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El estrés por salinidad es uno de los problemas ambientales con mayor impacto en la agricultura, ya que provoca cambios morfológicos, fisiológicos y genéticos en las plantas. Considerando el gran impacto de la salinidad, se buscan alternativas para mitigar el estrés en las plantas, en especial por cloruro de sodio (NaCl). Los productos a base de silicio (Si) tienen la capacidad de mejorar el crecimiento y desarrollo de las plantas, al estar expuestas en condiciones salinas. El objetivo de esta investigación fue evaluar la interacción NaCl-Si en la emergencia de plántulas de tres variedades de tomate. El diseño experimental fue completamente al azar con arreglo factorial de 32, donde el factor A fueron las concentraciones de cloruro de sodio (0 mM, 25 mM, 50 mM) y el factor B, las diluciones de Si (0 mM, 1 mM, 2 mM). Los resultados indican que las variedades de tomate fueron impactadas de diferente manera por la interacción NaCl-Si. En condiciones no salinas (0 mM de NaCl) el Si incrementó el crecimiento de tomate cherry y saladette, mientras que en condiciones de salinidad moderada (25 mM de NaCl) sólo el tomate saladette fue beneficiado.

La agricultura se enfrenta a nuevos retos cada vez más complicados ante un medio ambiente en constante cambio que ocasiona diferentes tipos de estrés en los cultivos, siendo uno de ellos la salinidad. Se han realizado numerosas investigaciones para conocer el efecto del estrés salino en la fisiología de las plantas, así como también diferentes maneras de afrontarlo y crear tolerancia y/o resistencia para que la productividad de los cultivos no se vea afectada, entre estas alternativas encontramos a los bioestimulantes. El bioestimulante CBX-103 que está compuesto por ácidos carboxílicos, succínicos, oligogalacturónidos, entre otros, los cuales se obtienen mediante una fermentación enzimática controlada del extracto vegetal de Saccharum officinarum L. En el presente estudio se demuestra que las aplicaciones foliares del bioestimulante CBX-103 en plantas de Arabidopsis thaliana Col 0 cultivadas bajo estrés salino incrementan el contenido foliar de prolina, disminuyendo significativamente los efectos nocivos del estrés, lo cual se demuestra a nivel biométrico y regulando los estados de crecimiento. Se propone como modo de acción una vía en la regulación energética de las plantas debido al incremento en la acumulación de prolina obtenida y al efecto de sus componentes.

Melatonin (N-acetyl-5-methoxytryptamine) is a molecule with a reported importance in increasing tolerance to several types of stress. The present study investigates the effect of melon (Cucumis melo L.) seed treatment with melatonin solutions (0, 10, 50 and 100 µM) at two durations (6 and 12 h) on germination and initial growth of melon plants in salt stress. Germination under salt stress (14 dS m-1 EC) suffered a decrease, which is reversed after seed treatment with melatonin and followed to 80% with 10 and 50 µM solutions. Then, considering plant growing in salt stress (8 dS m-1 EC), the best growth and physiological and biochemical responses (xylem water potential, leaf relative water content, total chlorophyll, root viability, proline, malondialdehyde content, peroxidase and catalase activity) were measured in plants derived from 50 µM seed treatment. No changes were observed at the anatomical level. Results suggest that melatonin can alleviate the effect of salt stress during seed germination and early plant growth. There is a dose-dependent response. [ABSTRACT FROM AUTHOR]

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Losrecursos genéticos de los tomates silvestres (Solanum spp.) han demostrado ser valiosos reservorios de genes de tolerancia al estrés biótico y abiótico. Dado el aumento de áreas agrícolas con incidencia de salinidad, es necesario identificar genes de tolerancia para ser transferidos a variedades comerciales. El objetivo de esta investigación fue identificar líneas con tolerancia a la salinidad en poblaciones silvestres nativas. Se evaluaron 96 líneas bajo dos concentraciones de NaCl (0 y 150 mM) durante las etapas de germinación y de plántula. Durante la germinación se evaluó el porcentaje de germinación y de plántulas normales, así como el índice de velocidad de germinación. Un total de 11 líneas mostraron tolerancia al estrés salino. En la etapa de plántula se evaluaron 41 líneas seleccionadas por su respuesta durante la germinación y se cuantificó el peso fresco y seco de la raíz y parte aérea, contenido relativo de agua, altura de la planta y longitud de la raíz. En esta etapa se identificaron seislíneas que mostraron mayor tolerancia a la salinidad. Las líneas identificadas con tolerancia a la salinidad se pueden utilizar como recursos en programas de mejoramiento genético.

La prolina es un aminoácido que se acumula en plantas en respuesta a condiciones de estrés. Se ha reportado que la aplicación exógena de prolina aumenta la tolerancia al estrés. Se realizó un experimento para evaluar el efecto de diferentes soluciones de prolina exógena aplicadas a plántulas de melón cultivadas en estrés salino. Se evaluaron cuatro concentraciones de prolina: 0, 5, 10 y 20 mM. Las plantas se cultivaron con una conductividad eléctrica de 8,0 dS m-1. Las plantas tratadas con prolina 10 y 20 mM tuvieron un mayor contenido de prolina así como un aumento de los parámetros de crecimiento. El contenido de clorofila tuvo el valor más alto para el tratamiento 10 mM. Los resultados sugieren que la aplicación exógena de prolina 10 y 20 mM permite aumentar la respuesta de tolerancia al estrés salino.

