Novel labor-saving strategy for hybrid rice seed production

Rice is one of the main food crops globally. With the continuous increase in population and the decrease in effective arable land area, increasing rice yield is necessary to ensure the food supply. Hybrid rice, which can combine the excellent traits of both parents, may exhibit greater growth potential, higher yield and better stress resistance. However, hybrid rice seed production requires manual flag leaf cutting to improve pollination, which is labor‑intensive and panicle-damaging.

In a new study published in the Journal of Integrative Agriculture, a team of researchers from Rice Research Institute ath the Anhui Academy of Agricultural Sciences/Key Laboratory of Rice Germplasm Innovation and Molecular Improvement developed a labor-saving strategy for hybrid rice seed production using a small flag leaf mutant, ym66, derived from radiation-mutagenized indica rice 93-11.

“The ym66 mutant, derived from irradiated 93‑11, has extremely short (~80% reduction), narrow (~85%), stiff flag leaves with fewer veins, compressed vascular bundles, and programmed cell death, along with altered internodes and smaller panicles,” shares senior and co-corresponding author Dahu Ni.

Genetic mapping and sequencing identified a 6‑bp insertion in the first exon of OsGATA15 in ym66. CRISPR knockout of OsGATA15 replicates the small flag leaf phenotype, while overexpression rescues it, confirming the gene's role.

“Using ym66, the restorer line NP27 was developed. It retains short, narrow flag leaves and compact plant type, with improved grain weight, stem thickness, and adequate pollen,” says Ni.

In seed production tests with sterile lines 1892s and 20y394, NP27 without leaf cutting achieved yields comparable to traditional cutting‑based methods, and produced F₁ hybrids with better plant architecture and grain quality.

“NP27 provides a “leaf‑cutting‑free” solution, saving labor and reducing seed production costs by 150–180 CNY per mu, while also improving hybrid rice traits,” adds Ni.

Contact Authors:

Correspondence Dahu Ni, E-mail: dahuni1974@163.com; Fengshun Song, E-mail: sfs108@163.com

Funder:

This research was supported by the Key Research and Development Program of Anhui Province, China (2023h11020006 and 2023n06020006), the National Natural Science Foundation of China (32301738), the Science and Technology Innovation and Breakthrough Plan Program of Anhui Province, China (202423m10050002), and the Jianghuai Granary Program, China (2026YL009).

Conflict of Interest:

The authors declare that they have no conflict of interest.

See the Article:

Quan G et al. 2026. A novel labor-saving strategy for hybrid rice seed production. Journal of Integrative Agriculture, 25(6): 2623–2626.