Location: Grape Genetics Research Unit (GGRU)
Project Number: 8060-21220-006-000-D
Project Type: In-House Appropriated
Start Date: Apr 1, 2013
End Date: Mar 31, 2018
1: Identify and characterize the molecular, genetic, functional genomic, and biological factors controlling grape resistance to fungal and oomycete pathogens, with primary emphasis on powdery mildew. 1.A. Determine the genetic basis, pathogen race-specificity, and cellular mechanisms of powdery mildew and downy mildew resistance in grape breeding populations. 1.B. Determine the genetic basis by which abiotic stresses transiently alter foliar gene expression and induce resistance to grape powdery mildew and to extreme weather events. 1.C. Determine the genetic basis of grapevine ontogenic resistance to powdery mildew through quantitative trait locus analysis. 2: Characterize the genetic, genomic, and physiological aspects of grapevine abiotic stress tolerance and environmental adaptation. 2.A. Evaluate physiological variation in candidate thermal and dehydration stress traits from wild grapevine germplasm and mapping populations. 2.B. Identify and characterize candidate loci, linked genetic markers, or expression level changes for improved deep supercooling and environmental adaptation in grapevine. 3: Elucidate the key genetic and genomic factors controlling grape quality, including grape flavor and aroma, natural drying-on-vine, and berry size. 3.A. Determine genetic control of grape berry secondary metabolite production utilizing rapid-cycling grape germplasm populations. 3.B. Identify candidate genes or linked genetic markers associated with natural Dry-on-Vine raisins. 3.C. Determine the genetic basis of berry quality traits of muscadine grapes through quantitative trait locus analysis. 4: Develop and utilize novel or improved methods and genetic systems for grapevine breeding and genetic studies including, but not limited to, marker-assisted selection, germplasm for rapid trait evaluation, and transgenic solutions for introducing novel variation. 4.A. Develop Scout as a rapid-cycling system for trait evaluation and integration. 4.B. Develop and utilize transgenic and mutation technologies to introduce novel genetic variation for trait improvement. 4.C. Develop, evaluate, and apply computational methods for linking high quality large volume grapevine genotypic data with economically important grapevine traits and phenotypes.
Grape production and product quality are substantially harmed by diseases and adverse environmental conditions. This research project provides genetic solutions to biotic and abiotic stresses, while maintaining high fruit quality. Our general strategies are: A) Utilization of existing or created populations and germplasm for characterizing traits of interest and their underlying molecular mechanisms through trait, marker, and functional analyses; B) Integration of desirable alleles into prebreeding lines via molecular markers and rapid-cycling breeding systems; and C) Development of alternative solutions to complex problems through transgenic technologies. The following knowledge and products will be delivered at the end of this project: 1) Molecular markers useful in grape scion breeding that predict multiple sources of disease resistance, abiotic stress tolerance, fruit quality, and precocious flowering; 2) Enhanced understanding of critical genetic processes underlying these traits; 3) Development of novel germplasm resources, including rapidly flowering genetic lines, for the genetic dissection and stacking of traits of interest; and 4) Improved capacity of grape breeders to develop superior lines through marker-assisted breeding and other technology-driven approaches. Successful accomplishment of this project will accelerate development of improved grape cultivars to maintain the competiveness of the US grape industry, by reducing fungicide applications in new plantings, expanding the options for grape growers faced with climate change or in new production regions, and opening new market niches for novel grape products.