Tocopherols, tocotrienols and fatty acids as indicators of natural ageing in Pinus sylvestris seeds

During long-term storage, Scots pine ( Pinus sylvestris L.) seeds are susceptible to ageing, leading to declined vigour and poor germinability. To characterize biochemical changes associated with this ageing, vitamin E and fatty acid compositions of Scots pine seeds stored for 3-31 years were analysed. The seeds contained seven homologues of the vitamin E family: alpha-, beta-, delta- and gamma-tocopherols (T) and alpha-, delta- and gamma-tocotrienol (T3). The major tocopherol was gamma-T, constituting on average 62.1% of total vitamin E. Total vitamin E concentration was markedly lower in older seeds, e. g. 21-year-old seeds contained 52% less vitamin E than the reference for high-quality seed. The a- T concentration was affected the most by seed age, whereas the gamma-T concentration decreased more gradually and the concentrations of the other E vitamers seemed to remain relatively constant during natural ageing. Ageing also induced changes in the fatty acid composition of the seeds, e. g. a 29.6% reduction in the unsaturation/saturation ratio. These biochemical changes were associated with decreased germinability and increased electrolyte leakage.