THE INFLUENCE OF THE GREENHOUSE-EFFECT ON WHEAT (TRITICUM-AESTIVUM L)GRAIN LIPIDS

There have been few studies conducted with the objective of investigat ing comprehensively the 'greenhouse effect' on wheat growth using fiel d-grown crops and even less on the effects on the lipid composition of harvested grains. Therefore, the aim of this study was to define any changes in wheat grain acyl lipids which could result from alterations in environmental growth conditions predicted to mimic the 'greenhouse effect'. Quantitative changes were recorded for both the non-starch a nd starch lipids. When supplied with low concentrations of nitrogen fe rtilizer, plants showed increased amounts of total grain lipids when g rown under an elevated (700 mu l l(-1)) carbon dioxide atmosphere. Inc reasing the ambient temperature by 4 degrees C, however, reduced the t otal lipid content of grains. Wheat plants treated with high concentra tions of nitrogen fertilizer accumulated less lipid compared to low ni trogen controls. Qualitative changes were also observed in the proport ions of non-starch and starch lipid classes. However, changes in total acyl composition were limited to starch grain acyl lipids, as a resul t of changes in atmospheric carbon dioxide, growth temperature and nit rogen fertilizer application. The alterations in wheat lipids observed are likely to affect the properties of the flour produced from the gr ains.