Chongqing - On March 13, a unique collection of 170 grams of germplasm resources concluded its 155-day odyssey in space, recently arriving back at the  Western (Chongqing) Science City aboard the Shenzhou-16 spacecraft.

Chongqing has undertaken space breeding on an organized and substantial scale for the first time. The space journey included five types of distinctive germplasm resources, with a total of 14 samples from the Chongqing Academy of Agricultural Sciences, marking a significant milestone in the city's scientific endeavors.

Space breeding outshines traditional methods with its higher mutation rates and shorter cycles, enabling the rapid development of germplasm resources with enhanced qualities like higher yields, disease resistance, and early maturity.

After 155 days of space-induced mutations, these resources offer valuable samples for research and the development of superior new varieties.

"After learning that the seeds had safely returned, I was very excited," said Zhang Yimo, a researcher at the Institute of Vegetables of the Chongqing Academy Of Agricultural Sciences. 

Previously, the Chongqing Academy Of Agricultural Sciences' Institute of Vegetables sent germplasm resources to space. This time, aiming for seeds with more stable traits, distinctive features, and better prospects, the institute chose its "ace" resources, including mung beans, tomatoes, rapeseed, rice, and Er Cai seeds, characteristic of the Sichuan and Chongqing regions, for the space mission.

This means that 20 grams of Er Cai seeds, approximately 20,000 in total, will be sent into space. "This year, we plan to minimize intervention after planting the seeds to let their natural traits fully emerge, and subsequently, we'll select any advantageous mutations," Zhang explained.

Not all seeds will transform into select specimens; only those impacted by cosmic particles will be chosen upon return to Earth. Due to the unpredictable nature of genetic mutations, not every seed will exhibit beneficial changes. Thus, only seeds meeting specific criteria will be retained.

"Space breeding, also known as aerospace breeding, is a method of radiation breeding. There is about a 0.1% chance of mutation, which means, among the 20,000 Er Cai seeds, more than 100 seeds will mutate, but the changes could be for better or worse," Zhang said.

Space-exposed seeds undergo years of selective cultivation. The newly returned Er Cai seeds to Chongqing are stored for cold preservation, with sowing scheduled for around August or September this year.

Zhang stated that interventions will be minimized after this year's planting to let the seeds' traits naturally emerge and to identify beneficial mutations. Zhang anticipates that within 3 to 5 years, these "space seeds" will yield Er Cai with improved characteristics.