A Preliminary Study Of The Diversity Of Black Currant (Ribes Nigium L.) Ascorbic Acid Levels And Biosynthesis

The experiment was conducted from2010-2013years in the Northeast AgriculturalUniver-sity bla-ck currant Germplasm Resources Garden, with51varieties in nursery as exper-imental material, studied the diversity of different varieties of ascorbic acid level, and to evalu-ate the exi-sting germplasm resou-rces of ascorbic acid in fruit, selected8varieties represent-ing different lev-els of high school low from further research. In this paper, different varie-tiesof black currant fruit in different mature period of fruit as the experimental material, the level ofascorbic acid, glutath-ione, ascorbic acid and glutathione (GS H), the redox state of asc-orbatemetabolism related enzy-me activity, ascorbic acid degradation and appl-ied AsA and oxalic acid(OA) on the metabolism of AsA was studied, in order for the follow-up research work of blackcurrant in AsA, and provide a theoretical basis and related functional breeding of black currant.The results were as follows:1. The HPLC measurement results show that different varieties of black currant ascorbicacid level there is significant diversity, the highest content of Westland1-2361.58mg/100g thelowest black Fung144.79mg/100g, onlyWest to1-240.04%. Depending on the ASA content,man-made black currant is divided into three levels of high, medium and low.2.The content and redox state of AsA and GSH of different varieties of black currant fruit,the res-ult showed there were rich diversity of levels of AsA and GSH among different varietiesof black curr-ant. The contents of T-AsA, Ludtke was2.06times to black Feng. The contents ofT-GSH,has no obvio-us difference between different varieties,black feng was highest,ludtke waslowest,both were1.95times. There was not a significant correlation between contents of ASAand GSH. T-AsA content and AsA/DHA ratio was significantly positively correlated, whichshowed the redox state of AsA has important significance in accumulation and maintenance ofAsA.3.The activities of APX、DHAR、MDHAR、GR were determined in the experiment, theactivity of DHAR、MDHAR and APX had significantly positively related to content of AsA. Theactivity of DHAR and MDHAR had significantly positively related to AsA/DHA,which showedthe redox state of AsA has important significance in accumulation and maintenance of AsA.4.The level of AsA in different varieties of black currant had the same changing trend withthe growth and development of fruit, although contents of AsA between two species had very great differrence.All present increased at the early development stage but decreased later, thatAsA cont-ent increased significantly at the first three weeks after the flushing, then reached themaxi-mum in three week and decreased and maintained essentially constant after seven weeks.The activity of APX、DHAR、MDHAR、GR and level of GSH had no significantly positivelyrela-ted to AsA,the level of AsA depe-nds on the balance between an abolism and degradationmetabo-lism.5.Exogenous AsA and OA had a certain influence to the level of AsA and GSH in the plant,mak-ing the level of AsA in the piant having a certain increase,illustrating the disassemble ofAsA can pro-duce OA,then OA have the feedback inhibition to the degradation and pathways ofAsA, high level of OA can inhibit the degradation of AsA and to improve the level of AsA inplant. App-lied AsA fruit T-ASA, ASA, DHA, T-GSH, GSH and GSSG content are on the rise,but, ASA/DHA and GSH/GSSG ratio declined slightly. AsA-GSH cycle, high levels of ASAaffect the acti-vity of the enzyme, the incr-ease in APX activity carried out thereby changingthe redox state of AsA promote circulation.6. Ribes currant fruit ascorbic acid accumulation rule: in the early stage of fruitdevelopment, that is, until three weeks after fruit set, fruit AsA content increased rapidly. To4weeks after fruit set fruit began expanding growth in the AsA content began to fall. Until thefruit begins to turn color, the enla-rgement of the growth rate decreases, the ASA contentdecreases the rate began to decrease, until the fruit is ripe, the total content of ascorbic acid(T-AsA) did not change signif-icantly.