Woody species do not differ in dormancy progression: Differences in time to budbreak due to forcing and cold hardiness

Abstract

SignificanceBetter knowledge of dormancy (plant “hibernation”) is required to understand future adaptation of woody perennial plants facing warmer climates. Typical dormancy research uses time to budbreak to define the transition from a warm temperature nonresponsive to a responsive state (long vs. short time to budbreak). Based on this phenotyping method, species diverge in dormancy transition times during winter. Here, dynamics of bud cold hardiness (lowest survival temperature) for many species are used to show convergence in their response to winter chilling. Therefore, previous studies determining chilling requirement based on budbreak may describe adaptation to an environment but do not accurately describe physiological dormancy transitions. Further, cold hardiness dynamics can be used for field predictions of bud cold hardiness and budbreak.