Individual and combined effects of pre- and post-anthesis temperature on protein composition of two malting barley cultivars

The present study has investigated the individual and combined influence of pre- and post-anthesis temperatures and cultivars on the protein composition in barley grains. Two barley cultivars were grown in soil and hydroponic systems in daylight chambers with different pre- and post-anthesis temperatures. Size exclusion (SE)-HPLC was used to evaluate the protein composition in mature barley grains. The results showed that individual and interactive effects of pre- and post-anthesis temperatures and cultivar variations influenced protein composition in the barley grains. Pre-anthesis temperature greatly affected the amounts of total sodium dodecyl sulphate (SDS) extractable proteins (TOTE) and explained 30% of the variation in TOTE. The barley cultivars accounted for 20% of the variation in TOTE. Variation in malting barley cultivars was found to influence the SDS extractable small monomers (41% of the variation). Percentage of SDS un-extractable polymeric proteins in total amount of polymeric proteins (%UPP) was governed by post-anthesis temperature, accounting for 11% of the variation and cultivar differences accounted for 7% of the variation. Thus, the climatic conditions during the specific growing period and a choice of cultivars played a major role in determining the protein composition and ultimately the malting quality of spring barley.