El silicio5/7/2023 ![]() ![]() Since the beneficial effects of this element are apt to be observed in plants which accumulate Si, the silica gel deposited on the plant surface is thought to contribute to the beneficial effects of Si, which may be small under optimized growth conditions, but become obvious under stress conditions. ![]() Evidence is lacking concerning the physiological role of Si in plant metabolism. Plants take up Si in the form of silicic acid, which is transported to the shoot, and after loss of water, it is polymerized as silica gel on the surface of leaves and stems. Si fertilizer is applied to crops in several countries for increased productivity and sustainable production. Silicon (Si) has not been proven to be an essential element for higher plants, but its beneficial effects on growth have been reported in a wide variety of crops, including rice, wheat, barley, and cucumber. The inner part of the two-layered cells revealed as almost pure cellulose, oriented parallel along the fiber. Pectin and hemicelluloses (glucomannan) were found in high levels in the epidermal layer and in a clearly distinguished outer part of the hypodermal sterome fibers. No silanol group vibration was detected in the silicified epidermal layer below and association with pectin and hemicelluloses indicated. From this, we concluded that these protrusions were almost pure amorphous, hydrated silica. In the spectrum extracted from the knob region as main contributions, a broad band below 500 cm(-1) attributed to amorphous silica, and a band at 976 cm(-1) assigned to silanol groups, were found. ![]() Accumulation of silica was imaged in the knobs and in a thin layer below the cuticula. This enabled direct visualization of differences in chemical composition and extraction of average spectra from defined regions for detailed analyses, including principal component analysis (PCA) and basis analysis (partial least square fit based on model spectra). Two-dimensional spectral maps were acquired on cross sections of Equisetum hyemale and Raman images calculated by integrating over the intensity of characteristic spectral regions. These questions were addressed by using high resolution (<1 microm) Confocal Raman microscopy. Aspects of silica deposition, its association with other biomolecules, as well as the chemical composition of the outer strengthening tissue still remain unclear. No se logró demostrar que la incorporación de silicato de magnesio como parte de la fertilización mineral, permitiría disminuir la aplicación de P en el cultivo de maíz.Įquisetaceae has been of research interest for decades, as it is one of the oldest living plant families, and also due to its high accumulation of silica up to 25% dry wt. No obstante, el efecto observado se atribuyó al magnesio, por lo que se descartó el posible efecto del silicio sobre las variables evaluadas. Los resultados obtenidos mostraron diferencias significativas (p-valor < 0,05) para el peso seco de planta, longitud de mazorca y peso de 100 granos, especialmente en tratamientos que incluyeron silicato de magnesio en la fertilización mineral. Las variables analizadas fueron altura de planta, número de hojas, peso seco de planta, longitud de mazorca, peso de mazorca, peso de 100 granos y rendimiento de grano. ![]() El estudio se realizó en la finca La Vega, propiedad del Tecnológico de Costa Rica, ubicada en Florencia de San Carlos, Alajuela, Costa Rica. Se realizó un experimento para evaluar el efecto de la inclusión de silicato de magnesio en la fertilización mineral del cultivo de maíz (Zea mays). La esencialidad de los elementos minerales para el desarrollo confortable y productivo de los vegetales, se ha basado en tres principios que se enuncian a continuación: Justus von Liebig, (1840): La ley del mínimo, dice que el nutriente que se encuentra menos disponible es el que limita la producción, aun cuando los demás estén en cantidades suficientes. nH 2 O) continuando con los procesos biológicos, fisiológicos y productivos relacionados con el Si y concluiremos con el origen mineral del Si soluble. Iniciaremos nuestra discusión a partir de la descripción de los cuerpos de sílice (SiO 2. El silicio (Si), es un elemento químico metaloide, número atómico 14 y masa molecular 28.0855 g mol -1, y segundo elemento más abundante en la corteza terrestre, tal vez por ello no es considerado como un elemento esencial para el desarrollo sustentable de los organismos fotosintéticos, y ha sido un tema de gran debate, nosotros aquí expondremos brevemente el ciclo biogeoquímico del Si en los ecosistemas fotosintéticos. ![]()
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