Cítricos, es uno de los más importantes cultivos de frutales en el mundo y son susceptibles a sales. Los efectos negativos de las sales generalmente reducen producción y calidad de fruta. Para evaluar los efectos de la salinidad en algunos parámetros de crecimiento, un experimento en invernadero fue conducido con los cultivares ‘Mihowase’, ‘Primosole’ y ‘W. Murcott’ en los patrones ‘Cleopatra’ y ‘Swingle citrumelo’ El experimento fue conducido en la Estación Experimental Agraria (EEA) del Instituto Nacional de Innovación Agraria (INIA), Huaral-Donoso a 90 km al norte de Lima. Las plantas fueron irrigadas con una solución salina ClNa y con una conductividad eléctrica de 0.5 o 4.5 dS/m. Las variables evaluadas fueron caídas de hojas, peso fresco y seco de tallos, hojas y raíces y contenido de agua por las plantas. Los resultados mostraron que el patrón ‘Cleopatra’ es más tolerante que ‘Swingle citrumelo’. Las variedades afectaron todas las variables de los dos patrones, siendo más notorio en la cantidad de pelos absorbentes de las raíces. La selección de plantas de mandarinas para producción debería considerar combinación variedad/patrón.

Background: The introduction of species with tolerance to salinity is one of the strategies to reduce the harmful effect of salts in the eastern region of Cuba. The species Vigna unguiculata L., shows rusticity and capability of adaptation, however, it is necessary to search for cultivars with greater tolerance and symbiotic nitrogen fixation possibilities to increase yields. Objective: To determine the behavior of the bradyrizobium-cowpea bean relationship under salinity conditions, based on variables related to symbiotic nitrogen fixation, growth and development. Methodology: An experiment was carried out under controlled glass house conditions at the CSIC, Madrid, Spain. Two cultivars were used; IITA-Precoz and IT 86 D-715, which were inoculated with Strain VIBA-1 of Bradyrhizobum liaoningense. Treatments were Hoagland nutrient solution (control) and nutrient solution with 150 mM NaCl (saline). A completely randomized design with eight replications was used. At 40 days after germination, variables related to symbiotic nitrogen fixation, growth and development, protein concentration of the cytosolic soluble fraction of leaves and nodules were evaluated. Results: Although salinity negatively affected both cultivars, the damage did not manifest with the same intensity. IT 86 D-715 was less affected by showing less damage on the variables number of nodules, ARA, protein concentration in nodules and leaves, accumulation of leaf and root biomass, so its tolerance was greater. The IITA-Precoz cultivar was more susceptible, all the variables were notably affected under stress conditions, therefore, its tolerance level is lower. Implications: The cultivar IT 86 D-715 can be used in salinized soils due to its high tolerance, which is evidenced in variables of growth development and atmospheric nitrogen fixation. Conclusions: The cultivar IT 86 D-715 presents a greater capacity for symbiotic nitrogen fixation under salinity conditions and the tolerance index in all the growth and development variables evaluated was higher than IITA-Precoz, for which it presents a high susceptibility level.

In the semiarid region of Brazil, salts found in water used in irrigation. The objective of was to analyze the influence of foliar fertilization with nitrogen as a mitigation of the salt stress of passion fruit seedlings. The design was randomized blocks, with the treatments generated from the Box's Central Composite matrix, with five electrical conductivities of irrigation water (ECw) (0.50; 0.98; 2.15; 3.32; 3.80 dS m-1) and five doses of foliar nitrogen fertilization (0.0; 0.30; 1.15; 1.97; 2.30 g L-1), with four replicates. The growth and photosynthetic pigments were evaluated Application of nitrogen doses attenuated the effect of salinity on morphophysiological aspects of passion fruit seedlings. The increase in the salinity of the water caused negative effects on the characteristics the growth and photosynthetic pigments. [ABSTRACT FROM AUTHOR]

Se realizó un experimento en invernadero con macetas de agrolita, irrigadas con soluciones de cloruro de sodio (NaCl) a concentraciones de 0, 1.28, 2.56, 3.84, 5.12, 6.40 y 7.68 g L-1. El objetivo fue evaluar la emergencia, altura, diámetro del tallo, longitud de la raíz, número de hojas y acumulación de biomasa total de plántulas de Tabebuia rosea y Gliricidia sepium de la Selva Baja Caducifolia de Oaxaca y determinar su tolerancia a la sal. Los resultados indican que el incremento salino retardó la emergencia y disminuyó el crecimiento de las plantas de ambas especies. Las plantas testigo fueron significativamente superiores a las crecidas en los tratamientos salinos (P = 0.05). La reducción del crecimiento fue diferencial, ya que concentraciones > 6.40 g L-1 inhibieron la emergencia de plántulas de Tabebuia rosea, mientras que niveles > 5.12 g L-1 produjeron enanismo en las plántulas de Gliricidia sepium. Salinidades > 1.28 g L-1 provocaron quema de tejidos vegetales y toxicidad. En conclusión, Tabebuia rosea, es menos tolerante que Gliricidia sepium a la salinidad clorhídrica. El modelo matemático propuesto, fue consistente con el efecto salino en la disminución del peso seco total de plantas.

