Bibliographic Review

F. Mani*

C. Hannachi

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

Abstract - Sprouting is one aspect of tuber physiological age that begins with potato tuber initiation. During sprouting, proteomic and physiological processes do happen but they do not lead to immediate morphological changes. But these processes are relevant for the number of sprouts produced after breaking of the dormancy and for the growth vigour of the seed tuber. This review propose that sprouting phasis is a complex process that depends mainly on genetic background, stage of tuber development, environmental and management conditions during tuber growth and storage, it also depends of mother tuber. In addition, temperature, humidity, water supply, as well as the photoperiod during plant growth are important environmental factors that regulate potato tuber sprouting. Storage temperature and gas composition regulate dormancy and sprouting. Many chemicals are used to inibit or to induce sprouting in potato. Hormonal regulation through endogenous an exogenous phytohormones is primordial in controlling sprouting in potato.

Keywords: Potato / sprouting / hormones / regulation / environmental conditions.

Read more

A. Sebei*

K. Harbaoui

S. Ferjaoui

M. L.Bouslama

M. Bessaker¹

Centre Régional de Recherches en Grandes Cultures de Béja.

Abstract - Bread wheat (Triticum aestivum L.) is one of the most important cereals in the human and animal nutrition due to their sub-products utility. The main objective of this study is to analyze the range of grain yield variability and associated parameters of fifteen bred wheat varieties. Phenotypic and genotypic correlation between all parameters was studied in order to build a strategy to improve the performance of this species. These genotypes were sown during 2010-2013 cropping seasons at the experimental Unit of Oued Beja. Significant difference for all studied parameters between varieties was recorded indicating the existence of sufficient genetic variability within genotypes. High phenotypic and genotypic variation coefficients were recorded for grain yield, yield per spike and number of grains per spike. There are 29,86 et 21,29% respectively for the grain yield, and 23,91 et 14,48% respectively for the number of grains per spike. Indeed, these two parameters have a high phenotypic variation comparing with the genotypic variation. These values are respectively 0,107 and 0,039 for the grain yield and 36,7 and 36,16. For the number of grain per spike.These two parameters have a very high phenotypic variance and a low heritability in a broad sense which is about 36,7 and 36,16 respectively. Therefore, we can conclude that these two parameters have an interesting correlation with the grain yield. They represent the principal contributors of yield building. In fact, they could be taken in consideration in the wheat yield improvement program.

Key words: Heritability, variation coefficient, yields per spike, number of grain per spike, variability.

Résumé - Le blé tendre (Triticum aestivum L.) est l’une des céréales les plus importantes dans la nutrition humaine et animale pour ses dérivées et ses sous-produits. L’objectif de cette étude est d’analyser l’ampleur de la variabilité du rendement et les paramètres qui lui sont associés de quinze variétés de blé tendre. Le niveau de corrélation phénotypique et génotypique entre ces paramètres est également étudié afin de mettre une stratégie pour améliorer le rendement de cette espèce. Les génotypes ont été semés durant les campagnes 2010-2013 à l’Unité Expérimentale Oued Béja. Des différences significatives pour tous les paramètres étudiés entre ces variétés ont été enregistrées ce qui montre l’existence d’une variabilité génétique suffisante au sein des génotypes. Des coefficients de variation phénotypique et génotypique élevés ont été enregistrés. Ils sont respectivement de 29,86 et 21,29% pour le rendement en grains, 23,91 et 14,48% pour le rendement par épi et 23,89 et 14,37% pour le nombre de grains par épi. Le rendement et le nombre de grains par épi ont une variance phénotypique très élevée par rapport à la variance génotypique avec des valeurs respectives de 0,107 et 0,039 pour le rendement en grain et 118,07 et 42,7 pour le nombre de grains par épi. La plus faible héritabilité au sens large a été enregistrée chez ces deux derniers paramètres. Elle est respectivement de l’ordre de 36,7 et 36,16. Cependant, ces deux paramètres ont une corrélation génotypique intéressante avec le rendement en grains. Par conséquent, nous pouvons conclure qu’ils représentent les principaux facteurs contribuant à l’élaboration du rendement en grains et doivent être pris en considération dans un programme d’amélioration de blé tendre.

Mots clés : coefficients de corrélation, héritabilité, nombre de grain par épi, rendement par épi, variabilité.

Read more

Y. ZAOUCHI ^*

S. REZGUI¹

F. BEN JEDDI 

S. LABIDI

T. BETTAIEB

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

Abstract - The study is an evaluation of the potential of arbuscular endomycorhization by a complex of indigenous strains, on ornamental ligneous’s nutrition and growth: Jacaranda mimosifolia D.Don. One year old plants are grown for 6 months at 25 ° C in a greenhouse and watered every two days until field capacity. The inoculum consists of five strains: Glomus constrictum, Glomus geosporum, Glomus fuegianum, Glomus irregulare et Glomus sp. The inoculum is added by percentages of pot volume: 10% and 20% (M1 and M2 treatments). Treatments are compared to controls having 10% and 20% autoclaved inoculum (treatment T1 and T2). Other fertilized treatments are composed of 10% and 20% of autoclaved inoculum each one added 4 g / pot of Osmocote EXACT standard-Scotts (15+ 9+ 12 (+2.5)) (treatment F1 and F2). Three repetitions are achieved for each treatment. The results show that the mycorrhization rate variation is not effected by added inoculum proportion. This is due to the heterogeneity of inoculant structures concentration found in the proportions of added mycorrhizal substrate. Mycorrhization Rates of M1 and M2 are 57.1% and 37.85% respectively. Mycorrhization of M1 treatments increases the levies in nitrogen and phosphorus, in the aerial parts (p = 0.01) and that of nitrogen, phosphorus (p = 0.01) and potassium (p = 0.05) in the root parts. For M2, the mycorrhization increases the levies of nitrogen (p = 0.05), phosphorus and potassium (p = 0.01) in the aerial parts and root phosphorus (p = 0.05). Improved nutrition leads to a significant increase in aerial and root dry biomass, height, leaf area and root volume of M1 (p = 0.01) and aerial dry biomass, heights and root volumes of M2 (p = 0.01). Mycorrhization improves more efficiently the nutritional yield and Jacaranda’s growth then fertilization.

