Irrigation with saline water can act as an alternate water resource and thus plays an important role in saving freshwater resources as well as promoting agriculture. Furthermore, salinity stress is ...considered one of the major abiotic stress factors, which strongly reduces crop productivity. In this context, the present work was conducted to examine the effect of exogenous salicylic acid (SA) application on salt stress tolerance of strawberry plants. For this purpose, strawberry plants (
Fragaria vesca
L.), three months old, were treated with three SA concentrations (0 mM, 0.25 mM and 0.5 mM), then subjected to 80 mM NaCl or not. After five weeks of treatment, growth responses, water status, photochemical efficiency and oxidative stress indicators were measured. The obtained results showed that irrigation with saline water negatively affected the growth parameters, the leaf water potential (LWP), the relative water content (RWC), the stomatal conductance (gs) and photochemical efficiency (Fv/Fm). While, the total protein content, the electrolyte leakage (EL), the malondialdehyde (MDA) and the hydrogen peroxide (H
2
O
2
) contents were increased in stressed plants compared to unstressed ones. Salt stress also leads to the activation of the antioxidant enzymes. However, the exogenous application of SA under salt stress conditions reduced the H
2
O
2
accumulation, the electrolyte leakage and the MDA content. It has also improved the growth parameters, the LWP, the RWC, the gs, the Fv/Fm, the protein content and the antioxidant enzyme activities (POD, CAT and SOD) in the treated plants compared to those without SA application. Therefore, the beneficial effect of 0.25 mM SA on
Fragaria vesca
L. salinity tolerance may provide some practical basis for strawberry cultivation under saline conditions.
Worldwide population is in permanent growth, leading to an over-presser on the food resources. This demand leads to an over-exploitation of land and water resources. Recently, the quinoa plant has ...attracted attention as alternative crop with high nutritive value and high tolerance to the marginal conditions. In this study, a field experiment was conducted during two successive seasons to investigate the effect of deficit irrigation on the agronomic performance. Four treatments of deficit irrigation (100%, 50%, 33% ETc and rainfed) were applied to one variety in the first season and to four genotypes (two varieties and two lines). The results were evaluated by measuring biomass and seed quinoa yield, water-use efficiency, harvest index, seed size and 1000 seeds weight. Results show that the implementation of deficit irrigation is an appropriate strategy to reduce the use of agricultural water and maintain relatively high yields. On the other hand, the results of the economic quality reflected by the size and weight of seed yield, indicates that quinoa can be considered a well-adapted to the conditions of water scarcity culture. According to agronomic parameters, L143 line followed by the line L11 showed a high potential of adaptation under the different treatments of stress, while the “Puno” variety presented the best performance under the favorable conditions of irrigation (100% ETc).
Seed germination is the critical stage for species survival. Salinity affects germination and seedling growth and yield of several crop species, such as broad bean. That is why this study was carried ...to evaluate the effects of NaCl on seed germination and influence of salicylic acid on seed in order to improving salt tolerant on broad bean. Vicia faba L. is an important pulse crop in the Mediterranean region. In many cases broad bean is grown on saline soils where growth and yield are limited by salinity. The results showed that Irrigation with saline water significantly reduced all seed germination parameters in comparison with the respective control. Alleviation of growth arrest was observed with exogenous applications of salicylic acid (SA) under salt stress conditions. Overall, the positive effect of SA towards resistance to the salinity of V. faba L. will provide some practical basis for V. faba L cultivation.
The objective of this study was to investigate the drought-related adaptation strategies of two quinoa (Chenopodium quinoa Willd.) cultivars grown under controlled conditions. After 34 days of ...growth, water was withheld until plants were severely wilted, then they were re-watered and left to recover. 20 days later the experiment was reproduced. We analyzed growth, biomass, stomatal density, leaf water status, chlorophyll and malonyldialdehyde (MDA) content. Results showed that under water stress growth, biomass, stomatal density and leaf water status were significantly affected. On the other hand, results showed that water stress in the initial period can significantly increase the tolerance to drought during later phases. The data showed that quinoa drought tolerance may result from its capacity to maintain cell health status. Our findings provide new tracks into the mechanisms of drought tolerance in quinoa plants.
Given the current water shortage in North Africa, improving water management to produce more crop per drop is vital. In addition, the introduction of droughtâtolerant, less waterâconsuming crops ...such as quinoa is of great interest. To understand the response of quinoa to water stress in terms of biomass and grain yield under various irrigation management strategies, the SALTMED model was employed using field measurements during the cropping seasons of 2011 and 2012 at a site in the Marrakech region, south Morocco. Quinoa showed its ability to grow in the south of Morocco and give a good yield under full irrigation. However, the experimental and modelling results showed that under rainfed and deficit irrigation, the grain yield was lower than under the full irrigation treatment and was dependent on water deficit level. The study revealed that a reasonable grain yield of quinoa can only be obtained if it was subjected to moderate water stress conditions. The results indicated that the SALTMED model is able to simulate the quinoa biomass and grain yield under various water deficit levels and that the model can be used in the evaluation of different irrigation strategies.
