以5年生翠冠品种为试验材料,研究低温对梨花器官冻害、抗氧化系统及授粉受精的影响。结果表明,0℃持续3小时处理时,梨花器官均无冻害,且坐果率较高;-2℃持续1.5小时处理时,花器官冻害率为43.56%,其中花柱部分受冻的花可坐果,其坐果率为46.01%,但部分幼果出现畸形现象;-2℃持续3小时冻害率为85.50%,坐果率降为24.01%;-4℃时,花器官均受冻害且不坐果。低温胁迫中不同花器官保护酶活性的变化呈现一定差异,花瓣中的超氧化物歧化酶、过氧化氢酶、过氧化物酶活性均随胁迫温度加深和持续时间的 Five-year-old Cuiguan varieties were used as experimental materials to study the effects of low temperature on the frost damage, antioxidant system and pollination and fertilization of pear organs. The results showed that there was no frost damage in pear organs at 0 ℃ for 3 hours, and the fruit set rate was high. When treated at -2 ℃ for 1.5 hours, the frost damage rate of flower organs was 43.56% The fruit setting rate was 46.01%, but some of the young fruit appeared deformity. The frostbite rate was 85.50% for 3 hours at -2 ℃, and the fruit setting rate was reduced to 24.01%. At -4 ℃, the flower organs were frostbite and did not set fruit. The changes of protective enzyme activities in different floral organs showed some differences under low temperature stress. The activity of superoxide dismutase, catalase and peroxidase in petals increased with the deepening of the stress temperature and the duration