L. Ben Haj Said ^1*

H. Najjaa ²

M. Neffati ²

S. Bellagha ¹

¹Department of Food Technology, National Institute of Agronomy of Tunisia, University of Carthage. Laboratory of Economy, Sciences and Food technology, LR03AGR01 INAT, 43, Avenue Charles Nicolle, 1082, Tunis Mahrajene, Tunisia.

²Range Ecology Laboratory, Institute of Arid Areas IRA, 4119 Medenine, Tunisia.

Abstract - Allium roseum leaves were found to be rich in polyphenols and flavonoids and had high antioxidant activity. Allium roseum leaves thermo-physical characterization shows that the increase in water activity and the decrease in temperature significantly augment the equilibrium water content of Allium roseum leaves. A significant difference between desorption and adsorption (hysteresis effect) was found at lower temperature (20°C) and it disappeared at higher temperatures. GAB and Peleg models were found to better describe the relationship between equilibrium moisture content, water activity and temperature. The isosteric heats of desorption and adsorption were determined from experimental sorption isotherms and then correlated with corresponding equilibrium moisture contents. Desorption isosteric heat decreased continuously with the increase of the equilibrium moisture content, and was always higher than adsorption heat. In this case and from a moisture content of 0.15 kg water/kg db, adsorption isosteric heat was constant and about 40.68 kJ/mol.

Keywords: Rosy garlic leaves / bioactive composition / sorption isotherms / modeling / isosteric heat of sorption.

Read more

A. OTHMANI¹

M. MOSBAHI²

S. AYED¹

H. SLIM-AMARA³

M. BOUBAKER⁴

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

²Higher Agriculture School of Mogran, Zaghoan

³Higher Agriculture School of ChottMeriem, Sousse

⁴Genetic and Plant Breeding Laboratory, Department of Agronomy and Biotechnology, National Agronomic Institute of Tunisia, 43, Avenue Charles Nicole, 1082 Tunis, Tunisia

Abstract - Seventy four Tunisian bread wheat accessions were characterized using seven morphological traits: spike color, spike shape, spike density, beak shape, beak length, glume shoulder shape, grain color and grain size. Accessions with white spike, tapering spike shape, lax spike density, moderately curved beak shape, long beak, slightly sloping glume shoulder shape, white yellow and small grain were dominant. Based on the Shannon–Weaver Diversity Index (H’), accessions showed a great morphological diversity in beak length and glume shoulder shape (H’ = 0.82) illustrating a large diversity in this collections . Results showed that lowest values of H’ were obtained in spike density (0.10), spike color (0.17), spike shape (0.23), grain size (0.42), beak shape (0.62) and grain color (0.62). This data revealed that morphological traits might be used for an effective characterization of Tunisian bread wheat diversity and also the need to conserve and safeguard genetic diversity of this crop.

Keywords: bread wheat / morphology / diversity index / Tunisia

Read more

S. Ayadi¹

Z. Chamekh^1*

C. Karmous²

S. Jallouli¹

N. Ahmed¹

Z. Hammami¹

S. Rezgui¹

Y. Trifa¹

¹National Institute of Agriculture of Tunis, 43, Avenue Charles Nicole, 1082 Tunis, Tunisia.

²Department of Plant Sciences, Agricultural High School of Mateur. Route de Tabarka, 7030, Mateur. Tunisia.

Abstract - In Tunisian agriculture system, nitrogen (N) is the most important and used fertilizer for sustaining durum wheat (Triticum turgidum ssp durum) growth and improving yield. The aim of this study was to assess genotypic differences for N agronomic and physiologic efficiencies at three nitrogen levels (0, 75 and 150 kg N/ha). A set of four durum wheat genotypes was used and is constituted by two improved cultivars (Om Rabia and Khiar) and on two landraces (Bidi AP4 and Azizi AC2). A field trial was conducted under sub-humid climate conditions in northern Tunisia. A complete randomized block design with four replications was used. The results showed that increasing N up to 75 kg N/ha increased yield and its attributes of durum wheat. Increasing N up to 75 kg N/ha seems able to ensure the production potential of indigenous genotypes (Azizi and Bidi). On the contrary the improved varieties still respond to a greater nitrogen input. It is possible that improved genotypes require higher levels of nitrogen in order to fully express their genetic potential. In addition, we have showed that a significant genotypic variation in the N agronomic efficiency.

