Context:
Researchers—primarily from the Chinese Academy of Sciences—have created the first-ever rice pangenome, an advanced reference genome that includes genetic data from 144 wild and cultivated rice varieties across Asia.
Understanding the Rice Pangenome:
The rice pangenome is different from a traditional reference genome. A reference genome typically identifies the core genes of a species, but a pangenome includes both the common genes and the unique genes found in different varieties of rice. This allows scientists to gain a broader understanding of genetic diversity. In this study, researchers mapped out 3.87 billion base pairs of new genetic sequences not found in the current reference genome (O. sativa ssp. japonica).
Key Findings from the Pangenome Study
The study found 69,531 genes, which include 28,907 core genes shared by all rice varieties and 13,728 genes specific to wild rice.
· Approximately 20% of the genes identified were exclusive to wild rice species, offering valuable resources for improving rice's environmental adaptation, phenotypic plasticity, and regeneration potential.
· The research also confirmed that Asian cultivated rice evolved from a wild rice variety called Or-IIIa, a variant of O. rufipogon, which is the ancestor of japonica rice. The domestication of indica rice occurred when ancient japonica spread across Asia and crossed with local wild rice populations.
Importance of Rice in Global Food Security:
Rice (Oryza sativa L.) is a crucial staple for nearly two-thirds of the world's population, particularly in countries like India. It is the primary crop grown during the monsoon season (June to September) in India, which produced a record 220 million tonnes in 2024-25 across 51,000 hectares, with an average yield of 4.2 tonnes per hectare.
· However, rising global temperatures due to climate change pose a serious threat to rice production, reducing yields and increasing risks like arsenic uptake.
· Since 1901, India’s average temperature has risen by 0.7°C, and 2024 was the hottest year on record, with the minimum temperature 0.9°C higher than the long-term average.
· To address these challenges, the Indian Council of Agricultural Research (ICAR) has developed two genome-edited rice varieties, Samba Mahsuri and MTU 1010, which promise better drought resistance and higher yields.
Benefits of the Rice Pangenome:
· The pangenome study bridges the genetic gap between wild and cultivated rice, providing a foundation for improving rice varieties.
· By integrating genes from wild rice, scientists can develop new varieties that are more resilient to climate change, diseases, and environmental stress.
· The ability to introduce traits like drought resistance and disease tolerance will be crucial in maintaining rice production in the face of global warming.
Conclusion:
The creation of the rice pangenome is a breakthrough in understanding the genetic diversity of rice. By using this information, scientists can develop rice varieties that are more productive, resistant to diseases, and adaptable to changing climates. These innovations are essential for ensuring the future sustainability of rice production, which is vital for food security worldwide. The research not only improves our knowledge of rice genetics but also opens new possibilities for breeding climate-resilient rice varieties to meet future challenges.
