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Hajlaoui H.,Institute National Of Recherche En Genie Rural | Ayeb N.E.,University of Monastir | Garrec J.P.,French National Institute for Agricultural Research | Denden M.,Institute Superieur Agronomique Of Chott Mariem
Industrial Crops and Products | Year: 2010

The comparative effects of salt stress on osmotic adjustment and solutes accumulation in relation to root-leaf tissue senescence of two silage maize varieties were examined. Studies were carried out with seedlings of two forage maize varieties (Aristo and Arper) subjected to 0, 34, 68 and 102 mM NaCl for 6 weeks under glasshouse conditions. Osmotic potential (OP), osmotic adjustment (OA) and solutes accumulation were quantified in primary roots and in three leaf stages (young, mature and senescent leaves). Moreover, in order to assess the distribution of proline and glycine betaine during root development, the two components were analyzed at different position from the primary root apex of both varieties. The total dry matter was significantly dropped with increasing salinity and reduction was greater in Aristo than in Arper. Salt stress impact in terms of ionic status was more pronounced in roots than in leaves and in older leaves than younger ones. In this setting, Aristo displayed a more sensitivity than Arper. A close relationship between the age of root-leaf tissue and proline and glycine betaine allocation, as salinity response, was shown. During the stress treatment, the accumulation of the two components was higher in growing regions of roots and in young leaves. While total free amino acids (FAA) and sugars were accumulated in roots as well as leaves but preferentially in the mature leaves. The capacity of OA was greater in young than in mature and/or senescent leaves and the contribution efficiency of organic solutes to this occurrence tended to be higher in Arper than in Aristo. Moreover, glycine betaine and proline appeared to be the main solutes that contributed ably to OA mainly in growing regions followed by sugars and other FAA. Inorganic solutes (K+ and Ca2+), however, did not seem to play an important role in OA since their amounts were often reduced in response to salt tolerance. © 2009 Elsevier B.V. All rights reserved.


Sai Kachout S.,University of Tunis | Ben Mansoura A.,Institute National Of Recherche En Genie Rural | Jaffel Hamza K.,University of Tunis | Rejeb M.N.,Institute National Of Recherche En Genie Rural | Ouerghi Z.,University of Tunis
Acta Physiologiae Plantarum | Year: 2011

The impact of salinity and water stress was analyzed in the xero-halophyte Atriplex hortensis using two varieties: green orach (A. hortensis var. purpurea) and red orach (A. hortensis var. rubra). A. hortensis L. is a C 3 species well adapted to salt and drought conditions. To collect information on the physiological impact of different salt and water deficit levels on their water stress resistance, plants were exposed for 3 months to solution containing four levels of NaCl or to water stress regimes including four levels of field capacity. Osmotic potential at zero turgor Ψ s 0, osmotic potential at full turgor (Ψ s 100), relative water content (RWC), ion concentration (Na +, K +, Ca 2+, Mg 2+, and Cl -), and malondialdehyde (MDA) were determined at the end of the treatment. The salinity and water stress induced a decrease in Ψ s 100, Ψ s 0, and RWC in both varieties, recorded changes being higher in plants of red variety than those of green variety. Both varieties specifically accumulated Na + in response to drought and salt stress, suggesting that this element could play a physiological role in the stress response of this xero-halophyte species. In contrast, the presence of NaCl and water stress induced a decrease in K +, Ca 2+, and Mg 2+ concentration in both varieties. Salinity clearly induced an increase in Cl - concentration in all tissues, but water stress had no impact on this parameter. MDA concentration increased in response to water stress and exogenous NaCl. Based on these findings the more drought-tolerant red orach may be grown in water-limiting soils. © 2010 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.


Iglesias A.,Technical University of Madrid | Mougou R.,Institute National Of Recherche En Genie Rural | Moneo M.,Potsdam Institute for Climate Impact Research | Quiroga S.,University of Alcalá
Regional Environmental Change | Year: 2011

This study links climate change impacts to the development of adaptation strategies for agriculture on the Mediterranean region. Climate change is expected to intensify the existing risks, particularly in regions with current water scarcity, and create new opportunities for improving land and water management. These risks and opportunities are characterised and interpreted across Mediterranean areas by analysing water scarcity pressures and potential impacts on crop productivity over the next decades. The need to respond to these risks and opportunities is addressed by evaluating an adaptive capacity index that represents the ability of Mediterranean agriculture to respond to climate change. We propose an adaptive capacity index with three major components that characterise the economic capacity, human and civic resources, and agricultural innovation. These results aim to assist stakeholders as they take up the adaptation challenge and develop measures to reduce the vulnerability of the sector to climate change. © 2010 The Author(s).


