Effects of Different Plant Growth Regulators on the Fruit Quality of Ilex verticillata

LIU Jiaqi; ZOU Yiping; YIN Yawen; HAO Mingzhuo

doi:10.15933/j.cnki.1004-3268.2025.01.013

Abstract：To investigate the regulatory effects of different plant growth regulator treatments on the fruit quality of Ilex verticillata'Oosterwijk',2-year-old potted seedlings were utilized as materials.Prohexadione-calcium and mepiquat chloride were mixed in varying concentrations,and their effects were compared with different concentrations of uniconazole and paclobutrazol,along with a control group treated with water.Spraying was conducted on the entire leaf surface during the first fruit enlargement period and ripening stage after fruit setting,followed by sampling upon maturity.Morphological indicators such as fruit length,width,single fruit weight,and moisture content were measured,along with peel chromaticity and fruit hardness.Additionally,pigment contents including chlorophyll,carotenoid,anthocyanin,along with flavonoid content,soluble sugar content,and vitamin C content were determined,for conducting inter-indicator correlation analyses.The effects of each treatment were analyzed using the membership function method.Results indicated that the fruit shape index after treatment with various agents exceeded that of the control,suggesting a trend towards regular and plump fruit shape.The highest single fruit weight was observed under T4 treatment(5％ uniconazole 3.30 g/L),with an average of 0.44 g.The treatment with the highest average moisture content was T3(5％prohexadione-calcium 0.67 g/L+98％mepiquat chloride 0.30 g/L),with a content of 65.73％.All treatments enhanced fruit brightness and color saturation,with the highest L* and a* values observed under T5 treatment(5％uniconazole 2.00 g/L)treatment.However,there was no significant difference in b*values among treatments.The highest carotenoid content was recorded under T1 treatment(5％prohexadione-calcium 2.00 g/L+98％mepiquat chloride 1.00 g/L),at 0.022 mg/g.Treatment T5 showed a significant increase in anthocyanin content compared to the control,reaching 190.57 μg/g.The total flavonoid content of I.verticillata'Oosterwijk'fruits showed an initial increase followed by a decrease with increasing spray concentration of the agents,with the highest soluble sugar content observed under T2 treatment(5％prohexadione-calcium 1.30 g/L+98％mepiquat chloride 0.67 g/L).The highest vitamin C content was observed under T3 treatment,with an increase of 38.34％compared to the control group.The rankings of membership function values for each treatment group were T5＞T2=T7＞T3＞T4＞T6＞T1＞CK,indicating that spraying twice with 5％uniconazole at 2.00 g/L during fruit enlargement and ripening stages resulted in the optimal fruit quality.