Dynamic changes of starch accumulation and enzymes relating to starch biosynthesis of kernel during grain filling in waxy and non-waxy winter wheat.

Two different wheat varieties were used to study the dynamic changes of the accumulations of amylose and amylopectin,starch accumulation rate and the activity changes of key enzymes involved in starch biosynthesis in the kernel during grain filling.The results showed that the beginning biosynthesis of amylopectin was earlier than that of amylose,based on the result of amylose appeared at 7 days after anthesis in non-waxy wheat,meanwhile,amylopectin appeared before 7 days after anthesis and the waxy wheat varieties only had amylopectin.The changes of amylose and amylopectin accumulating rates of both waxy and non-waxy wheat varieties showed a single peak curve.The accumulation courses of both amylopectin and amylose were well fitted to the logistic equation by relating amylopectin and amylose contents against days post anthesis.The simulation parameters revealed that the higher contents of amylopectin and amylose resulted from greater accumulation rate and mean accumulation rate,but accumulation duration probably played a less important role for them.The results indicated that the activity changes of the adenosine diphosphorate glucose pyrophrylase(AGPP),soluble starch synthase(SSS),granule-bound starch synthase(GBSS) and starch branching enzyme(SBE) were all in the pattern of a single-peak curve,and peaked at 20～25 days after anthesis.The accumulation rate of amylose was significantly or highly significantly correlated with the activities of AGPP,SSS,GBSS and SBE,the accumulation rate of amylopectin was significantly correlated with the activity of SSS,and the accumulation rate of starch was significantly or highly significantly correlated with the activities of AGPP and SSS.