S05 - Session O6 - From phenotype to genotype: Rosa arvensis as a reference genetic model for the description of genetic variations in rose

Authors: Pascal Heitzler *

Rosa arvensis is a diploid synstylae species, largely distributed throughout temperate Europe. During the last 20 years, a considerable effort was made to bring R. arvensis as an attractive model for genetics and suitable for a maximal range of research topics for rose. For example, the genetics of the S-RNase-dependent incompatibility in rose, was carried out from this original material (Vieira et al., 2021, Scientific Reports 11). An experimental and conservatory rosarium was dedicated and the following framework was adopted to restore, maintain and develop R. arvensis biodiversity and to investigate the species genetically. First, exceptional variants/mutants were screened from field expeditions. Some variants fit with earlier descriptions of now lost plants, whereas some others are unrecorded from both science and horticulture, but altogether this work reconstitutes somehow, most of the intra-specific biodiversity that was recorded mainly between 1800 and 1940. Second, a restricted core collection of heritage roses, that includes the old pioneer lines (the most upstream branches of the founding historic pedigrees), and also the variants from non-European species, was established. A substantial part of all these independent and historic genetic strains, were crossed (and when possible, their characters introgressed) to R. arvensis 'Osenbuhr' the reference standard plant, genome of which has been recently sequenced (Raymond et al., 2018, Nature Genetics 50). Altogether, combined botanical and genetic approaches allow a fine description of 200 independent characters and in part, the nature of their inheritance. Most of the characters have been formally compiled according to genes and alleles and this is now ready for publication as a repository with update annotated genetic data for the international community. I would like to take the opportunity of the symposium to discuss about conventions for the gene nomenclature.