Quelato de hierro y agua de coco en la germinación in vitro de rossioglossum grande (orchidaceae)

Rossioglossum grande (Lindl.) Garay and amp; G.C. Kenn es una orquídea nativa mexicana considerada en peli-gro de extinción por la NOM-059-Semarnat-2010. Teniendo en cuenta que la germinación asimbiótica in vitro es una herramienta estratégica para la conservación de orquídeas amenazadas, en este estudio se generó información básica mediante la comparación de la germinación de R. grande en medios Knudson C (KC) y Dalla Rosa y Laneri modificado con quelato de hierro y agua de coco (DR). Para el efecto se utili-zaron un cultivo madre (CM) y dos subcultivos (C1 y C2) y los tratamientos se dispusieron en un diseño experimental totalmente aleatorio. Los resultados se analizaron mediante análisis de varianza y comparación de medias con la prueba de Tukey (P ≤ 0.05) y Chi-cuadrada. A 60 días en el CM el medio de cultivo DR favoreció el desarrollo, la tasa de sobrevivencia y disminuyó la clorosis de los protocormos. A los 12 meses se presentó mayor desarrollo y mayor regeneración de protocormos. En los subcultivos C1 y C2 se registraron resultados similares lo que confirma que el DR acelera el desarrollo de los protocormos e incrementa su tamaño y tasa de regeneración. En síntesis, el empleo de hierro-quelato y agua de coco promueven el desarrollo in vitro de protocormos de R. grande

Aplicación de visión por computadora en la evaluación del desarrollo in vitro de protocormos de Oncidium sphacelatum Lindl., (Orchidaceae)

Se presenta una aplicación de visión por computadora diseñada para monitorear el desarrollo de protocormos de orquídea en condiciones in vitro, con el objetivo de evaluar el proceso de germinación de manera eficiente, rápida y objetiva. A partir de fotografías digitales, se evaluó el desarrollo de protocormos de Oncidium sphacelatum Lindl. (Orchidaceae) en términos de tamaño (medido a través de su área en pixeles), el cambio de etapa fenológica dentro del proceso de germinación (medido a través del factor de redondez) y el estado de salud (por tonalidad de color). La programación desarrollada para que el ordenador sea capaz de este tipo de análisis, se compone de una etapa de segmentación para discernir los pixeles de interés (protocormos) del fondo, una de entrenamiento-aprendizaje para establecer criterios de segregación y una última de clasificación. La programación se realizó mediante la plataforma Matlab R2012a. Las características obtenidas por el sistema permiten proporcionar de manera automática, digerida y objetiva, información útil para la evaluación del proceso de germinación de las orquídeas en condiciones in vitro, con un significativo ahorro en termino de horas/trabajo y desgaste físico del operador humano, sin perturbar la calidad de la evaluación

Respuesta agronómica del pepino (Cucumis sativus L.) a la aplicación de abonos orgánicos en diferentes sistemas de producción (REVISIÓN)

