This 1st International Symposium on Reproductive Biology of Fruit Trees, was organized entirely in virtual form, under the aegis of the International Society of Horticulture, ISHS, from 8 to 10 November 2021, by two co-organizers, E. Costes (UMR Agap Institute, Montpellier, France) and H. Flachowsky (Julius Khun Institute, Dresden, Germany). Two researchers from the INRAE department Plant Biology and Improvement (BAP) were invited as speakers (F. Andres, UMR Agap Institute and B. Wenden, UMR BFP), respectively on dormancy control mechanisms and flowering date modeling in fruit trees.

More than a hundred scientists were present, coming from 32 countries from Japan to Chile, the European participation was strong, mainly France, Spain, Italy, Germany, with a presence of Belgium, Hungary, Serbia and Czech Republic too.
The works presented were about numerous fruit species, temperate, Mediterranean and tropical. Proceedings of the Symposium will be published after review of the papers, in spring 2022 in an electronic format. This event strongly contributes to the visibility of the research conducted in the BAP Department on the understanding of Reproductive Biology in fruit species.
In total, during 8 sessions, 38 oral presentations and 30 posters were presented.
The objective of this International Symposium was to allow the meeting and the exchanges between researchers on the topics related to the Reproductive Biology in fruit species. For our unit AGAP Institute, it allowed to make known the work conducted in the team Evolutionary structure of citrus, polyploidy and genetic improvement (SEAPAG) and Architecture and Flowering of Fruit Species (AFEF). F. Luro, UMR Agap Institute (Corsica, France) working on citrus fruits presented his work on the use of the specificities of the reproductive biology of these species for plant breeding. Two PhD students from the AFEF team, J. Garighan and F. Belhassine, presented their work on apple, on the role of small RNAs in the regulation of dormancy on the one hand and on the relationship between floral induction, tree architecture and physiological state (hormonal and carbonaceous) of the buds in contrasting apple genotypes.
From the ISHS point of view, this Symposium also had the challenge to gather the members of two working groups "Flowering, Fruit Set and Alternate Bearing" Chaired by Pr Francesco Marra (Univ. of Palerma, Italy) and "Floral Biology in Fruit Trees", Chaired by Dr Encarnacion Ortega (Cebas-CSIC, Murcia, Spain).
Eight thematic sessions and round tables, covered the different dimensions of Reproductive Biology of fruit species:

• Genetic and molecular control of floral induction and flowering regularity
• Genetic and molecular control of dormancy and flowering
• Genetic and molecular control of pollination incompatibility
• Environmental factors and pheno-climatic models
• Flower development and sexuality
• Pollination, fertilization and fruit development
• Environmental factors and fruit set
• Horticultural management of fruit production regularity

After these exchanges and this collaboration, a 2nd Symposium in 2024 is planned and will be organized by the group of the Volcani Institute (Agricultural Research Organization, Israel).

Valorization

As the Horticultural Society aims to promote young PhD students, two Young Mind Awards were given : M. Stanton Univ. California, (USA) for his oral presentation: " The combination of a novel pollen counting methodology and light microscopy reveal pollen abnormalitie ", H. Palmers (Univ. of Leuven, Belgium) for his poster: " Occurrence and mechanistic basis of diplogamete formation in apple (Malus x domestica Borkh.) ". An article will be published in Chronica Horticulturae.
The proceedings of the Symposium will be published after review of the papers, in spring 2022, in an electronic format.