Coronatine Induces an Accumulation of Anthocyanin and Starch in Purple-fleshed Sweetpotato(Ipomoea batatas Lam.)

[Objective]The objective of this research was to examine the effects of COR on anthocyanin and starch content in storage roots of two PFS genotypes,and to explore the relationships between anthocyanin synthesis and starch accumulation.[Method]A field experiment was carried out to determine the changes in yield components,yield,contents of anthocyanin and starch,activities of phenylalanine ammonia-lyase(PAL)and adenosine 5-diphosphate glucose pyrophosphorylase(AGPase)in two genotypes of PFS(Ipomoea batatas L.,var.‘Ayamurasaki’and‘Jishu18’).[Result]The application of COR significantly increased starch and anthocyanin content in storage roots of Jishu18 across developmental stages by inducing the activities of PAL and AGPase,and finally enhanced yield by promoting fresh weight of storage roots.Ayamurasaki was insensitive to treatment with COR although its PAL activity temporally increased.The starch and anthocyanin content of Aya,and the anthocyanin content of Jishu18 increased progressively across developmental stages with or without COR application,but the starch content of Jishu18increased initially,then decreased before increasing again without application of COR.Treatment with COR reduced downward trend of starch accumulation in Jishu18.Thus,the effect of COR on accumulation of anthocyanin and starch in storage roots of PFS differs according to genotypes.[Conclusion]The application of0.05μmol/L COR may increase starch and anthocyanin content in PFS genotypes with lower starch and anthocyanin content in storage roots.