Salinity is one of the main factors that causes losses in crops up to 50%, which puts world food security at risk. During evolution, plants have acquired defense mechanisms, which are regulated by specific genes whose main function is to counteract damage by salinity. Genetic variability in crops is necessary for stress-tolerant genotypes to occur. One of the strategies that can be used to find tolerance is the combination of mutagenesis and plant tissue culture, since thousands of plants are produced in confined spaces and short periods; in addition, with the use of selective agents such as NaCl plants can be obtained tolerant to salinity. This review will address topics related to plant tissue culture, induced mutagenesis and the combination of both as strategies to obtain salinity tolerant plants of agricultural interest. [ABSTRACT FROM AUTHOR]

En la actualidad la comunidad científica internacional promueve cada vez más el uso de alternativas ecoamigables con el medio ambiente para la solución de problemas agrícolas como la salinización de los suelos. El uso de la homeopatía agrícola como una de estas alternativas se ha incrementado por su inocuidad y probada efectividad. En el presente estudio se evaluó el efecto atenuador del estrés salino (NaCl), del medicamento homeopático Natrum muriaticum (NaM), en la tasa fotosintética y variables morfométricas de plantas de frijol común (Phaseolus vulgaris L.) variedad Quivicán de testa blanca en etapa de crecimiento vegetativo inicial. Se aplicó un diseño experimental completamente al azar, con arreglo factorial (2A × 4B) donde A son los niveles de salinidad (0 y 75 mM), B las dinamizaciones homeopáticas centesimales (NaM-7CH, NaM-13CH, NaM-7+13CH) y agua destilada como control (AD), con cinco réplicas por tratamiento. Se realizaron mediciones de la tasa fotosintética (TF) dos veces por semana y al concluir el periodo de evaluación experimental (35 días), se midieron las variables morfométricas. En general las variables morfométricas evaluadas se incrementaron con la aplicación de los tratamientos homeopáticos NaM-7CH y NaM-7+13CH, siendo mayor el incremento en longitud de raíz (LR) y biomasa fresca de hojas (BFH) incluso en las plantas sometidas a estrés salino (75mM de NaCl). La tasa fotosintética (TF) en las plantas sometidas a estrés salino alcanzó el mayor valor con NaM-7CH, observándose un incremento mayor al 50% en TF con respecto al tratamiento control (AD). Estos resultados demuestran un gran potencial de la homeopatía agrícola como alternativa bio-segura y de bajo costo para incrementar la tolerancia al NaCl de P. vulgaris L. y lograr mayores áreas de este cultivo.

Se realizó un experimento para evaluar el efecto del ´priming´ de semillas sobre la germinación y crecimiento inicial de plantas de melón en salinidad. Se compararon dos agentes osmóticos (NaCl y CaCl.) y dos duraciones de tratamiento (2 y 4 días). Se evaluó el porcentaje de germinación y crecimiento de las plántulas a una conductividad eléctrica de 8.0 dS m-1. Se midió el contenido total de clorofila, contenido relativo de agua, viabilidad de raíces, contenido de prolina, pérdida relativa de electrolitos, concentración de malondialdehído, actividad peroxidasa y la catalasa, proporción de Na./K. en partes verdes y pérdida de K. por raíces. La mejor germinación se obtuvo cuando las semillas se trataron con NaCl o CaCl. durante dos días. El ´priming´ mejoró los parámetros de crecimiento y las plantas mostraron una mejor respuesta en todos los parámetros bioquímicos evaluados. Los resultados sugieren que el ´priming´ podría usarse para mejorar el rendimiento de las semillas y las plántulas en situaciones de alta salinidad.

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Introducción: Los brasinoesteroides (BR) y sus análogos son compuestos que han sido utilizados satisfactoriamente, a nivel internacional, en la inducción de tolerancia a estreses abióticos en las plantas. El objetivo fundamental de esta investigación fue determinar el efecto que la aplicación exógena de los brasinoesteroides y sus análogos ejercían en la tolerancia de plántulas de tomate al estrés por temperaturas altas y el papel de la homeostasis de brasinoesteroides y del estrés oxidativo en dicha tolerancia. Además, determinar los efectos que los brasinoesteroides y sus análogos ejercen en el crecimiento de plantas de arroz sometidas a estrés salino, así como los principales mecanismos fisiológicos y bioquímicos asociados a esta respuesta. Métodos: Se ejecutó un experimento donde se utilizaron diferentes genotipos caracterizados por cambios genéticos que originan niveles endógenos diferentes de la castasterona. Para combinar el interés teórico con el práctico se ejecutaron experimentos con el genotipo Amalia, cultivo extendido en Cuba Para determinar la influencia que ejercía el tratamiento a las semillas con BR y sus análogos en el crecimiento de plántulas de arroz en medio salino, se ejecutaron varios experimentos en condiciones semicontroladas. Resultados: Los experimentos ejecutados demostraron que, la termotolerancia de plántulas de tomate depende de la actividad del dominio quinasa del receptor tBRI1 de los BR, así como la participación del estrés oxidativo en la termotolerancia inducida por estos compuestos. Se informó, también, que el análogo MH-5 fue más efectivo que el BB-6, en proteger a las plántulas de tomate cultivar Amalia del choque térmico. En cuanto a la protección de las plantas de arroz ante el estrés salino, se informan, por primera vez, de manera integral, las respuestas fisiológicas y bioquímicas asociadas a la protección inducida por la 24-epibrasinólida (EBL) y el Biobras-16; lo que permitió proponer un modelo de acción de la EBL en plantas de arroz sometidas a estas condiciones. Se demostró, que, aunque ambos compuestos protegieron a las plantas, las respuestas fisiológicas y bioquímicas asociadas a dicha protección son diferentes.

