Seed set with potato pollen stored at low temperatures

Pollen from several tuber-bearingSolarium species was exposed to liquid nitrogen (LN2) and tested forin vitro germination and seed set capabilities. Pollen placed in LN2 or in the vapor phase above LN2 retained high levels ofin vitro germination after 11 to 24 months of storage. This pollen also set significant numbers of seed. Brief drying of the pollen over anhydrous CaCl2 prior to freezing increased survival in most samples. Rehydration of dried, LN2 treated pollen prior toin vitro germination testing was necessary to obtain maximum germination percentages. Rehydration, however, was not necessary for seed set, and in several samples decreased seed set compared to pollen that was not rehydrated. Storage of pollen from tuber-bearingSolanum species in LN2 appears to be practical for maintaining pollen for crossing and for germplasm preservation.