Effects Of Different Bags On Fruit Quality And Aroma Components In Grape Cv.’Marselan’

In this experiment,11-year-old‘Marselan’grapes were used as test materials.Single-layer black bags,single-layer white bags,single-layer yellow bags and single-layer brown bags were used for testing,with no bag as the control.The effects of different fruit bags on the developmental dynamics in fruit,sugar acid,endogenous hormones and aroma components in the peel were studied,and the effects of different fruit bags on the comprehensive quality of the fruit in‘Marselan’were discussed.The main conclusions of the experiment are as follows:1.Relative to the control,the single grain weight,peel color index,soluble solids,soluble sugar content and sugar acid ratio of‘Marselan’fruit with black bags were significantly reduced by 36.63%,87.15%,40.60%,38.82%,57.08%at 90 days after flowering,respectively.However,the L value and titratable acid in fruit with the black bag were 34.62%and 30.63%higher than that of the control,respectively.At 100 and125 days after flowering,the difference in individual weight,peel turnover rate,soluble solids,soluble sugar content,and titratable acid between bagged fruit and the fruit became smaller.The fruit shape index did not change significantly from 90 days to 125 days after flowering.2.Relative to the control,bagging inhibited the synthesis of GA₃.From 90 to125 days after flowering,the contents of GA₃ in bagged fruits were 0.00μg/g,while it was the highest in the control fruit at 90 days after flowering,which was 160.23μg/g.The content of ABA in the pericarp increased,and it was 74.09%higher in the black bag than that in the control fruit at the 90 days after the flower,whereas bagging had no significant effect on the content of IAA and ZR.The ratio of（IAA+GA₃+ZR）/ABA in bagged fruits was significantly lower than that in control fruits from 90 days to 125 days after flowering,and the ratio of control fruit at 90 days after flowering was the highest,which was 155.64.3.Different fruit bags had different effects on aroma types and contents in pericarp.From 90 days to 125 days after flowering,the total amount of aromatic substances in each treatment decreased first and then increased.The total amount of aroma from single layer black bag was 81.26%higher than that of the control fruit at90 days after the flowering.Among them,the content of hexanol,trans-2-hexene-1-alcohol,geraniol,phenylacetaldehyde and heptene was significantly higher than that of the control fruit.The total amount of aroma in the bagged fruit was significantly smaller than that in the control fruit at the 125 days after the flowering.Among them,the control fruit accounted for 63.94%of the total aldehydes,which was significantly higher than that of bagged fruits.With the ripening of fruit,bagging reduced the kinds of esters,ketones and carboxylic acids,and increased alkenes and alkanes.The single layer black color promoted the synthesis of tetradecane and inhibited the synthesis of3-hexenal,while the unbagging inhibited the synthesis of cis-3-hexen-1-ol,cumene and dioctylmethane.4.Through the analysis of the principal components of the fruit quality,endogenous hormones,and aroma components from different fruit bags in‘Marselan’,it was found that the main influencing factors of the comprehensive quality from the bagged fruit were single grain weight,fruit shape index,sugar acid and color at the 90days after flowering.The main influencing factors at the 100 days after flowering were sugar acid,endogenous hormone and the esters,phenols and ketone in the aroma components.At the 125 day after flowering,the main factors were sugar acid ratio,brightness and aroma components.According to the comprehensive evaluation,the influence of fruit bagging on fruit quality was in the order:black bag>brown bag yellow bag>white bag>CK.