关键词: ‘巨玫瑰’葡萄, 赤霉酸, 噻苯隆, 涩味

Abstract: In order to explore the effects of exogenous gibberellic acid (GA3), thidiazuron (TDZ) and their combination with different concentrations on the astringency of ‘Jumeigui’ grape berry skin. Taking ‘Jumeigui’ grape as material，grape clusters were evenly dipped with GA3 (T1: 12.5 mg/kg GA3; T2: 25 mg/kg GA3; T3: 50 mg/kg GA3), TDZ (T4: 1.25 mg/kg TDZ; T5: 2.5 mg/kg TDZ; T6: 5 mg/kg TDZ) or their combination (T7: 25 mg/kg GA3+2.5 mg/kg TDZ) during the early stage of fruit physiological drop and the early stage of the fruit enlargement. Astringent substance content was analyzed regularly. The tannin distribution of fruit was observed by paraffin section. The results showed that tannin cells in the peel treated with different concentrations of GA3 or the combination were sparsely distributed. While tannin cells in the peel treated with different concentrations of TDZ were densely distributed, with more layers and deeper colors. The content of soluble tannin, insoluble tannin, total tannin, flavonoids, and total phenol of ‘Jumeigui’ grape fruit skin treated with different concentrations of GA3 or combination were less than that of control, and the anthocyanin content was higher than that of control. However, the content of soluble tannin, insoluble tannin, total tannin, flavonoids, total phenol and anthocyanin of ‘Jumeigui’ grape fruit skin treated with different concentrations of TDZ were all higher than that of control. The result of principal component synthetic evaluation showed that the order of the astringent taste compounds of eight treatments was T6＞T4＞T5＞CK＞T7＞T2＞T3＞T1. It showed that GA3 treatments had the best effect on reducing the astringency of grape peel, and the concentration of 12.5 mg/kg GA3 treatment was the best, followed by the mixed solution treatment. TDZ treatments were not conducive to reducing the astringency of grape peel. The above results provided a theoretical basis for improving the astringency of fresh grape berries by using plant growth regulators.

Key words: ‘Jumeigui’ grape, GA3, TDZ, astringency taste compound