QUALITATIVE AND QUANTITATIVE VARIATION AMONG HIGH-MOLECULAR-WEIGHT SUBUNITS OF GLUTENIN DETECTED BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Reversed-phase high-performance liquid chromatography (RP-HPLC), in conjunction with a selective precipitation procedure, was used to reveal biochemical variation among Glu-B1 high molecular weight (HMW) glutenin subunit 8 and among Glu-A1 HMW-glutenin subunit 2** in different New Zealand wheat cultivars. This heterogeneity was not recognized by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The technique could be used in breeding programmes to confirm the HMW-glutenin subunit composition of parents and promising selections. Quantitative analysis was carried out of glutenin subunits from the New Zealand cultivar Otane, which is of good breadmaking quality and has HMW-glutenin subunits 2, 2*, 7, 8 and 12, and Karamu, which is of poor breadmaking quality and has HMW-glutenin subunits 2, 7, 8 and 12. Although the cultivars had similar levels of storage protein, the good quality Otane had greater absolute and relative concentrations of the HMW-glutenin subunits associated with good baking performance. In addition, Otane had a greater total concentration of HMW-glutenin subunits than Karamu, both in terms of the summed HMW-glutenin subunit peak areas and as a relative proportion of the total storage protein present. Such quantitative relationships may prove to be useful for quality prediction. © 1991, Academic Press Limited. All rights reserved.