Effect Of Methods Of The Crop-load Control On Anthocyanin In Grapes

The anthocyanin compounds in grape skins from Vitis viniferal L. Cabernetsauvignon were investigated by High Performance Liquid Chromatography (HPLC）for revealing the changes of the total content of anthocyanin and the contents of fivebasic monomers of anthocyanin (Malvidin-3-0-Glucoside, Delphinidin-3-0-Glucoside,Petunidin-3-Glucoside, Peonidin-3-0-Glucoside and Cyanidin-3-0-Glucoside) duringmaturation process. On this basis, the effects of different methods of crop-load control(Deblossoming, cluster-thinning and berry-thinning) on total contents of anthocyaninand the five monomers in grape skins and their otherness were carried out.The results indicated that the total contents of anthocyanin and the five basicmonomers in grape skins were raised with the increasing maturity of grape andpeaked when the grapes are fully ripen. The content of Malvidin-3-0-Glucoside is thehighest among the five monomers of anthocyanin, Peonidin-3-0-Glucoside,Delphinidin-3-0-Glucoside, Petunidin-3-Glucoside and Cyanidin-3-0-Glucoside werefollowed.The total contents of anthocyanin in grape skins were all significantly increasedby different methods of crop-load. Thereamong, the total content of anthocyanin ingrape skins by berry-thinning was raised superlatively, when the grapes werecompletely ripen, the content was reached114.1A520/g and was2.1times that of thecontrol (CK); meanwhile the total contents of anthocyanin in grape skins bydeblossoming and cluster-thinning were raised54.9%and58.8%compared to thecontrol (CK), respectively. With regard to the total contents of the five monomers ofanthocyanin, deblossoming was ineffective; but berry-thinning and cluster-thinningwere effective obviously and tolerably, respectively were1.42times and1.45timesthat of the control (CK).Cluster-thinning and berry-thinning can evidently improve the contents of thefive monomers of anthocyanin, on the other side, deblossoming can visibly increasethe contents of Delphinidin-3-0-Glucoside, Peonidin-3-0-Glucoside,Malvidin-3-0-Glucoside, for Cyanidin-3-0-Glucoside and Petunidin-3-Glucoside theimprovement were not obvious.Different crop-loads and its methods caused divers effects on contents of eachmonomer of anthocyanin: berry-thinning was most influenced in the contents of Malvidin-3-0-Glucoside and Peonidin-3-0-Glucoside but least in the content ofDelphinidin-3-0-Glucoside; cluster-thinning improved the contents ofCyanidin-3-0-Glucoside, Petunidin-3-Glucoside and Delphinidin-3-0-Glucoside mostsignificantly; deblossoming was least effected on the contents ofMalvidin-3-0-Glucoside, Peonidin-3-0-Glucoside, Cyanidin-3-0-Glucoside andPetunidin-3-Glucoside except Delphinidin-3-0-Glucoside, the influence ofdeblossoming was least among this three methods of crop-load.