Figure 1.

Longitudinal and transversal high-definition thermal recordings of Vaccinium macrocarpon freezing patterns in freezing tolerant terminal buds. Time stamps represents the time elapse under the freezing treatment, only comparable under the same sampling date. Arrows highlight ice formation propagation. (A-C) Thermal images of transversal sections at the base of the bud. This sequence of images shows ice propagation from the base of the stem toward the exposed cut, where ice did not reach the surface. (D) Fresh cut of a transverse section made at the base of the bud. (E–G) Thermal images of transversal sections of the stem. This sequence of images shows ice propagation from the base of the stem toward the exposed cut, where ice reaches the surface. Ice formation reaches the surface first, most likely, through vascular tissues. (H) Fresh cut of a transversal section made at the stem zone. (I–K) Thermal images of shoots partially defoliated. This sequence of images shows ice propagation from the base of the stem toward the bud, where ice propagation stops at the base of the bud (J). Minutes later, ice formation is initiated in the bud (K). (L) Fresh shoot manually defoliated depicting location of bud base (upper dashed line) and stem zone (lower dashed line). Scale bar = 0.5 mm.