Abstract
Xylem parenchyma cells of most boreal trees including conifers adapt to subfreezing temperature by deep supercooling. Present study showed that crude extracts from xylem of several conifers had effect to promote supercooling of small water droplets with AgI as an ice-nucleating substance. Fractionation of the crude extracts from xylem of Larix kaempferi indicated that any substances except for soluble sugars were responsible for the promotion of supercooling, possibly by inhibiting or reducing ice nucleation. We also showed that the extracts from xylem of L. kaempferi had effect to promote supercooling, not only of small water droplets (2μl) but also of bulk water (1ml).
