On December 4, rice and Arabidopsis seeds, which had experienced a full life cycle of 120 days in space, returned successfully with the Shenzhou XIV spacecraft. This means that China has successfully carried out the experiment of rice whole life cycle culture from seed to seed for the first time in the world. It is reported that the scientific name of this research is "molecular mechanism of flowering regulation of higher plants under microgravity", which was undertaken by the team of Zheng Huiqiong from the Center for Excellence and Innovation in Molecular Plant Science of the Chinese Academy of Sciences. So, why did you carry out this experiment? What are the gains? Why should we send rice and Arabidopsis to space? Zheng Huiqiong introduced that rice is the main food crop of mankind, feeding nearly half of the world's population, and is also the main candidate food crop for the future manned deep space exploration life support system. Rice breeding using space microgravity is one of the important directions of space botany research. "Seeds are not only the food of human beings, but also the carrier for breeding the next generation of plants. If human beings want to survive in space for a long time, they must ensure that plants can complete generation alternation in space and successfully reproduce seeds. However, previously, only Arabidopsis, rape, pea and wheat were cultivated from seed to seed in space, while rice, the main food crop, has not been cultivated in space for the full life cycle." The model plant Arabidopsis mainly undertakes the research of "flowering". Zheng Huiqiong said: "Flowering is the premise of seed production. We systematically studied the impact of space microgravity on plant flowering using the model plant Arabidopsis." Zheng Huiqiong introduced what happened to rice and arabidopsis during their space trip. The on orbit experiment started with nutrient solution injection on July 29, 2022 and ended on November 25, 2022. The experiment completed the whole life cycle of arabidopsis and rice seed germination, seedling growth, flowering and seed setting. During this period, astronauts carried out three sample collections on orbit - rice samples at booting stage on September 21, samples at flowering stage of Arabidopsis on October 12, and samples at seed maturity stage of rice and Arabidopsis on November 25. After collection, the samples at flowering or booting stage are stored in the - 80 ℃ low-temperature storage cabinet, and the samples at seed maturity stage are stored in the 4 ℃ low-temperature storage cabinet. Zheng Huiqiong said that three space experiments were completed this time. First, the whole life cycle culture experiment of rice from seed germination, seedling growth, heading and seed setting was completed on orbit, and the images were acquired for analysis. Second, the spatial ratooning rice after cutting was successfully cultivated and produced mature seeds (second crop). Third, the image observation and analysis of the response of key genes of Arabidopsis seed germination, seedling growth and flowering regulated by different biological clocks to space microgravity were completed on orbit, and samples were collected on orbit. Now, the samples have been transferred to the Molecular Plant Science Innovation Center of the Chinese Academy of Sciences in Shanghai for further detection and analysis. What are the preliminary findings of the experiment? By analyzing the images obtained in space and comparing with the ground control, it is found that the space microgravity has an impact on a variety of agronomic traits of rice, including plant height, number of tillers, growth rate, water regulation, light response, flowering time, seed development process and seed setting rate. Scientists have gained some initial knowledge