Z. Jmal¹

S. Labidi¹

Y. Dalpé²

S. Slim¹

A. Lounès-Hadj Sahraoui ³

F. Ben Jeddi ¹

¹ Université de Carthage. Laboratoire des Sciences Horticoles, Institut National Agronomique de Tunisie, 43 Avenue Charles Nicolle 1082 cité Mahrajène, Tunis. Tunisie.

² Agriculture et agroalimentaire Canada. Avenue 960, Carling. Ottawa, Ontario K1A0C6, Canada.

³ Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), Université du Littoral Côte d'Opale, 50, rue Ferdinand Buisson, F-62228 Calais, France.

Abstract - Arbuscular mycorrhizal fungi (AMF) play a fundamental role in the survival of plant species in marginal soils, particularly low halomorphic funds (sebkhas). Twelve sites around a sebkha in north-eastern Tunisia were surveyed for flora diversity and soil characteristics. Arbuscular mycorrhizal fungi colonization was examined on the roots of sampled plants. The extraction of AMF spores from the soil samples was carried out in the spring period.The isolated spores were counted and seven AMF species were identified: Funneliformis geosporus, Rhizophagus irregularis, Claroideoglomus etunicatum, Funneliformis mosseae, Septoglomus constrictum, Rhizophagus diaphanus and Rhizophagus fasciculatus. Diversity of AMF and plant species in the investigated sites varied depending on soil salinity. The soil electrical conductivity ranged from 2.18 mS /cm (S5) to 98.67 mS /cm (S3). All studied sites, except S2, S5 and S8, were classified as very highly saline soils (> to 16 mS/cm).These later were characterized by the presence of the AMF species: Funneliformis geosporus and Claroideoglomus etunicatum. Only 29 on the 68 collected plant species presented arbuscular mycorrhizal structures in their roots. These plants belong to five botanical families: Asteraceae, Fabaceae, Oxalidaceae, Malvaceae and Poaceae. Fourty one percent of the sampled plants belongs to the Asteraceae family.

Keywords: Asteraceae, Saline soils, biodiversity

Résumé - Les champignons mycorhiziens arbusculaires (CMA) jouent un rôle fondamental dans la survie des espèces végétales dans les sols marginaux, particulièrement les bas fonds halomorphes (sebkhas). Douze sites limitrophes d’une sebkha située au nord-est de la Tunisie ont été prospectés sur les plans floristiques qu’édaphique. Le statut mycorhizien de toutes les espèces échantillonnées a été défini et les spores des CMA de la rhizosphère des plantes de chaque site ont été extraits durant la saison printanière. Les spores isolées ont été dénombrées et sept espèces de CMA identifiées: Funneliformis geosporus, Rhizophagus irregularis, Claroideoglomus etunicatum, Funneliformis mosseae, Septoglomus constrictum, Rhizophagus diaphanus et Rhizophagus fasciculatus. La diversité des CMA et des espèces végétales prospectées a varié d’un site à l’autre selon la salinité du sol. La conductivité électrique des sols a varié de 2,18 mS/cm (S5) à 98,67 mS/cm (S3). Tous les sites ont été classés très fortement salins (> à 16 mS/cm) sauf S2, S5 et S8. Les sols très fortement salins sont représentés particulièrement par les espèces de CMA Funneliformis geosporus et Claroideoglomus etunicatum. Seulement, 29 espèces végétales sur 68 ont révélé la présence de structures mycorhiziennes arbusculaires intraracinaires. Ces dernières appartiennent principalement à 5 familles botaniques, astéracées, fabacées, oxalidacées, poacées et malvacées, les astéracées prédominent avec 41 % des espèces.

Mots clés: Astéracées, Sols salins, biodiversité.

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Dhaouadi L¹

Ben Maachia S¹

Mkademi C²

Oussama M³

Daghari H⁴

¹Centre Régional de Recherche en Agriculture Oasienne Dégache Tozeur, TUNISIE

²Faculté des sciences Université de Gafsa, TUNISIE

³Spanish National Council for Scientific Research CEBAS-CSIC / Department of irrigation, Spain.

⁴ Institut National d’agronomie, TUNISIE

Abstract - Deguache Oases, localized in south-west of Tunisia, are subject to cumulative effects of climate change and irrational irrigation management. This work was conducted to evaluate and compare irrigation technics adopted under date palms in a plot of 1ha in this oasis (Irrigation basin, Bubbler, mini-diffuser and underground irrigation). The experimental soil hydrodynamic characterization revealed that the soil is sandy, the bulk density of about 1.44 g / cm3, the conductivity at saturation Ks is about 2410-3 cm / s and the volumetric water content at field capacity and permanent wilting point are respectively 10.95% and 6.15%. The monitoring of moisture and soil salinity under these techniques for four successive irrigations showed that depletion of water was concentrated along the root zone between 0.8 and 1.2m, the soil salinity is lower under the bubbler and the bowl technics compared to other ones. In addition, the best irrigation efficiency is for the Bubbler technic (78%).

