On exploring strategies to prevent spring freeze damage and elucidating the mechanisms of cold acclimation in Vitis
Restricted (Penn State Only)
- Author:
- Persico, Meredith
- Graduate Program:
- Horticulture
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 29, 2024
- Committee Members:
- Surinder Chopra, Program Head/Chair
Kathy Kelley, Major Field Member
Helene Hopfer, Outside Field Member
Jason Londo, Special Member
Michela Centinari, Chair & Dissertation Advisor
Misha Kwasniewski, Outside Unit Member - Keywords:
- Vitis
cold tolerance
ecophysiology
budbreak
freeze damage
wine quality - Abstract:
- Grapevine freeze damage limits production potential worldwide. In spring, freeze events near budbreak can damage and kill young growing tissues, causing crop losses, and therefore economic losses, for grape growers. In winter, the sensitivity of cultivated grapevines, Vitis vinifera, to low temperatures limits crop potential for the following season and the success of V. vinifera cultivars in cool climates. Climate change is creating new challenges for grape growers to prevent freeze damage in vineyards. Global warming is accelerating the time to grapevine budbreak and early-season phenology in late-winter and spring, leaving young growing tissues more susceptible to damage from freeze events; as a result, it has become increasingly urgent to provide grape growers with solutions to mitigate spring freeze damage. Cultivated grapevines require both decreasing daylength and temperatures in autumn to gain cold tolerance (i.e., “cold acclimate”) to survive low winter temperatures. The increased frequency of heatwaves and warm spells with global warming may undermine grapevine cold acclimation in autumn and reduce bud cold tolerance in winter, but the impacts of higher temperatures, or the plasticity of grapevine cold acclimation, is not yet understood. This dissertation seeks to 1) investigate cultural methods to mitigate spring freeze damage and examine the impacts of these methods on vine productivity and wine quality, and 2) determine the impacts of heat fluctuations on grapevine dormancy induction, cold acclimation, and cold tolerance at the molecular and physiological level. This dissertation summarizes four doctoral research studies. The first two studies (Chapters 2 and 3) investigate the efficacy of two methods to delay grapevine budbreak and mitigate spring freeze damage for V. vinifera winegrape cultivars Riesling (white-fruited) and Lemberger (red-fruited) in a cool climate vineyard over two study years. Chapter 3 investigates the impacts of delaying grapevine budbreak on wine chemical composition and consumer perception for V. vinifera cv. Lemberger over three years at a cool climate site. An additional two studies, Chapters 4 and 5, examine the impacts of elevated temperatures in late-summer and autumn on grapevine resource allocation, dormancy induction, cold acclimation, and cold tolerance. Chapter 4 explores the impacts of two simulated heatwaves on the molecular and whole plant mechanisms related to cold acclimation for V. vinifera cv. Cabernet Franc. Chapter 5 introduces a second grapevine species, the wild-type grapevine V. riparia and compares how V. vinifera and V. riparia differ in their response to a simulated heatwave at the end of the growing season prior to leaf-fall. This dissertation seeks to 1) help practitioners mitigate freeze damage in vineyards without compromising wine quality, and 2) advance the science of grapevine cold tolerance by investigating the underlying mechanisms and plasticity of cold acclimation for Vitis species.