, Megan L; Miller, Timothy J; Kay, Kathleen M

2015-03-01

• Ultraviolet (UV) floral patterns are common in angiosperms and mediate pollinator attraction, efficiency, and constancy. UV patterns may vary within species, yet are cryptic to human observers. Thus, few studies have explicitly described the distribution or ecological significance of intraspecific variation in UV floral patterning. Here, we describe the geographic distribution and pattern of inheritance of a UV polymorphism in the model plant species Mimulus guttatus (Phrymaceae). We then test whether naturally occurring UV phenotypes influence pollinator interactions within M. guttatus.• We document UV patterns in 18 annual and 19 perennial populations and test whether UV pattern is associated with life history. To examine the pattern of inheritance, we conducted crosses within and between UV phenotypes. Finally, we tested whether bee pollinators discriminate among naturally occurring UV phenotypes in two settings: wild bee communities and captive Bombus impatiens.• Within M. guttatus, perennial populations exhibit a small bulls-eye pattern, whereas a bilaterally symmetric runway pattern occurs mainly in annual populations. Inheritance of UV patterning is consistent with a single-locus Mendelian model in which the runway phenotype is dominant. Bee pollinators discriminate against unfamiliar UV patterns in both natural and controlled settings.• We describe a widespread UV polymorphism associated with life history divergence within Mimulus guttatus. UV pattern influences pollinator visitation and should be considered when estimating reproductive barriers between life history ecotypes. This work develops a new system to investigate the ecology and evolution of UV floral patterning in a species with extensive genomic resources. © 2015 Botanical Society of America, Inc.