Changes Of Sugar And Acid Components And Related Enzyme Activities During Fruit Development Of Actinidia Arguta

The types,contents,and dynamic changes of the constituent sugar acids in fruits play a fundamental role in the formation of fruit flavors,and have been an important research topic for fruit quality in recent years.In order to explore the sugar and acid components and their accumulation,metabolism and regulation mechanism in Actinidia arguta,in order to formulate scientific cultivation management techniques and lay a scientific basis for regulating the intrinsic quality of fruits,we use ’Kuilv’,’HuanyouNo1’and ’Jiaohe 08-03’ Actinidia arguta varieties(lines)were used as test materials.The acid components in fruits were measured by HPLC,the sugar components and the activities of sugar-acid related enzymes were measured by a spectrophotometer.Sugar acid component and changes of sugar acid content and related enzyme activities during fruit growth,determine the correlation between sugar acid component and sugar acid accumulation in fruits and their related enzyme activities.The test results are as follows:(1)The fruits of the three tested varieties(lines)belonged to the sucrose-dominant type.The sucrose content in the fruits of ’Kuilv’,’HuanyouNo1’and’Jiaohe 08-03’accounted for 66.0%,69.4%and 74.2%of the total sugar,respectively.During the growth of fruits,the trends of the soluble sugar components were generally the same.The absolute value of fructose content in the middle stage of fruit growth was the highest,followed by glucose,and the lowest was sucrose,and the fructose content was much higher than sucrose and glucose contents.The sucrose content of ’Kuilv’and ’Jiaohe 08-03’began on August 10,and the sucrose content of ’HuanyouNol ’fruit increased rapidly from August 30.The sucrose content in the harvest period both ranked first However,glucose gradually increased from August 30,and glucose and fructose contents were similar when harvested.(2)During the fruit growth process,SPS and SS of the three Actinidia arguta cultivars(lines)jointly participate in sucrose synthesis.The SS activity increases slightly earlier than SPS,but the activity is lower and increases slowly.Considering the contribution of SPS,Degree is greater.Although the decomposition enzymes AI and NI have increased during the sucrose accumulation process,their decomposition effect is weaker than that of SS and SPS,so the overall accumulation trend is maintained.(3)The fruits of the three varieties(lines)of Actinidia arguta belong to the dominant type of citric acid.The fruits of the three tested varieties(lines)mainly contained citric acid,quinic acid,ascorbic acid,malic acid,oxalic acid,and shikimic acid.Lactic acid was also detected in ’Kuilv’,but no tartaric acid was detected.The citric acid content was 53.1%,43.8%,and 48.7%in the fruits of‘Kuilv’and‘Jiaohe 08-03’and ’HuanyouNol ’,respectively.The change trend of organic acid components during the fruit growth of the three Actinidia arguta cultivars(lines)was generally the same.Quinic acid is much higher than citric acid,malic acid,and ascorbic acid in the early stages of fruit growth,while citric acid,malic acid,and ascorbic acid are equivalent in the initial stages of fruit growth;quinic acid shows a downward trend with the growth of fruits However,citric acid gradually increased,citric acid jumped to the first position,quinic acid dropped to the second position after the fruit matured,and the content of malic acid and ascorbic acid changed little.(4)During the fruit growth process,CS,PEPC,NAD-MDH and Cyt-ACO of three Actinidia arguta cultivars(lines)participated in the synthesis of citric acid.CS activity is significantly and positively correlated with citric acid content.Its contribution is greater than PEPC.NAD-MDH promotes the synthesis of malic acid and indirectly participates in the synthesis of citric acid.Its role cannot be ignored.Although Cyt-ACO and citric acid show a significant positive correlation,their activity levels are low and their cumulative effect on citric acid is not significant.Mit-ACO and NAD-IDH are not conducive to the accumulation of citric acid.