The following work was developed with the objective to evaluate the cucumber crop in different systems: open field, macro-tunnel and shade mesh from April 24th to August 31st of 2016. In each system, different sources of fertilization were tested and the doses were according to the need of nutritional crop. The fertilization sources were: vermicompost, compost, cattle and sheep manure and a control treatment (chemical fertilization). Morphological variables were evaluated: height (cm) and stem diameter (mm); growth indices: Absolute Growth Rate (g day) and Crop Growth Rate (m2 g day); yield (kg m2) and fresh fruit masses (g). A randomized block design with a factorial arrangement (3 x 5) with five replications was used and the Tukey mean comparison test (α≤0.05) was run for the variables that showed significant. The best morphological growth dynamics was observed with the use of organic fertilizers. Growth rates had similar behaviors depending on the system and fertilization. The best yields 23,434, 18,795 and 19.59 kg m2 were registered in the chemical fertilization interaction within the macro-tunnel, shade mesh and open field systems, respectively. The bovine and ovine manures and vermicompost recorded fresh fruit masses (481.08, 453.67 and 425.28 g respectively) higher than that registered with chemical fertilization (396.28 g). Therefore, the organic fertilizers used are presented as a fertilization alternative for cucumber cultivation. El presente trabajo se realizó con el objetivo de evaluar el cultivo del pepino en diferentes sistemas: campo abierto, macro-túnel y malla sombra del 24 de abril al 31 de agosto de 2016. En cada sistema se probaron diferentes fuentes de fertilización y las dosis dependieron del requerimiento nutricional del cultivo. Las fuentes de fertilización fueron: lombricomposta, composta, estiércoles bovino y ovino, así como un tratamiento testigo (fertilización química). Se evaluaron variables morfológicas: altura (cm) y diámetro (mm) del tallo; índices de crecimiento: Tasa Absoluta de Crecimiento (g día) y Tasa de Crecimiento del Cultivo (m2 g día); rendimiento (kg m2) y masas frescas de los frutos (g). Se utilizó un diseño en bloques al azar con arreglo factorial (3 x 5) con cinco repeticiones y se corrió la prueba de comparación de medias de Tukey (α≤0.05) para las variables que mostraron diferencias significativas. La mejor dinámica de crecimiento morfológica se observó con la utilización de los abonos orgánicos. Los índices de crecimiento tuvieron comportamientos similares en dependencia del sistema y de la fertilización. Los mejores rendimientos 23.434, 18.795 y 19.59 kg m2 se registraron en la interacción fertilización química dentro de los sistemas macro-túnel, malla sombra y campo abierto respectivamente. Los estiércoles bovinos, ovino y la lombricomposta registraron masas frescas de frutos (481.08, 453.67 y 425.28 g respectivamente) superiores a lo registrado con la fertilización química (396.28 g). Por lo tanto, los abonos orgánicos utilizados se presentan como alternativa de fertilización para el cultivo del pepino.&nbsp

Seedling competition between Pennisetum setaceum (Poaceae) and three native weeds of La Primavera wood, Guadalajara, Jalisco (México)

Pennisetum setaceum (Forssk.) Chiov., 1923 is an exotic grass from the Arabian Peninsula that has been very successful as an ornamental plant worldwide in recent years. Unfortunately, it has proved to be a very competitive invader, causing ecological problems in several regions of the world. We don't know exactly how this species interacts with native weeds in Mexico. Our study aims to show the interactions of Pennisetum with three species of native weeds in the surroundings of the metropolitan area of Guadalajara, Jalisco, Mexico: Aeschynomene villosa var. longifolia (Micheli) Rudd, Desmodium aparines (Link) DC. and Paspalum notatum (Flüggé). The seeds of Pennisetum were tested in monospecific groups (competing against itself) and in association with each of the native species mentioned and with a treatment together with all the compound of the species mentioned, thus simulating what could happen in natural conditions upon the arrival of the seeds of P. setaceum in a degraded soil of Guadalajara. The results show how the biomass produced and the speed of growth of Pennisetum can be a real alarm for the conservation of local germplasm

Metallic elements in foliar material and fruits of three tree species as bioindicators

This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use. Highlights Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals. The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06% The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents. The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use.This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use. Highlights Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals. The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06% The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents. The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use

Indicators of restoration strategies in land uses: metallic and non-metallic elements

