Author ORCID Identifier:
Date of Graduation
12-2025
Document Type
Thesis
Degree Name
Master of Science in Horticulture (MS)
Degree Level
Graduate
Department
Horticulture
Advisor/Mentor
Worthington, Margaret
Committee Member
Vieira, Caio
Second Committee Member
Lee, Jacquelyn
Third Committee Member
Adams, Rich
Keywords
Grape; KASP; Muscadine; Recombination; Vitis rotundifolia; Vitis vinifera
Abstract
The Vitis genus comprises two subgenera, Vitis (2n = 38) and Muscadinia (2n = 40), both cultivated for wine, juice, and fresh-market fruit. Vitis vinifera cultivars produce high-quality fruit but are highly susceptible to diseases endemic to the southeastern United States, while muscadines (Muscadinia rotundifolia) provide exceptional disease resistance, heat tolerance, and environmental adaptability. Hybridizing these subgenera offers a path to combine fruit quality with disease resistance; however, wide Vitis × Muscadinia (V × M) crosses remain difficult due to differences in chromosome number, genetic divergence, and reproductive barriers that reduce fertility and recombination. Recent breeding efforts have introgressed stenospermocarpic seedlessness from V. vinifera into muscadines, but no molecular markers for this trait have been validated in Muscadinia. In chapter one, we describe the development and validation of two Kompetitive Allele Specific PCR (KASP) markers targeting known causal variants for stenospermocarpy (VviAGL11) and male sterility (VviINP1). Marker performance was validated in 918 V × M hybrids from the University of Arkansas Division of Agriculture Fruit Breeding Program and a diverse set of wild and cultivated Vitis and Muscadinia accessions. Across both subgenera, the seedless and flower sex markers achieved accuracies of 99.7% and 100%, respectively, demonstrating robust cross-subgenera performance and providing cost-effective tools for early selection of desirable genotypes. Chapter Two investigated the inheritance of reproductive, fruit, and agronomic traits in a wide V × M mapping population derived from a cross between AM-116 (M. rotundifolia) and the seedless, perfect-flowered V × M hybrid JB15-43-N0-25. Whole-genome sequencing and rhAmpSeq genotyping data were used to visualize Vitis introgressions through chromosome painting, perform Principal Component Analysis (PCA), and create a high-density linkage map. Recombination was suppressed in homeologous regions with Vitis introgressions compared to homologous regions. Principal component analysis of chromosome 18 revealed yield-related clustering patterns associated with the Vitis seedless introgression, highlighting how genomic divergence contributes to sterility and limits recovery of fertile, recombined hybrids. Together, these findings offer insight into sterility, recombination, and introgression in interspecific hybrids and provide new molecular breeding tools supporting future breeding strategies for improved V × M cultivars.
Citation
Vaughn, I. (2025). Validation of Diagnostic Markers and Linkage Mapping in Vitis × Muscadinia Hybrids. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6020