El objetivo de esta revisión es dar a conocer la problemática que genera el estrés salino en diversos cultivos tales como trigo, pimiento, tomate, melón, brócoli, fresa y chile ancho, ya que esta dificultad no sólo aqueja al sector agropecuario, sino a toda la humanidad, puesto que los efectos se ven reflejados en muchos de los alimentos que el hombre consume. La salinidad es uno de los factores abióticos que limitan la productividad agrícola en México, en donde, de 29.3 millones de hectáreas que son utilizadas para esta actividad, 500,000 son improductivas debido a la alta concentración de sales que poseen. Los efectos van desde necrosis foliar, reducción de crecimiento del cultivo, pérdida de capacidad de germinación, afección en la producción de etileno, disminución de peso del fruto, entre otros. Abstract The objective of this review is to present the problems generated by salt stress in various crops such as wheat, pepper, tomato, melon, broccoli, strawberries and chile ancho, as this difficulty is not only afflicting the agricultural sector, but all humanity, since the effects are reflected in many of the food that man consumes. Salinity is one of the abiotic factors that limit agricultural productivity in Mexico, where, from 29.3 million hectares are used for this activity, 500,000 are unproductive due to high salt concentration they have. The effects range from leaf necrosis, reduced crop growth, loss of germination capacity, condition in ethylene production, fruit weight reduction, among others. Keywords: salt stress, food, productivity .

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Las altas concentraciones de sales en el suelo afectan adversamente el cultivo de Aloe vera, y puesto que se ha demostrado que en otras plantas el calcio ayuda a contrarrestar los efectos de la salinidad, en este trabajo se indagó acerca de los efectos de la aplicación radical de Ca2+ en plantas de A. vera sometidas a estrés salino, con la finalidad de comprobar si mejora su adaptación a la salinidad. A tal efecto, se midió la biomasa fresca, volumen foliar, número de hojas nuevas y número y longitud radical. Todas las variables se vieron disminuidas por la aplicación del NaCl; sin embargo, de manera general, la suplementación con 10 mmol m-3 CaCl2 a 100 mmol m-3 NaCl, tuvo efectos positivos sobre estas variables, aumentando, en muchos casos, los parámetros disminuidos por NaCl, lo cual resulta propicio para el cultivo de sábila en zonas que presenten problemas de altos contenidos de sales disueltas en el suelo.

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Copyright of Terra Latinoamericana is the property of Sociedad Mexicana de la Ciencia del Suelo A.C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oryza sativa L. "rice" (Paceae) is one the most important crops worldwide. However, it is drastically affected by salinity. Therefore, the objective of this research was to determine the effect of salinity over the absolute growth rate (AGR) and the relative water content (RWC) of rice varieties IR-43 and amazonas. "Rice" seedlings were grown in hydroponic conditions with nutritive solution La Molina® and arranged in a factorial design. 16-day plantlets were treated with NaCl solutions 0, 100, 150 and 200 mM to determine AGR and RWC at 8-day-treatment. Salinity stress affected both variables. IR-43 was more affected when treated with 200mM NaCl, showing AGR of 12.46 and 19.04 mm/day in shoots and roots respectively; when treared with 100 mM, RWC was 73.35%. The Amazonas variety had more tolerance to salinity, with AGRs of 21.25 and 22.54 mm/day in shoots and roots treated with 200mM NaCl, respectively; and RWC was 78.47% at 100mM. The reduction in growth could be caused by changes in cell water state caused by salinity and changes in nutrient and water uptake. The differences in stress response to salinity in both rice varieties showed advantages in osmotic adjustment and regulation to maintain cell homeostasis of Amazonas over IR-43 rice varieties. [ABSTRACT FROM AUTHOR]

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El algarrobo blanco (Prosopis alba G.) es una especie nativa de la región fitogeográfica del Chaco Occidental. Pese a que es considerada tolerante a la salinidad, los mecanismos fisiológicos que le confieren dicha característica no han sido dilucidados. Este trabajo tuvo como objetivo evaluar el impacto del estrés salino sobre la nutrición mineral y la fotosíntesis, en plántulas de algarrobo blanco. Las plántulas se cultivaron hidropónicamente con o sin la suplementación de 500 mM de NaCl. Se realizaron mediciones de emisión de fluorescencia de la clorofila a, y se cuantificaron las concentraciones de Na+, K+, Cl-, NO3- y la actividad nitrato reductasa (ANR). Luego de 7 días de tratamiento se determinó la biomasa de raíces y hojas. Se utilizó un diseño experimental completamente aleatorizado, con 10 repeticiones y los datos se analizaron con ANOVA y Test de Tukey. El estrés salino inhibió el crecimiento de la parte aérea y no afectó el crecimiento radicular. La salinidad aumentó las concentraciones foliares de Na+ y Cl-, y disminuyó las concentraciones de K+ y NO3- y la ANR. También se observó una disminución en los valores de qP, Fv/Fm y ETR, con un aumento en NPQ, demostrando que el estrés salino produjo fotoinhibición.

S.bonariensis (malva blanca), tolerante a Glifosato, es importante en Argentina en cultivos de siembra directa. En laboratorio se determinó el comportamiento germinativo de la especie en diferentes condiciones de temperatura (5, 10, 15, 20, 25, 30, 35, 40, 20/10, 25/15 y 30/20 °C con fotoperiodo de 12 hs de luz); de estrés salino (soluciones de Cloruro de sodio de 0; 30; 50; 70; 90; 130 y 150 mM) e hídrico (soluciones de polyethylene glycol de 0; 0,2; -0,4; -0,6; -0,8; -1,0 MPa). El diseño fue completamente aleatorizado con cuatro repeticiones. Se analizó la temperatura con modelos lineales generalizados y prueba DGC para diferencias entre las medias. Para el estrés hídrico y salino se analizó con regresión no lineal. A temperatura constante, la germinación máxima se dio a los 15 y a los 20 ºC (77 y 76%), disminuyó un 49% a 25 ºC, se registraron valores iguales o inferiores al 5% a 30 y a 35 ºC y fue nula a 5 y a 40 ºC. No se observaron diferencias significativas en los porcentajes de germinación en condiciones de alternancia térmica, en todos los casos superó el 50%. Al incrementar las concentraciones de cloruro de sodio la germinación decreció en forma exponencial. El 66% de la germinación se registró en el testigo y disminuyó al 10% a 130 mM, siendo inhibida a 150 mM. Cuando el estrés hídrico aumentó de 0 a -0.6 MPa la germinación decreció del 64% al 8% y fue inhibida a -0.8 MPa. La semilla podrá germinar en regiones templadas cálidas, siendo tolerante a la salinidad y medianamente tolerante al estrés hídrico.

