16 research outputs found

    Macromorphological variation of the invasive Silverleaf nightshade (Solanum elaeagnifolium Cav.) and its relation to climate and altitude in Morocco

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    La relation entre certains traits morphologiques et le potentiel invasif des plantes exotiques envahissantes a été signalée. En plus, l’invasion biologique est souvent associée à une évolution rapide des espèces introduites. L’objectif de cette étude a été d’établir la structure de la variabilité morphologique de Solanum elaeagnifolium et de vérifier si l’invasion au Maroc a été suivie par une évolution rapide qui pourrait affecter son potentiel invasif. Au total, 709 individus issus de 218 sites présentant différentes conditions écologiques ont été caractérisés pour 12 variables. L’Analyse Ascendante Hiérarchique et l’Analyse Discriminante Linéaire, ont pu établir quatre morphotypes. Les traits liés au nombre total de branches et de baies sont ceux qui discriminent le plus entre les morphotypes. La description des quatre morphotypes implique une évolution rapide de cette espèce au Maroc. Cette évolution a donné naissance à de grands plants avec un nombre de baies très élevé. Cependant, les plants de taille réduite prédominent et sont les plus invasifs. La répartition géographique des quatre morphotypes indique que S. elaeagnifolium est une plante r-stratégiste, particulièrement dans les conditions écologiques les plus sévères. Cette stratégie lui permet d’allouer la grande partie de son énergie à la reproduction et de devenir plus invasive par conséquent. Mots-clés: Solanum elaeagnifolium, traits morphologiques, potentiel invasif, morphotypes, facteurs écologiques.The relationship between some morphological traits and the invasive potential of invasive alien plants has been reported. Also, biological invasion is often associated with rapid evolution in introduced species. The study aim was to provide the structure of morphological variation of the invasive Solanum elaeagnifolium and to assess if the invasion of Morocco was followed by a rapid evolution that may affect its invasive potential. A total of 709 individuals from 218 sites, sampled across different ecological conditions, were characterized for 12 variables. The structure of the morphological variation by Hierarchical Cluster Analysis and Linear Discriminant Analysis has determined four morphotypes. Traits related to the total number of shoots and berries are those that discriminate the most between morphotypes. The description of the four morphotypes implied a rapid evolution in this species in Morocco. This evolution has resulted in large plants with a very high number of berries. However, the smallest morphotype is still predominating and is the most invasive. The geographical distribution of the four morphotypes indicates that S. elaeagnifolium tended to be an r-strategist plant, especially in the most severe ecological conditions. This strategy allows S. elaeagnifolium to allocate most of the energy to reproduction and therefore become more invasive. Keywords: Solanum elaeagnifolium, morphology traits, invasive potential, morphotypes, ecological factors

    Towards a comprehensive characterization of durum wheat landraces in Moroccan traditional agrosystems: analysing genetic diversity in the light of geography, farmers’ taxonomy and tetraploid wheat domestication history

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    Background: Crop diversity managed by smallholder farmers in traditional agrosystems is the outcome of historical and current processes interacting at various spatial scales, and influenced by factors such as farming practices and environmental pressures. Only recently have studies started to consider the complexity of these processes instead of simply describing diversity for breeding purposes. A first step in that aim is to add multiple references to the collection of genetic data, including the farmers' varietal taxonomy and practices and the historical background of the crop. Results: On the basis of interview data collected in a previous study, we sampled 166 populations of durum wheat varieties in two traditional Moroccan agrosystems, in the Pre-Rif and Atlas Mountains regions. Using a common garden experiment, we detected a high phenotypic variability on traits indicative of taxonomical position and breeding status, namely spike shape and plant height. Populations often combined modern (short) with traditional-like (tall) statures, and classical durum squared spike shape (5 flowers/spikelet) with flat spike shape (3 flowers/spikelet) representative of primitive domesticated tetraploid wheat (ssp. dicoccum). By contrast, the genetic diversity assessed using 14 microsatellite markers was relatively limited. When compared to the genetic diversity found in a large collection of tetraploid wheat, it corresponded to free-threshing tetraploid wheat. Within Morocco, the two studied regions differed for both genetic diversity and variety names. Within regions, neither geography nor variety names nor even breeding status constituted strong barriers to gene exchange despite a few significant patterns. Conclusions: This first assessment of morphological and genetic diversity allowed pointing out some important factors that may have influenced the structure and evolutionary dynamics of durum wheat in Morocco: the significance of variety names, the occurrence of mixtures within populations, the relative strength of seed exchange between farmers and local adaptation, as well as the fate of modern varieties once they have been introduced. Further, multidisciplinary studies at different spatial scales are needed to better understand these complex agrosystems of invaluable importance for food security

    Impact du relief et des circuits semenciers locaux sur la diversité agro-morphologique du blé dur (Triticum turgidum ssp. durum) dans la vallée d'Er Rich à Imilchil (Maroc)

