Objective  Viability of stored Chrysanthemum× morifolium pollens were determined for germplasm preservation.

  Method  Pollen viability of 10 chrysanthemum cultivars were determined by an in vitro germination method for medium selection. Viability of pollens stored in the selected medium at 4℃, −20℃ or −80℃ for 60 d and 120 d was monitored every 15 d. After a 120 d storage, hybridization pollination with the pollens was performed for fructification evaluation.

  Result  The medium for optimum pollen germination was ME₃ with the additions of 200 g·L⁻¹ PEG 4 000 and 6 g·L⁻¹ agar. All pollens stored in the chosen medium germinated with a significantly superior rate. The pollen viability decreased after 60d storage. Among the 10 chrysanthemum, Variety ‘5’, ‘52’, ‘64’, and ‘85’ had slower declining rates on the pollen viability but higher viability after the 120 d storage at −80℃ with full fructification upon pollination than the others. Of the 4 varieties, Variety ‘5’ had the highest pollen fructifying rate of 8 seeds per inflorescence on average.

  Conclusion  The medium for pollen germination and genotype of cultivar as well as the temperature and duration of storage could all affect the viability of the chrysanthemum pollens. On the optimally formulated medium at −80℃ for 120 d, the pollens from Variety ‘5’ maintained a high viability with full fructification at pollination for satisfactory chrysanthemum cross breeding.