发展直播再生稻是我国南方稻区增加复种指数，提高稻谷总产量和农民收入的一种绿色高效的水稻轻简化种植模式。水稻再生力高低是决定再生季产量的关键因素，而再生力主要受源库关系的影响。目前，关于源库调节对水稻再生力与再生季产量方面的研究报道较少且主要集中于移栽再生稻，而对直播再生稻的相关研究更是鲜有报道。本项目以源-库理论为依据，从减源（疏叶）、疏库（去花）和减源疏库综合措施入手，采用作物栽培学、生理学和生物化学等方法，（1）探索影响直播再生稻再生力与再生季产量的主要源、库因素；（2）探究减源、疏库及减源疏库组合对直播再生稻再生芽萌发、再生季产量的影响机制；（3）探明直播再生稻再生季的源库平衡规律。以期通过上述研究工作来探明直播再生稻再生季源-库平衡的机理；明确提高直播再生稻再生季产量的源库调节机制和途径。为进一步提高直播再生稻再生季产量提供理论依据。

Development of direct-seeded ratoon rice is a green, efficient, and simplified planting pattern, which increases the multiple cropping index and the total rice yield and farmers' income in south China. Ratooning ability is the key to determine the grain yield in ratoon season, however, the ratooning ability is mainly affected by the relationship between source and sink. At present, there are few reports on the effects of source-sink regulation on rice ratooning ability and grain yield in ratoon season, and most of them focus on transplanted ratoon rice, while studies on direct-seeded ratoon rice are rarely reported. Based on the theory of source-sink, this project focuses on the influence of sources-sink regulation on the ratooning ability through comprehensive measures of reducing source (leaf cutting), thinning sink (spikelet thinning), and adopting crop cultivation, physiology and biochemistry methods. The aims of our proposed project are: (1) to identify the main source and sink factors affecting the ratooning ability and grain yield of direct-seeded ratoon rice; (2) to explore the effects of reducing source, thinning sink on germination of regenerated buds and grain yield of direct-seeded ratoon rice and the associated mechanisms; (3) To clarify the source-sink balance law of direct-seeded ratoon rice. The final objective is to explore mechanism of source-sink balance in ratoon season and to clarify the source-sink regulation mechanism and ways to improve the grain yield in ratoon season of direct-seeded ratoon rice. The output of the proposed project will provide theoretical basis for further improving the grain yield of direct-seeded ratoon rice.