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    Phenotypic diversity of 101 durum wheat landrace populations collected from the oasis of the Oriental Atlas Mountains (Morocco) was studied. Nine characters (morphological and agronomic) were measured on the 3030 lines (30 lines per population). The frequencies of each phenotypic class were used for the estimate and the analysis of diversity, by considering the geographical zones of origin and the gradients of altitude. The Shannon-Weaver diversity index (H’) showed a wide variability for all considered traits. This index varies from one area to another and from one altitudinal class to another. The mean H’ recorded for all areas was 0.62, indicating the presence of a high degree of polymorphism among the studied durum wheat landrace populations. The results of the multiple component analysis and the hierarchical clustering showed that the geographical proximity and altitude play a main function in the discrimination and the structure of the studied durum wheat populations. The information gathered from this study could be used in conventional breeding programs and in situ conservation of the diversity. La diversitĂ© phĂ©notypique de 101 populations locales de blĂ© dur issues des oasis de montagnes de l’Atlas oriental (Maroc) a Ă©tĂ© Ă©tudiĂ©e. Neuf caractères (morphologiques et agronomiques) ont Ă©tĂ© mesurĂ©s sur les 3030 lignĂ©es (30 lignĂ©es par population). Les frĂ©quences de chaque classe phĂ©notypique ont Ă©tĂ© utilisĂ©es pour l’estimation et l’analyse de la diversitĂ©, en considĂ©rant les zones gĂ©ographiques d’origine et les gradients d’altitude. L’indice de diversitĂ© de Shannon-Weaver (H’) a montrĂ© une forte variabilitĂ© pour l’ensemble des caractères considĂ©rĂ©s. Cet indice varie d’une zone Ă  une autre et d’une classe d’altitude Ă  une autre. Le H’ moyen obtenu pour l’ensemble des zones est de 0,62, indiquant la prĂ©sence d’un degrĂ© Ă©levĂ© de polymorphisme au sein des populations locales de blĂ© dur collectĂ©es. Les rĂ©sultats de l’analyse en composantes multiples ainsi que de la classification hiĂ©rarchique ont montrĂ© que la proximitĂ© gĂ©ographique et l’altitude jouent un rĂ´le majeur dans la discrimination ainsi que sur la structuration des populations de blĂ© dur Ă©tudiĂ©es. Les informations recueillies Ă  partir de ces rĂ©sultats peuvent ĂŞtre exploitĂ©es dans des programmes de sĂ©lection conventionnels et de conservation in situ de la diversitĂ©. Mots clĂ©s: Populations locales, diversitĂ© phĂ©notypique, structuration, conservation in situ, blĂ© dur (Triticum turgidum ssp. durum)

    Clinical and genetic data of Huntington disease in Moroccan patients

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    Background: Huntington's disease (HD) occurs worldwide with prevalence varying from 0.1 to 10 /100,000 depending of the ethnic origin. Since no data is available in the Maghreb population, the aim of this study is to describe clinical and genetic characteristics of Huntington patients of Moroccan origin.Methods: Clinical and genetics data of 21 consecutive patients recruited from 2009 to 2014 from the outpatient clinic of six medical centers were analyzed. Statistical analysis was performed using descriptive statistics.Results: Twenty one patients from 17 families were diagnosed positive for the IT15 gene CAG expansion. Clinical symptoms were predominantly motor (19/21). Twelve patients had psychiatric and behavioral disorders, and 11 patients had cognitive disorders essentially of memory impairment. Analysis of genetic results showed that 5 patients had reduced penetrant (RP) alleles and 16 had fully penetrant (FP) alleles. The mean CAG repeat length in patients with RP alleles was 38.4 ± 0.54, and 45.37 ± 8.30 in FP alleles. The age of onset and the size of the CAG repeat length showed significant inverse correlation (p <0.001, r = -0.754).Conclusion: Clinical and genetic data of Moroccan patients are similar to those of Caucasian populations previously reported in the literature.Keywords: Huntington disease/diagnosis, Huntington disease/epidemiology, Huntington disease/genetics, Trinucleotide repeat expansio

    Clinical and genetic data of Huntington disease in Moroccan patients

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    Background: Huntington's disease (HD) occurs worldwide with prevalence varying from 0.1 to 10 /100,000 depending of the ethnic origin. Since no data is available in the Maghreb population, the aim of this study is to describe clinical and genetic characteristics of Huntington patients of Moroccan origin. Methods: Clinical and genetics data of 21 consecutive patients recruited from 2009 to 2014 from the outpatient clinic of six medical centers were analyzed. Statistical analysis was performed using descriptive statistics. Results: Twenty one patients from 17 families were diagnosed positive for the IT15 gene CAG expansion. Clinical symptoms were predominantly motor (19/21). Twelve patients had psychiatric and behavioral disorders, and 11 patients had cognitive disorders essentially of memory impairment. Analysis of genetic results showed that 5 patients had reduced penetrant (RP) alleles and 16 had fully penetrant (FP) alleles. The mean CAG repeat length in patients with RP alleles was 38.4 \ub1 0.54, and 45.37 \ub1 8.30 in FP alleles. The age of onset and the size of the CAG repeat length showed significant inverse correlation (p <0.001, r = -0.754). Conclusion: Clinical and genetic data of Moroccan patients are similar to those of Caucasian populations previously reported in the literature

    Les ressources phytogenetiques au Maroc : analyse de la variabilite genetique d'une espece fourragere, la luzerne (Medicago sativa L.)

