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

Abstract

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: α-, β-, δ- and γ-tocopherols (T) and α-, δ- and γ-tocotrienol (T3). The major tocopherol was γ-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 α-T concentration was affected the most by seed age, whereas the γ-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.

Keywords:

• Germinability
• Scots pine
• vitamin E

Financial support for this work was generously provided by the Foundation for Research in Natural Resources in Finland.