Mougou R.,Institute National Of Recherche En Genie Rural | Mansour M.,Center Regional Of Recherches En Horticulture Et Agriculture Biologique | Iglesias A.,Technical University of Madrid | Chebbi R.Z.,Institute National Of Recherche En Genie Rural | Battaglini A.,Potsdam Institute for Climate Impact Research
Regional Environmental Change | Year: 2011

In the Maghreb and North African regions, the interannual climate variability causes severe impacts on agriculture through long drought episodes. Impacts are expected to increase due to projected climate change. Decreasing water availability will have a direct impact on the agriculture sector and could endanger the socioeconomic development and social stability in Tunisia where rain-fed agriculture represents the main occupancy and means of subsistence for the large rural population. © 2010 Springer-Verlag.


Kachout S.S.,University of Tunis | Mansoura A.B.,Institute National Of Recherche En Genie Rural | Mechergui R.,Institute National Of Recherche En Genie Rural | Leclerc J.C.,Equipe dEcophysiologie Appliquee | And 2 more authors.
Journal of the Science of Food and Agriculture | Year: 2012

BACKGROUND: Three annual Atriplex species-A. hortensis var. purpurea, A. hortensis var. rubra and A. rosea-growing on soil with various levels of the heavy metals copper, lead, nickel, and zinc, have been investigated. RESULTS: Metal accumulation by Atriplex plants differed among species, levels of polluted soil and tissues. Metals accumulated by Atriplex were mostly distributed in root tissues, suggesting that an exclusion strategy for metal tolerance widely exists in them. The increased concentration of heavy metals in soil led to increases in heavy metal shoot and root concentrations of Ni, Cu, Pb and Zn in plants as compared to those grown on unpolluted soil. Accumulation was higher in roots than shoots for all the heavy metals. None of the plants were suitable for phytoextraction because no hyperaccumulator was identified. However, plants with a high bioconcentration factor and low translocation factor have the potential for phytostabilization. Similarly, the correlation between metal concentrations and translocations in plants (BCFs and TFs) using a linear regression was also statistically significant. CONCLUSION: Among the plants studied, var. purpurea was the most efficient in accumulating Pb and Zn in its shoots, whereas var. rubra was most suitable for phytostabilization of sites contaminated with Cu and Ni. © 2011 Society of Chemical Industry.


Badreddine B.S.,Institute Superieur Des Science Et Technologies Of Lenvironnement Of Borj Cedria | Olfa E.,Institute National Of Recherche En Genie Rural | Samir D.,Institute National Of Recherche En Genie Rural | Hnia C.,Institute National des science Appliquees et Technologiques | Lahbib B.J.M.,Institute National Of Recherche En Genie Rural
Asian Pacific Journal of Tropical Medicine | Year: 2015

Objective: To evaluate toxic activities of essential oils obtained from Rosmarinus officinalis and Lavandula stoechas against the fourth larval instars of Orgyia trigotephras. Methods: A total of 1 200 larvae were divided into three groups I II III. Group I was to investigate the effect of extracted essential oils from these aromatic plants as gastric disturbance. Bacillus thuringiensis and ethanol were used as control group. Group II was used as contact action and Group III was used as fumigant action. Decis and ethanol were used as control group. During the three experiments, the effect of essential oils on larvae was assessed. Results: The chemical composition of essential oils from two medicinal plants was determined and, their insecticidal effects on the fourth larval state of Orgyia trigotephras were assessed. The two simples presented an insecticidal activity, nevertheless Rosmarinus officinalis essential oil was less efficient compared to Lavandula stoechas one are discussed. Conclusions: The relationship between the chemical composition and the biological activities is confirmed by the present findings. Therefore the potential uses of these essential oils as bioinsecticides can be considered as an alternative to the use of synthetic products. © 2015 Hainan Medical College.


Hichem H.,Institute National Of Recherche En Genie Rural | El Naceur A.,University of Monastir | Mounir D.,Institute Superieur Agronomique Of Chott Mariem
Photosynthetica | Year: 2010

The effect of four different NaCl concentrations (from 0 to 102 mM NaCl) on seedlings leaves of two corn (Zea mays L.) varieties (Aristo and Arper) was investigated through chlorophyll (Chl) a fluorescence parameters, photosynthesis, stomatal conductance, photosynthetic pigments concentration, tissue hydration and ionic accumulation. Salinity treatments showed a decrease in maximal efficiency of PSII photochemistry (F v/F m) in dark-adapted leaves. Moreover, the actual PSII efficiency (φ PSII), photochemical quenching coefficient (q p), proportion of PSII centers effectively reoxidized, and the fraction of light used in PSII photochemistry (%P) were also dropped with increasing salinity in light-adapted leaves. Reductions in these parameters were greater in Aristo than in Arper. The tissue hydration decreased in salt-treated leaves as did the photosynthesis, stomatal conductance (g s) and photosynthetic pigments concentration essentially at 68 and 102 mM NaCl. In both varieties the reduction of photosynthesis was mainly due to stomatal closure and partially to PSII photoinhibition. The differences between the two varieties indicate that Aristo was more susceptible to salt-stress damage than Arper which revealed a moderate regulation of the leaf ionic accumulation. © Springer Science+Business Media B.V. 2010.


