揭示东北粳稻孕穗期不同时段低温对产量的影响,建立气温和积温对粳稻产量影响模式和指标。利用高山自然温度梯度,在长白山北坡开展水稻盆栽低温处理试验。试验设7个海拔高度（低温强度）处理,3个低温持续时间（2、3、5天）处理,并设3个低温影响时段（孕穗前期、中期和后期）,1个适温对照;用试验数据建立回归方程。结果表明,粳稻孕穗关键期低温对产量的影响十分显著,影响模式符合对数或线性函数,温度越低,低温持续时间越长,导致温度影响系数越大,相对单产越低;产量与低温时段日平均气温的关系比日均最低气温更密切。孕穗期不同时段低温对水稻单产的影响有差异,穗分化前期2天短期低温对产量的影响略大于中期和后期,前期和中期（花粉母细胞减数分裂期前后）持续3天低温的影响更显著一些,但3个时段持续5天左右低温的影响都特别显著,都导致严重减产。总体而言,粳稻孕穗关键期连续2、3、5天的平均气温每降低1℃,水稻减产率分别上升2.0、3.2、4.5个百分点;穗分化前期、中期和后期出现低温过程,期间冷积温每增加10℃∙d,水稻减产率依次上升9.1、8.3、7.7个百分点;孕穗关键期冷积温在6、12、18℃∙d以上,分别导致水稻发生轻度、中度和重度低温冷害。

To understand the yield response of japonica rice of northeast China to low temperature in different time periods of booting stage, and to establish the model and index of the influence of temperature and accumulated temperature on japonica rice yield, we utilized the law of air temperature decreasing with altitude and conducted a natural low-temperature rice pot experiment on the north slope of Changbai Mountains. In the experiment, we selected seven altitudes (low temperature strength), three durations of low temperature (2, 3 and 5 d), three periods of low temperature influence at booting stage (early, middle and late period), and used one proper temperature as control. The experimental data were used to establish a regression equation. The results showed that the response of rice yield change to low temperature at booting stage was significantly sensitive, while the influencing mode was in accordance with logarithmic or linear function. The lower the temperature and the longer the low temperature duration time, the greater the temperature influence coefficient and the lower the rice yield per unit area. The relationship of rice yield with daily mean temperature was closer than that with daily minimum temperature. The influence of low temperature at different booting periods on rice yield was different. The influence of short-term low temperature in 2 days in early panicle differentiation period was slightly greater than that in middle and late period. The influence of low temperature lasting for 3 days in early and middle panicle differentiation period (before and after meiosis of pollen mother cell) was more significant. The influence of low temperature lasting for 5 days in each of the 3 periods could be particularly significant, and all could result in a severe yield reduction. In summary, the rate of rice yield reduction will be increased by 2.0, 3.2 and 4.5 percentage points respectively with every 1℃ decrease of the average temperature lasting for 2, 3 and 5 d during the key period of the booting stage. The rate of rice yield reduction will be increased by 9.1, 8.3 and 7.7 percentage points when the cold accumulated temperature is increased by every 10℃∙d at the early, middle and late panicle differentiation period. When the cold accumulated temperature in the key booting stage is more than 6, 12 and 18℃∙d, the light, moderate and severe rice chilling injury will occur, respectively.