The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activities that are involved in the pathway ofstarch-sugar metabolism aiming at identifying the main factors that influence the chipcolor. The results showed that low temperature in storage was a main factor thataccelerated the accumulation of RS of the stored tubers and a very significant linearrelationship existed between RS content and chip color index (CCI) of the tubers. Furtheranalysis elucidated that when tubers stored at 4℃, the activities of ADP glucosepyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase(SuSy) were negatively exponential to the RS content significantly while that of acidinvertase and alkaline invertase was significantly linear to RS content. It suggestedthat these enzymes could play main roles in the cold sweetening of potato tubers throughregulating starch-sugar metabolism.