keys words: Date palm, irrigation technics, efficiency, oasis

Résumé - Les oasis de Deguache, situées au sud-ouest de la Tunisie, sont soumises à des effets cumulés d’une part des changements climatiques et d’autre part d’une gestion irrationnelle de l’irrigation. Ce travail a été effectué afin d’évaluer et comparer des techniques d’irrigation adoptées sous palmiers dattiers dans une parcelle de 1ha de cette oasis (Irrigation par cuvette, par Bubbler, par mini-diffiseur et irrigation souterraine). Une caractérisation hydrodynamique expérimentale des sols de la parcelle d’étude a révélé que le sol in-situ est sableux, son densité apparente est de l’ordre de 1.44 g/cm³, la conductivité à la saturation Ks est environ de 2.410^-3 cm/s et les teneurs en eau volumiques à la capacité au champ et au point de flétrissement permanent sont respectivement 10.95% et 6.15%. Le suivi de l’humidité et de la salinité des sols sous ces techniques pour quatre irrigations successives a montré que l’épuisement de l’eau ce concentre le long de la zone racinaire 0.8 à 1.2m, que la diminution de salinité des sols est remarquable sous la technique bubbler par rapport aux autres techniques et que ce dernier est la technique la plus efficiente (78%).

mots clés: palmier dattier, techniques d’irrigation, efficience, oasis.

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Y. M'SADAK^*

M. MAKHLOUF

S. EL AMROUNI

Université de Sousse, Institut Supérieur Agronomique de Chott-Mariem, BP 47- CP 4042, Tunisie

Abstract - In Tunisia, the production of olive oil generates two byproducts: solid waste (pomace) and liquid waste (olive mill wastewater) whose anarchic discharges threaten the environment. Under these conditions, the search for efficient biological technologies for treating such organic waste becomes an urgent necessity. The fields of application of these olive-products are many and varied. This work deals with the qualitative characterization of the biomass in the delegation of Kalâa Kebira (governorate of Sousse), to appreciate their organic exploitation (both aerobic and anaerobic). To do this, physico-chemical and environmental analyzes were performed. All determined characteristics (pH, electrical conductivity, organic matter, suspended solids ...) ensure the implementation of the Co-composting process of olive biomass (pomace olive and/or olive mill wastewater) with a vegetal ground product (wet and coarse nitrogen) and the anaerobic digestion process of olive mill wastewater. The most relevant results are concerned, on the one hand, the possibility of practicing Co-composting of pomace with organic animal resources available in sufficient quantities in the study area, and secondly, estimating interesting as possible for energy production olive mill wastewater.

Keywords: Pomace, olive mill wastewater, qualitative characterization, Co-composting, Biomethanation.

Résumé - En Tunisie, la production d’huile d’olive génère deux sous-produits : effluents solides (grignons) et effluents liquides (margines) dont les rejets anarchiques menacent l’environnement. Dans ces conditions, la recherche des technologies biologiques performantes pour le traitement de ces résidus organiques devient une nécessité urgente. Les champs d’application de ces sous-produits oléicoles sont nombreux et variés. Le présent travail porte sur la caractérisation qualitative de cette biomasse dans la délégation de Kalâa Kébira (gouvernorat de Sousse), afin d’apprécier leur exploitation biologique (tant aérobie qu’anaérobie). Pour ce faire, des analyses physico-chimiques et environnementales ont été réalisées. Toutes les caractéristiques déterminées (pH, Conductivité Électrique, Matière Organique, Matières En Suspension, …) garantissent la mise en œuvre du procédé de Co-compostage de la biomasse oléicole (grignons et/ou margines) avec un broyat végétal (humide, grossier et azoté) et du procédé de digestion anaérobie des margines. Les résultats les plus pertinents obtenus ont concerné, d’une part, la possibilité de la pratique du Co-compostage des grignons avec des ressources organiques d’origine animale, disponibles en quantité suffisante dans la région d’étude, et d’autre part, l’estimation de la production énergétique possible fort intéressante pour les margines.

Mots clés : Grignons, margines, caractérisation qualitative, Co-compostage, Biométhanisation.

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Y. ZAOUCHI^*

S. REZGUI

T. BETTAIEB

Institut National Agronomique de Tunisie (INAT), 1082 Tunis - Mahrajène, Tunisie

Abstract - The study focuses on the effects of mycorrhization by arbuscular fungi on adaptation capacity in urban conditions of an ornamental woody: Jacaranda mimosifolia D.Don.. The adaptation state is estimated by the photosynthetic efficiency system. The results observed on mycorrhized plants are compared to fertilized treatments with 2g and 4g of OSMOCOT EXACT standard- Scotts (15+ 9+ 12 (+2.5)) and controls. Young plants fertilized with 0g, 2g and 4g of OSMOCOT, are supplemented with a complex of indigenous mycorrhizal strains or a commercial product known as Symbivit®. These are respectively added by doses of 1kg / plant and 25 g / plant.

