Les études moléculaires sur le palmier dattier (Phoenix dactylifera L.) : Article de synthèse.

Le palmier dattier possède certaines caractéristiques qui en font des organismes difficiles à étudier pour la localisation et l’identification des gènes. L’amélioration de la productivité, la qualité du fruit et la résistance aux stress biotiques et abiotiques est le principal objectif des analyses moléculaires chez le palmier dattier. Dans ce papier, nous examinons les progrès considérables dans ce domaine et leur état. On a passé en revue les progrès des études de la génomique chez le palmier dattier afin de fournir une référence utile aux chercheurs travaillant dans ce domaine. Le progrès des techniques moléculaires facilitera les programmes d'amélioration au moyen de la sélection moléculair

The Genetic Diversity Analysis of Tunisian Male Date Palm Cultivars (Phoneix dactylifera L.) Revealed by Phenotypic and Molecular Markers

Tunisian oases reveal an important genetic heritage of date palm cultivars, with various qualities of use. Since the beginning of the century, this heritage has evolved to a selective orientation based on the monoculture of "Deglet Nour," this orientation risks causing the loss of many cultivars. The male of the date palm is part of this heritage and so far remains marginalized. Although they are important for the date palm production cycle, it is in this context that lies our work to study the genetic diversity of a collection of male date palm pollinators from southern Tunisia. The morphological study of the 20 date palm pollinators using 45 IPGRI (International Plant Genetic Resources Institute) descriptors showed significant discrimination, with a similarity index ranging from 0.207 to 0.457, divided them into five similarity groups. The use of 7 ISSR (Inter Simple Sequences Repeat) primers resulted in 64 reproducible bands, of which 57 were 90% polymorphic, and statistical analysis showed a more or less significant genetic diversity with genetic distances 0.491 to 0.873. According to the Mentel test, a non-significant weak correlation (r = 0.015) was noted between the molecular and morphological data. However, the processing of molecular data by various methods generated very significant correlations. Indeed, the correlation between the SM (Simple matching) coefficient and the DICE coefficient showed an important correlation with r = 0.748, which confirms the discriminating power of the ISSR markers in studying the genetic diversity of date palm pollinators

Diversité génétique des cultivars locaux de melon (Cucumis melo L.) collecté au sud tunisien: Valorisation pour un programme de sélection et de conservation génétique

Ce travail a pour objectif d’étudier la diversité génétique des cultivars locaux de melon collecté au sud tunisien. La caractérisation morphologique de 22 cultivars locaux de melon en se basant sur 32 traits a montré qu’ils se distinguent de la variété commerciale Ananas. En effet, les cultivars locaux du Sud se caractérisent par leur précocité, avec des fruits de plus gros calibre et une faible teneur en sucre. La diversité moléculaire des cultivars de melon, évaluée à l'aide de quatre marqueurs RAPD, a montré un taux de polymorphisme global de 95 %. L’analyse ACP selon les trois premiers axes qui résument 54,7 % de la variabilité totale indique une séparation nette entre la variété Ananas et les cultivars locaux. Les corrélations entre les matrices de distance des données morphologiques et des données moléculaires ont montré que les paramètres longueur des fruits, diamètre des fruits, taille de l’attache pistillaire et l’épaisseur maximal de la chair sont significativement corrélés avec plusieurs marqueurs RAPD. Cette étude a montré une nette distinction entre les cultivars locaux de melon et celui commercial, ce qui a un impact pratique par la sélection des cultivars les plus intéressants ou leur utilisation comme géniteurs pour améliorer les variétés commerciales

Mineral fruit composition variation alongside Phoenix dactylifera L. cultivars dependently on geographical origin and agronomic traits.

