The Change Of Anthocyanin And Sugar And Acid In Peach Fruit And The Effect Of Bagging On Them

To examine the variations of anthocyanin, sugars and acid contents in peach and the influences affected by bagging measurement during different fruit development stages, anthocyanin, sugars and acid contents were determined by high-performance liquid chromatography (HPLC), the phenylalanine ammonia-lyase (PAL) and UDP glucose-flavonoid-3-o-glycosyltranfe-rase (UFGT) activities were also assayed, the results were showed as follows:1. Anthocyanin accumulation in "Huyou 007" nectarine exhibited an increase-decrease-increase variation trend, in red juicy peach "Hongfeng" began at 20d before harvest, whereas in yellow-white juicy peach "Qingshui" began at 5d with little amount.2. Relations between anthocyanin concentration in peach peel and sugars, acid concentration in peach flesh varied with peach cultivars. Anthocyanin concentration in "Huyou 007" and "Hongfeng" had a significant negative correlation with fructose and glucose in peach flesh but a significant positive correlation with sucrose, while in "Qingshui" had a positive correlation only with sucrose in peach skin.3. At rapid coloration stage, acid content in flesh decreased and in peel increased, which suggested that the acid content increment in peel might have close relations to anthocyanin synthesis in skins.4. PAL is not a key enzyme for anthocyanin synthesis, UFGT activity had a certain relation to anthocyanin synthesis in nectarine but no obvious relations in juicy peach.5. Bagging could restrain anthocyanin accumulation in peach peel whereas debagging could restore anthocyanin synthesis. After debagging, anthocyanin concentration in "Huyou 007" and "Hongfeng" were lower but in "Qingshui" was higher than that of control.6. Bagging and debagging had more complex influences to sugar content of juicy peach. There were no corresponding relations of sugar content and anthocyanin variation in peach skins. 7. The effects of bagging on acid content in peach fruit varied with peach cultivars. Bagging increased acid content of juicy peach peel, debagging decreased it. There is a closely correlation between anthcyanin and acid in Hongfeng cultivars. Bagging had no effect on acid content of nectarine flesh but increased acid content of juicy peach flesh. Debagging decreased acid content of peach flesh.8. Bagging could affect PAL and UFGT activities in peach peel, which indicated that PAL and UFGT had relations to anthocyanin synthesis.