Pollen collection and viability-preserving storage techniques for male parent plants in hybrid rice

<bold>Objective</bold> The achievement of complete assisted pollination in hybrid rice seed production constitutes an effective approach to addressing the issue of flowering asynchrony during seed production and improving seed yield，while the efficient collection and preservation of pollen represent the core of this technology. <bold>Method</bold> This study systematically evaluated the efficiency of two pollen collection methods，the effects of different desiccants and their ratios to pollen，and drying temperatures on pollen viability preservation.Additionally，the optimal storage temperatures for varying periods and suitable revival methods after storage were identified.The research aims to establish an integrated technical framework for the entire process of paternal pollen collection，drying，storage，and revival in hybrid rice seed production. <bold>Result</bold> The results demonstrated that：（1）The pollen collection yield and pollen viability of Method（1）were significantly superior to those of the collection rack；it could collect 0.8 g of pollen within 8 minutes，which was twice the amount of the latter. The optimal pollen collection period was the first 3 days of the flowering cycle.（2）Silica gel proved superior to the other two tested desiccants，with a pollen-to-silica gel ratio of 1：2 yielding the best drying and viability preservation results.（3）The optimal pollen storage temperature varied with storage duration：10 ℃ was suitable for ultra-short-term storage（&lt;24 h），while -30 ℃ and -80 ℃ better preserved pollen viability during short-term storage （5-20 d）.For long-term storage（90 d），-80 ℃ yielded the highest viability.（4）Post-storage revival methods were temperature-dependent： room-temperature thawing（28 ℃）worked best for 4 ℃-stored pollen，tap-water rinsing（14-20 ℃）for pollen stored at -10 ℃/-20 ℃，and 38 ℃ water-bath thawing was optimal for -30 ℃/-80 ℃-stored pollen. <bold>Conclusion</bold> This study successfully established a comprehensive technical system for pollen collection，drying，storage，and thawing，which lays a solid foundation for achieving “fully-assisted pollination” in hybrid rice seed production.