Yaniv, Z., Department of Medicinal Spice and Aromatic Plants, A.R.O., The Volcani Centre, Bet Dagan, Israel
Ranen, C.
Levy, A.
Palevitch, D.

The oil content and yield of evening primrose (Oenothera lamarckiana L.) seeds decreased significantly at high temperatures (32 °C) compared with lower ones (25 °C and below), under controlled growing conditions. Moreover, the fatty acid composition of the seed oils was also affected by the temperature regime. Higher oleic acid levels and lower linoleic and γ-linolenic acid (GLA) levels were characteristic of the seeds developed at higher temperatures. The opposite trend was observed at lower temperatures. In field experiments, seeds of O. lamarckiana plants sown in autumn contained lower oleic acid levels, and higher linoleic acid and GLA levels than seeds of spring plantings. This effect was also demonstrated for seeds developed on the same stem inflorescence under increasing temperatures during the season in the field. Changes in fatty acid composition during various stages of seed development were observed. © 1989 Oxford University Press.