In the heart of China, scientists are unlocking the secrets of rice, the world’s most important food crop. Their work could revolutionize agriculture, particularly in the energy-intensive rice sector, by optimizing yield and adaptability. At the forefront of this research is Qingmei Su, a scientist from the State Key Laboratory of Rice Biology and Breeding at the China National Rice Research Institute and the State Key Laboratory of Molecular Developmental Biology at the Chinese Academy of Sciences.
Su and her team have been delving into the genetic intricacies of rice, focusing on four key genes: Ghd7, Hd3a, RFT1, and Gn1a. Their findings, published in the journal ‘Crop Journal’ (translated from ‘Zhongzhi Xuebao’), offer a new strategy for molecular breeding that could significantly enhance grain yield and adaptability in rice.
The team’s research reveals that the interplay between these genes significantly influences the heading date—the time when the plant starts to flower—and grain yield. Under long-day conditions, the gene Hd3a promotes heading while negatively regulating plant height and grain number. In contrast, Ghd7 positively regulates heading date, plant height, and grain number by inhibiting both Hd3a and RFT1. However, this effect varies under different photoperiods, with Ghd7’s influence weakening under short-day conditions.
“Understanding these genetic interactions allows us to fine-tune the heading date and grain yield,” Su explains. “This is crucial for adapting rice to different ecological regions and improving overall yield.”
The researchers found that increasing Ghd7 expression leads to later heading and increased grain number, but only up to a certain point. Once the heading date exceeds 94 days, the grain number no longer increases. This discovery is pivotal for breeders aiming to optimize yield without compromising the plant’s lifecycle.
Moreover, the gn1a allele was found to increase grain number by 16.5% to 42.5%. When combined with elite alleles from Ghd7, Hd3a, RFT1, and Gn1a, the grain number increased by up to 240.9%. This finding underscores the potential of elite gene combinations in enhancing rice yield.
The team proposes a new breeding strategy that leverages these genetic insights. Under long-day conditions, they recommend using the Ghd7Hd3aRFT1gn1a combination, while under short-day conditions, the Ghd7hd3aRFT1gn1a combination is suggested. This strategy has already shown promising results, improving the yield of the high-quality Northeast variety Kongyu 131 (KY131) by 69.1% in Beijing and 93.7% in Hainan.
The implications of this research are far-reaching. For the energy sector, which is heavily invested in rice production, this could mean more efficient use of resources and reduced environmental impact. By optimizing yield and adaptability, farmers can produce more rice with less energy, contributing to a more sustainable agricultural system.
This study, published in ‘Crop Journal’, not only advances our understanding of rice genetics but also paves the way for innovative breeding strategies. As we face a future with a growing population and changing climate, such advancements are crucial for ensuring food security and sustainability. The work of Su and her team is a testament to the power of scientific research in shaping the future of agriculture.