Blueberries (Vaccinium corymbosum L.) are the fourth most economically important berry in the world. Its consumption responds to the existing interest on the antixodant compounds contained in its fruits and that are benefitial to human health. The production of blueberries is affected by water and salinity stress. Knowning the agronomic responses of this crop to stress helps to design actions for its handling. The aim of this study was to find out the effect of water and salinity stress on the agronomic variables of blueberry plants. As dryness and salinity increase, the growth of plants and the yield of blueberry fruits are reduced. To test this hypothesis, one-year old plants were exposed to water and salinity stress, in a hydroponic system, using tezontle as a substrate and a modified Steiner universal nutrient solution. The following variables were measured: dry matter of the root, stem, leaf and fruit, foliar area, root length, and height (plant), and specific weight, and equatorial and longitudinal diameters (fruit). A randomized complete block design was used and the treatments were: 1) control, with the 100 % of the daily demand of water and with an osmotic potential (PO) of -0.027 MPa; 2) salinity stress, with two PO levels (-0.041 and -0.054 MPa), both with 100 % of the daily demand of water; 3) water stress, with 33 % (H33) and 66 % (H66) of the daily demand of water, with a PO of -0.027 MPa. ANOVA was used to analyze the results and the means were compared using a Tukey test (p≤0.05). There were four repetitions -with 20 experimental units, and three plants per each experimental unit-which were used to analyze the results. There were statistical differences (p≤0.05), as a result of salinity stress in the root length variables and in all variables in the treatments with water stress. Results indicate that blueberry plants are sensitive to water and salinity stress, which have a negative effect on the growth of this species. However, water stress has a greater impact on the growth and production of blueberry plants, unlike salinity stress, which can increase the size of the fruit when applying an osmotic potential equal to -0.41 MPa. [ABSTRACT FROM AUTHOR]

En plántulas de alfalfa (Medicago sativa L.) se evaluó la germinación y el crecimiento y su tolerancia al estrés osmótico inducido por Polietilenglicol 6000 (PEG6000) y salinidad (NaCl) en tres genotipos distintos: Dk166, Verdor y Salina. Esta investigación se llevó a cabo con un diseño experimental completamente aleatorizado, con cinco réplicas y los parámetros que se determinaron fueron: energía y poder germinativo, largo de hojas y peso fresco y peso seco de raíces y hojas. Los resultados mostraron que la germinación fue retrasada en todas las variedades con ambas soluciones, con diferencias entre genotipos. El crecimiento de las plántulas, bajo un ligero estrés mostraron un incremento de la biomasa aérea y en un estrés hídrico y salino severo, muerte de las plantas excepto en Var. Salina (tolerante). PEG causó muerte en la variedad Verdor que mostró más sensibilidad a PEG que a NaCl. En raíces, los genotipos más sensibles frente a leves estrés salinos detuvieron su crecimiento y bajo leves situaciones de estrés hídrico lo incrementaron. Nuestros estudios nos permiten definir las variedades comerciales de Medicago sativa como moderadamente tolerantes a salinidad y sequía la variedad DK166, sensible o intolerante a salinidad y sequía la variedad Verdor y con una alta tolerancia a salinidad e insensible a sequía la variedad Salina.

Water is a resource for agriculture, urban and industrial activities. It is insufficient in the arid climate areas in the north east of Brazil. Saline water is as an alternative to the expansion of agricultural irrigation areas. Our objective was to assess the effect of irrigation with saline water and nitrogen fertilization on sunflower (Helianthus annuus L.) cv. EMBRAPA 122-V2000 growth. This study was carried out in a greenhouse at the Campina Grande Federal University, Paraiba, Brazil, between April and July 2012. The experimental design was completely random with three replications in a 5×5 factorial arrangement; salinity levels in irrigation water, with electrical conductivity (ECa) of 0.7, 1.7, 2.7, 3.7 and 4.7 dS m-1 (25 °C) and N doses of 50, 75, 100, 125 and 150 mg kg-1 as factors, in 75 experimental units. The variables evaluated during the growth cycle were: plant height, stem diameter, number of leaves, leaf area, flowering onset, maximum inflorescence opening, inner and external flower diameter, and chlorophyll content. The results with ECa of 0.7 dS m-1 linearly decreased. The salinity of the irrigation water and nitrogen fertilization interaction was not significant in the evaluated variables, except for the plant height 15 d after sowing. The flowering variables were delayed as the salinity of the irrigation water increased and chlorophyll content decreased, but increased with N. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Establishment of the perennial forage legume Lotus tenuis Waldst. & Kit is difficult in central-north areas of Argentina because thermal and water stressful conditions during summer. In the present study, germination behavior and initial growth was evaluated for a naturalized population of L. tenuis from center-north of Santa Fe province and it was compared with the Aguapé commercial cultivar. Constant and alternating germination temperatures and initial growth, under controlled conditions of light and temperature, were assessed under salinity stress. Higher temperatures negatively affect the germination of both materials, under stressful and non-stressful conditions. Salinity tolerance was higher at lower constant temperature and alternating. Salinity negatively affects biomass production in initial growth although biomass allocation was not affected. The cv. Aguapé showed a better behavior than naturalized material. [ABSTRACT FROM AUTHOR]

