Effects of Freeze‐Drying on Permeability and Respiration of Germinating Lily Pollen

The germination of lily pollen ( Lilium longiflorum cv. Ace) was impaired by freeze‐drying. This loss of viability was associated with a modified pattern of respiration and an increased leakage of soluble carbohydrates, phosphate, and ninhydrin‐positive material into the culture medium. 2,4‐Dinitro‐phenol, (DNP), an uncoupler of oxidative phosphorylation showed a decreased ability to stimulate O 2 uptake in freeze‐dried pollen. The altered viability, respiration, and permeability resulted from drying under vacuum and not the initial freezing of the pollen. Mature lily pollen contained approximately 0.3 “Ai phosphate, of which 15 % was inorganic phosphate and about 50 %> was acid soluble organic phosphate of unknown identity.