Vin

Understanding phenological hyperdiversity in Vitis vinifera

Winegrapes (Vitis vinifera ssp.) are one of the world’s most lucrative and important crops, and also one of the most responsive to climate, with some researchers suggesting terroir equates to climate. A major way this climate sensitivity is exhibited is through phenology—especially the timing of budburst, flowering and veraison. Winegrape varieties (e.g., Pinot Noir versus Cabernet Sauvignon) show high diversity in their phenology—and related temperature requirements for flowering and veraison.

Given their high responsiveness to climate, climate change impacts on winegrapes have the potential to be quite high, yet variation between varieties in their temperature requirements and tolerances should provide some buffering if viticulturists understand this variation and can build upon and develop it. Understanding this variation, however, requires improved studies of phenology that can tease out genetic versus environmental drivers of phenology to build better models of how temperature triggers phenological events, how these triggers vary across varieties and the underlying genetic architecture that creates the hyperdiversity in climate requirements between varieties.

Working with Dylan Burge, Kim Nicholas, and Andy Walker, we are combining phenological observations from a common garden with genetic surveys of winegrapes to (1) build robust phenological models of the diversity of temperature requirements between varieties and (2) identify the genetic regions that map to this phenological variation. Our major goal is to understand how genetic diversity predicts phenological variation in order to improve prediction and forecasting of variety-level responses to climate change, with possible implications for breeding improved varieties for novel climates.