Category: Volume 33
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In vitro micropropagation of local alfalfa Medicago sativa L. Gabsi.

Micropropagation in vitro de la luzerne locale Medicago sativa L. Gabsi.

R. LAAMARI^1,3

M. MARS¹

M.P.S. Fevereiro²

A. FERCHICHI³

¹Aridoculture and oases cropping laboratory , arid area institute (IRA) Medenine Tunisia.

²Institute of chemical and biological technology ( ITQB), 2780 Oeiras, Portugal.

³National Agronomic Institute of Tunisia (INAT) 43, Av. Charles Nicole, 1082 Tunis, Tunisia.

Abstract - In order to find an appropriate media enabling the in vitro regeneration of a whole plant of M.sativa L. Gabsi through micropropagation using leaf explants (cotyledon), we tested three different shoots developing media with three cytokinins: zeatin (Z), BA and TDZ on two different provenances of local M.sativa L. Gabsi 2 and 19. Secondly two different roots developing media, MS and MS / 2, were tested on the newly formed shoots. The medium Z, although it doesn’t always gave the best response rate, he gave the well developed shoots (up to 10 mm for M.sativa L. 19) with the lower vitrification rate (53, 12% for M.sativa L. 19). The MS medium doesn’t enable root formation on shoots grown on media Z, BA and TDZ while the medium MS / 2 allowed the formation of roots on shoots grown on the Z medium. The best combination of media allowing shoots and roots developing for both provenances of M.sativa L. Gabsi is that of Z medium with the MS / 2 medium.

Keywords: Lucerne, in vitro, micropropagation, Zeatin, TDZ, BA.

Résumé - Cet article est un essai de régénération in vitro de luzerne locale Medicago sativa L. Gabsi par la voie de micropropagation. Le but à partir de ce travail est de trouver une combinaison adéquate de milieux de formation de pousses et de racines permettant la régénération in vitro d’une plante entière à partir d’un explant de feuilles (cotylédons). Deux provenances de luzerne locale M. sativa L.Gabsi, 2 et 19, sur lesquelles on a testé trois milieux différents de formation de pousses avec trois cytokinines : la zeatine (Z), la BA et le TDZ. En deuxième partie deux différents milieux de formation de racines, MS et MS/2, ont été appliqués aux pousses néoformées. Le milieu Z, bien qu’il n’a pas toujours donné la meilleure réponse des explants, il a donné les pousses les plus développées avec le pourcentage de vitrification le plus faible. Le milieu d’enracinement MS n’a permis la formation de racines sur aucunes des pousses cultivés sur les milieux Z, BA et TDZ. Le milieu MS/2 a permis la formation de racines sur les pousses cultivées sur le milieu Z. La meilleure combinaison de milieux assurant la meilleure formation des pousses et des racines pour les deux provenances est celle du milieu Z avec le milieu MS/2.

Mots clés: luzerne, in vitro, micropropagation, Zeatine, BA, TDZ.

Category: Volume 33
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Prospection, morphological and Pomological identification of olive ecotypes (Olea europaea. L.) in the Degache oasis (Tozeur, Tunisia)

Prospection et identification morpho-pomologique des écotypes d’olivier (Olea europaea. L.) dans l’oasis de Degache (Tozeur, Tunisie)

S. BEN MAACHIA^1*

F. BEN AMAR²

¹Regional Research Center of Oasis Agriculture. km1 Tozeur road Degache. PB: 62, 2260 Degache, Tozeur, Tunisia.

²Olive Institute, Sfax, airport Road. PB :1087, 3000 Sfax, Tunisia.

Abstract - The exploration of the olive tree in the oasis of Degache (Tozeur, Tunisia) performed during the years 2009 and 2010 has enabled us to identify 53 ecotypes. The characterisation of the ecotypes in the region was interested the pomology and the morphology of the fruit, the endocarp and the leaf during three years (2010 to 2012). In total, 17 characters have been notes. The characters of the leaf is slightly variable since the diversity indices of Nei and Shannon and Weaver are lower than 0.08. The characters of the fruit and the endocarp are more variables with higher indices than 0.20 with the exception of the summit of the fruit and the mucro of the endocarp (indices lower than 0.17). The two indices of diversity are closely correlated with a coefficient of determination of 0.94. The pomological characterization indicates that the weight of the fruit varies from 2 to 9.6 g and the weight of the endocarp from 0.25 to 1.15 g, while the weight ratio flesh/endocarp varies from 4.03 to 11.46. These characters are more variable than the characters of the length and the width and their ratio with coefficients of variation greater than 19.75 %. The hierarchical classification of the ecotypes allows distinguishing several groups which proved the broad existing variability. The factorization analysis has identified two main components which are positively correlated with the characters of the fruit and the endocarp.

Keywords: Tunisia, genetic resources, Oases, Olive, Diversity, characteristics.

Résumé - La prospection de l’olivier dans l’oasis de Degache (Tozeur, Tunisie) effectuée durant les années 2009 et 2010 a permis d’identifier 53 écotypes. La caractérisation des écotypes prospectés dans la région a intéressé la pomologie et la morphologie du fruit, du noyau et de la feuille durant trois années (2010 à 2012). Au total, 17 caractères ont été notés. Le caractère de la feuille est assez peu variable puisque les indices de diversité de Nei et de Shannon et Weaver sont inférieurs à 0,08. Les caractères du fruit et du noyau sont plus variables avec des indices supérieurs à 0,20 à l’exception du sommet du fruit et le mucron du noyau (indices inférieurs à 0,17). Les deux indices de diversité sont étroitement corrélés avec un coefficient de détermination de 0,94. La caractérisation pomologique indique que le poids du fruit varie de 2 à 9,6 get le poids du noyau de 0,25 à 1,15 g tandis que le rapport pulpe/noyau varie de 4,03 à 11,46. Ces caractères sont plus variables que les caractères longueur et largeur et leur rapport avec des coefficients de variation supérieurs à 19,75 %. La classification hiérarchique des écotypes permet de distinguer plusieurs groupes qui témoignent de la large variabilité existante. L’analyse de factorisation a généré deux composantes principales qui sont corrélés positivement avec les caractères du fruit et du noyau.

