Physiology trait and growing region climate data compiled from the literature for 34 wine grape cultivars

Selection for crop cultivars has largely focused on reproductive traits,
while the impacts of global change on crop productivity are expected to
depend strongly on the vegetative physiology traits that drive plant
resource use and stress tolerance. We evaluated relationships between
physiology traits and growing season climate across winegrape cultivars to
characterize trait variation across growing regions and elucidate the
mechanisms that adapted grapevines to hot, dry conditions. We compiled
values from the literature for seven water use and drought tolerance
traits and growing season climate. Cultivars with a lower maximum stomatal
conductance and stem embolism resistance were associated with regions with
a higher mean temperature and vapor pressure deficit (VPD) (r2 = 0.20 –
0.49, P < 0.02, N = 10 – 22). A more negative water potential
threshold for 50% stomatal closure was associated with cooler regions in
correlations across studies, but with a higher VPD across cultivars from a
common garden comparison (r2 = 0.24 – 0.67, P < 0.03, N = 15 – 18).
Overall, warmer, drier regions selected for traits that would reduce
transpiration and conserve soil water longer into the growing season, but
potentially increase stomatal and temperature limitations on
photosynthesis under future, hotter conditions.