Cryorésistance de la levure de boulangerie Saccharomyces cerevisiae dans les pates crues surgelées. Etude physiologiques et ultrastructurales

* INRA, CR de Nantes. Unité Régionale de Documentation. BP 71627, 44316 Nantes Diffusion du document : INRA, CR de Nantes. Unité Régionale de Documentation. BP 71627, 44316 Nantes Diplôme : Dr. d'Universit

Exploration of genetic diversity within Cichorium endivia and Cichorium intybus with focus on the gene pool of industrial chicory

The present study used 15 simple sequence repeat loci to characterize the genetic diversity of the germplasm that originated the current industrial chicory and to establish the relationships between and inside Cichorium intybus L. and Cichorium endivia L. Initially we analyzed 19 cultivated C.endivia accessions, 27 wild and 155 cultivated C. intybus accessions distributed among three groups: 83 root chicories, 42 Witloof and 30 leaf chicories. The leaf chicories comprised cultivars corresponding to the Radicchio, Sugarloaf and Catalogne subgroups. The latter has not been previously included in any genetic diversity study. Subsequently, 1297 individuals from the 15 modern root chicory cultivars at the origin of the breeding of the current industrial root chicory cultivars were analyzed. Although the accessions of C.endivia and C. intybus were clearly separated from each other, seven wild C. intybus individuals were genetically closer to C. endivia than to C. intybus , revealing complex genetic interrelationships between these species. The differentiation of C. intybus into three cultivar groups (Witloof, root chicory and leaf chicory) was confirmed. The leaf chicory individuals were divided into three genetic subgroups, corresponding to the Radicchio, Sugarloaf and Catalogne cultivars, thus attesting to the validity of the classification based on morphological factors. Clear differentiation was ob- served among the Belgian, Polish and Austrian modern industrial root cultivars, but not among the French industrial modern root cultivars. The high phenotypic and genetic variability of the modern industrial root cultivars indicates that this germplasm constitutes a useful gene pool for cultivar improvement and selection

Chromosome doubling of Cichorium intybus L. haploids through protoplast regeneration

Industrial chicory (Cichorium intybus L.) is mainly grown for inulin production. To enhance production and uniformity, hybrid cultivars are preferred. Therefore, a controlled pollination system and homozygous parental lines are needed. The most desirable pollination control system is cytoplasmic male sterility (CMS). A new, naturally induced CMS has been reported by Van der Veken et al. (2018). To regenerate homozygous parental lines of modern industrial chicory cultivars, different haploid inducing techniques have been compared and evaluated. The only successful method was intergeneric hybridization with Cicerbita alpina (Doré et al., 1996), yielding haploid plants. Here we show that protoplast regeneration is an efficient tool for chromosome doubling of these haploids. The presented method can be used for chromosome doubling of slowly developing haploids

Pupils’ perceptions of geography in Dutch primary schools : goals, outcomes, classrooms environment and teacher knowledge and performance

Concerns about the decreasing quality of geography education within primary schools can be linked to a decrease of time spent on geography education and, for example, to low achievement on national or school-specific tests. Learning outcomes for geography stay behind in relation to what experts believe that pupils should perform. Results indicate that pupils would like to gain more theoretical knowledge and get more help from teachers to apply actual and conceptual knowledge within new subject content. Pupils also wish to have more active, inquiry-based teacher activities during the lessons, and to be actively coached and motivated by the teacher