Study On Sugar Accumulation And Related Enzyme Activities During Fruit Development Of Actinidia Kolomikta

The type and content of sugars in fruits and their dynamic changes are the important basis of fruit quality formation and one of the hot spots of research.Actinidia kolomikta is very popular and has a great market potential,but it is basically in the wild and rarely cultivated on a large scale,not to mention the research reported on sugar accumulation during fruit development.In order to investigate the mechanism of sugar accumulation during fruit development of Actinidia kolomikta,Actinidia kolomikta in Changbai Mountain was used as experimental material to determine the changes in sugar content,changes in the activity of enzymes related to sugar metabolism and the reciprocity of sugar content and related enzyme activities during fruit development:(1)Mature Actinidia kolomikta are dominated by sucrose accumulation,supplemented by glucose accumulation and to a lesser extent by fructose accumulation.It is evident that Actinidia kolomikta are sucrose-dominant.(2)The activities of both sucrose phosphate synthase and sucrose synthase varied significantly during fruit growth and development of Actinidia kolomikta,but the trends of the changes were different.The activity of sucrose phosphate synthase was low in the early stage of fruit development and decreased to the lowest point on July 31,then increased rapidly again,with the most obvious increase in the softening stage.The activity of sucrose synthase was high and increased rapidly at the beginning of fruit development,reaching a peak on July 17,then decreasing rapidly,reaching a minimum on July 31,then increasing slowly again,with a greater increase in activity during the fruit softening stage.The activity of acid and neutral converting enzymes was low and did not change much throughout fruit development.The activity of acid converting enzymes gradually decreased with fruit growth and development.The activity of neutral converting enzymes remained low and varied little throughout the growth of the fruit.(3)A significant positive correlation was shown between sucrose phosphate synthase and sucrose during fruit development of Actinidia kolomikta,and the point of increase of sucrose phosphate synthase was consistent with and earlier than that of sucrose.It can be seen that the accumulation of fruit sucrose is closely related to sucrose phosphate synthase.In the process of sucrose accumulation catabolic enzymes,acidic converting enzymes and neutral converting enzymes have low activity and little change during the whole growth and development of fruits,and their catabolic effect is weaker compared with sucrose phosphate synthase,and the synthesis of sucrose is greater than catabolism.The results of this paper will not only further understand the mechanism of sugar accumulation in Actinidia kolomikta,but also regulate and improve the process of sugar accumulation in fruit,providing a scientific basis for improving fruit quality and breeding new varieties.