Abstract: In order to understand why the weedy rice seeds could survive in field under winter conditions, dry seeds of Dandong weedy rice and rice cultivar Roshihikari were soaked in water for several hours, then transferred to -20℃ and stored for seven days, finally geminated under 25 ℃ condition. The germination rate of the control, Koshihikari, was dramatically reduced from 98 0% to 4.0% after soaking for one hour, and no seedlings could survive if soaking time was extended to 1.5 hours, while the seeds of Dandong weedy rice geminated normally after one hour soaking, and its seedling survival rate was up to 2.3% even soaked for three hours. Dandong weedy rice could germinate at 11℃, its critical temperature for germination was lower than that of the control. The potential values of the tolerance of weedy rice to freeze were discussed.

Key words: weedy rice, freezing tolerance, low temperature, germination

摘要： 为了解丹东杂草稻种子冬季在野外能存活的原因，将丹东杂草稻和对照品种越光的干种子在水中浸不同时间，后在-20℃下处理7 d，在25℃下发芽。对照品种越光在浸种1 h后冷冻处理，其种子的发芽率从98％降为4％，浸种时间延长到1.5 h已不能成苗，而丹东杂草稻种子在1 h浸种处理后，其发芽基本不受影响，甚至在3 h浸种处理后成苗率仍达2.3％。在不同低温下发芽试验中发现丹东杂草稻在11℃能发芽，杂草稻的发芽临界温度要比对照越光低。讨论了杂草稻种子抗冻的潜在价值。 

关键词: 杂草稻, 耐冻性, 低温, 发芽