| Grape exhibits a predominance of phenolic content compared with other fruit trees;phenolic substances also have great significance in plants development and human health.In rencently years,most areas of Sichuan Basin successively introduced many table grape cultivars and became the emerging area of table grape cultivation in china.Moreover,a series of cultivation technology centered on ‘rain shelter cultivation with double film cover’ were invented,which provided a strong technical support for the development of grape industry in this area.Vineyards in southern China may be affected by low light conditions,a high rainfall,and relatively low thermal amplitude during the berry development,clear difference with other viny regions in China,while the formation mechanism of berry quality（e.g.phenolic compound）under this climate has not been studied so far.Therefore,in order to detect the type,content and metabolism mechanism of phenolic compound in table grape fruits in Sichuan Basin,determination of the phenolic content of 80 table grape cultivars,the influence of different cultivation measures on the phenolic content of grape,qualitatively and quantitatively analysis of the phenolic substances during grape development by liquid chromatography-mass spectrometry,the analysis about gene family of stilbenes synthase and the content of resveratrol were conducted in present study.The main findings are shown as follows:1.80 table grape cultivars were used as metarials to respectively determine the contents of total phenolics,total flavonoids,total flavanols,total flavonols and total anthocyanins in skin and pulp of ripening grapes.The results indicated that the content of phenolic compounds was distinct in different cultivars.In general,the phenolic compounds in skin were higher than those in pulp,and the grape with purple-red & purple-black skin were higher than those in yellow-green skin.Among the purple-red & purple-black grape,‘Zaoxiawuhe’,‘Zitian’,‘Summer Black’ and ‘Sweet Sapphire’ possessed the higher content of phenolic,while in the yellow-green grape were ‘Zuijinxiang’,‘Jinshouzhi’,‘Guifeimeigui’ and ‘Shine Muscat’ were higher.2.The content of phenolic compound in different treatments（potassium sulfate,potassium dihydrogen phosphate,clusters thinning and leaf removal）in ‘Summer Black’grape were studied.The results showed that 50 kg per 667 m2 of potassium sulfate,3 g·L-1 of potassium dihydrogen phosphate separately sprayed on the end of veraison or in combination with the early stage of veraison,90-95 berry per cluster,picking off 4 leaves at the base of of bearing branch could effectively increase the content of phenolic compounds of ripening berry,such as flavonoids,flavanols,flavonols and anthocyanins.3.The skins of ‘Summer Black’（SB）and ‘Shine Muscat’（SM）grape were used as materials to to identify and quantify flavonoids metabolites on young（Y）,veraison（V）and mature（M）stage by LC–MS/MS,and quantitative PCR were performed to analyze the transcript level of flavonoids synthesis related genes during berry development.A total of138 metabolites were detected in ‘Summer Black’ and ‘Shine Muscat’skin,including 16 flavanones,37 flavones,20 flavone C-glycosides,33 flavonols,12 flavanols,5proanthocyanidins,11 anthocyanidins,4 isoflavones.Main differential components were flavones,flavonols and flavone C-glycosides between SBY and SBV;flavones,flavonols,flavanones and flavone C-glycosides between SBV and SBM;while flavones,flavonols,flavone C-glycosides and flavanones between ‘Shine Muscat’ contrast groups（These flavonoid class contained different metabolites）.Besides,flavones,flavonols and flavone C-glycosides were common main difference contributors in the three developmental stage of ‘Summer Black’and ‘Shine Muscat’ attributing to the dramatically lower genes expressions in‘Shine Muscat’ than‘Summer Black’except F3 H and FLS.Anthocyanins were the differential metabolites in ripening stage;malvidin 3,5-diglucoside was the main component of ‘Summer Black’ color and accounted for 85.9% of total anthocyanins content,which may attribute to UFGT,OMT,MYBA1 and MYBA2 significantly up-regulated 2272,19,374 and 3558 times when ripening respectively.4.Based on the bioinformatic technique,the members of stilbene synthases（STS）gene family were screened and their transcriptional patterns were analyzed in ‘Summer Black’ grape during the development of berry.Also,the content of different type of resveratrol was determined.A total of 48 members of the STS gene family were identified and distributed in tandem on chromosomes 10 and 16.The members of STS gene family showed a variety of expression patterns during grape berry and leaf development,but the expression level of most members was higher at 20-40,70-80 days after anthesis,the stage of leaf maturity and senescence.Three types of resveratrol,including trans-resveratrol（trans-res）,trans-piceid（trans-pd）,cis-piceid（cis-pd）,were detected in the skin of‘Summer Black’ grape.During the berry development,trans-res reached the maximum at30 days after anthesis,and then decrease rapidly,but slowly increased again to the sub-peak from veraison to 80 days after anthesis.The trans-pd content increased slowly during 20-60 days after anthesis,and then accumulated rapidly with berry ripening.Moreover,the content of cis-pd matained in low level before veraison,but with the onset of veraison,the cis-pd content increased rapidly until the berry was ripe.In general,the content of cis-pd was the highest in mature berry,followed by the trans-pd,and lowest in trans-res.5.High performance liquid chromatography was conducted to analyze the content of phenolic acid compounds among ‘Summer Black’ and ‘Shine Muscat’ grape skin during the development of berry.Seven phenolic acids were identified in two cultivars,among which the content of chlorogenic acid was significantly higher than others.During the berry development of ‘Summer Black’,the contents of protocatechuic acid,vanillic acid,p-hydroxybenzoic acid,chlorogenic acid and caffeic acid were higher in the early stage of development,while ferulic acid was higher in the late stage,but p-coumaric acid did not significant change.As for ‘Shine Muscat’,the content of protocatechuic acid,vanillic acid,chlorogenic acid,caffeic acid and ferulic acid was higher in early stage;p-coumaric acid higher in the late stage;p-hydroxybenzoic acid content fluctuated.When berry ripening,the contents of protocatechuic acid,caffeic acid,p-coumaric acid and p-hydroxybenzoic acid in ‘Shine Muscat’ skin were higher than ‘Summer Black’,about 1.17,1.08,2.44,3.41times;while chlorogenic acid,vanillic acid and ferulic acid in ‘Summer Black’ skin were1.12,2.11 and 1.76 times higher than‘Shine Muscat’. |