Mots clés: Tunisie, ressources génétiques, Oasis, Olivier, Diversité, caractéristiques.

Category: Volume 33
Hits: 6575

Biochemical characterisation and bioremediation study of dimethoate and chlorpyrifos tolerant bacterial strains isolated from an agricultural soil.

A. BEN SALEM^1,2

S. AZZOUZ²

A. MOUGOU²

R. SALGHI³

H. CHAABANE²

S. FATTOUCH¹

¹Laboratory of engineering of proteines ans bioactives molecules, National Institut of Applied Science (INSAT) Urban North center Bp676, 1080 Charguia-Tunisia

² Department of Plant Protection and Post-Harvest Diseases, National Institute of Agronomy, 43 Street Charles Nicolle Mahragène City 1082 Tunisia.

³Laboratory of Environmental Engineering and Biotechnology, ENSA, Universtity of Ibn Zohr, Agadir, Morocco.

Abstract - Biodegradation processes are increasingly attracting scientists’ interest as novel technological methods to detoxify natural matrices contaminated with various pollutants.
Herein, we aimed to isolate, screen and characterize bacteria which tolerate the two pesticides compounds (chlorpyrifos and dimethoate). In order, to distinguish biotic and abiotic pathways responsible of chlorpyrifos and dimethoate break-down, batch of soil have been respectively conserved at their natural form or sterilized. Dissipation of chemical compounds in non-sterile soils followed first-order exponential decay kinetics and the half- life (t_1/2) of chlorpyrifos and dimethoate ranged from 2.5 to 3.5 and 2.2 to 3.3 respectively. The difference between sterile and non-sterile soils indicates that abiotic dissipation was predominant in the dissipation of chlorpyrifos in Tunisian soil. However, in the case of dimethoate, a microbial activity seems to play a key role in the dissipation of this compound in Tunisian soil.
Bacteria strains that could persist in the presence of the both organophophorous compounds were isolated and identified by biochemical test. The obtained results from pesticides enriched cultures showed the presence of identical strains in both treatments: Enterobacter cloacae, and Panteoa sp. However, specific strains were isolated only for each active compounds, Enterobacter cloacae, Panteoa sp, Pseudomonas putida and Enterobacter cloacae, Pantoea sp, Chromobacterium violaceum, Serratia plymuthica, Pseudomonas aeruginosa following treatment with dimethoate and chlorpyriphos, respectively.

Keywords: organophophorous, degradation process, API-Test, soil bacteria

Category: Volume 33
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Nasal and rectal carriage of coagulase positive Staphylococcus in healthy goats

M. DAALOUL-JEDIDI

A. SOUDANI

L. MESSADI

Immunology and microbiology laboaratory – National School of Veterinary Medicine, La Manouba University, 2020 Sidi Thabet – Tunisia.

Abstract - Coagulase positive Staphylococcus species are important opportunistic pathogens in most animals which could be considered as a potential source of infection and dissemination to the environment. Prevalence studies and accurate identification of Coagulase Positive Staphylococcus species are essential in veterinary microbiology. A total of 153 healthy goats from North and North West of Tunisia were screened for coagulase positive Staphylococcus species nasal and rectal carriage. Bacteriological tests were performed. Staphylococcus spp. was detected in 120 of 153 studied goats (77.4%) and an overall prevalence of 22.2% of coagulase positive Staphylococcus species isolates was observed. This study showed the identification of S. aureus and S. pseudintermedius in 25 and 7 strains, respectively.

Keywords: Healthy goats; nasal carriage; Rectal carriage; S. aureus; S. pseudintermedius; Tunisia

Category: Volume 33
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Ploidy level, genome size and genetic variability among a collection of Medicago sativa L. Gabsi as revealed by flow cytometry

R. LAAMARI^*1,3

S. OCHATT²

A. FERCHICHI³

¹ Laboratoire d’Aridoculture et des Cultures Oasiennes, Institut des Régions Arides de Médenine (IRA), Route du Djorf km 22,5, Médenine Tunisie.

² UMR 1347 Agroécologie, AgroSup/INRA/uB, Pôle GEAPSI, laboratoire de Physiologie Cellulaire, Morphogenèse et Validation (PCMV), 17 rue Sully, BP 86510, F-21065 DIJON FRANCE

³ Institut National Agronomique de Tunisie (INAT) 43, Av. Charles Nicole, Cité Mahrajène 1082 Tunis, Tunisie.

Abstract - The flow cytometry technique has been applied in order to check the ploidy level of seven provenances of local alfalfa (Medicago sativa L.) Gabsi, to estimate the genome (pg DNA) size of these alfalfa lines and to verify whether any genetic differences existed between these provenances belonging to the same population. Flow cytometry technique enabled us to show that all sources are tetraploid but also showed genetic variability that can be explained by the effect of microclimate, even if it is obvious that all these sources belong to a same unique population.

Keywords: alfalfa, flow cytometry analysis, tetraploid.

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