东北水稻生长发育和产量对夜间升温的响应

 采用两套开放式增温系统，在吉林公主岭开展了4年的水稻全生育期夜间增温试验。结果表明，全生育期冠层夜间温度平均升高0.7℃~1.0℃，水稻始花期提前2~3 d，但灌浆时间延长1~2 d。夜间增温对水稻净光合速率无显著影响，但显著提高剑叶面积、花后总绿叶面积和叶面积指数，其中吉粳81和吉粳83叶面积指数提高了40.0%和45.5%。夜间增温下，水稻地上部生物量和籽粒产量呈现递增趋势，增幅皆为10%左右；有效穗数和每穗粒数分别提高7.0%和5.7%。夜间温度升高主要通过缓解低温对水稻生长的影响，其对东北寒地水稻的直接效应将以增产为主。

Responses of Rice Growth and Grain Yield to Nighttime Warming in Northeast China

To learn the actual responses of rice growth to warming, especially nighttime warming in Northeast China will benefit the strategy decision making for food security in China. By using two field warming methods, a four year experiment was conducted to investigate actual rice responses to nighttime warming for an entire growth cycle in Gongzhuling County, Jilin Province, China. The results showed that nighttime warming of 0.7-1.0℃ on rice canopy could advance rice initial flowering date by two to three days, but the grain filling stage was prolonged slightly by one to two days. There was no significant impacts of warming on rice net photosynthetic rate, but nighttime warming significantly increased the flag leaf area, the total green leaf area and the leaf area index (LAI) during post flowering phase. Compared to the un warmed control, the LAI of Jijing 81 and Jijing 83 significantly increased by 40.0% and 455%, respectively. Nighttime warming tended to enhance rice aboveground biomass and grain yield by 10%, and significantly increased the numbers of productive panicle and spikelet per panicle by 7.0% and 5.7%, respectively. It indicate that nighttime warming may benefit rice production through mitigating the low temperature limitation to rice growth in Northeast China.