Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing Institute of Vegetable Science, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
State Key Laboratory of Plant Genomics, National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
Theor Appl Genet. 2023 Aug 22;136(9):197. doi: 10.1007/s00122-023-04428-5.
A practical approach for the rapid generation and feasible application of green hypocotyl male-sterile (GHMS) tm6 dfr lines in tomato hybrid breeding was established. Male sterility enables reduced cost and high seed purity during hybrid seed production. However, progress toward its commercial application has been slow in tomato due to the disadvantages of most natural male-sterile mutants. Here, we developed a practical method for efficient tomato hybrid seed production using a male-sterile system with visible marker, which was rapidly generated by CRISPR/Cas9-mediated gene editing. Two closely linked genes, TM6 and DFR, which were reported to be candidates of ms15 (male sterile-15) and aw (anthocyanin without) locus, respectively, were knocked out simultaneously in two elite tomato inbred lines. Mutagenesis of both genes generated green hypocotyl male-sterile (GHMS) lines. The GHMS lines exhibited male sterility across different genetic backgrounds and environmental conditions. They also showed green hypocotyl due to defective anthocyanin accumulation, which serves as a reliable visible marker for selecting male-sterile plants at the seedling stage. We further proposed a strategy for multiplying the GHMS system and verified its high efficiency in stable male sterility propagation. Moreover, elite hybrid seeds were produced using GHMS system for potential side effects evaluation, and no adverse influences were found on seed yield, seed quality as well as important agronomic traits. This study provides a practical approach for the rapid generation and feasible application of male sterility in tomato hybrid breeding.
建立了一种快速生成和可行应用绿色下胚轴雄性不育（GHMS）tm6 dfr 系的实用方法，用于番茄杂种优势育种。雄性不育可降低杂种种子生产过程中的成本并提高种子纯度。然而，由于大多数天然雄性不育突变体的缺点，番茄在其商业应用方面进展缓慢。在这里，我们开发了一种使用具有可见标记的雄性不育系统进行高效番茄杂交种子生产的实用方法，该系统是通过 CRISPR/Cas9 介导的基因编辑快速产生的。我们同时敲除了两个紧密连锁的基因 TM6 和 DFR，它们分别被报道为 ms15（雄性不育 15）和 aw（无花青素）基因座的候选基因，这两个基因位于两个优秀的番茄自交系中。两个基因的突变产生了绿色下胚轴雄性不育（GHMS）系。GHMS 系在不同的遗传背景和环境条件下表现出雄性不育。由于花青素积累缺陷，它们还表现出绿色下胚轴，这可以作为在幼苗阶段选择雄性不育植物的可靠可见标记。我们进一步提出了一种繁殖 GHMS 系统的策略，并验证了其在稳定雄性不育传播中的高效率。此外，使用 GHMS 系统生产了优良的杂交种子，用于潜在的副作用评估，发现对种子产量、种子质量以及重要的农艺性状没有不良影响。本研究为番茄杂种优势育种中雄性不育的快速生成和可行应用提供了一种实用方法。
