Tandem Mass Spectrometric Determination of Glycolipids in Wheat Endosperm: A New Tool for Breeders to Rank and Select Early Seed Generations

Abstract

Wheat breeding for end-use quality is enhanced by development and application of a selective and sensitive method for ranking early generation cultivars as part of the effort of generating desirable wheat lipids. A desirable wheat lipid, the increased concentration of which in hard wheat flour correlates positively with bread loaf volume, is digalactosyldiglyceride (DGDG). A mass spectrometric test for DGDG was applied to 100-mg samples of flour isolated from the F6 generation of hard winter wheats. The test enables prediction of desirable lipids in early generations so that decisions about the F6 progeny improve wheat breeding efficiency. Previous attempts to screen wheat cultivars for desirable glycolipids were constrained by sample size, lipid extraction and purification, and time. Here, we present flour glycolipid data obtained from individual wheat plants grown in short rows in two nurseries. The endosperm (100 mg) representing several kernels was exhaustively extracted with a total lipid solvent. Following isolation of the lipids and addition of an internal standard, the lipids were subjected to tandem mass spectrometry (MS–MS). The concentration of DGDG in the flour from five to seven kernels was found to vary by a factor of two within single nurseries. Thus, early generation lipid screening enables informed selection for this hard wheat quality indicator.