Abstract:

As a major food crop and industrial raw material in China，sweet potato faces serious constraints to sustainable industrial development due to the intergenerational accumulation of viral diseases caused by its asexual propagation. Virus-free tissue culture technology is the core means for controlling viral diseases；however，the variety dependence of virus elimination efficiency，the risk of virus re-infection，and the lag in long-term preservation technology for tissue-cultured plantlets have become key bottlenecks limiting the continuous supply of elite germplasm. This paper systematically reviews the research progress on virus elimination and long-term preservation of tissue-cultured sweet potato plantlets，with a focus on integrating the characteristics and transmission mechanisms of mixed virus infections，diversified optimization pathways for shoot tip meristem culture，establishment of grading evaluation and propagation systems for virus-free plantlets，integrated application of virus detection technologies，and exploratory practices in cryopreservation. The review indicates that mixed infection of sweet potato viral diseases is common，and the coordinated control of vector insects is inseparable from the production of virus-free seedlings. The introduction of exogenous hormone regulation，development of variety-specific protocols，and incorporation of physical factors such as light quality have driven the evolution of virus elimination technology from single shoot tip culture to multi-factor synergistic optimization. The establishment of grading standards for virus-free plantlets and innovations such as mini-tuber seedling production have effectively improved transplant survival rates and year-round supply capacity. Virus detection has formed a combined strategy of preliminary screening and confirmatory testing，and is gradually being incorporated into standard procedures for variety promotion. Regarding long-term preservation，the limitations of traditional subculture are becoming increasingly prominent，and cryopreservation technologies，represented by the vitrification method，show application prospects；however，improving post-thaw survival rates and monitoring genetic stability remain core challenges that urgently need to be addressed. Current research is shifting from single-technology breakthroughs to systematic integrated innovation. Future efforts should focus on the original innovation of broad-spectrum antiviral strategies，the standardization of cryopreservation systems，and long-term monitoring of genetic stability of post-preservation materials，so as to promote the deep integration of advanced virus elimination technology and reliable preservation technology，thereby providing theoretical support for the high-quality development of the sweet potato seed industry and the safe conservation of germplasm resources.

Key words: sweet potato, virus elimination, tissue culture, virus detection, germplasm resources