Abstract: In this paper， cryopreservation procedure of Guangfeng medicinal yam shoottip by encapsulationvitrification would be optimized by the method of plant tissue culture， and the genetic stability of regenerated plantlets after cryopreservation would be tested with AFLP molecular markers and flow cytometry methods. At the same time， this cryopreservation procedure by encapsulationvitrification would be applied to other local varieties of Jiangxi yam， in order to lay the theoretical and technical foundation for longterm conservation of genus Dioscorea germplasm. The results showed that: The better preculture time of Guangfeng medicinal yam shoottips was 5 d， the better sucrose concentration in preculture medium was 075 mol·L-1; The better loading time was 40 min; The better dehydration temperature was 0 ℃， the better dehydration time was 60 min; 7day dark culture could significantly improve the survival rate of shoottips after cryopreservation. At last， the genetic stability of regenerated plants was detected by AFLP molecular marker and flow cytometry （FCM）， and no abnormal bands and chromosome ploidy changes were found. At the same time， no significant variation of stomatal parameters of leaves was observed. The cryopreservation technique was used in other genotypes of Jiangxi yam， the survival rate was about 40%-85%. Therefore， cryopreservation procedure by encapsulationvitrification could guarantee the genetic stability of Jiangxi yam germplasm resources. The results of this study provided a certain technical support for the establishment of cryopreservation bank of Jiangxi yam germplasm resources.

Key words: Jiangxi yam, shoottip, encapsulationvitrification, cryopreservation, genetic stability