The estuarine crustaceans are exposed to frequent and abrupt environmental salinity changes that involve adjustments at different levels in muscle tissue. The histochemical composition of fiber types of the claw closer muscle of Cyrtograpsus angulatus and Neohelice granulata (Dana, 1851) under hyper regulatory conditions was analyzed. Cryosections of the muscle were treated with myosin-adenosine triphosphatase (m-ATPase), succinic dehydrogenase (SDH), periodic acid Schiff (PAS) and Sudan Black B. The mean diameters, the relative area and the proportion of each muscle fiber type were calculated. Types I and IV would belong to 'extreme' groups, whereas types II and III would be considered 'intermediate'. Type I fibers were large and exhibited a weak reaction to all techniques; type IV fibers were small and reacted strongly to histochemical tests. Types II and III prevailed in C. angulatus whereas type II predominated in N. granulata. Type IV fibers were absent in C. angulatus and scarce in N. granulata. The claw closer muscle of N. granulata and C. angulatus exhibited differential responses under reduced salinity at a histochemical level. Therefore, the existence of different adjustment mechanisms facing salinity stress is suggested. [ABSTRACT FROM AUTHOR]

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Salinity is one of the most pressing stresses today and brassinosteroids are compounds which, not only stimulate plant growth but also improve plant tolerance to salt stress. In this paper, the effect of foliar spraying with a brassinosteroid analogue (Biobras-16, BB-16) on rice seedlings under this kind of stress was evaluated. For this purpose, rice young plants cv. J-104 were sprayed with BB-16 (0; 0,01; 0,1; 1 µmol L-1), half of them was treated with NaCl (100 mmol L-1) for seven days and later, these plants were transferred to nutrient solution to assess recovery during fourteen days. The growth evaluations (shoot and root length and dry mass) were made at the beginning and the end of saline treatment and seven and fourteen days after the recovery. From the results of this experiment, the best BB-16 concentration was chosen and a second experiment, following the same methodology, was performed and, where, the growth indicators and some biochemical indicators such as malondialdehyde, proline, chlorophylls and the activities of peroxidase and catalase enzymes were determined. Results demonstrated, in general, that the foliar spraying with BB-16 0,1 µmol L-1 increased the length of rice seedlings under saline conditions what appears to be associated with increased antioxidant defenses as well as an increase of the concentration of chlorophylls, chlorophyll a fundamentally. [ABSTRACT FROM AUTHOR]

High concentrations of salts in the soil adversely affect the cultivation of Aloe vera and since it has been shown that in other plants calcium helps counteract the effects of salinity, this paper presents results on effects of the radical application Ca2+ to A. vera plants subjected to salt stress, to check if calcium improves its adaptation to salinity. For this purpose, the fresh biomass, leaf volume, number of new leaves and number and root length was measured. All variables were diminished by the application of NaCl; however, in general, supplementation with 10 mmol m-3 CaCl2 100 mmol m-3 NaCl, had positive effects on these variables, increasing, in many cases those reduced by NaCl parameters, which is good news for successfully growing aloe in areas where there are problems with dissolved salts in the soil. [ABSTRACT FROM AUTHOR]

Spirostanic analogues of brassinosteroids are synthesized, compounds in Cuba and some of their formulations have demonstrated to enhance the growth when plants grow under saline stress. Recently, a new analogue (Biobras-25) which should have a good biological activity has been synthesized. For this reason, the objective of this paper was to evaluate rice seedling growth under NaCl stress by fourteen days, when the seeds were treated with Biobras-25 or Biobras-16. Two experiments were performed, in the first one, rice seeds of cv. INCA-17 were soaked in BB-25 or BB-16 solutions (0; 0,005; 0,05 y 0,5 mg L-1) and after germination, they were placed in pots which contained Hoagland nutritive solution with the addition or not of NaCl 0,1 mol L-1 and remained during fourteen days in a growth room. At the end of the experiment, root and shoot length and dry mass were evaluated to 25 plants by treatment. Later, a second experiment was performed with the best concentrations of both formulations and, also, the growth indicators described above, leaf proline, a, b and total chlorophylls and total carotenes were determined. Results showed that both analogues exhibited a distinct behavior. Biobras-25 not only enhanced significantly seedling growth under NaCl stress but also increased significantly pigment concentration and decreased the proline content in leaves. [ABSTRACT FROM AUTHOR]

Salinity is one of the adverse environmental condition that cause high affectations to agricultural crops. The objective was to evaluate the combined effect of low doses of X-rays and different concentrations of Biobras-16 on tomato plants grown in saline conditions. The experiment was carried out at "Jorge Dimitrov" Agricultural Research Institute during the years 2009 to 2012. Fresh tomato seeds of variety cv. Vyta were exposed to X-ray doses of 20, 25 and 30 Gy and 15 days after transplantation the plants were sprayed with two concentrations (1,5 and 2,0 mg L-1) of Biobras-16. Two substrates were used, one consisting of a Vertisol soil salinized with electrical conductivity of 6 dS m-1 extract of soil saturation and Vertisol soil no salinized. The best combination of treatments was observed for 30 Gy +2,0 mg L-1, which increased significant (p≤0,05) the salt tolerance in plants, the tomato yield and its components. [ABSTRACT FROM AUTHOR]

