Optimisation de la transformation génétique de la pomme de terre par Agrobacterium tumefaciens. Utilisation de la résistance à l'hygromycine comme marqueur sélectif

Optimization of potato genetic transformation by Agrobacterium tumefaciens using hygromycin resistance as selective marker. The objective of this work is the optimization of a genetic transformation and a regeneration protocol of transgenic plants in Solanum tuberosum cv Désirée using hygromycin resistance as selective marker. The gene Cat2 of Nicotiana plumbaginifolia and the gene SU2 of Gossypium hirsutum, both coding for catalases, have been used. Two antibiotic concentrations (5 and 10 mg . l -1 of culture medium) combined with two preculture periods (5 and 20 days) on non-selective medium were tested. Coculture medium was supplemented with 10 mg . l -1 of acetosyringone to test its effect on potato transformation. The addition of this phenolic compound to the coculture medium affected positively the regeneration aptitude of transgenic SU2 plants. Only the combination of 5 mg . l -1 of hygromycin and 20 days of preculture without antibiotic allowed the obtention of plants transformed with the gene SU2. Screening of the rooted shoots with PCR showed 45% of transgenic plants for both molecular constructions used

Effects of crop sequences on soil population dynamics of Monosporascus cannonballus ascopsores and Monosporascus root rot and vine decline incidence

[EN] Crop sequences effect on the soil population dynamics of Monosporascus cannonballus ascospores and the incidence of Monosporascus root rot and vine decline (MRRVD), was investigated in a field in which three different cucurbit crops: melon, watermelon, and watermelon grafted onto Cucurbita rootstock, and tomato, were grown during two consecutive growing seasons. Cultivation of melon or watermelon crops in the first growing season resulted in an increase of soil ascopore densities. But, on the contrary, the soil ascospore densities in the second growing season were lower when grafted watermelon or tomatos were cultivated in the first growing season. In the second growing season, MRRVD incidence for each cucurbit crop was significantly different depending on the previous crop, being in general higher when melon or watermelon were the previous crops, slightly lower when the previous crop was grafted watermelon and the lowest when the previous crop was tomato. Disease incidence corresponded with the percentage of isolation of M. cannonballus from the roots, being always significantly lower when the previous crop was tomato. These results demonstrate the potential of crop rotation as a management strategy to reduce infection and reproduction of M. cannonballus, ascospore densities in soil and disease incidence in cucurbits.Ben Salem, I.; M'hamdi, M.; Armengol Fortí, J.; Boughalleb-Mhamdi, N. (2015). Effects of crop sequences on soil population dynamics of Monosporascus cannonballus ascopsores and Monosporascus root rot and vine decline incidence. International Journal of Current Microbiology and Applied Sciences (Online). 4(9):482-500. http://hdl.handle.net/10251/89413S4825004

The Importance of Viscoplastic Strain Rate in the Formation of Center Cracks during the Start-Up Phase of Direct-Chill Cast Aluminum Extrusion Ingots

A comparison of experimental observations and computer simulations shows that trends in the occurrence and severity of center cracks in direct-chill (DC) cast ingots due to different initial casting speed histories may best be explained by the changes in viscoplastic strain rate close to the center of the base of the ingot. The thermomechanical histories of five ingots were simulated and correlations between stresses, strains, strain rates, and liquid pressure drops due to feeding restrictions were considered

Semi-solid constitutive parameters and failure behavior of a cast AA7050 alloy

Materials innovation institute (www.m2i.nl) research framework, project number M42.5.09340; Norsk Hydro Fond for SINTEF; Modelling assisted INnovation for Aluminum DC Casting process (MINAC

The Edge of Perinatal Viability:Understanding the Dutch Position

Contains fulltext : 231104.pdf (publisher's version ) (Open Access

Resistencia aumentada a Rhizoctonia solani por la expresión combinada de quitinasa y proteínas inactivantes de los ribosomas en patatas transgénicas

