Hybrid seed production hinges on male sterility systems to manage pollination. While traditional three-line systems are effective, they are often complex and labor-intensive. Two-line systems, which utilize thermosensitive or photoperiod-dependent male sterility, offer broader applicability but are prone to instability due to environmental fluctuations. These challenges underscore the urgent need for a more reliable and manageable two-line system for hybrid breeding.
Conducted by researchers at the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, this study (DOI: 10.1093/hr/uhad218) was published on October 27, 2023, in Horticulture Research. The team used CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeat) to edit Oxophytodienoic acid reductase 3 (OPR3) genes in Brassica napus, creating male-sterile lines that can regain fertility through jasmonate treatment. This development marks a major leap forward in hybrid seed production, offering a more stable and controllable system for breeders.
The study introduced a novel two-line pollination control system by mutating two OPR3 homologs in Brassica napus using CRISPR/Cas9. The edited plants exhibited complete male sterility, which could be reversed with methyl jasmonate (MeJA) treatment. This method not only ensured stable male sterility but also allowed precise fertility control, addressing the instability issues of conventional two-line systems. Hybrids derived from these sterile lines demonstrated significant heterosis, validating the system's efficiency. The technology is straightforward and adaptable, with broad potential applications across other Brassica species, streamlining hybrid seed production and boosting agricultural efficiency.
Dr. Hongtao Cheng, a principal researcher of the study, remarked, “This breakthrough provides a novel route for stable and efficient hybrid seed production in rapeseed and other Brassica crops. CRISPR technology enables precise control over male sterility and fertility, a critical step towards sustainable agriculture and future crop improvements.”
This CRISPR-based two-line system for rapeseed hybrid production holds significant potential for expanding agricultural applications. The approach can be adapted to other Brassica species, potentially transforming hybrid breeding across diverse crops. By enhancing the stability and efficiency of hybrid seed production and reducing dependence on environmental factors, this technology paves the way for more resilient and sustainable agricultural practices worldwide.
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References
DOI
10.1093/hr/uhad218
Original Source URL
https://doi.org/10.1093/hr/uhad218
Funding information
This work was supported by the Agricultural Science and Technology Innovation Project (CAAS-ZDRW202105), the Sci-Tech Innovation 2030 Agenda (2022ZD04009), the National Key Research and Development Program of China (2022YFD1200804), Key Research Projects of Hubei Province (No. 2021EHB026 and 2022BBA0039), and the Fundamental Research Funds for Central Non-profit Scientific Institution (No. 1610172020001).
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number two in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.