BioProject

Grapevine cluster compactness is a multi-componential trait of agronomical interest; it greatly influences the vineyard management and the visual aspect of table grape. Clusters with greater compactness are more susceptible to disease. The compactness can be break down in a patchwork of agronomical traits, each having agronomical importance that includes parameters related to inflorescence and cluster architecture (cluster length and width, length of pedicels, etc.), fruitfulness (number of berries, number of seeds) and berry (size, shape, volume...). Through visual evaluation of a collection of 730 clones from the cultivar Tempranillo and 501 clones from Garnacha Tinta we identified and fully phenotyped distinct clones which transcriptomes were compared at key developmental stages in order to identify the genes playing a role in mechanisms involved in cluster compactness such as the ones determining number of berries, cluster length or berry size. Key genes involved in this process were identified. The findings lead us to hypothesize that berry size and/or number at ripening are greatly influenced by the rate of cell replication in flowers during the first stages after pollination. Overall design: A total of 57 samples were hybridized. Comparison G1 was performed between clones showing differences in the cluster compactness and in the total number of berries per cluster and berries size (compact: clone 1134. loose: clone 0368). Comparison G2 was performed between two compact clones (Garnacha Tinta 147 and 1134) significantly differing for cluster length and number of nodes (branches) of the rachis. Comparison G3 was performed with two loose clones (Garnacha Tinta 681 and 1154) differing in the number of nodes of the rachis (p<0.01). Comparisons G4 and T were performed between clones showing differences in the cluster compactness and in the total number of berries per cluster (compact: clones 0906 and 0126. loose: clones 1154 and 1041).