Effects of deficit irrigation on accumulation of sugar and activity of sugar metabolism-related enzymes of Lycium barbarum L.

A study was conducted on the effects of water deficit on accumulation of sugar and activity of sugar metabolism-related enzymes of Lycium barbarum through controlling irrigation amount to keep the soil water at different levels(T1,18.20%;T2,19.50;T3,20.60%;T4,22.40%;T5,23.50%).The results showed that the 100-grain weight presented a descending trend with the intension of water stress,and it was significantly lower in T5 than that in other treatments.The hexose content(glucose and fructose) of Lycium barbarum L.presented a trend of escalation through the whole fruit development,and the sucrose accumulation declined gradually.The content of hexose and sucrose in each treatment had significant difference in mature stage,and it was significantly higher in T1 and T2 than in T5.The invertase activity sustained at a high level,and showed a trend of rise first,then fall.The decreased invertase enzyme activity is beneficial to sugar accumulation.The activity of sucrose synthase and sucrose phosphate synthase was low and showed a decreased trend.Synthase activity showed an uptrend along with the intension of water stress,which was consistent with sucrose accumulation trend.Water deficit increased hexose content and improved fruit quality,however,serious water deficit decreased fruit yield.