Soil salinity constitutes one of the main causes for crop yield reduction. A significant part of the Ecuadorian highland soils are considered as high-salinity because of their pyroclastic nature, the effects of erosion and the poor use of irrigation water. The tree tomato (Solanum betaceum) grows all across the highlands and in many cases is subject to high-salinity stress. The objective of the present study was to determine the level of tolerance to sodium chloride (NaCl) for in vitro cultured tree tomato. Plants were obtained from seven or eight locations depending on the essay performed. Seed germination, plantlet development from simple-node culture and in vitro plant growth were evaluated, using different NaCl concentrations. For the seed germination assays, an average of 62% of germination was obtained in a concentration of 50mM NaCl for the seven locations evaluated, and an average of 57% germination in a concentration of 75mM. For plant growth from single node culture, seven locations were evaluated and growth was observed in concentrations of up to 100mM NaCl for plants from all locations except Quero. Finally, the analysis of salinity stress tolerance limits for plantlet growth showed different responses in individuals from eight sampling locations, where plantlets from Chaltura tolerated up to 175 mMNaCl. These results confirm a difference in salinity tolerance from individuals between locations. The highest tolerance level was observed in plants from Chaltura, while the lowest tolerance level was observed in plants from Quero. This information is basic for future transcriptome studies, where genes involved with salinity tolerance can be identify in this interesting Andean crop.

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Objective: to study the effect of co-inoculation with Ensifer meliloti and Halomonas maura of the leguminous Medicago sativa L., on growth, nutritional and functional value, grown under salinity conditions.Methods: plants of M. sativa were grown in a solution with a mixture of salts (CaSO4, MgCl, NaCl and NaHCO 3) and were co-inoculated with its specific rhizobium and the halophilic moderated bacterium H. maura. Different physiologic parameters were determined, as well as, nitrogen and minerals content. Furthermore, an assay of in vitro digestibility was carried out.Results: salinity had a negative effect on the plants; however, co-inoculation increased yield, nitrogen content, total minerals, Ca and Mg. Moreover, physiologic parameters as water potential and leghemoglobin content in fresh nodules were higher compared to those of plants inoculated only with E. meliloti. Both, salinity and bacterial treatment with E. meliloti and H. maura increased the antioxidant capacity of the legume, in dialyzates and retentates collected after an in vitro digestibility assay.Conclusion: co-inoculation of plants with E. meliloti and H. maura could improve the alfalfa yield under specific salinity conditions, increasing the nutritional and functional value of the plants. M. sativa could be considered in the formulations of nutritional supplements for the human diet. [ABSTRACT FROM AUTHOR]

Salinity is a growing threat to the productivity of soybean cultivars (Glycine max L. Merril) and different strategies have been adopted to overcome this problem. Commercial exploitation of tolerant genotypes to salinity is a good alternative to obtain economical yields in these areas. For this reason, it is important to have rapid methods to assess the tolerance to this stress especially in the early stages of growth. The aim of this study was to evaluate the salt tolerance in nine soybean genotypes. Experiments were carried out in a greenhouse under controlled conditions. The rate of salinity tolerance of germination (IG), shoot length (ILB), root length (ILR), shoot dry matter (IMSB) and root (IMSR), as well as injury of cell membrane were measured in all genotypes treated with NaCl (chloride sodium) at concentrations 0 to 150 mM. The results obtained based on physiological criteria allowed the identification of AT22 and INCASoy36 as the most tolerant cultivars compared to other genotypes, thus those genotypes seem to be promising to achieve higher productivity in areas affected by salt. [ABSTRACT FROM AUTHOR]

During their life cycle, plants are exposed to various types of external stressors, preventing the maintenance of homeostasis. Salinity is one of the main adverse factors affecting plant growth and causes great losses in the yield of many crops. In the world there are large areas of saline soils of which are largely agricultural soil. In Cuba 20% of agricultural land are at risk due to salinity; the provinces where Nicotiana tabacum is growing, are not exempt from this problem. The plants have various types of stress responses as synthesis antioxidant metabolites and enzymes which contribute to the process of acclimation The effect of salt stress on processes of photosynthesis, respiration, biomass formation and defense response systems in plants of N. tabacum `Criollo'98', excellent for the production of Habanos, was determined. The photosynthetic activity was affected in the early hours of face plants to salinity conditions imposed in hydroponics conditions (Hoagland solution supplemented with 150 mmol L -1 NaCl); however recovery was observed in a short period of time (7 d). Higher concentration of total chlorophyll and carotenoids was detected in the leaves of plants with the saline treatment, which is interpreted as a possible photosynthetic acclimation to salinity. Respiratory activity was similar in salt treated and control plants. Another answer acclimation of plants was evidenced by a greater value of root: shoot biomass ratio in salt treated plants, which could contribute to increased water uptake by the roots in these stressful conditions. The stomata of the plants under salt stress reacted partially closing, reaching values of 30 % to 50 % of the maximum apertures recorded during the diurnal cycle of control plants; this decrease in stomatal opening did not influence the CO2 fixation of stressed plants. Although it was observed an acclimation of photosynthesis in saline conditions, the leaf area and plant biomass were drastically decreased; this was associated with damage to cell membranes and changes in antioxidant enzyme activity. Catalase and guaiacol peroxidase activity in the leaves were 4 and 3-fold higher (relative to controls) after 1 and 3 h of being plants under saline treatment respectively. SOD activity decreased 3 fold relative to the control in the first hour of applying salt stress and increased to values similar to control between 3 and 52 hours later. [ABSTRACT FROM AUTHOR]

