Annual Variation in the Sterol Content of Digitalis purpurea L. Seedlings

Abstract

Seedlings from a single lot of D. purpurea L. seeds were germinated in batches for 13 mo. A total lipid extract was made which was resolved into esterified and unconjugated plus glycosylated sterol fractions. The amounts of sterol in each fraction and in the total were compared for seedlings germinated at different times of the years. The amount of esterified sterols reached a maximum value from March-June, and a low value from July-Jan. In Jan. a sharp increase began which lasted until March. Amounts of unconjugated and glycosylated sterols were elevated from March-June, low from July-Oct., and on the rise from Nov.-March. These data correlate with an annual cycle in seed germination. The phase of maximum sterol content of seedlings is followed by a period of null germination.