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    SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

    Impact du relief et des circuits semenciers locaux sur la diversité agro-morphologique du blé dur (Triticum turgidum ssp. durum) dans la vallée d’Er Rich – Imilchil (Maroc)

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    Phenotypic diversity of 101 durum wheat landrace populations collected from the oasis of the Oriental Atlas Mountains (Morocco) was studied. Nine characters (morphological and agronomic) were measured on the 3030 lines (30 lines per population). The frequencies of each phenotypic class were used for the estimate and the analysis of diversity, by considering the geographical zones of origin and the gradients of altitude. The Shannon-Weaver diversity index (H’) showed a wide variability for all considered traits. This index varies from one area to another and from one altitudinal class to another. The mean H’ recorded for all areas was 0.62, indicating the presence of a high degree of polymorphism among the studied durum wheat landrace populations. The results of the multiple component analysis and the hierarchical clustering showed that the geographical proximity and altitude play a main function in the discrimination and the structure of the studied durum wheat populations. The information gathered from this study could be used in conventional breeding programs and in situ conservation of the diversity

    Anchoring durum wheat diversity in the reality of traditional agricultural systems: varieties, seed management, and farmers’ perception in two Moroccan regions

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    Background: Traditional agrosystems are the places were crop species have evolved and continue to evolve under a combination of human and environmental pressures. A better knowledge of the mechanisms underlying the dynamics of crop diversity in these agrosystems is crucial to sustain food security and farmers’ self-reliance. It requires as a first step, anchoring a description of the available diversity in its geographical, environmental, cultural and socio-economic context. [br/] Methods: We conducted interviews with farmers cultivating durum wheat in two contrasted traditional agrosystems of Morocco in the Pre-Rif (163 farmers) and in the oases of the Atlas Mountains (110 farmers). We documented the varietal diversity of durum wheat, the main characteristics of the farms, the farming and seed management practices applied to durum wheat, and the farmers’ perception of their varieties. [br/] Results: As expected in traditional agrosystems, farmers largely practiced diversified subsistence agriculture on small plots and relied on on-farm seed production or informal seed exchange networks. Heterogeneity nevertheless prevailed on many variables, especially on the modernization of practices in the Pre-Rif region. Fourteen (resp. 11) traditional and 5 (resp. 3) modern varieties were identified in the Pre-Rif region (resp. in the Atlas Mountains). The majority of farmers grew a single variety, and most traditional varieties were distributed in restricted geographical areas. At the farm level, more than half of the varieties were renewed in the last decade in the Pre-Rif, a more rapid renewal than in the Atlas Mountain. Modern varieties were more prevalent in the Pre-Rif region and were integrated in the traditional practices of seed production, selection and exchange. They were clearly distinguished by the farmers from the landraces, the last ones being appreciated for their quality traits. [br/] Conclusions: The surveyed traditional agrosystems constitute open, dynamic and heterogeneous entities. We suggest that competing factors could favour or limit the cultivation of improved varieties and the erosion of original durum wheat diversity. This first description opens the way to focused further investigations, including complementing variety names with cultural, genetic and phenotypic information and unravelling the multidimensional factors and consequences of modern variety adoption

    Drought-Tolerance QTLs Associated with Grain Yield and Related Traits in Spring Bread Wheat

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    The present research aims to identify the efficient combination of drought-tolerance selection criteria and associated quantitative trait loci. A panel of 197 bread wheat genotypes was evaluated for yield- and drought-tolerance-related traits in two environments (favorable and semiarid) for 2 years (2015–2016). Grain number, biomass, number of fertile spikes per plant and ground cover exhibited a significant correlation with grain yield and constitute potential secondary selection criteria for yield under drought conditions. About 73 significant marker–trait associations were detected along various chromosomal positions. The markers “wsnp_Ex_Rep_c67786_66472676” and “ExcalibuR_c24593_1217” exhibited important genetic gains associated with yield increase under drought (11 and 7%, respectively). The markers “KukRi_c94792_127” and “wsnp_Ex_c298_580660” showed a significant correlation with grain yield, biomass and grain number and were associated with a significant increase in yield performance at the semiarid site (+6 and +7%, respectively). The ground cover was found associated with grain yield and biomass through the markers “wsnp_Ex_Rep_c67786_66472676” (+11%) and “KukRi_c49927_151” (+10%). One marker “TduRuM_contig25432_1377” on chromosome 5B at 20 cM was consistently correlated with the number of fertile spikes across both environments. Further research should be considered to validate the efficiency of these markers to undertake selection for drought tolerance under various environments and genetic backgrounds
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