Advances in phenology and harvest characterization of the Chilean Vitis sp. germplasm collection and its use in table grape breeding

Abstract

Germplasm collection and characterization is essential for plant breeding. Chile holds a collection of 347 Vitis accessions at Instituto de Investigaciones Agropecuarias, La Platina, that have been successfully used to develop new table grape cultivars such as Maylen®. Located in the central valley of Chile, a section of the Vitis collection was characterized for two consecutive seasons for phenology as well as fruit quality parameters at harvest. In terms of phenology, the collections can be grouped in four main clusters, with a higher representation of individuals at the middle and late timing. Fruit phenotyping showed significant differences among wine and table grapes for cluster and berry weight, seed number and fresh seed weight, polar and equatorial diameters, as well as the ratio among these parameters. Interestingly, rachis weight, a novel parameter associated with fruit storage capacity, did not show differences among groups. Other novel traits, such as the combination of commercial seedleesness and berry equatorial diameters above 2cm were less represented, suggesting the need to create and introduce genetic variability for table grape breeding purposes.