Land management practices can have an impact on the environmental quality of soil and contribute to identifying the source of its pollution. The objective of this study was to determine presence of metallic and non-metallic elements as indicators of land use impact (livestock management, restoration strategies and without management practices) in the Monte Caldera communal lands located in Cerro de San Pedro, San Luis Potosi, Mexico. Eighteen samples were collected at depths of 0-10 cm and 10-20 cm for each land use. Total concentrations of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu were determined by X-ray fluorescence. Mean concentrations ranged in the following order: Ti>Zr>Rb>V>Sr>Zn>Cr>Pb> Cu>Th>U>As, with concentrations for Ti, Cr, Th, U and As exceeding technical reference values for phytotoxic soils. Significant differences were evidenced by ANOVA between land use (Th, Pb, Rb, Cu) and soil depth (U, Pb, and As). Land use practices associated with restoration resulted in a positive environmental impact. These findings underscore the need to conduct follow-up studies in the area and further examine the relationship of such practices with other environmental factors. Highlights: Soil management practices can affect the environmental quality of this resource and help diagnose the source of its contamination. It is necessary to evaluate the Impact of land use on livestock management, restoration strategies, and without management or conservation areas. By X-ray fluorescence technique the total concentration of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu was determined. Ti, Cr, Th, U and As exceed the technical reference values for consideration as phytotoxic in soils. Land use associated with reclamation practices is an indicator of a positive influence on improving soil quality.Land management practices can have an impact on the environmental quality of soil and contribute to identifying the source of its pollution. The objective of this study was to determine presence of metallic and non-metallic elements as indicators of land use impact (livestock management, restoration strategies and without management practices) in the Monte Caldera communal lands located in Cerro de San Pedro, San Luis Potosi, Mexico. Eighteen samples were collected at depths of 0-10 cm and 10-20 cm for each land use. Total concentrations of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu were determined by X-ray fluorescence. Mean concentrations ranged in the following order: Ti>Zr>Rb>V>Sr>Zn>Cr>Pb> Cu>Th>U>As, with concentrations for Ti, Cr, Th, U and As exceeding technical reference values for phytotoxic soils. Significant differences were evidenced by ANOVA between land use (Th, Pb, Rb, Cu) and soil depth (U, Pb, and As). Land use practices associated with restoration resulted in a positive environmental impact. These findings underscore the need to conduct follow-up studies in the area and further examine the relationship of such practices with other environmental factors. Highlights: Soil management practices can affect the environmental quality of this resource and help diagnose the source of its contamination. It is necessary to evaluate the Impact of land use on livestock management, restoration strategies, and without management or conservation areas. By X-ray fluorescence technique the total concentration of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu was determined. Ti, Cr, Th, U and As exceed the technical reference values for consideration as phytotoxic in soils. Land use associated with reclamation practices is an indicator of a positive influence on improving soil quality

Metales pesados en polvo atmosférico depositado en hojas de Acacia farnesiana (Fabaceae) y Prosopis laevigata (Fabaceae)

Atmospheric dust establishes an element of study to know the distribution of pollutant particles such as heavy metals and their effects on ecological systems. The objective was to determine the elemental composition of particles deposited in two species of trees as an indicator of environmental impact in San Luis Potosí, México. The distribution of Acacia farnesiana and Prosopis laevigata trees was taken into account in five soil uses to collect leaf material and extract atmospheric dust during the spring and summer seasons, determining the concentration of heavy metals using the ICP-MS technique. The results indicated the presence of Al> Cu> Zn> Pb> V> As> Ni> Cd> Ti> Cr> Co. Correlations with values of r2> 0.90 were presented between V-Ti, Ni-V, Ni-Ti, Al-Ti and Cr-V. The species factor conditioned the concentrations of Al, Ti, V, Cr, Ni and Zn mainly in the particles deposited in Prosopis leaves. Particles of nine elements were conditioned by the activities of the five land uses, where the use of mineral soil affected by the presence of Al, Cd, Co, Pb, Cu and Zn. Concentrations of Cd were 6.2 times higher in the use of mining soil than in the agricultural sector; 5.9 and 5.4 times the concentrations of Co and Pb in the use of mining soil with respect to the trade and service respectively. The season had only significant effects on Cr and Pb particles. This study indicates the existence of pollutants that can affect ecological systems so it falls within the context of continued evaluation of environmental impacts.El polvo atmosférico se establece como elemento de estudio para conocer la distribución de partículas contaminantes, como son los metales pesados y sus efectos sobre los sistemas ecológicos. El objetivo fue determinar la composición elemental de las partículas depositadas en dos especies de árboles como un indicador de impacto ambiental en San Luis Potosí, México. La distribución de los árboles de Acacia farnesiana y Prosopis laevigata se tomó en cuenta en cinco usos del suelo para recolectar material foliar y extraer el polvo atmosférico durante la primavera y el verano, determinando la concentración de metales pesados utilizando la técnica ICP-MS. Los resultados indicaron la presencia de Al> Cu> Zn> Pb> V> As> Ni> Cd> Ti> Cr> Co. Se presentaron correlaciones con valores de r2> 0,90 entre V-Ti, Ni-V, Ni-Ti, Al-Ti y Cr-V. El factor especie condicionó las concentraciones de Al, Ti, V, Cr, Ni y Zn principalmente en las partículas depositadas en las hojas de Prosopis. Las partículas de nueve elementos fueron condicionadas por las actividades de los cinco usos de la tierra, donde el uso del suelo mineral se vio afectado por la presencia de Al, Cd, Co, Pb, Cu y Zn. Las concentraciones de Cd fueron 6,2 veces más altas en el uso de suelo minero que en el sector agrícola; 5,9 y 5,4 veces las concentraciones de Co y Pb en el uso del suelo minero con respecto al comercio y al servicio, respectivamente. La temporada solo tuvo efectos significativos sobre las partículas de Cr y Pb. Este estudio indica la existencia de contaminantes que pueden afectar los sistemas ecológicos, por lo que entran en el contexto de la evaluación de los impactos ambientales.Fil: Jorge Alcalá Jáuregui. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Juan C. Rodríguez Ortiz. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Alejandra Hernández Montoya. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: María Flavia Filippini. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Eduardo Martinez Carretero. Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Paola Elizabeth Díaz Flores. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Ángel Natanael Rojas Velázquez. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Humberto Rodríguez-Fuentes. Universidad Autónoma de Nuevo León (México). Facultad de Agronomía.Fil: Félix Alfredo Beltrán Morales. Universidad Autónoma de Baja California Sur (México

