The relationship of starch metabolism to grain size in wheat

Abstract

The present investigation was aimed at determining the levels of important enzymes of starch metabolism at different stages of grain development in wheats differing in final grain size and starch content per grain, to ascertain whether these enzymes have some relationship with grain size and/or starch content. Active starch synthesis in these varieties started from 14 days onward and continued till 35 days after anthesis. Invertase was active only during initial stages of grain development. Sucrose-UDP-glucosyltransferase had maximum activity at the 14 and/or 21 day stage and was present throughout the period of grain development. UDP- and ADP-glucose pyrophosphorylases and amylase were most active during the period of active starch synthesis and at the same time tended to parallel grain size and starch content at different stages of grain development.