31 research outputs found

    Genetic variation in responses to salt stress in Tunisian populations of Medicago ciliaris

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    Soil salinity is one of the most serious environmental factors affecting crop productivity around the world. We used a morpho-physiological approach to investigate the salt responses of four Tunisian natural populations of Medicago ciliaris. Forty-six lines of M. ciliaris were grown under a control treatment and 100 mM NaCl. We measured 11 quantitative traits of shoot and root growth during harvest. An analysis of variance showed that the variations in salt response can be explained by the effects of the population, line, treatment, and interactions between the population and treatment and the line and treatment. Most of the measured traits showed significant differences between the studied populations under the control treatment and salt stress

    Variability in Responses to Phoma medicaginis Infection in a Tunisian Collection of Three Annual Medicago Species

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    Spring black stem and leaf spot, caused by Phoma medicaginis, is an issue in annual Medicago species. Therefore, in this study, we analyzed the response to P. medicaginis infection in a collection of 46 lines of three annual Medicago species (M. truncatula, M. ciliaris, and M. polymorpha) showing different geographic distribution in Tunisia. The reaction in the host to the disease is explained by the effects based on plant species, lines nested within species, treatment, the interaction of species × treatment, and the interaction of lines nested within species × treatment. Medicago ciliaris was the least affected for aerial growth under infection. Furthermore, the largest variation within species was found for M. truncatula under both conditions. Principal component analysis and hierarchical classification showed that M. ciliaris lines formed a separate group under control treatment and P. medicaginis infection and they are the most vigorous in growth. These results indicate that M. ciliaris is the least susceptible in response to P. medicaginis infection among the three Medicago species investigated here, which can be used as a good candidate in crop rotation to reduce disease pressure in the field and as a source of P. medicaginis resistance for the improvement of forage legumes

    Graves' Disease Associated with Cerebrovascular Disease and Antiphospholipid Antibody Syndrome

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    Thyroid disorders are commonly associated with coagulopathy. Patients with hyperthyroidism have increased risk for developing thromboembolic accidents, which are favoured by a simultaneous presence of antiphospholipid antibodies syndrome. in this paper, we describe the case of a patient with Graves' disease, who developed strokes with antiphospholipid antibodies syndrome

    Harnessing the potential of endophytes: Sustainable solutions for enhancing forage crop resilience and soil fertility

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    Environmental changes pose significant challenges to sustainable agriculture, adversely affecting crop production and soil fertility. Factors such as drought, salinity, pathogens, and soil type exert their influence on the behavior of fodder crops by altering their morphological, biochemical, and molecular mechanisms, ultimately leading to reduced yields and productivity. Consequently, there is a pressing need to develop mitigation strategies aimed at enhancing the tolerance of forage crops to both biotic and abiotic stresses, addressing a critical challenge in sustaining their growth. In recent times, the use of biofertilizers has emerged as an environmentally friendly alternative to chemical fertilizers, holding promise for sustainable horticultural, agricultural, and forestry production systems. Notably, endophytic microorganisms play a pivotal role in promoting plant growth through direct or indirect mechanisms. Additionally, endophytic bacteria actively regulate gene expression responsible for the production of antioxidant enzymes, various phytohormones, siderophores, and ROS scavenging enzymes, all of which contribute to supporting the growth of host plants even in extreme environments. Consequently, there is a growing focus on understanding and validating the mechanisms through which beneficial plant endophytes interact to combat both biotic and abiotic stresses. This review emphasizes the potential of endophytes as biofertilizers, biocontrol agents, and contributors to the mitigation of abiotic and biotic stresses, all of which play crucial roles in maintaining the development of forage crops and soil fertility

    Case Report Graves' Disease Associated with Cerebrovascular Disease and Antiphospholipid Antibody Syndrome

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    Thyroid disorders are commonly associated with coagulopathy. Patients with hyperthyroidism have increased risk for developing thromboembolic accidents, which are favoured by a simultaneous presence of antiphospholipid antibodies syndrome. in this paper, we describe the case of a patient with Graves' disease, who developed strokes with antiphospholipid antibodies syndrome