Date palm gives fruits that make a significant human dietetic through great amounts of different sugars supplement and of minerals. Water, ash and six minerals contents were investigated in dates of 131 individual trees. The geographical effect in mineral content was carried out on tow cultivars, Deglet nour and Alig. New oases of Jerid region, compared to other origins, gave date of Deglet nour with the highest levels of the studied parameters except for the ash and the Calcium contents which were stable between oases. However, old oasis of Jerid region had fruit Alig with the upper levels in phosphorus (0.1 g/100g), sodium (54.76 ppm), magnesium (0.05 g/100g) and iron (0.77 mg/100g); but the lowest in total mineral content (1.75 g/100g) and manganese (0.14 mg/100g). The effect of agronomic traits (maturity period and fruit consistency) was studied basing on 38 different cultivars. Concerning the maturity period, fruits of early ripening cultivars exhibited an elevated concentration in iron (0.87 mg/100g) and calcium (0.024 g/100g) in comparison with those of later maturity cultivars which had the highest ash percent (1.59 g/100g). For the fruit consistency, soft fruits showed the greater Iron content (0.84 mg/100g) but the dry ones exhibited the highest potassium content (0.57 g/100g). These results proposed to consumers that they have to consider the provenance, the fruit consistency and the maturity period which looks as a good indicator for mineral content

Modified Chitosan Immobilized on Modified Sand for Industrial Wastewater Treatment in Multicomponent Sorption: Shrimp Biowaste Processing

In this paper, modified chitosan immobilized on modified sand (MCs/MS) was synthesized and characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDXA). MCs/MS composite was used to remove Reactive Red 23 (RR23), Reactive Blue 19 (RB19) and Iron III (Fe3+) in three single-component and three binary, RR23+RB19, RR23+Fe3+ and RB19+Fe3+. Batch experiments were carried out for adsorption kinetics, isotherms and thermodynamics. Operational parameters studied were pH, contact time, temperature, adsorbate and adsorbent concentrations. Adsorption kinetics in single and binary systems of components followed pseudo- second-order kinetics model. The isotherm data in single and binary systems followed Freundlich isotherm model. Thermodynamic parameters have disclosed that the adsorption is exothermic and not spontaneous with a physical adsorption for both single and binary systems. The results showed that MCs/MS composite was an effective adsorbent to remove hazardous pollutants with a removal rate between 80% and 99.6%, the optimal contact time was between 120 and 180 min for all components in single and multicomponent system. Keywords : Modified chitosan immobilized on modified sand, Multicomponent system, Reactive Red 23, Reactive Blue 19, Iron III, Hydrothermo-Chemical method

Oligonychus afrasiaticus (Mcgregor) : Problématiques d’infection du palmier dattier et son contrôle : Révision de littérature

Oligonychus afrasiaticus constitue l’un des acariens les plus destructifs du palmier dattier. Il est très répandu dans le monde. Diverses stratégies sont utilisées dans sa lutte sans qu’elles réussissent, toutefois, à l’éliminer. On décrit dans cet article la biologie de l’espèce ainsi que les méthodes chimiques et biologiques utilisées dans son contrôle et on finit par poser certaines problématiques relatives à la cause de son émergence et les refuges qui abritent cet acarien durant tous les mois de l’année

Phylogeographical Analyses of a Relict Fern of Palaeotropical Flora (Vandenboschia speciosa): Distribution and Diversity Model in Relation to the Geological and Climate Events of the Late Miocene and Early Pliocene

