Relationship between temperature, respiratory loss of sugar and premature dehardening in dormant Scots pine seedlings

摘要: Increased intracellular sugar concentration is an important contributor to the increased cold tolerance of conifers in winter. This study examines extent which wintertime respiratory loss sugars leads premature dehardening. Two-year-old seedlings Scots pine (Pinus sylvestris L.), grown and cold-hardened field, were exposed different temperature regimes for 16 weeks while dormant. To minimize short-term carry-over effects, after treatments, all conditioned 5.5 degrees C watered before assessment non-structural carbohydrates tolerance. Needle was decreased by 54, 32, 21 9% following treatment at 5.5, 0, -1.5 -8.5 C, respectively. Sugar did not decrease as much root tissues needles because starch mobilized roots. Cold analyzed controlled freezing, causing initial 10% damage (LT(10)) plotted a function needle concentration, revealing strong, linear relationship. When one-third had been consumed, LT(10) from -24.5 -16.5 when one half -10 C. Consequences these findings field performance are discussed relation climatic variation change.