Phenotypic and genetic characterization of berry shape in table grape

Póster presentado en la 11th International Conference on Grapevine Breeding and Genetics, celebrada en Pekín del 29 de julio al 2 de agosto de 2014.Berry shape displays a wide range of phenotypic variation in grapevine and particularly among table grape cultivars where a broad diversity of shapes from spherical to cylindrical and horn types has been described. We are interested in understanding the genetic and molecular basis of berry shape variation in this species and thus we are following different approaches, from the phenotypic characterization at the morphological, histological and transcriptome levels to the genetic analyses of this trait within a collection of table grape cultivars as well as in a segregating F1 progeny derived from the hybridization between Red Globe and Crimson Seedless cultivars. Morphological analyses suggested a relationship between the shape of the ovary in the flower at anthesis and the final fruit shape. The quantitative genetic analysis of berry shape was initially based on berry length, berry diameter and the quotient of both variables named as berry shape. For both berry length and diameter we detected a complex genetic structure including two major QTL in LG 5 and 18 and minor effect QTL in LG1, 6, 12, 14 and 19. However, the final shape was mainly controlled by the QTL in LG5 and other minor QTL that affected size through their specific effects on berry length or diameter. Furthermore, the genetic analysis of ovary shape in anthesis flowers, based on the evaluation of the same variables analyzed in fruits, confirmed the existence of both common and specific genetic determinants in the control of both the ovary and the fruit shape, which could suggest that fruit shape is partially determined during preanthesis flower development. Transcriptome comparison between preanthesis flowers from siblings with extreme spherical and elliptical berries in the Red Globe x Crimson Seedless F1 progeny that were selected for their genotype at LG5 QTL putatively conferring these phenotypes allowed the identification of putative candidate genes for this major effect QTL.Acknowledgments: Projects: BIO2008-03892 and BIO2011-26229. Fellowships: BES-2009-027462 and BES-2012-053617.Peer Reviewe