Germination en serre des microtubercules de pomme de terre (Solanum tuberosum L.) produits in vitro : influence du diamètre, de la densité de plantation et de l'âge des microtubercules sur le rendement

National audienc

Protein changes in Solanum tuberosum during in vitro tuberization of nodal cuttings

International audienc

Protein changes in Solanum tuberosum during storage and dormancy breaking of in vitro microtubers

International audienc

Assessment of SCAR markers to design real-time PCR primers for rhizosphere quantification of Azospirillum brasilense phytostimulatory inoculants of maize

International audienceAims: To assess the applicability of sequence characterized amplified region (SCAR) markers obtained from BOX, ERIC and RAPD fragments to design primers for real-time PCR quantification of the phytostimulatory maize inoculants Azospirillum brasilense UAP-154 and CFN-535 in the rhizosphere. Methods and Results: Primers were designed based on strain-specific SCAR markers and were screened for successful amplification of target strain and absence of cross-reaction with other Azospirillum strains. The specificity of primers thus selected was verified under real-time PCR conditions using genomic DNA from strain collection and DNA from rhizosphere samples. The detection limit was 60 fg DNA with pure cultures and 4 · 103 (for UAP-154) and 4 · 104 CFU g)1 (for CFN-535) in the maize rhizosphere. Inoculant quantification was effective from 104 to 108 CFU g)1 soil. Conclusion: BOX-based SCAR markers were useful to find primers for strainspecific real-time PCR quantification of each A. brasilense inoculant in the maize rhizosphere. Significance and Impact of the Study: Effective root colonization is a prerequisite for successful Azospirillum phytostimulation, but cultivation-independent monitoring methods were lacking. The real-time PCR methods developed here will help understand the effect of environmental conditions on root colonization and phytostimulation by A. brasilense UAP-154 and CFN-535

Pretreatments, conditioned medium and co-culture increase the incidence of somatic embryogenesis of different Cichorium species

Somatic embryogenesis (SE) in Cichorium involves dedifferentiation and redifferentiation of single cells and can be induced by specific in vitro culture conditions. We have tested the effect of various treatments on the incidence of SE (ISE) of an interspecific embryogenic hybrid (C. endivia x C. intybus) and of different commercial chicories (C. endivia and C. intybus) that are typically recalcitrant to SE in standard culture conditions. We found that the ISE of the hybrid is significantly increased by pretreatment of tissues by submersion in solutions of glycerol, abscisic acid, spermine, putrescine or of combinations of these compounds. Interestingly, the most efficient of these pretreatments also had an unexpectedly high effect on the ISE of the C. intybus cultivars. The ISE of the hybrid and of the commercial chicories were increased when explants were co-cultured with highly embryogenic chicory explants or when they were cultured in conditioned medium. These observations established that unidentified SE-promoting factors are released in the culture medium. HPLC analyses of secreted Arabino-Galactan Proteins (AGPs), which are known to stimulate SE, did not allow identifying a fraction containing differentially abundant AGP candidates. However, pointing to their role in promoting SE, we found that the hybrid had a drastically higher ISE when amino sugars and L-Proline, the putative precursors of secreted AGPs, were both added to the medium

Didactic Strategies Stop The Development Of Critical Thinking In University Students

La educación debe evolucionar para afrontar los retos que plantea el futuro, en la actualidad vivimos en un mundo globalizado que comparte grandes cantidades de información en tiempo real, el problema radica en que no toda la información es fiable, por consiguiente, es necesario generar estrategias efectivas en las aulas, buscando que el estudiante genere independencia de pensamiento para que desarrolle criterios propios de pensamiento crítico, lo anterior permite que el estudiante adquiera adquirir las destrezas para generar habilidades de pensamiento superior que lo lleven a la independencia intelectual.Education must evolve to meet the challenges of the future, we live in a globalized world that shares large amounts of information in real time, the problem is that not all information is reliable, therefore it is necessary to generate strategies Effective in the classroom, seeking the student to generate independence of thought to develop criteria critical thinking, the previous allows the student to acquire the skills to generate higher thinking skills that lead to intellectual independence

The role of the antimicrobial compound 2, 4-diacetylphloroglucinol in the impact of biocontrol Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators

International audiencePseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (Phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. Here, the effects of synthetic Phl and Phl+ Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators were investigated. Most A. brasilense strains were moderately sensitive to Phl. In vitro, Phl induced accumulation of carotenoids and poly-β-hydroxybutyrate-like granules, cytoplasmic membrane damage and growth inhibition in A. brasilense Cd. Experiments with P. fluorescens F113 and a Phl- mutant indicated that Phl production ability contributed to in vitro growth inhibition of A. brasilense Cd and Sp245. Under gnotobiotic conditions, each of the three strains, P. fluorescens F113 and A. brasilense Cd and Sp245, stimulated wheat growth. Co-inoculation of A. brasilense Sp245 and Pseudomonas resulted in the same level of phytostimulation as in single inoculations, whereas it abolished phytostimulation when A. brasilense Cd was used. Pseudomonas Phl production ability resulted in lower Azospirillum cell numbers per root system (based on colony counts) and restricted microscale root colonization of neighbouring Azospirillum cells (based on confocal microscopy), regardless of the A. brasilense strain used. Therefore, this work establishes that Phl+ pseudomonads have the potential to interfere with A. brasilense phytostimulators on roots and with their plant growth promotion capacity