263 Selected Seed Treatments to Enhance Germination of Oil-bearing Oenothera Species

Abstract

The oil extracted from seed of selected accessions of Oenothera, also known as the wildflower evening primrose, has documented medical applications. Evening primrose oil contains from 0.0 to 12.0% gamma-linolenic acid (GLA) (C 18:3, delta 6, 9, 12). This unique fatty acid, which occurs in only a few plant species, can correct deficiencies in the delta 6 desaturase enzyme. Low levels of this enzyme prevent formation of the long chain fatty acids responsible for the production of prostaglandins and thromboxanes. Supplementation of the diet with evening primrose oil rich in GLA ensures adequate levels of these essential products. Inconsistent seed germination, poor emergence, and small seed size of accessions containing higher levels of GLA have limited commercial production of this crop. Currently, most producers establish their field through transplants. In this project, methods of improving seed germination have been explored. Seed coatings using diatomaceous earth were shown to facilitate handling and improve germination in the laboratory. Osmotic priming and red light exposure were also evaluated as means of improving germination.