|FRESNEDO RAMIREZ, JONATHAN - The Ohio State University|
Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 10/15/2018
Publication Date: 6/1/2019
Citation: Fresnedo Ramirez, J., Lee, S.A., Ledbetter, C.A. 2019. The genetic dissection of the natural dry-on-vine (NDOV) trait in grapevine. Acta Horticulturae. 1248:409-416.
Technical Abstract: The impact of mechanized raisin harvesting has been positive in terms of reducing crop losses thanks to the development of varieties exhibiting the natural dry-on-vine trait (NDOV) in grape germplasm. However, while drying rates of specific genotypes are being determined and cultivars are being released, genetic components influencing NDOV are yet unknown. A deeper understanding of genetic mechanisms influencing NDOV will enable scientists to develop tools for breeding applications, such as molecular markers for seedling selection, and to formulate strategies for further study of NDOV and its biochemical basis, which may provide insights on agricultural management practices. Previous genetic mapping attempts of the NDOV trait using distinct phenotypic data were unsuccessful. A study in tomato demonstrated that the gene Cpw1 affects fruit cuticle leading to fruit dehydration on the plant. Hence, Cpw1 was selected as a potential candidate underlining the NDOV phenotype in grapevine. By using the grapevine genome reference sequence, two loci were identified as having homology to tomato Cpw1, one on chromosome 3 and another on chromosome 18, the latter having greater sequence identity and then called VviCpw1. Sequences of these loci were retrieved from genome sequences of ‘Thompson Seedless’, ‘Pinot Noir’, ‘Flame Seedless’, ‘Cabernet Sauvignon’, and Vitis cinerea B9. Multiple sequence alignments were examined for polymorphism. The DNA sequence of VviCpw1 has been cloned from the NDOV raisin cultivar ‘Sunpreme’ and introduced in tomato to verify function. In addition, screening for polymorphisms in raisin-related germplasm, with and without the NDOV trait, is underway using AmpSeq, while obtaining supporting phenotypic data from NDOV-segregating germplasm. Studies on cuticle features are also envisioned. The results from this study will enable development of tools and a body of knowledge for further understanding of the NDOV trait in grapevine.