Keywords: durum wheat / N agronomic efficiency / N physiologic efficiency genetic variability.

Read more

R. MZID¹

A. othmani²

L. FKI²

S. JOUA³

N. DRIRA²

¹ Laboratoire de Physiologie Moléculaire des Plantes (LPMP). Centre de Biotechnologie de Borj Cédria (CBBC). BP901, Hammam-Lif 2050, Tunisie

² Laboratoire de biotechnologies Des Plantes, Faculté des Sciences de Sfax. Route de Soukra Km 3,5, BP 802, 3018 Sfax, Tunisie

³ Department of Biological & Environmental Sciences. Qatar University. P.O. Box 2713, Doha, Qatar

Abstract - Date palm (Phoenix dactylifera L.), is one of the most important cultivated fruit crop. It constitutes the main factor of ecologic and socio economic stability in the Saharan and sub-Saharan areas. Selective assays based on mutagenesis have been investigated and aimed either at the elaboration a fighting strategy against the bayoud plague due to the Fusarium oxysporum fsp albedenis or to enlarge the biodiversity in this phytogenic resources. Diverse buds and immature inflorescences sampled from the Deglet Nour variety were used to regenerate vitroplants. Embryogenic cals were irradiated by gamma rays in order to induce genomic mutations. Study of the vitroplants’ variability was carried out by the help of the random amplified polymorphic DNA method (RAPD). By using universal primers. Data have permitted to produce a large number of vitroplants derived from the treated emryogenic cals.. In addition, the RAPD banding profiles generated using universal primers were nearly similar suggesting that the derived vitroplants are characterised by a gentic stability. Taking in account the observed satbility, we assume that the gamma rays did not induce obvious variations in the date palm’s genome.

Keywords: Date palm/ vitoplants/ Gamma rays / RAPD/ genetic stability

Résumé : Le palmier dattier (Phoenix dactylifera L.), fait figure à part parmi les espèces végétales cultivées. En effet, il présente pour les régions sahariennes et subsahariennes, une importance écologique et socio-économique considérable. Face aux problèmes posés par le Bayoud, maladie cryptogamique mortelle, causée par Fusarium oxysporum fsp albedinis, des essais de sélection par mutagenèse induite sont entrepris afin d’enrichir les ressources génétiques et d’améliorer les variétés existantes. des inflorescences femelles ainsi que des bourgeons végétatifs axillaires et apicaux prélevées sur des palmiers adultes de la variété Deglet Nour ont été utilisées pour la régénération de vitroplants. Les cals embryogènes ont été irradiés par des rayonnements ionisants gamma afin d’induire des variations génétiques. l’analyse de la variabilité génétique a été effectuée par la technique d’amplification aléatoire de l’ADN polymorphe (RAPD). Les résultats montrent qu’il est possible d’obtenir plusieurs vitroplants à partir des cals embryogènes. En effet les doses d’irradiation 15, 30 et 45 Gy n’affectent pas les capacités morphogénétiques de ces cals. En outre, les profils RAPD générés par les différentes amorces testées en présence de l’ADN cellulaire total issu des différents clones étudiés se sont avérés similaires. Ce résultat témoigne d’une grande stabilité génétique qui caractérise les vitroplants. Tenant compte de la stabilité génétique observée chez tous les vitroplants analysés, nos résultats suggèrent que les rayonnements ionisants de type gamma n’induisent pas de variations génotypiques décelables par la technique RAPD.

Mots clés : palmier dattier / vitoplants/ rayonnements Gamma / RAPD/ stabilité génétique

Read more

F. Mani *

C. Hannachi

High Agronomic Institute Chott Mariem. Laboratory of Hortical and in Vitro Sciences, Chott Mariem , Sousse, 4042, Tunisie

Abstract - Tuberization is a critical stage of potato growth. Some studies reported that many molecules act as signalling potato tuberization. Identification of proteomic and genomic profile of potato during tuberization give some new signalling genes and proteins regulatig potato tuberization. Besides, new studies pointed the critical role of transcription factors in tuberization induction. This review present some genes, transcription factors and proteins implicated in hormonal regulation of tuber induction and repression under different environmental factors.

Keywords: Potato / genes / proteins / transcription factors / tuberization.

Read more