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

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

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

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

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)

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 diversité phénotypique de 101 populations locales de blé dur issues des oasis de montagnes de l’Atlas oriental (Maroc) a été étudiée. Neuf caractères (morphologiques et agronomiques) ont été mesurés sur les 3030 lignées (30 lignées par population). Les fréquences de chaque classe phénotypique ont été utilisées pour l’estimation et l’analyse de la diversité, en considérant les zones géographiques d’origine et les gradients d’altitude. L’indice de diversité de Shannon-Weaver (H’) a montré une forte variabilité pour l’ensemble des caractères considérés. Cet indice varie d’une zone à une autre et d’une classe d’altitude à une autre. Le H’ moyen obtenu pour l’ensemble des zones est de 0,62, indiquant la présence d’un degré élevé de polymorphisme au sein des populations locales de blé dur collectées. Les résultats de l’analyse en composantes multiples ainsi que de la classification hiérarchique ont montré que la proximité géographique et l’altitude jouent un rôle majeur dans la discrimination ainsi que sur la structuration des populations de blé dur étudiées. Les informations recueillies à partir de ces résultats peuvent être exploitées dans des programmes de sélection conventionnels et de conservation in situ de la diversité. Mots clés: Populations locales, diversité phénotypique, structuration, conservation in situ, blé dur (Triticum turgidum ssp. durum)

Clinical and genetic data of Huntington disease in Moroccan patients

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

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.)

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