Résumé
The determination of tree sexual type during the production of seedlings in nurseryconstitutes a major issue for the set up of efficient orchards. In the case of carob trees(Ceratonia siliqua), a multi-use tree of high socio-economical added value in Mediterraneanregions, the majority is dioecious but some are also hermaphrodite. Physiological differencesbetween carob male and female have been described but the development of robust indicatorsof tree sexuality remains of particular interest for the carob sector.Carob tree is highly dependent on arbuscular mycorrhizal (AM) symbiosis, and bacterialendophytes are also hypothesized to play a role in carob nutrition. Symbiotic communitiesare known to be key factors of plant nutrition and growth, affecting greatly plant physiology.The intimate connection between physiology and symbiotic community of carob may suggesta potential specificity of symbionts regarding the carob sexual type.In the framework of the international project DYNAMIC (Deciphering sYmbiotic Networksin cArob-based MedIterranean agro-eCosystems), a metabarcoding approach was developedto characterized the symbiotic microbial diversity and assemblages associated to carob treesin the Mediterranean basin. The results may provide new guidelines for the determinationof bio-indicators of tree sexual type and the design of more productive orchards.