This research was done at Jorge Dimitrov Agricultural Research Institute in November 2011. The objective was to study the effect of salinity on the relative water content (RWC) and the concentration of pigments in plants of three varieties of beans (Phaseolus vulgaris L.): HOL-17 HOL-35 HOL-74, using a saline soil (CE 5.2 dS.m-1) and a non-saline soil as control. The Relative Water Content (RWC) was determined by the method described by Yamasaki and Rebello and the concentration of pigment by the methodology of Lichtenthaler and Wellburn. The results indicated a significant decrease in the RWC in the saline treatment , in the three studied varieties compared to the untreated (the control) variety. The content of chlorophyll b was affected in the three varieties under saline conditions, while HOL-17 and HOL-74 varieties exhibited a significant increase in the concentration of carotenoids, which suggests a protective mechanism of chlorophyll photooxidation induced by salt stress. [ABSTRACT FROM AUTHOR]

The chitosan is widely used in agriculture for having a strong fungistatic effect, also it has other properties such as extending the post harvest life of fruits and vegetables and stimulating the plant growth, among others. However, the use of this biopolymer for inducing salinity tolerance has been few studied, so the objective of this work was to check if chitosan-treated seeds are able to reverse the effects caused by salinity in the rice seedling growth and some biochemical indicators associated to this response. To do this, rice (Oryza sativa L.) seeds variety INCA LP-5 were treated for 24 hours with different concentrations of chitosan (0, 100 and 500 mg L-1). The germinated seeds were transferred to pots containing diluted Hoagland nutritive solution supplemented or not with NaCl 100 mmol L-1 and they were placed in a growth chamber with controlled conditions. The growth and biochemical indicators were evaluated eleven days after stress treatment. Seeds treated with chitosan 100 mg L-1 stimulated shoot length and dry matter in saline medium grown seedlings and lowered malondialdehyde and increased proline levels. Both chitosan concentrations enhanced the activities of catalase and peroxidase enzymes, although a higher effect was obtained with chitosan 500 mg L-1. [ABSTRACT FROM AUTHOR]

Se estudió,, la respuesta de Clitoria ternatea en condiciones de estrés salino a la inoculación con aislamientos nativos y cepas comerciales de rizobios. El estudio se realizó,, en condiciones de invernadero y de campo. El efecto de tres cepas de rizobio (Jd19, 1031 y 1032) en el rendimiento y parámetros de la fijación de nitrógeno se comparó,, con el testigo y el tratamiento con fertilización nitrogenada.

La salinidad es una preocupación en la Argentina que, ocupa el tercer lugar después de Rusia y Australia en cuanto a la superficie del suelo afectado por la salinidad. El propósito de esta revisión es indicar la contribución de los científicos argentinos en el tema general de las plantas leñosas perennes y la salinidad. Quedan expresamente excluidos de esta revisión los estudios de la vegetación de lugares salinos y las investigaciones realizadas sobre especies no leñosas. En Argentina, la atención se ha centrado particularmente en la tolerancia a la salinidad de los árboles del bosque nativo, en especial en los miembros del género Prosopis, en los efectos de la forestación sobre el agua y la salinidad del suelo, y en los microorganismos que interactúan con árboles y arbustos en condiciones salinas. Además de estos temas específicos, se ha trabajado sobre la tolerancia a la salinidad en otros árboles y en arbustos del género Atriplex.

Con la finalidad de conocer el efecto de la radiación y la salinidad sobre la fotosíntesis de diferentes tipos ecogeográficos de Phaseolus vulgaris ‘cargamanto’ (andino suramericano) y ‘carioca’ (mesoamericano), se realizaron mediciones de potencial osmótico, acumulación de sodio, intercambio gaseoso, fluorescencia de la clorofila y contenido de pigmentos en hojas de fríjol cultivadas en condiciones de invernadero con solución nutritiva. El tratamiento lumínico consistió en cubrir las plántulas con una malla de polietileno que obstruye el paso de la radiación fotosintéticamente activa en 50%. Posteriormente, las plantas expuestas a las condiciones de radiación del invernadero y las plantas con sombra se sometieron a dosis crecientes de 30 mM de cloruro de sodio hasta llegar a las concentraciones de 30, 60, 90 y 120 mM, y otras quedaron como tratamiento control. El estrés salino y lumínico alteró la fotosíntesis, pero el ecotipo andino presentó una capacidad de ajuste mayor a los diferentes factores y al estrés abiótico en relación con el ecotipo mesoamericano. Las plantas expuestas y con sombra presentaron diferencias significativas en los parámetros de intercambio gaseoso, potencial osmótico y concentración de sodio en las hojas, en condiciones de estrés salino; pero en las plantas expuestas y estresadas con NaCl, las variaciones fueron más contrastantes en relación con las que se hallaban bajo sombra. La interacción de la sombra con la salinidad presentó respuestas únicas y diferenciales en comparación con las alteraciones producidas por cada factor evaluado independientemente.

The ultrastructure of leaves chloroplast and root nodules from cowpea plants (Vigna unguiculata (L.) Walp.), var. IT 86 D-715, subjected to saline stress was evaluated by Transmission Electron Microscopy (TEM). Plants were exposed at 150 and 0,02 mM of NaCl treatments, considering 0,02 mM salt level as control. Native strain VIBA-1 (Bradyrhizobium liaoningense) isolated from saline soils of Cauto Valley (Cuba) was inoculated at sowing. Forty days after germination, samples of the same age and position from leaves and root nodules were taken for microscopy observations. Some ultrastructural modifications were detected by the salt effect in chloroplasts, mainly triggered by the great increase in the size of the starch granules. These modifications produced altered grana distribution. In nodule structure, when saline stress was applied, a weakness of peribacteroid membrane and high number of vesicles into infected cells were noted. Symbiosomes started deteriorating with some broken peribacteroidal membranes. A high vesiculation and degradation of some cellular organelle into uninfected cells were observed. [ABSTRACT FROM AUTHOR]