Deconstructing cold hardiness: Supercooling ability and chilling requirements in the wild North American grapevine vitis riparia

Authors: Londo, Jason; KOVALESKI, ALISSON - Cornell University

Submitted to: Australian Journal of Grape and Wine Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2018
Publication Date: 3/14/2019
Citation: Londo, J.P., Kovaleski, A.P. 2019. Deconstructing cold hardiness: Supercooling ability and chilling requirements in the wild North American grapevine vitis riparia. Australian Journal of Grape and Wine Research. 25:276-285.

Interpretive Summary: Grapevine production in limited by many different biotic and abiotic factors, such as pests, pathogens, drought, and temperature. The ability to survive winter temperatures and avoid frosts in spring are two of these factors which currently limit grapevine production in the Midwest, North, and Northeast US. As climate becomes more variable, the traits of cold hardiness and dormancy become more important for sustainable viticulture. This research study was conducted to examine these two traits in a wild grapevine species (Vitis riparia) that is commonly used in grapevine breeding programs due to its impressive cold hardiness. We examined the cold hardiness and dormancy traits in 43 different V. riparia accessions over two different years. Using a method called differential thermal analysis, which measures the lethal temperature of the dormant bud, we examined cold hardiness in 43 different V. riparia samples over two years. We also measured the chilling requirement, a measurement of dormancy. The results of the study demonstrated that early winter cold hardiness is strongly determined by air temperatures and all V. riparia accessions initially responded similarly. However, by late winter, the V. riparia accessions began responding in a significantly different manner, some losing cold hardiness faster than others. This study demonstrates that cold hardiness can be deconstructed into two different phenotypes; one defined by early winter response, and a second determined by temperature responsiveness during late winter These traits identified germplasm with enhanced winter survival for future breeding efforts as well as describe a robust phenotype for genetic mapping.

Technical Abstract: Grapevine production in cool climates is limited by aspects of winter survival. Cold hardiness traits are key to future viticultural sustainability as climate variation, including acute cold events, are predicted to increase. This study examines variation in dormant bud cold hardiness and chilling requirement in the dominant wild species used to incorporate cold hardiness traits into new hybrid grapevine cultivars, Vitis riparia. Dormant cuttings of 43 genotypes of Vitis riparia were assayed over two years using low temperature exotherms to determine cold hardiness and forcing assays to determine dormancy status. Results demonstrate significant differences in maximum cold hardiness and deacclimation rate between genotypes. All V. riparia respond to temperature in the same manner during the endodormant period of early winter acclimation. However, responses to warming temperatures during ecodormancy are significantly different and suggest a potential adaptive response. These traits interact to determine genotypic differences in early versus late winter cold hardiness. This study demonstrates that cold hardiness can be deconstructed into two different phenotypes; one defined by dormancy induction and early winter response, and a second determined by temperature responsiveness during deacclimation. These two traits identified germplasm with enhanced winter survival as well as describe a robust phenotype for genetic mapping.