According to Xinhua News Agency (Xinhua)reported on Jan. 5, Wang Kejian's team, State Key Laboratory of Rice Biology, China Rice Research Institute, Chinese Academy of Agricultural Sciences, established a rice apomixis system by using gene editing technology, successfully cloned hybrid rice seeds, so that hybrid rice traits can be steadily inherited to the next generation. The results were published online on the 4th evening in the Journal Nature Biotechnology.
Hybrid rice is superior to its parents in vigor, stress resistance, adaptability and yield, and has made important contributions to agricultural production. The data show that the annual planting area of hybrid rice in China is more than 240 million mu, accounting for 57% of the total planting area of rice, and the yield of hybrid rice is about 65% of the total yield of rice. Hybrid rice produces about 2.5 million tons a year and can feed an additional 70 million people a year.
Because the offspring of hybrid seeds will have character of segregation and can not maintain their heterosis, breeders have to spend a lot of manpower, material and financial resources on seed production every year, and farmers have to buy new seeds every year.
"Scientists have long believed that apomixis can solve this problem. Asexogenous reproduction is a reproductive mode through seed asexual reproduction. It can not change the heterozygous genotype of hybrid varieties with the change of generations, thus achieving the fixation of heterosis, which is expected to bring a new revolution to agricultural production. Wang Kejian said.
In the experiment, the Indica-Japonica Hybrid Rice Chunyou 84 was selected as a model variety for rice apomixis research. Four genes related to rice reproduction were knocked out by CRISPR/Cas9 gene editing technology in Chunyou 84, resulting in apomixis traits and cloned seeds similar to hybrid rice. By further testing, the researchers determined that the offspring grown from cloned seeds were highly similar to the first generation of hybrid rice.
"This work proves the feasibility of apomixis in hybrid rice. It is a major breakthrough in the field of apomixis and has great theoretical significance." Yuan Longping, the father of hybrid rice and academician of the Chinese Academy of Engineering, said he hoped that researchers would make further efforts to apply the results to production as soon as possible.
