Influence Of Reflective Mulch And Leaf Removal On Fruit And Wine Quality Of ‘Cabernet Gernischt'

This experiment takes Cabernet Gernischt as experimental subject,which is a kind of wine grapes growing in Longhu production area of Penglai in Yantai.It aims to figure out the impact of reflective mulch?referred to as LM hereinafter?and leaf removal?referred to as LR hereinafter?of different periods and the change of viticultural practices on the grapes and the quality of wine.To provide simple and economical and efficient cultivation measures for Yantai production areas to improve the quality of fruits and wine.The results will be described below.1.The impact of different treatments on inter-fruital microclimate:Both LM+LR and LM during flowering phase can enhance the intensity of solar radiation between fruits and UV light.The intensity of UV light of the group,LM+LR during flowering on the initial stage of veraison reached 33.4?M·m^-2·s^-1,which increased by 125.93%compared with the contrast group?Routine management:neither reflective mulch nor leaf removal;referred to as CK hereinafter?.However,the intensity of UV light of the other group which was LM during flowering phase,merely increased by around 30%compared with the CK.The intensity of UV light of LM+LR during flowering phase was increased by148.16%on veraison phase,while the LM during flowering is 163.18%.2.The impact of different treatments on the photosynthetic characteristics of leaves:Doing both LM and LM+LR during flowering phase can improve the net photosynthetic rate,transpiration rate and stomatal conductance of grape leaves to varying degree,and reduce the concentration of intercellular CO₂.LM during flowering phase contributed to the highest net photosynthetic rate,which was 1.11 times as fast as the CK.Its stomatal conductance and transpiration rate both increased by 39.47%and 20.70%respectively,compared with the CK.3.The impact of different treatments on the quality of ripe fruits:The treatment of LM and LM+LR both can dramatically improve the content of anthocyaninphenolic of fruits.This content grew respectively to 1.27 times,1.26 times and 1.20 times as high as that of the CK when conducting LM,both LM and LR during flowering phase,and both LM and LR during veraison.LM+LR during flowering phase and veraison both can improve the content of phenolic and tannin of fruits.The content of phenolic can increase by 19.91%and 24.01%with LM+LR during flowering phase or conversion period,while the content of tannin is 14.37%and 21.56%.4.The impact of different treatments on the expression of structural genes during the production of anthocyanin:VvPAL,VvCHS,VvF3H,VvDFR and VvUFGT in the skin of grapes,which are used to compose anthocyanin,were tested through fluorescence quantitative PCR on 29^thAugust of veraison and 8^thOctober of maturation period.The content of VvPAL,VvF3H and VvDFR of grapes,with LM+LR during flowering phase and at the 80%treatment of version,were remarkably high than the CK,whose content of these three genes were respectively 34%,37%and 49%.After the completion of veraison,VvPAL,VvCHS and VvDFR all took on more active expressions,which contributed to the production of delphinidin.5.The impact of different treatments on the kind and content of anthocyanin monomer of ripe fruits:There were twelve kinds of anthocyanin monomer in both experimental and contrast groups of 2018,while the kinds in experimental group of 2019increased by one to two.The content of anthocyanin monomer in experimental group increased,especially the content of dimethylanthocyanin-3-O-glucoside monomer.LM during flowering phase led to the highest content of 162.52 mg·Kg^-1,which increased by87.43%compared with the CK.The degree of acylation is relatively high with LM during flowering phase,which was up to 58%in the testing of 2018 and 2019.6.The impact of different process on the substance of phenolics:Different treatments can improve the chroma of wine,among which the value of chroma of grapes with LM+LR during veraison enhanced the most—1.49 times as high as the CK.The treatment,however,did not have obvious effect on tone and tannin.The content of phenolic in wine also increased after different treatments.It increased drastically in grapes with LM+LR during veraison,respectively 302.72 mg·L^-1—1.24 times as high as the CK.The highest content of anthocyanin is 42.17%higher than the CK,appearing in those grapes who had LM+LR during flowering phase.The treatment had little effect on tannin.The content of tannin of grapes processed with LM+LR during veraison is at most 0.32 g·L^-1higher than the CK.The treatment of LM during flowering phase obviously raise the content of flavonoids and anthocyanins monophenol in wine,which are 1.19 times and 1.40 times higher that the CK.7.The impact of different treatments on the aroma substances and content of wine:Treatment has little effect on the kind of aroma in wine in 2018.They affected the content of important compositions in aroma greatly.LM during flowering phase can notably increase the content of aliphatics,C₁₃-Norisoprenopids,terpeniods and aromatics in aroma,which were 1.33,1.51,1.35 and 1.5 times as high as the CK.The content of important fragrant substances like butyl acetate and methyl octoate with the scent of fruits and flowers,and?-ionone with violet flower fragrance,are above 50%higher than the CK,while the content of nerol and 4-vinyl guaiacol with orange blossom aroma are higher above 130%.In the experiment of 2019,LM+LR during flowering phase can produce more aroma substances than merely conducting LM.The former one sharply enhanced the content of aliphatics,like hexanol and ethyl decanoate,which are 59.08%and 67.36%higher than the CK.The overall content of aroma substances was 1.73 times as high as the CK,especially that of 2-phenylethanol with honey and rose fragrance,which was 1.66times than the CK.