Samira Ben-Menni Schuler was granted a predoctoral grant (F.P.U. program) from the Spanish Government. Hammadi Hamza was granted by a postdoctoral fellowship (Erasmus Mundus-Al Idrisi II scholarship) from the European Union. The authors thank all those people and institutions that facilitated or helped in the collection of samples (in alphabetical order: angel Banares, Antonio Delgado, Brother Anthony, Government of Ireland, Elizabeth Ojeda, Emer Ni Dhuill, Gobierno de Canarias, Ibai Olariaga-Ibarguren, Inaki Sanz-Azkue, Junta de Andalucia, Kristyna Hanuova, Miguel Perez-Gutierrez, Parque Nacional de Garajonay, Ranger Brian Duffy, Sito Chinea, Yves Krippel). We also thank Ana Garcia-Garcia for technical assistance in SDM analysis. This research was funded by the Regional Andalusian Government, grant number P10-RNM-6198.Fern phylogeographic studies have mostly focused on the influence of the Pleistocene climate on fern distributions and the prevalence of long-distance dispersal. The effect of pre-Pleistocene events on the distributions of fern species is largely unexplored. Here, we elucidate a hypothetical scenario for the evolutionary history of Vandenboschia speciosa, hypothesised to be of Tertiary palaeotropical flora with a peculiar perennial gametophyte. We sequenced 40 populations across the species range in one plastid region and two variants of the nuclear gapCp gene and conducted time-calibrated phylogenetic, phylogeographical, and species distribution modelling analyses. Vandenboschia speciosa is an allopolyploid and had a Tertiary origin. Late Miocene aridification possibly caused the long persistence in independent refugia on the Eurosiberian Atlantic and Mediterranean coasts, with the independent evolution of gene pools resulting in two evolutionary units. The Cantabrian Cornice, a major refugium, could also be a secondary contact zone during Quaternary glacial cycles. Central European populations resulted from multiple post-glacial, long-distance dispersals. Vandenboschia speciosa reached Macaronesia during the Pliocene–Pleistocene, with a phylogeographical link between the Canary Islands, Madeira, and southern Iberia, and between the Azores and northwestern Europe. Our results support the idea that the geological and climate events of the Late Miocene/Early Pliocene shifted Tertiary fern distribution patterns in Europe.Spanish Government European Commission(Erasmus Mundus-Al Idrisi II scholarship) from the European Union - Regional Andalusian Government P10-RNM-619

Comparison of the effectiveness of ISSR and SSR markers in determination of date palm (Phoenix dactylifera L.) agronomic traits

Abstract Date palm (Phoenix dactyliferaL.) is extensively cultivated in the Middle East and in North Africa. Seven ISSR markers and five SSR loci were selected and used to evaluate genetic diversity in twenty-six Tunisian cultivars. ISSR primers amplified a total of 43 polymorphic DNA fragments. The average was 6.1 fragments per primer. The microsatellites examined in this study were highly polymorphic possessing a great number of alleles with an average of 7.2 alleles per locus. Principal component analyses based on Nei Genetic distances showed groups of cultivars with a common maturity period and a common fruit consistency. SSR markers discriminate the fruit characteristics subpopulations in a more convincing way than ISSR markers. The Mantel test emphasizes a significant correlation between genetic distance and fruit consistency. A significant difference was observed between soft and dry subpopulations using ISSR data and between semisoft and the other fruit consistency subpopulations using SSR data

First study of Genetic diversity in watermelon (Citrullus lanatus) germplasm collected from Southern Tunisia using RAPD markers

The genetic diversity in local Tunisian watermelon (Citrullus lanatus) was studied using RAPD markers. Eight watermelon cultivars originating from south of Tunisia and belong to four populations were analysed and compared to two commercial varieties (Giza and Sugar-baby) widely produced in this area. Five of nine RAPD primers generated a total of 86 reproducible bands, 85 of which were polymorphic (98.4%). Cluster analysis of the accessions considered in this study employing RAPD data indicated that commercial varieties are significantly different of all the local cultivars. The relationships among the local cultivars (four populations) showed that Medenine population and the most genotypes of Benguerdane population were grouped together and significantly different from Kebili population. The AMOVA showed significant differentiation between populations (27%). In addition, the data showed clusters according to some fruit characteristics such as fruit shape and fruit weight. This proved that RAPD markers are useful for germplasm discrimination as well as for investigation of patterns of variation in watermelon

Pre-designing of a mechatronic system using an analytical approach with dymola

This paper presents a pre-dimensioning method applied to a mechatronic system and regarding the vibrational aspect, through a simple modeling process in Dymola environment. We study the vibration transmission between dynamic exciters (motors) and receivers (electronic cards) which are located on a simply supported rectangular plate, using an analytical approach. This new method will allow us to perform representative and robust modeling and simulation. The solution for this issue would be a pre-sizing and pre-positioning procedure. It aims to determine a set of possible technical solutions and principal characteristics before the definitive choice of components and precise sizing of the system. The presented method predicts also behaviour of the mechatronic system. In order to validate the model with respect to the finite element method, selected simulation results are presented