Effects Of Exogenous Rapeseed Lactones On The Accumulation Of Phenolic Compounds And Fruit Quality Of ’Merlot’ Grape

In this study,12-year-old ’Merlot’(Vitis vinfera L.cv.Merlot)grape was used as the test material,and 0.2,0.4 and 0.6 mg/L of 2,4-Epibrassinolide,in order to study the effect of different concentrations of EBR on the accumulation of phenolic compounds in different parts and fruit quality of ’Merlot’grapes during the ripening process,to provide a theoretical basis for further application of EBR in actual production to regulate the accumulation of phenolic substances in wine grapes and fruit quality.The results of this study are as follows:1.The effect of EBR on the accumulation rule of total phenolic content in different parts of ’Merlot’grape.EBR treatment was carried out before the color conversion period,and each treatment increased the total phenolic content.In the peel,the total phenols first increased and then decreased and tended to be stable.Among them,0.2 and 0.4 mg/LEBR had the best effects.The total phenolic content in the pulp showed a downward trend,and the total phenolic content in the 0.2 mg/L EBR treatment was significantly increased compared with the control;the 0.4 and 0.6 mg/L EBR treatments could increase the total phenolic content in the seeds at the early stage of color change,the effect at maturity was not significant;the total phenolic content in fruit stem showed a slow upward trend,and the improvement effect of 0.6mg/L EBR treatment was better.2.The effect of EBR on the accumulation rule of tannin content in different parts of ’Merlot’ grape.EBR treatment was carried out before the veraison period,and the tannin content in the seeds was the highest;the tannin content in the peel and pulp showed a gradual upward trend,and each treatment could increase the tannin content,of which 0.2mg/LEBR.The treatment effect was the best.In the pulp part,the treatment effect of 0.6 mg/LEBR at the ripening stage was the best;as the fruit matured,the tannin content in the seeds also gradually decreased.Compared with the control,it may be due to the fact that the spraying time is too short and the hormone has not exerted its effect;from 80d to 90d after flowering,0.2mg/LEBR treatment slowed down the decrease of tannin content in fruit seeds;in fruit stalk,0.6mg/LEBR treatment.The tannin content was significantly higher than that of the control group.3.The effect of EBR on the accumulation regularity of total flavonoids in different parts of ’Merlot’grape.EBR treatment was carried out before the veraison period,and the total flavonoid content in the peel and pulp showed a trend of first decreasing and then increasing.Each treatment had a certain increase in the content of flavonoids in the peel and pulp.Among them,0.2 mg/LEBR.The treatment effect was better;the content of total flavonoids in the seeds and stalks showed a decreasing trend,and the content of total flavonoids in the seeds was the highest.At the early stage of veraison,0.2mg/LEBR treatment had the best effect,and as the grapes matured,0.6mg/LEBR treatment had better effect.4.The effect of EBR on the accumulation regularity of flavanol content in different parts of’Merlot’ grape.EBR treatment was carried out before the veraison period.The content of flavanols in the peel was the highest among the four parts.It began to rise and stabilized in the early period of veraison,and decreased in the fruit ripening period.Compared with the control,each treatment increased,but the improvement effect was not significant,and the treatment effect of 0.2mg/LEBR was better;the flavanol content in the pulp gradually decreased with the grape ripening process,and 0.2mg/LEBR at the early stage of veraison could significantly inhibit the decrease of the flavanol content;the content of flavanols in fruit seeds and pedicels showed a trend of first rising and then decreasing,and 0.2mg/LEBR treatment had the best effect.5.The effect of EBR on the accumulation rule of anthocyanins in different parts of ’Merlot’ grape.Anthocyanins are mainly concentrated in the peel.EBR treatment was carried out before the veraison period,and the anthocyanin content of the four parts of the fruit showed a steady upward trend.In the peel,the 0.4mg/LEBR treatment had a better effect on the improvement of the anthocyanin content in the peel.In the early stage of color change,0.6mg/LEBR treatment can significantly increase the anthocyanin content of the pulp,and when the grapes enter the ripening stage,the improvement effect of 0.4mg/LEBR treatment.In fruit seeds,all treatments can increase the content of anthocyanins,but the effect is not significant at the early stage of veraison period.6.The efffect of EBR on the internal and external quality of ’Merlot’ grapes.EBR treatment was carried out before the veraison period,the horizontal and vertical diameter and 100-grain weight of fruits in each treatment group were higher than those in the control group,among which 0.4mg/LEBR treatment had better effect,but there was no significant difference in the maturity stage;at the same time,0.4mg/LEBR treatment/LEBR treatment effectively promoted the accumulation of total sugar,sucrose and reducing sugar;0.6mg/L EBR treatment group had the best effect on reducing titratable acid in fruit;EBR treatment increased soluble solid content as follows:EBR 0.2mg/L L>EBR 0.4 mg/L>EBR 0.6 mg/L,but the effect at maturity was not significant.