Effect of sulphur application on lipid, RNA and fatty acid content in developing seeds of rapeseed ( Brassica campestris L.)

Abstract

Changes in the contents of lipid, RNA and fatty acids were determined in the developing seeds of rapeseed ( Brassica campestris L. cv. Pusa Gold) grown with or without sulphur. In +S treatments, S was applied either as a single dose (T 2) or the same dose was split in two (T 3) or three (T 4) portions. Rapid accumulation of lipids started at 7 days after flowering (DAF) and continued until 35 DAF. Application of S increased the lipid content in the seeds from the initial stage. The maximum increase was observed, when S was applied in three portions. There was a positive strong co-relation between S and lipid content in the seeds. RNA content increased from 7 to 35 DAF, followed by a decline until maturity. Application of S increased the RNA content in the seeds, compared to control (T 1). Among the +S treatments, i.e. T 2, T 3 and T 4, the treatment T 4 resulted in the maximum increase in RNA of developing seeds. The fatty acid composition of the oil changed substantially during seed development. S application in three portions increased the oleic acid (18:1) content, and decreased the erucic acid (22:1) content over other treatments. This leads to a reduced 22:1/18:1 ratio and thus, improves the quality of oil. The ratio of erucic acid to oleic acid (22:1/18:1) is closely related to the N:S ratio in the seeds.