Abstract: A study on techniques to enhance cold resistance of seedlings of Pinus bungeana was coducted for over 9 years.The experimental results showed that the chloroplast,mitochondrum and the membraneous System in cells were often damaged and caused serious water—lose in shenyang region during winter hence pine seedlings could not survive properly, however, vinyl-film or straw curtain in addtion were proved to be the best materials to protect the seedlings from the cold and 81%~97.5% seedlings could survive.The key measures of raising seedlings of P.bungesna in Shenyang region inclued the storage of seed mixed with sand under temperature 0—3℃ after hot water soaking; transplanting of seedlings not at age 4 years and paying attention to water management; and covering the seedlings with vinyl—flim for the first two years after sowing and transplanting. The 6—7 years old seedlings or those which had been trasplanted over3—4years might safely survive the cold winter.In addition,seed was soaked with Brassonolide(0.01μg/mL),see germination percentage could be increased by 47%. BR(0.01μg/mL) was sprayed in growing Stage to increase winter survival rate by 10.6%~14.5% Under rice-straw cover.

Key words: Pinus bungeana, Cold resistance, Freeze—Prevention measure