In the heart of Thailand, researchers at the Rice Science Center of Kasetsart University have made a significant breakthrough that could reshape the future of rice cultivation, particularly for upland varieties. Led by Thanyakorn Rongsawat, a team of scientists has identified key genetic regulators that could enhance the tillering capacity of upland rice, making these resilient varieties more suitable for lowland environments where yields are typically higher.
Tiller number is a critical factor in rice yield, as it directly influences the plant’s productivity. Upland rice varieties, known for their adaptability to fluctuating water availability, often fall short in lowland ecosystems due to their limited tillering capacity. To address this challenge, Rongsawat and his team employed QTL-seq analysis, a powerful tool for identifying quantitative trait loci, using populations derived from a cross between a high-tillering lowland indica parent (PTT1) and a low-tillering upland tropical japonica line (NDCMP49).
The study, published in the journal *BMC Plant Biology* (which translates to “Biological Research on Plant Biology” in English), revealed two major QTLs associated with tiller number on chromosomes 4 and 5, designated as qTN4 and qTN5. Through candidate gene analysis, the researchers pinpointed NAL1 and OsOFP19 as the putative genes underlying these loci.
“Our findings not only advance our understanding of the genetic regulation of tillering in rice but also provide practical tools for breeders,” Rongsawat explained. The team validated the role of NAL1 using CRISPR-Cas9 knockout mutants, confirming its function as a negative regulator of tillering. Plants with mutations in NAL1 exhibited significantly increased tiller numbers compared to the wild type.
Moreover, the study demonstrated the additive effect of qTN4 (NAL1) and qTN5 (OsOFP19), suggesting that these genes can be pyramided in breeding programs to enhance tiller number and overall yield. Functional KASP markers for NAL1 and OsOFP19 were developed and validated, offering a robust tool for marker-assisted selection (MAS).
The implications of this research are profound for the agricultural sector. By improving the tillering capacity of upland rice varieties, farmers can achieve higher yields in lowland conditions, thereby increasing food security and economic returns. The development of functional KASP markers also streamlines the breeding process, enabling more efficient and targeted selection of desirable traits.
As the global population continues to grow, the demand for food security and sustainable agricultural practices becomes ever more pressing. This research not only addresses these challenges but also paves the way for future innovations in crop improvement. By harnessing the power of genetic regulation, scientists and breeders can develop rice varieties that are not only resilient to environmental stresses but also highly productive.
In the words of Rongsawat, “This is just the beginning. Our work provides a foundation for further exploration and application of genetic tools in rice breeding, ultimately benefiting farmers and consumers alike.” The future of rice cultivation looks promising, with genetic research leading the way to more sustainable and productive agricultural practices.