    تصورات القطريين للدين: دراسة استكشافية

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    تسعى هذه الدراسة الميدانية الاستكشافية إلى معالجة مسألة التصورات الدينية لدى المجتمع القطري؛ من حيث دلالة مفهومها وموقعها، ومدى أهميتها لدى أعضاء المجتمع، من خلال مقاربة المصادر التي يستمد منها هذا المجتمع مختلف تصوراته حول الدين، باعتماد عدد من التساؤلات، يمكن إجمالها في الآتي: ما تصورات القطريين للدين؟ أي أبعاد الدين أكثر حضورًا في أذهان القطريين وممارساتهم؟ ما مصادر المجتمع القطري في تصوراته للدين؟ وتكمن أصالة هذه الدراسة في ربط التصورات الدينية لدى المجتمع القطري بممارسات أعضائه اليومية من جهة، والمصادر التي يستندون إليها في تعريف الدين نفسه من جهة ثانية، ما جعل هذه الدراسة متفردة في تغطية جانب بحثي مهم طال التغافل عنه، باعتماد منهج مختلط جمع بين الكيفي (النوعي) والكمي، بهدف خلق تكامل بين البيانات النوعية والكمية، مما من شأنه أن يقدِّم تحليلًا أكثر شمولًا وسلاسة في فهم تصورات القطريين للدين. وخلصت الدراسة أولًا: إلى أن كلًا من العقيدة والعبادات يمثلان النواة المركزية في تشكيل تصور القطريين عن الدين، فيما تعتبر بقية العناصر المحيطة بهما أبعادًا مساعدة في تشكيل ذلك التصور، ولا تعبر عن جوهره بالضرورة. وثانيًا: إلى أن هناك انسجامًا بين التصورات الاعتقادية والعملية، تمثل في وعي القطريين بأن أهمية عاداتهم وتقاليدهم نابعة من ارتباطها بالدين، لا من مخالفتها له

    Variability in Responses to Phoma medicaginis Infection in a Tunisian Collection of Three Annual Medicago Species

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    Spring black stem and leaf spot, caused by Phoma medicaginis, is an issue in annual Medicago species. Therefore, in this study, we analyzed the response to P. medicaginis infection in a collection of 46 lines of three annual Medicago species (M. truncatula, M. ciliaris, and M. polymorpha) showing different geographic distribution in Tunisia. The reaction in the host to the disease is explained by the effects based on plant species, lines nested within species, treatment, the interaction of species × treatment, and the interaction of lines nested within species × treatment. Medicago ciliaris was the least affected for aerial growth under infection. Furthermore, the largest variation within species was found for M. truncatula under both conditions. Principal component analysis and hierarchical classification showed that M. ciliaris lines formed a separate group under control treatment and P. medicaginis infection and they are the most vigorous in growth. These results indicate that M. ciliaris is the least susceptible in response to P. medicaginis infection among the three Medicago species investigated here, which can be used as a good candidate in crop rotation to reduce disease pressure in the field and as a source of P. medicaginis resistance for the improvement of forage legumes

    Evaluation of the morpho-physiological, biochemical and molecular responses of contrasting Medicago truncatula lines under water deficit stress

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    This article belongs to the Special Issue Molecular Analysis of Medicago Spp.Medicago truncatula is a forage crop of choice for farmers, and it is a model species for molecular research. The growth and development and subsequent yields are limited by water availability mainly in arid and semi-arid regions. Our study aims to evaluate the morpho-physiological, biochemical and molecular responses to water deficit stress in four lines (TN6.18, JA17, TN1.11 and A10) of M. truncatula. The results showed that the treatment factor explained the majority of the variation for the measured traits. It appeared that the line A10 was the most sensitive and therefore adversely affected by water deficit stress, which reduced its growth and yield parameters, whereas the tolerant line TN6.18 exhibited the highest root biomass production, a significantly higher increase in its total protein and soluble sugar contents, and lower levels of lipid peroxidation with greater cell membrane integrity. The expression analysis of the DREB1B gene using RT-qPCR revealed a tissue-differential expression in the four lines under osmotic stress, with a higher induction rate in roots of TN6.18 and JA17 than in A10 roots, suggesting a key role for DREB1B in water deficit tolerance in M. truncatula.This study was supported by the Tunisian Ministry of Higher Education and Scientific Research (CBBC02 LR15) and the National Research Foundation of South Africa (GUN 95358) in the framework of the Tunisian-South African Joint Research Collaboration Program (2016–2017).Peer reviewe

    Morpho-phenological diversity among natural populations of Medicago polymorpha of different Tunisian ecological areas

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    Medicago polymorpha is a herbaceous legume that can be a useful pasture plant, in particular, in regions with a Mediterranean climate. The genetic variation in 120 lines of M. polymorpha sampled from five regions in Tunisia was characterized on the basis of 16 morpho-phenological characters. Results from analysis of variance (ANOVA) showed that differences among populations and lines existed for all traits, with population explaining the greatest variation for measured traits. The populations of Enfidha and Soliman were the earliest flowering, while those of El Kef, Bulla Regia and Mateur were the latest. El Kef and Mateur exhibited the highest aerial dry weight while the lowest value was found for Soliman. Moderate to lower levels of heritability (H²) were registered for investigated traits. There was no significant association between pairwise population differentiation (QST) and geographical distances. Studied lines were clustered into three groups with 59 for the first group, 34 for the second group, and 27 lines for the third group. The lines of the first two groups showed the largest length of stems while those of the second group had the highest number of leaves. The variation of quantitative traits among populations was influenced by the altitude, temperature and relative humidity. Overall, the high levels of within population variation and the lack of correlation between population differentiation and geographical distances suggest a potentially important rate of long-distance seed dispersal and confirm the role played by natural selection in the population structure of Tunisian populations of M. polymorpha.Keywords: Medicago polymorpha, populations, quantitative traits, population differentiation, environmental parameter
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