Variation Among High Molecular Weight Subunits of Glutenin Detected by Capillary Electrophoresis

Capillary electrophoresis (CE) in conjunction with a selective precipitation procedure, was used to reveal biochemical variation amongGlu-1 HMW-glutenin subunits in wheat cultivars. The heterogeneity that was observed parallelled that recognized previously using SDS-PAGE, although some differences in relative mobility of protein bands were observed. Modifications of the CE method introduced in this paper allow the resolution of all HMW-glutenin subunits commonly found in wheat cultivars worldwide. On comparison of the results presented in this paper with those in current literature the inclusion of the precipitation step in the preparation of the HMW-glutenin subunits for CE analysis appears to give cleaner samples, with fewer interfering gliadin and LMW-glutenin subunits. The technique could be used, in conjunction with SDS-PAGE and/or RP-HPLC, in breeding programs to confirm the HMW-glutenin subunit composition of parents and promising selections and/or to establish the presence of «unusual» HMW-glutenin subunits. When glutenin subunits from two New Zealand cultivars were analysed qualitatively, Otane, a good breadmaking cultivar, showed relatively higher concentrations of HMW-glutenin subunits than did Karamu, a poor bread making cultivar, closely parallelling results obtained previously for these cultivars using RP-HPLC.