Technologies post-récolte pour la préservation de la qualité des dattes durant le stockage

Les dattes, fruits du palmier dattier (Phœnix dactylifera), constituent un produit à fort potentiel commercial à l’échelle mondiale et spécifiquement aux pays du Moyen-Orient et de l’Afrique du Nord. Les impacts quantitatifs et qualitatifs des altérations post-récolte sur les dattes imposent la recherche de méthodes appropriées pour leur conservation. Dans ce travail, nous passons en revue les types d’altération causées par divers facteurs biotiques et abiotiques pendant le stockage des dattes. Nous discutons les méthodes de traitements appliquées pour la préservation de la qualité et le rôle de type d’emballage adapté dans la conservation des attributs de qualité des dattes. Enfin, nous soulignons l’importance de la maîtrise des conditions et des bonnes pratiques de stockage dans la réussite du processus de conservation et de respect des normes de commercialisation des dattes

Study of the agro-morphological and technological genetic variability of the Mediterranean populations of durum wheat

Durum wheat (Triticum turgidum var. Durum) is the third mostly grown crop in the world and second in Morocco. This work aims to study the influence the genetic and the environmental effect on the adaptation, the yield and its components and on the grain quality of two durum wheat populations (76 durum accessions and 120 Recombinant Inbred Lines (RILs)). Two trials were installed in two INRA experimental stations, namely Sidi El Aidi (Settat) and Merchouch (Rabat). Several measurements on growth and phenological stages were carried out and analyzed and quality traits were measured in laboratory after harvest. The Principal Components Analysis (ACP) was performed to relate phenological traits and grain quality traits among RILs and accessions. Analysis of certain aspects of quality (Dodecyl Sodium Sulphates (SDS), Vitreousness Rate (TV), Yellow Index (IJ) and Ash content (TC) also allowed to detect an important and similar variability for the two populations. The electrophoresis analysis showed that 58% from the accessions and 62% of RILs present a good gluten force. Moreover, there were correlations between these characters on the one hand, and these characters and the agromorphologic characters on the other hand. A great multi-axis variability was observed which can serve as a base for new variation. This variation is controlled by many useful genes which can be used in durum wheat programs to release new varieties adapted to Moroccan environment and presenting good quality genes for durum wheat

The importance, biology and management of cereal cyst nematodes (Heterodera spp.)

Cereals are exposed to biotic and abiotic stresses. Among the biotic stresses, plant-parasitic nematodes play an important role in decreasing crop yield. Cereal cyst nematodes (CCNs) are known to be a major constraint to wheat production in several parts of the world. Significant economic losses due to CCNs have been reported. Recognition and identification of CCNs are the first steps in nematode management. This paper reviews the current distribution of CCNs in different parts of the world and the recent advances in nematode identification. The different approaches for managing CCNs are also discussed

In vitro colonization of date palm plants by Rhizophagus irregularis during the rooting stage

The use of in vitro culture of date palm plants Phoenix dactylifera, associated with arbuscular mycorrhizal (AM) fungi is a novel approach for the production of bio-fortified plants that are free of pathogens. Here, we report, for the first time, the in vitro mycorrhization of in vitro date palm plants using the AM fungus Rhizophagus irregularis MUCL 41833. Date Plants were used in an in vitro cultured system that consisted of a root compartment (RC) containing germinated seeds of Barrel Clover, Medicago truncatula, and spores of Rhizophagus irregularis as a mycorrhizal donor, and a hyphal compartment (HC) with a barrier separating the RC from the HC. In vitro cultured date palm plants, at the two-leaf stage, were placed in the HC section of the culture plate that after 6 weeks contained an active growing extraradical mycelium network of the fungus. Roots of the date palm became colonized after 10 weeks and hyphae, vesicles, spores and arbuscules, were detected. No differences were noticed in above-ground parameters between mycorrhized and non-mycorrhized plants, in which there was no fungus in the HC. However, the total root length was significantly higher and secondary and tertiary roots were significantly more numerous, in the mycorrhized plants. It is hypothesized that these differences are related to stimulating molecules released by the profuse extraradical mycelium of the fungus growing in close contact with the palm root system. Root colonization percentages were of the same order as those reported in pots cultures of the date palm plants. This work opens the door for the large-scale in vitro mycorrhization of date palm plants, potentially better adapted to acclimatization phase and possibly to the field