孕穗开花期低温胁迫对沈阳地区水稻生理生态及产量的影响研究

With the global warming and thermal condition improving, it is becoming more prevalent to plant the late maturity rice in middle and high latitude regions where the heat conditions was usually limited to rice growth. Simultaneously the temperature variation was changed dramatically pacing with the rising mean temperature; the late maturity rice would not ripe and make its production decrease steeply once it was at lower temperature year, which would be very dangerous to food safety in China...Generally, the researches believed the most sensitive stage of rice growth to chilling damage was at time of booting and blooming. The harm been due to low temperature at other periods can be remedied by more scientific cultivated practices...In this project, a semifield cultivation experiment will be conducted in Shenyang region by planting three variaty rices of different maturity stage, which are 9023 (middle), 9035 (middle and late) and 9036 (late), respectively. The rices will be exposure to low temperature with different intensities and durations at both booting and blooming stages. This study will employ portable LI-6400 infrared-gas analyzer, combining the analysis of chlorophyll, MDA, POD, PRO, SOD contents and activities in laboratory. The prospective results will be as follows: (1)to analysis the influences of chilling damage to three rice yields and their instructive indexes; (2)to describe the responses of photosynthesis, transpiration and stomatal conductance, and the contents and activities of chlorophyll, MDA, POD, PRO and SOD to low temperature; (3) to enhance the knowledge about the physiecological responses of different maturity stage rices to chilling damage; (4) and to draft the strategies on planting rices in proper proportions. These findings will be help to understand the patterns of chilling damage and their impacts on rice yield for disaster prevention and reduction, and to provide the more proper variety arrangements.

本研究以沈阳地区普遍栽种的9023（中熟）、9035（中晚熟）和9036（晚熟）三个不同熟期水稻品种为研究对象，采用半盆栽半大田的栽培措施，通过在孕穗、开花期不同强度及持续时间的低温处理，采用LI-6400光合/蒸腾测定技术、室内逆境指标分析技术，系统研究低温冷害对不同熟期水稻产量及产量构成的影响，分析不同熟期水稻的光合作用、气孔导度及各逆境生理指标对低温胁迫的响应特征，揭示低温冷害对不同熟期水稻影响的生理生态机制，阐明不同强度及持续时间的低温冷害对水稻产量影响的程度，探讨合理的品种搭配策略。研究结果可为气候变暖情景下，正确评价水稻栽种品种界限的北移和越区种植晚熟品种的安全性及合理搭配不同熟期水稻品种提供科学依据。

摘要：以沈阳地区栽种的中熟9023，中晚熟9035和晚熟9036水稻品种为研究对象，系统研究低温胁迫对不同熟期水稻生理生态及产量的影响，制定了沈阳地区不同熟期品种水稻的搭配策略。同时分析评价了东北地区持续低温指数（CCDI）的变化特征。主要研究结果如下：..（1）近45a，东北地区CCDI总体上呈降低趋势（p<0.01）。冬季CCDI降低幅度最大，夏季最小。温度升高的季节间差异大于CCDI降低的季节间差异。东北地区粮食产量的波动与CCDI显著相关，且纬度越低，CCDI增加造成粮食减产幅度越大。..（2）水稻产量对持续低温的响应与品种的熟期类型、遭遇低温时所处的关键期及低温强度的不同而不同。分蘖期的持续低温可使水稻的产量增加，增产幅度依次为9023>9035>9036。拔节期比正常低3℃持续5d的低温可使三个品种的水稻增产，增产幅度依次为9023>9035>9036，但低温强度达到5°C时，则会造成9035和9036减产。开花期遭遇持续低温均可导致三个品种（熟期）水稻减产，减产幅度依次为9036>9035>9023。..（3）持续低温会使叶片叶绿素的含量下降，而游离脯氨酸、还原糖含量、丙二醛含量、SOD含量、POD等的含量增加。不同关键期对比，低温胁迫对孕穗开花期生理过程的影响最大；而低温胁迫对不同品种的影响程度为9035>9036>9023。遭遇低温后转到正常的环境下，低温处理组水稻的生理指标均可得到一定程度的恢复，9023的恢复性要优于9035和9036，但三者都很难恢复到CK水平。..（4）持续低温对水稻光合过程的影响存在品种间差异。持续低温对9023光合能力的影响不大，但可导致9035和9036光合能力下降，且降幅随低温强度的增强而加大。随着品种熟期的延长，遭遇持续低温后光合的恢复能力变弱，晚熟品种光合能力的下降且很难恢复可能是造成其产量显著下降的主要原因。. （5）未来中熟品种的产量呈下降趋势，中晚熟和晚熟品种产量呈上升趋势，随品种熟期的延长，产量的年际波动增大。在2015年之后，中熟品种的栽种比例应逐步降低。中晚熟品种的栽种比例在2011-2030年间应逐步增大。按照搭配决策布局不同熟期品种，水稻的产量在2026-2030年间会比2006-2010年的平均单位面积产量增加1.36%，而2041-2050年间单位面积产量则可增加9.41%。