Fenet H.,Montpellier University | Mathieu O.,CHRU de Montpellier | Mahjoub O.,Institute National Of Recherche En Genie Rural | Li Z.,Montpellier University | And 3 more authors.
Chemosphere | Year: 2012

Treated wastewater is being increasingly used for irrigation and aquifer replenishment through artificial recharge. However, wastewater reuse can result in contamination of exposed soil and groundwater by chemicals such as some pharmaceuticals and their metabolites. The fate of these molecules depends largely on their capacity to sorb onto soil and aquifer materials during infiltration. In this study, the sorption isotherm of carbamazepine (CBZ), an anti-seizure medication, and two of its metabolites, i.e. carbamazepine-10,11-epoxide (CBZ-EP) and 10,11-dihydro-10,11-dihydroxycarbamazepine (DiOH-CBZ), were determined in two soils in laboratory assays. In the field, the presence of CBZ and its metabolites were investigated in soil and in groundwater underlying an irrigated area with treated wastewater. The results showed that CBZ had the highest carbon normalised sorption coefficients in the two tested soils (irrigated soil and a Lufa SP2.4 reference soil) followed by CBZ-EP and DiOH-CBZ, indicating the relatively higher mobility of CBZ metabolites compared to CBZ. The chromatographic analysis revealed that CBZ and its two metabolites were present in treated wastewater used for irrigation and in groundwater. In soil samples, CBZ concentrations showed a build-up taking place with irrigation. The mobility of metabolites in soil and their potential biodegradation require further investigation. © 2012 Elsevier Ltd.


Boughalleb F.,Institute Superieur Agronomique Of Chott Meriem Isa Cm | Hajlaoui H.,Institute National Of Recherche En Genie Rural
Acta Physiologiae Plantarum | Year: 2011

Photosynthetic gas exchange, vegetative growth, water relations and fluorescence parameters as well as leaf anatomical characteristics were investigated on young plants of two Olea europaea L. cultivars (Chemlali and Zalmati), submitted to contrasting water availability regimes. Two-year-old olive trees, grown in pots in greenhouse, were not watered for 2 months. Relative growth rate (RGR), leaf water potential (ΨLW) and the leaf relative water content (LWC) of the two cultivars decreased with increasing water stress. Zalmati showed higher values of RGR and LWC and lower decreased values of ΨLW than Chemlali, in response to water deficit, particularly during severe drought stress. Water stress also caused a marked decline on photosynthetic capacity and chlorophyll fluorescence. The net photosynthetic rate, stomatal conductance, transpiration rate, the maximal photochemical efficiency of PSII (Fv/Fm) and the intrinsic efficiency of open PSII reaction centres (F′v/F′m) decreased as drought stress developed. In addition, drought conditions, reduced leaf chlorophyll and carotenoids contents especially at severe water stress. However, Zalmati plants were the less affected when compared with Chemlali. In both cultivars, stomatal control was the major factor affecting photosynthesis under moderate drought stress. At severe drought-stress levels, the non-stomatal component of photosynthesis is inhibited and inactivation of the photosystem II occurs. Leaf anatomical parameters show that drought stress resulted in an increase of the upper epidermis and palisade mesophyll thickness as well as an increase of the stomata and trichomes density. These changes were more characteristic in cv. 'Zalmati'. Zalmati leaves also revealed lower specific leaf area and had higher density of foliar tissue. From the behaviour of Zalmati plants, with a smaller reduction in relative growth rate, net assimilation rate and chlorophyll fluorescence parameters, and with a thicker palisade parenchyma, and a higher stomatal and trichome density, we consider this cultivar more drought-tolerant than cv. Chemlali and therefore, very promising for cultivation in arid areas. © 2010 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.


PubMed | Institute Superieur Des Science Et Technologies Of Lenvironnement Of Borj Cedria, Institute National Des Science Appliquees Et Technologiques Tunis Tunisia and Institute National Of Recherche En Genie Rural
Type: Journal Article | Journal: Asian Pacific journal of tropical medicine | Year: 2015

To evaluate toxic activities of essential oils obtained from Rosmarinus officinalis and Lavandula stoechas against the fourth larval instars of Orgyia trigotephras.A total of 1 200 larvae were divided into three groups I II III. Group I was to investigate the effect of extracted essential oils from these aromatic plants as gastric disturbance. Bacillus thuringiensis and ethanol were used as control group. Group II was used as contact action and Group III was used as fumigant action. Decis and ethanol were used as control group. During the three experiments, the effect of essential oils on larvae was assessed.The chemical composition of essential oils from two medicinal plants was determined and, their insecticidal effects on the fourth larval state of Orgyia trigotephras were assessed. The two simples presented an insecticidal activity, nevertheless Rosmarinus officinalis essential oil was less efficient compared to Lavandula stoechas one are discussed.The relationship between the chemical composition and the biological activities is confirmed by the present findings. Therefore the potential uses of these essential oils as bioinsecticides can be considered as an alternative to the use of synthetic products.

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