Frost Survival Mechanism of Vegetative Buds in Temperate Trees: Deep Supercooling and Extraorgan Freezing vs. Ice Tolerance.

ABSTRACT: In temperate climates, overwintering buds of trees are often less cold hardy than adjoining stem tissues or evergreen leaves. However, data are scarce regarding the freezing resistance (FR) of buds and the underlying functional frost survival mechanism that in case of supercooling can restrict the geographic distribution. Twigs of 37 temperate woody species were sampled in midwinter 2016 in the Austrian Inn valley. After assessment of FR, infrared-video-thermography and cryo-microscopy were used to study the freezing pattern in and around overwintering vegetative buds. Only in four species, after controlled ice nucleation in the stem (-1.6 ± 0.9°C) ice was observed to immediately invade the bud. These buds tolerated extracellular ice and were the most freezing resistant (-61.8°C mean LT

SUBMITTER: Neuner G 

PROVIDER: S-EPMC6521125 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature