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Acheuk F.,University of Boumerdes | Cusson M.,Natural Resources Canada | Doumandji-Mitiche B.,Algeria National School of Agronomy
Journal of Insect Physiology | Year: 2012

The effects of a methanolic extract of the plant Haplophyllum tuberculatum (ME-Ht) and of teflubenzuron (TFB) were compared on several reproductive variables and ecdysteroid titers in the females of Locusta migratoria. The test products were administered orally to newly emerged females at doses of 1500 (ME-Ht) and 10. μg/female (TFB). The methanolic extract and TFB had comparable effects on several of the variables examined. Both significantly delayed the first oviposition and reduced fecundity and fertility. ME-Ht and TFB also displayed similar effects on ovarian growth, vitellogenesis and ecdysteroid titers. Both treatments induced a drop in hemolymph protein levels as well as a reduction in vitellogenin uptake by oocytes. This delay in oogenesis was accompanied by a resorption of terminal oocytes. However, whereas TFB completely blocked egg hatch, ME-Ht only had a modest inhibitory effect on this variable. Hemolymph and ovarian ecdysteroid titers, as measured by radioimmunoassay, were similar and low in both control and treated females, except for a peak observed only in control females at the end of vitellogenesis. We discuss the functional significance of the observed effects in the context of the putative modes of action of the methanolic plant extract and TFB. © 2011 Elsevier Ltd. Source


Makhzoum A.,University of Western Ontario | Benyammi R.,Algeria National School of Agronomy | Moustafa K.,Institute Mondor Of La Recherche Biomedicale | Tremouillaux-Guiller J.,University of Tours
BioDrugs | Year: 2014

Plant molecular pharming is a promising system to produce important recombinant proteins such as therapeutic antibodies, pharmaceuticals, enzymes, growth factors, and vaccines. The system provides an interesting alternative method to the direct extraction of proteins from inappropriate source material while offering the possibility to overcome problems related to product safety and source availability. Multiple factors including plant hosts, genes of interest, expression vector cassettes, and extraction and purification techniques play important roles in the plant molecular pharming. Plant species, as a biosynthesis platform, are a crucial factor in achieving high yields of recombinant protein in plant. The choice of recombinant gene and its expression strategy is also of great importance in ensuring a high amount of the recombinant proteins. Many studies have been conducted to improve expression, accumulation, and purification of the recombinant protein from molecular pharming systems. Re-engineered vectors and expression cassettes are also pivotal tools in enhancing gene expression at the transcription and translation level, and increasing protein accumulation, stability, retention and targeting of specific organelles. In this review, we report recent advances and strategies of plant molecular pharming while focusing on the choice of plant hosts and the role of some molecular pharming elements and approaches: promoters, codon optimization, signal sequences, and peptides used for upstream design, purification and downstream processing. © 2013 Springer International Publishing. Source


Srairi M.T.,Hassan II Agronomy and Veterinary Medicine Institute | Benyoucef M.T.,Algeria National School of Agronomy | Kraiem K.,Higher Institute of Agricultural science
SpringerPlus | Year: 2013

The Maghreb countries (Algeria, Morocco and Tunisia) have experienced since the early 1950s a rapid demographic growth coupled to a significant rhythm of urbanization. This has led to a marked increase in the demand of dairy products. In order to secure the supply, specific policies have been implemented. They mainly consisted in the establishment of a dairy industry, based on the processing of either raw milk produced locally (in Morocco and Tunisia) or imported milk powder (in Algeria). These divergent options have had significant consequences on the whole organization of the dairy chains in these countries, from cattle rearing practices, to milk collection and processing. They have also implied differences in milk and its derivatives' prices and levels of consumption. The paper draws a comparative analysis of milk chains within the three countries: a supply mainly based on imports in Algeria, whereas in Morocco and Tunisia, the demand is satisfied by a chain relying on locally produced cattle milk. The paper also emphasizes on the future challenges that will have to be addressed: a rising volatility of milk and other strategic inputs' prices (feed, machinery, cattle, etc.) in global markets, an improvement in consumers' awareness about milk quality, a further pressure on natural resources (mainly soils and water) to get more raw milk, in countries already suffering an acute water stress. The article also establishes recommendations about specific issues related to the development of the dairy chains in the context of North Africa. These are mainly linked to the fragmented offer induced by numerous smallholder farms, which implies obvious difficulties to assess the hygienic and the chemical quality of milk batches delivered daily. Moreover, this fragmented offer also means that specific support programs will have to be designed, as the vast majority of farms are not dairy specialized, expecting both milk and calf crop from their herds. © 2013 Kumar et al. Source


Benslimane H.,Algeria National School of Agronomy
EPPO Bulletin | Year: 2015

La tache helminthosporienne, maladie du blé, communément désignée par l'appellation anglo-saxonne « tan spot » est mondialement rencontrée dans les champs de blé, et peut causer d'importantes pertes. Elle est provoquée par un ascomycète Pyrenophora tritici-repentis, dont les différents isolats semblent très variables sur le plan génétique. Cette maladie est caractérisée par des symptômes typiques, une tache nécrotique entourée d'une chlorose. Huit races de son agent causal sont actuellement reconnues, sur la base des symptômes induits (Chlorose/Nécrose) sur une gamme d'hôtes différentielle. Ces symptômes sont le résultat d'une interaction spécifique entre la plante-hôte et au moins trois toxines spécifiques à l'hôte, Ptr ToxA, Ptr ToxB et Ptr ToxC. L'analyse de cette interaction a démontré que celle-ci apparait comme l'image inversée du modèle du gène pour gène décrit par de Flore. Le présent article est une première revue bibliographique en langue française cernant les grands aspects de cette maladie, son épidémiologie et la diversité de son agent causal. © 2015 OEPP/EPPO. Source


Adjlane N.,University of Boumerdes | Doumandji S.-E.,Algeria National School of Agronomy | Haddad N.,National Center for Agriculture Research and Extension
Cahiers Agricultures | Year: 2012

Honeybees, in addition to their production of honey, pollinate the flowers of fruit trees and other crops. Any threat to them, whether from pesticides, herbicides or diseases, therefore pose serious consequences not only for beekeeping, but also for agriculture in general. For several years, many beekeepers in Algeria have reported deaths in their apiaries. At present, we lack hard data on the causes of such mortality. In order to provide some answers to this problem, we conducted a field study with beekeepers in mid-northern Algeria. This study is complemented by information from the beekeeping cooperative, the technical institute of livestock and veterinary services department at the Ministry of Agriculture, and the regional laboratories of veterinary medicine. Analysis of the results shows bee diseases mainly represented by the Varroa and bee poisoning by insecticides, as well as ecosystem degradation (loss of honey flora) and climate change. All these factors threaten the local bee and have a negative influence on the production of honey. Source

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