In the course of a breeding programme for high-linolenic-acid linseed (oiWax, Linum usitatissimum L.) doubled-haploid hnes (DH-lines) of three F, hybrids were generated using an anther-culture technique. A total of 82 DH-hnes were generated and multiphed in 1993, of which 39 were suitable for testing in a repeated field trial in 1994. Yieid, fat content and fatty-acid composition were determined. The yield of the DH-lines was not significantly different from that of respective midparent values. Fatty-acid composition and fat content showed remarkable variation, and DH-lines exceeded cross parents in some cases for both fat content and linolenic-acid proportion. Superior DH-hnes surpassed mid-parent linolenic-acid-content values by 4.5% and fat content by 1.9%. The results indicate that anther culture is a useful tool in linseed breeding.

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Acyl lipids and their constituent fatty acids were studied in leaves, chloroplasts and bundle-sheath strands of the C4 plant Amaranthus paniculatus L. grown under normal and 4%-oxygen-containing atmospheres. In all fractions the major lipids were found to be monogalactosyldiacylglycerol, digalactosyldiacylglycerol, sulphoquinovo-syldiacylglycerol and phosphatidylglycerol. Significant quantities of phosphatidylcholine and phosphatidylethanolamine were restricted to leaves and bundle-sheath strands. All lipids, except phosphatidylglycerol where 3-trans-hexadecenoic acid was also present, contained palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. On a chlorophyll basis and compared with whole leaves, the amounts of phosphatidylcholine and phosphatidylethanolamine in bundle-sheath strands were considerably reduced. Three weeks after the change from a normal to a 4% atmospheric O2 level, the galactolipid content, particularly in the bundlesheath strands, was enhanced. There were no significant differences in the degrees of saturationunsaturation of total acyl lipid for the plants grown in the low oxygen and normal atmospheres, although under 4% O2 the phosphatidylglycerol contained an increased proportion of 3-trans-hexadecenoic acid at the expense of palmitic acid.

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