Phytic acid (Christian Möllers)

The high nutritional value of oilseed rape (Brassica napus L.) and rapeseed meal is restricted amongst others by its relatively high concentration of phytic acid. Phytate, the salt of phytic acid, myoinositol-hexakisphosphate (IP6), is the main storage form of phosphorus in seeds. Phytates have a low digestibility for monogasters, reduce the resorption of calcium, iron, magnesium, zinc and other trace elements, and form complexes with basic amino acids. As a result, large amounts of phytate-P are transferred with the manure to the environment, where it may contribute to the eutrophication of soils and waters. Supplementing diets with phytase - as already practised in intensive livestock areas - and growing cultivars with low levels of phytic acid in their seeds might help to reduce this problem. Mutant forms with reduced phytic acid content have been reported in other field crop species but so far not for oilseed rape.

Current research work in this field is related to
(a) analysis of genetic variation among winter oilseed rape genotypes for total phosphorus and phytate content in the seeds, (b) development of NIRS calibrations for seed total phosphorus and phytate content and (c) identification of mutant lines with reduced phytate content