Keywords: Mycorrhization / Jacaranda mimosifolia D.Don  / nutrition / growth.

Read more

M. ZAGHDOUDI*

O. BAATOUR

N. BENSALEM 

Z. OUERGHI ABIDI

Unité de Physiologie et Biochimie de la Réponse des Plantes aux contraintes Abiotiques, Département de Biologie, Faculté des Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisie.

Abstract - Plant tolerance to salt stress varies with the development stage. Seed germination seem to be a major factor limiting the establishment of plants under saline conditions. NaCl generate osmotic effects and ionic stress. It can also affect the activity of many enzymes such as PEPc, which play a key role in lipid degradation. The aim of this work is to investigate the effect of salt on germination, Na+, K+ uptake and their fluxes was recorded and PEPc enzymatic activity in two varieties of Linum usitatissimum. Seeds were germinated under control and saline (100, 200, 250 and 300 mM NaCl) conditions and the effect of salt stress on germination and enzymatic activity was determined. Salinity reduced final germination percentage and lowered germination rate only at concentrations higher than 200 mM, mainly by an osmotic effect. However, NaCl (100 mM) stimulated protein content and PEPc enzymatic activity. These results revealed that the two varieties of Linum usitatissimum are tolerant until 200 mM NaCl.

Keywords: Salinity, tolerance, germination, PEPc, Linum usitatissimum

Read more

S. El Adib^*1

S. Slim²

F.Ben Jeddi¹

¹ Université de Carthage. Laboratoire des Sciences Horticoles, INA Tunisie, 43, avenue Charles Nicolle, Tunis, 1082 Tunisie.

² Université de Carthage. Laboratoire des Sciences Horticoles, ESA Mateur.

Abstract - The Argan tree (Argania spinosa L. Skeels) contain two varieties, mutica (spineless) and apiculata (thorny). The seasonal effect along a cycle phénologique annual on the variation of the rates of arbuscules, vesicles and rate of mycorhizes total of two varieties of argan tree implanted in the arboretum of the INA TUNISIA was analyzed under the influence of the variation of the pluviometry and the thermal accumulation. During the wintry and spring seasons, the significant increase of the rates of arbuscules for both varieties with 67,75 % and 32,19 % respectively for mutica and apiculata in winter and 70,96 % and 28,14 % respectively for mutica and apiculata in spring. For vesicles, the optimum of the rates was noted in spring for both varieties with 25,22 % and 7,7 % respectively for mutica and apiculata. These seasonal variations are the results (profits) of the variation of the quantity of pluviometry and the thermal accumulation during all the cycle phénologique. So the quantity of pluviometry reached (affected) 200 ml in winter and mark his(her,its) maximum in spring with 356,75ml knowing that one autumn the pluviometry did not exceed(overtake) 100 ml. On the other hand, the variation of the maximal and minimal temperatures strongly influenced the rates of mycorhization of the roots of both varieties. So, for the spring season, the CT is 4368,95 C°J, in winter it is of 3936,13C°J while in summer it does not exceed(overtake) 1153,53 C°J. The rate of mycorhizes total counted on the roots of both varieties represents the result (profit) of the interaction of the rates of arbuscules and of and of vesicles on one hand, and the variation of the pluviometry and the temperature on the other hand.

Keywords: Argania spinosa / mycorhizes / pluviometry /thermal accumulate.

Résumé - L’Arganier (Argania spinosa L. Skeels) comporte deux variétés, mutica (inerme) et apiculata (épineuse). L’effet saisonnier le long d’un cycle phénologique annuel sur la variation des taux d’arbuscules, vésicules et taux de mycorhizes total de deux variétés d’arganier implantés dans l’arboretum de l’INA Tunisie a été analysé sous l’influence de la variation de la pluviométrie et du cumul thermique. Durant les saisons hivernale et printanière, une augmentation significative des taux d’arbuscules pour les deux variétés avec 67,75% et 32,19% respectivement pour mutica et apiculata en hiver et 70,96% et 28,14% respectivement pour mutica et apiculata au printemps. Pour les vésicules, l’optimum des taux a été noté au printemps pour les deux variétés avec 25,22% et 7,7% respectivement pour mutica et apiculata. Ces variations saisonnières sont les résultats de la variation de la quantité de pluviométrie et du cumul thermique durant tout le cycle phénologique. Ainsi la quantité de pluviométrie a atteint les 200 ml en hiver et marque son maximum au printemps avec 356,75ml sachant qu’on automne la pluviométrie n’a pas dépassée les 100 ml. D’autre part, la variation des températures maximales et minimales a fortement influencée les taux de mycorhization des racines des deux variétés. Ainsi, pour la saison printanière, le CT est de 4368,95 C°J, en hiver il est de 3936,13C°J alors que en été il ne dépasse pas les 1153,53 C°J. Le taux de mycorhizes total dénombré sur les racines des deux variétés représente le résultat de l’interaction des taux d’arbuscules et de vésicules d’une part, et la variation de la pluviométrie et de la température d’autre part.

Mots clés : Argania spinosa-mycorhizes-pluviométrie-cumul thermique.

Read more