Water shortage is a critical problem touching plant growth and yield in semi-arid areas, for instance the Mediterranean region. For this reason was studied the physiological basis of drought ...tolerance of a new, drought tolerant crop quinoa (Chenopodium quinoa Willd.) tested in Morocco in two successive seasons, subject to four irrigation treatments (100, 50, and 33%ETc, and rainfed). The chlorophyll a fluorescence transients were analyzed by the JIP-test to translate stressinduced damage in these transients to changes in biophysical parameter's allowing quantification of the energy flow through the photosynthetic apparatus. Drought stress induced a significant decrease in the maximum quantum yield of primary photochemistry (φ^sub P0^ = F^sub v^/F^sub m^), and the quantum yield of electron transport (φ^sub E0^). The amount of active Photosystem II (PSII) reaction centers (RC) per excited cross section (RC/CS) also decreased when exposed to the highest drought stress. The effective antenna size of active RCs (ABS/RC) increased and the effective dissipation per active reaction centers (DIo/RC) increased by increasing drought stress during the growth season in comparison to the control. However the performance index (PI), was a very sensitive indicator of the physiological status of plants. Leaf area index, leaf water potential and stomatal conductance decreased as the drought increased. These results indicate that, in quinoa leaf, JIP-test can be used as a sensitive method for measuring drought stress effects.
el objetivo del presente trabajo de investigación es analizar el marco normativo;
regulatorio para el control de las descargas de aguas residuales no domésticas a las redes de alcantarillado, con la ...finalidad de realizar propuestas que permitan su aplicación eficiente. Se considera que el tema se justifica por sí mismo, debido a la relevancia e importancia para el sector;
saneamiento. Asimismo, al ser un tema totalmente nuevo para el país, no existe experiencia previa, y la normatividad y regulación al respecto ha entrado en vigencia recién a partir del mes de setiembre del 2013.;
Para realizar dicho análisis y plantear algunas propuestas, el presente documento ha sido estructurado en cinco capítulos. Se inicia con una breve revisión de la organización del sector;
saneamiento, se describen los servicios de alcantarillado. Luego, en el siguiente capítulo, donde se desarrolla un análisis de la situación de las descargas de aguas residuales no domésticas, se explica las características físicas, químicas y bacteriológicas de las mismas, así como los impactos;
de la contaminación de dichas aguas en la infraestructura sanitaria. En el cuarto capítulo,se aborda de manera extensa la regulación de las descargas de aguas residuales no domésticas, desarrollando en primer lugar el marco normativo general y específico que circunscribe la aplicación de los;
VMA y, sobre la base de experiencias reales de EPS, se presenta un análisis del proceso de implementación del marco regulatorio que permite obtener conclusiones valiosas para el planteamiento de propuestas. En esta misma sección, se describen las principales limitaciones encontradas para la efectiva aplicación del marco regulatorio y se analiza brevemente la experiencia sobre el tema del presente trabajo de investigación en otros países como Chile, Colombia y México. En el último capítulo, se plantean algunas propuestas para modificar el marco normativo y se esbozan algunas estrategias y acciones específicas que podrían ser parte de;
un plan sectorial para facilitar la implementación de los VMA, considerándolo como un proceso que involucra diversos actores, más allá de las entidades del sector saneamiento. Finalmente, se presentan algunas conclusiones y recomendaciones.
Entamoeba histolytica, an intestinal parasite of global significance, poses substantial health risks with its associated high morbidity and mortality rates. Despite the current repertoire of ...molecular tools for the study of gene function in, the regulatory mechanisms governing its pathogenicity remain largely unexplored. This knowledge gap underscores the need to elucidate key genetic determinants orchestrating cellular functions critical to its virulence. Previously, our group generated an avirulent strain, termed UG10, with the same genetic background as the HM1:IMSS strain. UG10 strain, despite showing normal expression levels of well-known virulence factors, was unable to perform in-vitro and in-vivo activities related to amoebic virulence. In this study, we aimed to uncover the genome-wide modifications that rendered the avirulent phenotype of the UG10 strain through whole-genome sequencing. As a complementary approach, we conducted Methylated DNA Immunoprecipitation coupled with sequencing (MeDIP-seq) analysis on both the highly virulent HM1:IMSS strain and the low-virulence UG10 strain to uncover the genome-wide methylation profile. These dual methodologies revealed two aspects of the UG10 avirulent strain. One is the random integration of fragments from the ribosomal gene cluster and tRNA genes, ranging from 120 to 400 bp; and secondly, a clear, enriched methylation profile in the coding and non-coding strand relative to the start codon sequence in genes encoding small GTPases, which is associated with the previously described avirulent phenotype. This study provides the foundation to explore other genetic and epigenetic regulatory circuitries in E. histolytica and novel targets to understand the pathogenic mechanism of this parasite.
•Entamoeba histolytica has a genomic structure highly variable.•Using strains with different virulence phenotype can uncover virulence mechanisms.•UG10 strain exhibits low virulence phenotype in comparison with HM1:IMSS strain.•Whole genome sequence of UG10 strain revealed discreate modifications.•MeDIP-seq analysis revealed a differentially methylated upstream regions.
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