GROWTH TEMPERATURE AND LIPID-COMPOSITION OF CUCUMBER GENOTYPES DIFFERING IN ADAPTATION TO LOW-ENERGY CONDITIONS

Total lipid, phospholipid and fatty acid composition of leaf and root as well as leaf PG fatty acid composition were determined for two low temperature tolerant inbred lines of cucumber (Cucumis sativus L.) and a control variety, all grown at two temperature regimes. Hardly any genotypic differences were observed at either temperature regime. At low temperature the degree of unsaturation of fatty acids increased. There was no correlation between fatty acid composition of PG and genotypical differences in growth. However, at low temperature the inbred lines reacted by lowering the amount of PG without changing the proportion of relatively saturated PG fatty acids, while the control variety reacted by lowering the proportion of relatively saturated PG fatty acids at a stable PG content. In general, no valid selection criterion based on lipid composition was found, indicating that lipid composition at present shows no promise as a suitable selection criterion for genetic adaptation to low temperature conditions.