Nanocompuesto de Nitrógeno como Fertilizante de Liberación Lenta en Columnas de Suelo con Plantas de Lechuga

El uso continuo de fertilizantes nitrogenados en exceso genera riesgos ambientales al aumentar en el suelo la acumulación, volatilización y lixiviación de nitratos, que provocan pérdidas y baja eficiencia en la utilización de N. En este estudio, el objetivo fue evaluar la aplicación de nanocompuestos nitrogenados (NCN) como fertilizante de liberación lenta en el suelo y su efecto en el crecimiento del cultivo de lechuga. El NCN se preparó por la sorción de un surfactante catiónico en una arcilla de bentonita. El estudio se realizó en columnas de suelo, los tratamientos evaluados fueron relaciones de NCN y fertilizante convencional (FC) 25/0, 50/0, 75/0 y 100/0, 0/100, 25/75, 50/50 y 75/25. Las variables evaluadas fueron: peso fresco, biomasa seca, área foliar, conductividad eléctrica, concentración de NO3- en lixiviado y hoja, unidades SPAD y NDVI, además de la liberación del NCN en agua desionizada. Los resultados obtenidos indican que después de 40 días los tratamientos con NCN igualaron al control excepto el tratamiento 25/0 que redujo las variables peso fresco 20% y el área foliar 18% con respecto al control 0/100. Los valores de SPAD y NVDI no tuvieron diferencias significativas entre tratamientos. Las relaciones NCN/FC 0/100, 50/50 y 75/25 aumentaron 19% la concentración de nitratos en hojas. El tratamiento 100/0 aumentó biomasa seca total con 48%, 87% el volumen radical y 73% la biomasa seca de raíz. Los resultados de la liberación en agua desionizada confirmaron que el NCN libera gradualmente nitratos y en mayor cantidad que lo calculado. Finalmente, se concluye que el material nanocompuesto tiene el potencial de usarse como fertilizante de lenta liberación al aumentar crecimiento, por lo que podría ser una alternativa para reducir el uso de fertilizantes convencionales y disminuir las pérdidas de nitrógeno en suelo

Application of computer vision in the assessment of the in vitro development of Oncidium sphacelatum Lindl., (Orchidaceae) protocorms

We report an application of computer vision designed to monitor the in vitro development of Oncidium sphacelatum Lindl., orchid protocorms. Growth and development of protocorms was evaluated in terms of size (measured through the area in pixels), changing in its shape within the germination process (measured by the roundness factor) and state of health (color tone), using digital photos. Programming the software Matlab R2012a, we developed a type of analysis, consists of a first stage as segmentation to discern the pixels of interest (protocorms), a second stage of training and learning to establish criteria for segregation of interest object and a final stage as classification. Programming is performed by R2012a Matlab platform. The characteristics obtained by our system provide useful information for evaluating the germination process of in vitro propagation by orchid grains, with significant savings in terms of hours/work of the human operator