Chinese scientists achieve major hybrid rice breakthrough with near-100% cloning efficiency

Chinese scientists have made a major breakthrough in hybrid rice breeding with the development of “clonal hybrid rice,” which demonstrates near-100 per cent stable cloning efficiency and normal fertility, enabling hybrid vigour to be permanently passed down through seeds. The breakthrough is expected to revolutionise hybrid rice production and bolster global food security, the Global Times learned from the research team on Thursday. 

Hybrid rice achieves higher yields and greater resilience through hybrid vigour. However, the seeds of conventional three-line and two-line hybrid rice cannot be saved for replanting, as their traits separate in subsequent generations. This forces farmers to purchase new seeds every season, increasing production costs. 

The new hybrid rice developed by the research team led by Wang Kejian, a professor at China National Rice Research Institute, uses synthetic apomixis to produce clonal seeds and permanently preserve hybrid vigour. By fixing hybrid vigour, the technology could achieve “one-time hybridisation, lifelong use across generations.” In theory, obtaining just a single hybrid seed would allow continuous production of hybrid rice without the need for yearly seed production. 

The study was published in the international journal Vita on July 21.

According to Wang, hybrid rice can boost yields by 10 per cent to 30 per cent, but its adoption remains limited due to high seed production costs. It accounts for only about 50 per cent of rice cultivation areas in China and around 5 per cent globally. 

“Producing hybrid seeds costs 10 to 20 times more than conventional seeds, even before adding processing, storage, and transportation expenses, making the high-yield hybrid rice unaffordable for many developing regions, especially African countries where higher yields are most needed,” Wang told the Global Times on Thursday. 

After years of research, the team discovered a rice gene named “HUAXU” that can trigger parthenogenesis in hybrid rice egg cells, enabling the production of haploid offspring. 

Combining this strategy with a clonal gamete strategy, the team have developed hybrid rice lines with cloning efficiency exceeding 99 per cent across varieties, generations, and field conditions, while maintaining normal yields. 

According to Wang, the achievement has solved a globally recognised challenge in crop breeding – enabling hybrid rice to permanently preserve hybrid vigour through seeds. It is expected to fundamentally transform the traditional model of hybrid rice production, which relies on annual seed production, and provides new technological support for global food security. 

In addition, the hybrid rice technology, which eliminates the need for complex annual seed production, could also give breeders more flexibility in boosting genetic diversity and strengthening resistance to climate change, diseases, and extreme weather, Wang said. 

Hybrid rice is a crucial guarantee for China’s food security. China has fed nearly one-fifth of the world’s population with less than 9 per cent of the world’s arable land, and hybrid rice is the powerful support behind this miracle.

Today, China’s total grain output has remained stable at over 700 billion kilograms for two consecutive years, far exceeding the internationally recognised safety line of 400 kilograms per capita, statistics showed. China’s large-scale and sustainable capacity for food self-sufficiency is crucial for global food security and stabilising inflation levels worldwide.