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Présentation
Perpétuellement connue par son rôle environnemental indéniable, l’oléiculture occupe une position particulière dans l’agriculture et dans l’économie en Tunisie.

La forêt oléicole compte actuellement près de 70 millions de pieds d’oliviers couvrant 1,7 millions d’hectares dont 1.5 million d’hectares en plein répartis entre 1.4 million d’ha d’oliviers à huile et 19 mille ha d’oliviers de table et représentant prés de 79% de la superficie arboricole totale et 34% des terres labourables.

Adapté aux conditions édaphiques et climatiques de la Tunisie, l’olivier à huile s’étend sur tout le territoire national du Nord au Sud et sa culture contribue à la création d’emplois dans la mesure où le secteur fournit entre 20 et 40 millions de journées de travail par an.

La culture de l’olivier de table est concentrée au Nord du pays avec 74 %, 14.6% au centre et 11.4% au sud. Ces plantations sont réparties dans des parcelles de petites tailles et occupant une faible superficie de l’ordre de 5%.

La Tunisie a hérité d’un patrimoine génétique oléicole riche. A côté des deux principales variétés à huile : Chemléli et Chetoui, plusieurs travaux de prospection, d’identification et de caractérisation effectuées depuis les années 80 ont démontré que l’oliveraie tunisienne jouit d’une richesse variétale remarquable et ont permis de retenir 140 variétés et écotypes locaux : Oueslati, Zalmati, Zarrazi, Chemchali, Jerboui, Fakhari, Toffehi, Chemchéli Zarzis, Chemléli Jerba, Tounsi, Chemchéli Zarzis, Marsaline, Sayali et Jemri.

L’olivier à huile fait fonctionner un tissu industriel renfermant 1723 huileries dotées d’une capacité théorique de trituration d’olives de 44 077 tonnes par jour, 6 unités d’extraction d’huile de grignons, 4 raffineries dont l’activité essentielle est l’huile de graines en raison de la faible demande du consommateur tunisien en huile d’olive raffinée et 50 unités de conditionnement d’huiles alimentaires...  
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Publications récentes
11 Février 2016
 Reverse Transcription Polymerase Chain Reaction (RT-PCR) using new designed primers pair for Heat Shock Protein70 homologue (HSP70h) of Olive leaf yellowing-associated virus revealed 667 amplified product of 10 olive accessions collected from various olive-growing regions in Tunisia. Amplicons were cloned and sequenced. The sequences were deposited in the international databases. Pairwise sequence comparisons among 10 Tunisian isolates along with a reference sequence (AJ440010) extracted from GenBank revealed a nucleotide identity of 86.06-99.40 and an amino acid similarity of 91.89-99.55. Sequence multiple alignments were searched for evidence of recombination using three methods, ie. Differences of Sums of Squares (DSS) implemented in TOPALi v2.5 software and Single Breakpoint (SBP) along with GARD, a genetic algorithm, both incorporated in HyPhy package. All used methods pointed out the presence of putative breaking points in partially sequenced HSP70h-coding gene. Since failing to account for recombination can mislead the phylogeny inference and can elevate the false positive error rate in positive selection assessment, the use of GARD resulted in the reconstruction of different phylogenies on the left as well as on the right sides of putative recombination breaking points, and the 11 accessions were distributed into at least three clusters compared to MEGA6 software which delineated only two clades. Nonetheless, by dividing the aligned sequences at breakpoints into separate sequence sets, MEGA6 delineated a clustering pattern different from the former two. As a result, recombination reshuffled the affiliation of the different accessions to the clusters. Analysis of selection pressures exerted on HSP70h encoded protein using different models (SLAC, IFEL, FEL, REL, PARRIS, FUBAR, MEME, GA Branch, and PRIME) taking into account recombination, and implemented in HyPhy package, revealed that it underwent predominantly purifying selection as confirmed by Tajima’s D, Fu and Li’s D and F tests, and SNAP algorithm. However, a few sites were also under positive selection as assessed by various models such as FEL, IFEL, REL, MEME, and PRIME
05 Octobre 2015
 Sugarcane yellow leaf virus (SCYLV) is one of the most widespread viruses causing disease in sugarcane worldwide. The virus has been responsible for drastic economic losses in most sugarcane-growing regions and remains a major concern for sugarcane breeders. Infection with SCYLV results in intense yellowing of the midrib, which extends to the leaf blade, followed by tissue necrosis from the leaf tip towards the leaf base. Such symptomatic leaves are usually characterized by increased respiration, reduced photosynthesis, a change in the ratio of hexose to sucrose, and an increase in starch content. SCYLV infection affects carbon assimilation and metabolism in sugarcane, resulting in stunted plants in severe cases. SCYLV is mainly propagated by planting cuttings from infected stalks. Phylogenetic analysis has confirmed the worldwide distribution of at least eight SCYLV genotypes (BRA, CHN1, CHN3, CUB, HAW, IND, PER, and REU). Evidence of recombination has been found in the SCYLV genome, which contains potential recombination signals in
04 Août 2015
 This study investigated the direct effect of the insecticides deltamethrin and spinosad on three egg parasitoids species: Trichogramma oleae, T. cacoeciae and T. bourarachae. The parasitoid pupae were exposed to pesticide residues on fresh olive tree leaves at recommended concentrations (RC) at different time intervals: 3, 10, 17, 24 and 31 days after pesticide applications. Parasitism viability (% emergence from parasitized eggs) and adult emergence time (developmental time from pupa to adult emergence) were evaluated. Regarding to the International Organization of Biological Control (IOBC) guidelines, results of toxicity effects of insecticides show that: Deltamethrin was moderately harmful to all Trichogramma species at RC (Decis® 100 milliliters∙ha−1), however, spinosad was harmless to moderately harmful at RC (Tracer® 20 milliliters∙ha−1). Trichogramma species revealed differences with regard to adult emergence time and exhibited significant changes in parasitism viability with increasing time after pesticide treatment. While deltamethrin residues affected parasitism viability 31 days after the product application, spinosad displayed similar viability for almost species 24 days after the application. The usefulness of Trichogramma parasitoids used as biological control agents, in olive tree ecosystem, was discussed in integrated pest management programs for Prays oleae control when parasitoid species were exposed during pupal stage to the insecticide residue.
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