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Fert, agri-agence française, accompagne le groupe Fifata (Fikambanana Fampivoarana ny Tantsaha - ou Association pour le Progrès des paysans), dans le développement des économies agricoles. Le groupe défend " une agriculture familiale, professionnelle compétitive et qui s'agrandit ", et met en oeuvre des services agricoles répondant aux besoins de ces membres. Depuis 2015, plusieurs projets ont permis le développement de cette action de professionnalisation et d'organisation des producteurs agricoles au Sud d'Antananarivo. C'est dans le cadre du projet Ambioka / Afafi-Centre Nov.2020 – Nov.2024 que Fert et Fifata souhaitent s'engager dans le développement d'une filière de semences potagères locale pour laquelle elles ont sollicité le Cirad pour une expertise externe. L'objectif principal de cet accompagnement est de renforcer les connaissances techniques des agents du Ceffel (Conseil Expérimentation Formation en Fruits et Légumes), organisation spécialisée membre du groupe Fifata et partenaire du projet, sur la production de semences potagères afin de garantir leur qualité génétique, physiologique et sanitaire. Approfondir les bonnes pratiques et mettre en place des moyens d'évaluation de la qualité de la production de semences permettra à l'équipe Ceffel de maîtriser l'activité de multiplication puis de former et encadrer le réseau de producteurs multiplicateurs dans les différentes régions d'intervention.

The BRC GAMèT (Biological Resource Center: Graines Adaptées aux conditions Méditerranéennes et Tropicales) gather together since april 2019 within the new ARCAD building, three CRBs storing seeds genetic resources from INRA and Cirad institutes: CRB Zea, CRB-T and CRB Medicago. The objective is to manage in the same team the different seed collections including more than 30 000 accessions of cotton, corn, fonio, mil, peanut, rice, sorghum, Medicago and forest genetic resources. A team of twelve persons will join forces and methodologies to introduce, conserve distribute and multiply those seeds that represent a richness at national and international levels. The aim is to conserve the diversity of genetic resources at a quality level for the benefit of the scientific community and the public. The BRC belongs to the plant pilar of the French national network of BRC Rare and participate to the database project “Florilège”. Each plant is also link with research programs and scientific team in order to analyze and better involve genetic resources in scientific challenges such as climate change responses and integration into agro-ecological projects.

Rice is considered as a crop sensitive to salinity; however, it is grown mainly in deltaic areas with salt problems all over Europe. European rice breeding programs (France, Greece, Italy, Portugal and Spain) have established an European Rice Genetic Resources Collection (ERGRC) of some 450 accessions, mainly temperate japonica, extensively characterised for agronomic traits and maintained by CIRAD. The main goal of the present study is to identify within this collection, a set of best performing genes and alleles for salinity tolerance, as well as the associated donors and molecular markers for use in breeding programs. In order to obtain the general organisation structure of the ERGRC we assessed its genetic diversity through a Bayesian analysis of genotypic data over 26 SSR loci. A sub-sample of 200 accessions maximizing simultaneously allele number and allelic associations was then extracted for association analysis. The sub-sample was phenotyped for salinity tolerance at an early vegetative stage under controlled conditions, being leaf Na+/K+ ratio the most discriminating trait. Based on literature review, we assembled a list with more than 100 rice candidate genes for salt tolerance, which are involved in signaling, ion homeostasis, stress tolerance, transcription regulation, general metabolism and unknown functions. With this information, we developed a database of rice QTLs and candidate genes for salinity tolerance (http://tropgenedb.cirad.fr/html/rice_QTL.html). We selected 16 of these candidate genes for association analysis. SSR markers were used for the association analysis. A first set of 58 common SSR (www.gramene.org) covering these particular genes was used. In addition, we designed 320 SSR markers covering 100 kb up and downstream each candidate gene. In the end, we selected four of the designed SSR markers, the two closest to the gene and one in each end of the linkage disequilibrium region (100 kb each gene side). Results of association analysis between 16 target areas (using 60 SSR) and a dozen salinity tolerance traits are presented. Methodological constraints stem from the use of multi-allelic markers are discussed. (Texte intégral)