Potato (Solanum tuberosum L.) is susceptible to many fungal pathogens including Rhizoctonia solani. In the present study, the potato cultivar Desirée was transformed via Agrobacterium tumefaciens strain GV3101 containing the binary plasmid pGJ132 harboring both the chitinase (chiA) and rip30 genes. The potato leaf disc was used as an explant for transformation. PCR, Southern blot and Western blot were used for characterization of the transgenic plants. In this study it was shown that not all the plants developed in selective medium were positive for the corresponding gene using the PCR technique. Southern blot analysis confirmed that transgenic plants integrated 2-3 copies of chiA and rip30 genes respectively into their genome. The expression of the CHIA and RIP30 proteins was confirmed in the leaf extracts of the transgenic clones by Western blot analysis. Transgenic potato plants expressing rip30 and chiA genes showed enhanced resistance to R. solani in a greenhouse assay.La patata (Solanum tuberosum L.) es susceptible a muchos hongos fitopatógenos, incluyendo Rhizoctonia solani. En el presente estudio, se transformó el cultivar de patata ‘Desirée’ mediante Agrobacterium tumefaciens, cepa GV3101, que contiene el plásmido binario pGJ132 que alberga los genes quitinasa (chiA) y rip30. Se utilizaron discos de hojas como explante para la transformación de plantas. Se utilizaron las técnicas de PCR, Southern y Western blot para la caracterización de las plantas transgénicas. En este estudio se demostró, mediante PCR, que no todas las plantas que se desarrollaron en medio selectivo fueron positivas para el gen correspondiente. El análisis de Southern blot confirmó que las plantas transgénicas integraron en su genoma 2-3 copias de los genes chiA y rip30. Se llevó a cabo un ensayo de invernadero para evaluar la resistencia a R. solani de los clones transgénicos que expresan los transgenes. Las plantas transgénicas que expresan los genes rip30 y chiA mostraron una resistencia completa a R. solani

Evaluation de la durabilité des exploitations laitières tunisiennes par la méthode IDEA

Assessment of Tunisian dairy farms durability using IDEA method. The sustainability of 30 dairy farms was evaluated using IDEA method “Indicators of durability of farms”. Based on statistical methods (PCA, ACH), the three scales of sustainability (agro-ecologic, socio-territorial, and economic) have been characterized for the surveyed farms and has allowed to build groups. “Production system” typology is relevant for describing farms by agro-ecological and economical scales. The socio-territorial scale gives the limiting sustainability value for most farms. Inside this scale, the main way of progress relies on employment and services improvement (services, contribution to employment and collective work). Economically, sustainability is determined by the level of efficiency and depends on financial independence. Socio-territorial scale is the only one which is not linked to production system and is based on farmer’s way of life. On the other end, global sustainability evaluation of farm as well as creating collective references mean to be able to analyze links between the three scales of sustainability

Study on the usage of a commercial software (Comsol-Multiphysics (R)) for dislocation multiplication model

5th European Conference for Crystal Growth (ECCG), Bologna, ITALY, SEP, 2015International audienceElaboration of silicon ingots for photovoltaic application in Directional Solidification furnace leads to formation of dislocations mainly due to thermoelastic stresses, which impact photovoltaic conversion rate. Several research teams have created numerical simulation models using home-made software in order to study dislocation multiplication and predict the dislocation density and residual stresses inside ingots after elaboration. In this study, the commercial software Comsol-Multiphysics is used to calculate the evolution of dislocation density during the ingot solidification and cooling. Thermo-elastic stress, due to temperature field inside the ingot during elaboration, is linked to the evolution of the dislocation density by the Alexander and Haasen model (A&H model). The purpose of this study is to show relevance of commercial software to predict dislocation density in ingots. In a first approach, A&H physical model is introduced for a 2D axisymmetric geometry. After a short introduction, modification of Comsol (R) software is presented in order to include A&H equations. This numerical model calculates dislocation density and plastic stress continuously during ingot solidification and cooling. Results of this model are then compared to home-made simulation created by the teams at Kyushu university and NTNU. Results are also compared to characterization of a silicon ingot elaborated in a gradient freeze furnace. Both of these comparisons shows the relevance of using a commercial code, as Comsol (R) to predict dislocations multiplication in a silicon ingot during elaboration. (C) 2016 Elsevier B.V. All rights reserved