Study on the activity of enzymes involved with starch synthesis and accumulation in the grain of two types of wheat cultivars.

In order to provide reference to genetic improvement of wheat quality,the activity changes of enzymes involved in starch biosynthesis and the characteristics of starch accumulation in grains were investigated,and the relationship between them were analysed in four wheat cultivars as two groups,including Ningchun 16 and Annong 9912(lower starch content in grain) and E28 and Xinchun 24(higher starch content in grain).Correlation analysis indicated that there were obvious difference between lower starch content and higher starch content genotypes in starch about starch accumulating rate and kernel filling rate.The accumulation courses of amylopectin,amylose and total starch were well fitted to the logistic equation by relating amylopectin,amylose and total starch contents against days after pollination(DAP).The simulation parameters revealed that the higher contents of amylopectin and amylose resulted from earlier initiating accumulation time and greater accumulation rate.The activities of soluble starch synthase(SSS),granule bound starch synthase(GBSS),starch branching enzyme(SBE) and starch debranching enzyme(DBE) changed in the pattern of a single peak curve during grain filling,peak value was between 12 d and 24 d;The accumulation rate of amylose was highly significantly correlated with the activities of GBSS,and the accumulation rate of amylopectin was significantly or sharp significantly correlated with the activities of SSS and SBE;and the accumulation rate of starch was not correlated with the activities of starch debranching enzyme(DBE).Correlation analysis among activities of the starch synthesis enzymes indicated that starch debranching enzyme(DBE) of higher starch content genotype was significantly or sharp significantly correlated with the activity of SSS、SBE and GBSS,which were interacted in starch biosynthesis.