水稻花时调控机理与育种应用

水稻为严格自花授粉作物。花时是水稻的重要农艺性状，受到内部因素(植物激素、遗传因子等)和外部环境因素(温度、光照、湿度、CO₂浓度等)的复杂调控。合适的开花时间是水稻成功繁殖的重要保障。颖花过早开放会导致水稻易受低温、露水重引起的病虫害影响；而过晚开放易使水稻遭受高温胁迫，降低产量。此外，在杂交水稻制种过程中，确保父母本的花时一致是提高杂交水稻制种产量的重要条件之一。本文从控制水稻颖花开放的结构基础、生理基础、遗传基础以及分子机理等方面，系统总结了水稻花时调控的研究进展，提出了今后水稻花时研究应重点解决的问题，并讨论了花时性状的改良在水稻生产和籼粳亚种间杂交稻育种上的应用价值。

Regulation mechanism and breeding application of rice floret-opening-time

Rice (Oryza sativa L.) is a strictly autogamous crop. Floret-opening-time (FOT) is an important agronomic trait in rice, which is complicatedly regulated by internal factors (plant hormones, genetic factors, etc.) and external environmental factors (temperature, light, humidity, CO₂ concentration, etc.). Floret opening at an appropriate time is very critical for the success of rice reproduction. If the floret opens too early in the morning, rice is vulnerable to pathogen infection caused by low temperature and heavy dew. In contrast, if the floret opens too late, the seed setting of rice would be severely affected by high temperature in the afternoon. Moreover, synchronized FOT between the male and female parents is a key requirement for successful production of hybrid seeds. In this review, we summarize the research progresses on the regulation of FOT in rice, mainly focusing on the aspects including the structural basis, physiological basis, genetic basis and molecular mechanism of controlling rice floret opening. We also present some important topics for future in-depth studies of FOT. Finally, we discuss the value of modulating FOT trait for improving rice production and indica-japonica inter-subspecies hybrid rice breeding.