高CO2浓度对水稻产量形成的农艺调控及其机理研究

Since the industrial revolution, with the impact of human activities, atmospheric CO2 concentration continued rapid rise. As the substrate of plant photosynthesis, increasing atmospheric CO2 concentration ([CO2]) will have important impact on crops growth. Rice is one of the most important crops in the world, which provides the dietary staple for more than half of the world’s population. With the rapid growth in world population and the improvement in living standard, the coming decades will see soaring demand for rice. A lot of investigations conducted so far point that increasing atmospheric [CO2] promoted rice growth and increased grain yield, but it was not clear whether this effect varied with different cultivars and cultivation conditions. In view of the importance of rice in human diet, objectives of the proposed research are to elucidate how grain yield formation of rice will change under elevated [CO2]. The free air CO2 concentration enrichment (FACE) system will be used. Based on previous yield performance, rice cultivars with contrasting tolerance to elevated [CO2] will be tested in grain yield formation research. The multi-factor design will be applied to study the effects of elevated [CO2] on rice grain yield formation and its interaction with cultivation measures. The physiological mechanisms responsible for rice grain yield changes under elevated [CO2] will be studied through investigating the key metabolism processes during crucial stage of rice growth. The results of this research will provide pivotal information for target breeding of high response to elevated [CO2] rice cultivar with high grain yield and developing new cultivation technology for better rice production.

工业革命以来，由于人类活动的影响，大气CO2浓度持续快速升高，作为植物光合作用的底物，快速升高的CO2浓度将对作物生长产生重要影响。水稻是重要的粮食作物，随着人口的增长和生活水平的提高，未来世界对稻米的需求量将持续增加。前期研究发现，高CO2浓度促进水稻生长和产量增加，但这种现象是否受环境或栽培条件的影响及其作用机制尚不明确。本项目利用环境条件接近自然农田的开放式大气CO2浓度升高（FACE）平台，选用对高CO2浓度响应差异显著的水稻基因型为供试材料，设置多因子操作试验，研究大气CO2浓度升高对水稻产量形成的影响及其农艺调控途径；通过对供试水稻关键生育期主要生理代谢过程和产量构成因子对高CO2浓度响应的综合分析，明确水稻产量形成对高CO2浓度应答的主要生理指标和关键代谢步骤，阐明高CO2浓度影响水稻产量的生理基础，为培育对CO2高应答的水稻品种以及配套栽培技术的更新提供科学依据。

作为光合作用的底物，逐年升高的大气CO2浓度显著促进水稻生长和增产，但这种现象是否受环境或栽培条件的影响及其作用机制尚不明确。本项目利用环境条件接近自然农田的开放式大气CO2浓度升高（FACE）平台，选用对高CO2浓度响应差异显著的水稻基因型为供试材料，设置多因子操作试验，系统探索了CO2肥料效应的农艺调控措施及其机理。主要进展如下：归纳出对CO2肥料效应高应答水稻的共性特征均与库容相关，如分蘖能力强、生物产量高、穗型大、植株高等；明确了施氮量和移栽密度对CO2肥料效应均有一定的调节作用，且均存在明显的边际递减现象；发现水稻库容是限制CO2肥料效应的关键因子，且敏感品种和钝感品种存在明显差异；项目还进行了CO2与温度互作效应和基于高应答水稻特征的平台外品种筛选尝试，初步发现了大气温度升高会抵消部分CO2肥料效应的基本规律。综合上述结果，本研究为未来高CO2浓度背景下水稻高产育种和配套栽培技术的更新提供了科学依据。项目成功筛选培育出高应答水稻新品种1个，资助发表论文3篇，待发表2篇。培养硕士研究生2名，其中1名已经取得学位，培养博士后1名。项目投入经费16.0000万元，支出12.1228万元，各项支出均与预算相符，剩余经费3.8772万元，计划用于本项目研究后续工作。