The results show that the treatments with Symbivit® are less mycorrhized than those with the mycorrhizal substrate and the mycorrhization rates are respectively of 20.86% and 43.82%. Increasing the dose of fertilizer does not affect mycorrhization levels. This symbiotic association significantly improves the ETR of the plants as efficiently as fertilization (p = 0.05). Mycorrhization increases chlorophyll a, chlorophyll b and carotenoids yields respectively by 51.31%, 56.61% and 70.63% compared to controls and by 17.94%, 10.31% and 21.95% compared to fertilized plants. Mycorrhization acts on plants fluorescence. Compared to control, maximum quantum yield of PSII (Fv / Fm) increases by an average of 32.3% and initial chlorophyll fluorescence (F0) decreases by 20.71%.

Mycorrhized plants have more efficient photosynthetic systems and higher phosphorus levels than the control. Fertilization with a high dose induces a significant vegetative production in mycorrhized plants compared to control.

Keywords: Arbuscular mycorrhizal fungi; Jacaranda mimosifolia D.Don; photosynthesis; urban conditions.

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R. Ben Ayed^1*

K. Ennouri¹

H. Ben Hassen²

A. Rebai¹

¹ Molecular and Cellular screening Processes Laboratory.Centre of Biotechnology of Sfax, Tunisia

² Laboratory of Physics, Mathematics and Applications. Faculty of Sciences of Sfax, Tunisia

Abstract - Olive tree (Olea europaea L.) is mainly grown in the Mediterranean area, which is the most important oil-producing crop. In spite of its cultural, economic and nutritional importance, numerous DNA markers accomplished to compositional analyzes by bioinformatic tools have been used to illustrate and reveal homonyms, synonyms and unknown accessions. The objectives of this study were (1) to analyze 5 SNP and 8 SSR markers to characterize 12 olive genotypes originating from different regions of Tunisia and (2) to resolve the denomination ambiguity of Zalmati and Chemlali Tataouine cultivars. Analyses indicated the presence of two erroneous denominations of cultivars.

 Keywords: Olive tree, SNP, SSR, UPGMA, Authenticity, PCA, Misnaming, bioinformatic.

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A.OTHMANI¹

M.REZGUI²

S.CHERIF³

M.MOUELHI³

M.MELKI⁴

¹Regional Research Development Office of Agriculture in Semi Arid North West of Kef, Tunisia

²University of Carthage, Science and Agronomic Techniques Laboratory , National Agricultural Research Institute of Tunisia, Rue HédiKarray 2049 Ariana, Tunisia

³National Agricultural Research Institute of kef Station, Tunisia

⁴Higher Agriculture School of Kef, Tunisia

Abstract - Two experiments (field and pot) were conducted in a semi arid region (Kef/Tunisia) to study the response ofdurum wheatto water regimes based on shoot, root and some agronomic characteristics.Experiments were conducted on two Tunisian durum wheat Maâli (improved variety) and Chili (local variety) and three water regimes i) I2: 70 % of Field Capacity ii) I1: 40 % FC iii) I0: rainfall condition. At anthesis, in pot experiment, root length (RL), root volume (RV), root dry weight (RDW), shoot dry weight (SDW), root dry weight/ shoot dry weight ratio (RDW/SDW), leaf dry weight (LDW), leaf area (LA) and tillers and spikes dry weight (TSDW) were measured. At maturity,the number of spikes/plant (NS), the number of kernels/spike (NK), spike weight (SW), thousand kernel weight (TKW) and the harvest index (HI) were determined in field experiment. Variance analysis showed a high significant effect (P< 0.001) of water regimes on SDW, TSDW, NK and SW. The highest values were obtained under irrigated treatments (I2 and I1). Results indicated also that varieties had significant effect (P< 0.01 and P< 0.05) on RV, RDW, RDW/SDW, LA, NS and HI. In almost of these characteristics,Maâli variety exceeds Chili except in RV and LA.In pot and in field experiments showed that the application of water regimes caused an increase in durum wheat traits and that it is recommended to use improved variety Maâliin this region.

Key Words:durum wheat, water regime, water stress

Abbreviations: harvest index (HI), leaf area (LA), leaves dry weight (LDW),number of kernel/spike (NK), number of spikes/plant (NS), root dry weight (RDW), root dry weight/shoot dry weight ratio (RDW/SDW), root length (RL),root volume (VR), shoot dry weight (SDW), spike weight (SW),thousand kernel weight (TKW), tillers and spikes dry weight (TSDW).

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