Individual and interactive effects of genetic background and environmental conditions on amount and size distribution of polymeric proteins in wheat grain

Bread-making quality of wheat flour is influenced by wheat storage proteins. The percentage of sodium dodecyl sulphate (SDS)-unextracted polymeric proteins in total polymeric proteins (% UPP), as one important factors determining bread-making quality, is largely influenced by the individual and interactive effect of genetical background and environmental conditions. Four spring wheat cultivars were grown in green house. Two of the cultivars have high molecular weight glutenin subunits 5+10 while the other two have 2+12. Four different nitrogen regimes and two different temperature levels (distinguished as low and high temperature) were used. The results highlighted the importance of interactive influence of cultivars, nitrogen regimes and temperature levels for creating differences in the amount of % UPP during grain maturation period (GMP) and at maturity. The shift to end up with either high or low % UPP at maturity happened early during GMP (around 12 days after anthesis). Influences of cultivars on % UPP was found early during the GMP while influences of temperature and nitrogen regimes were seen much later during the GMP. The results will help in understanding the relationship between quality parameters of wheat flour and how these are influenced by different environmental and genetic factors.