Synchronization Induction Based on Precise Identification of Cell Cycle Progression to Enhancing Polyploid Induction

Asynchrony in the cell cycle is a critical limiting factor in the efficiency of polyploid induction. While cell cycle inhibitors can increase the proportion of cells suitable for chromosome doubling, efficient polyploid induction through synchronization requires precise identification of cell cycle progression. The present study, flow cytometry and EdU fluorescence labeling were used to precisely track the cell cycle progression of differentiated explants during in vitro culture. Results showed that the increase in the S phase began two days after differentiation, while the G2/M phase started on day four. Based on this, optimal treatment time points for synchronization were identified. Comet assays and other techniques were used to determine the appropriate concentration (1.5 mM) and duration (24 hours) of 5-aminouracil, which narrowed down the range of subsequent orthogonal experiments. This optimization significantly (p < 0.05) improved synchronization efficiency and increased the tetraploid induction rate to an average of 40.90%. These findings demonstrate that by precisely identifying key cell cycle phases, synchronization techniques can be efficiently optimized to enhance polyploid induction. Our findings offers a systematic method for improving breeding efficiency in woody plants and could advance the development of more efficient polyploid induction systems in plant breeding.