Date of Graduation

Summer 2021

Degree

Master of Science in Plant Science (Agriculture)

Department

College of Agriculture

Committee Chair

Chin-Feng Hwang

Keywords

marker-assisted selection, downy mildew, susceptible, resistant, DNA markers

Subject Categories

Agriculture | Biotechnology | Genetics | Genetics and Genomics | Horticulture | Life Sciences | Molecular Genetics | Plant Biology | Plant Breeding and Genetics | Plant Sciences | Viticulture and Oenology

Abstract

Downy mildew caused by the fungus, Plasmopara viticola in the grapes is one of the major diseases affecting crop yield throughout the world. Breeding grapes via conventional methods for the downy mildew resistance will take approximately 25-30 years to fully evaluate and release new cultivars. Because of the long breeding cycle in woody plant species like grape, developing DNA markers linked to genes or quantitative trait loci (QTLs) for horticultural traits can greatly accelerate the breeding process and allow a much more accurate selection of progeny. This study aims to determine the presence of resistance in the 267 F1 genotypes developed by crossing the downy mildew resistant cultivar, Vitis interspecific hybrid ‘Chambourcin’, and the disease susceptible cultivar, V. vinifera ‘Cabernet Sauvignon’ using DNA markers. ‘Chambourcin’ has the Rpv3 downy mildew resistance locus. Using 4 simple sequence repeats (SSR) markers linked to the Rpv3 locus, UDV730, UDV734, UDV736, UDV737, the Rpv3 resistance alleles were examined among the hybrid progenies via marker-assisted selection. The data was analyzed to confirm which resistance allele sizes were passed down from the pedigree of the ‘Chambourcin’ to the hybrid progeny. This study will help provide the industry stakeholders from the grape and wine community with new cultivars that are adapted to Missouri.

Copyright

©Kavya Sri Tummala

Open Access

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