Effects Of Bagging On Fruit Quality And Sucrose Metabolism-related Enzymes Of Kiyomi Tangor

Bagging cultivation was widely used in a variety of fruit production as the main technical measures of high-grade fruits, but less reports about the application on the citrus were issued. To study the effect of bagging on the activity of sucrose metabolism of Kiyomi Tangor, six kinds of bags (outer brown and inner red double bag, outer yellow and inner black double bag, single yellow bag, single white bag, outer brown inner black double-layer kraft paper bag and white single-layer non-woven bag) were used on Kiyomi Tangor fruit on 210 days after flowering (on December 4th). Meanwhile, the research of the bagging time and the different types of bags on the fruit quality of Kiyomi Tangor four times while 180,195,210 and 225 days after flowering were studied in 2013-2014. The study can provide a theoretical and practical basis for selecting the appropriate fruit bags and bagging date, and improving bagging Kiyomi fruit quality. The results were as follows:1、Effects of different bagging treatments on the soluble sugar contents and sucrose metabolism of Kiyomi tangor have been studied. The results showed that the sugars and related enzyme activities under bagging conditions had almost the same change trends with those of control fruits. But different fruit bags have different influence on the content of soluble sugar composition. Compared with the natural growth fruits (CK), soluble sugar contents in single bagging fruits were increased significantly. Non-woven fabric bags had the highest contents of sucrose, single yellow bags and single white bags had the highest contents of fructose and single white bags had the highest contents of glucose while the fruits were maturing. The neutral invertase (NI) activity, sucrose synthase (SS) activity and sucrose phosphate synthase (SPS) activity of fruits in single bagging were increased in some extents. Among 6 tested bags, the non-woven fabric bags affected more than others did, and there were not significant different between fruits in double bagging fruits and CK in most of the tested points. Acid invertase (AI) activity decreased with fruit development, and there were not significant different between fruits in bags and CK. According to above results, single bags were by upgrading the activity of NI, SS and SPS to increase the sugar contents, the one-layer bag with a certain light transmittance and light color was suitable for bagging of Kiyomi tangor.2、The bagging experiment with 6 different types of bags and at four different periods on the external quality of Kiyomi tangor fruits were conducted, the result indicated that the luster of Kiyomi Tangor fruits were promoted, the light shading property and the rind brightness being greater in earlier bagging treatments. Light shading property, the outer brown-inner red double bag and outer yellow-inner black double bag bagging significant impact on the peel brightness at 180 days after flowering. Bagging had no significant effect on fruit wall thickness and fruit shape index. The light transmittance of fruit bag and the fruit weight being greater in later bagging treatmentsbagging a significantly effect on the fruit weight at the last two (210 and 225 days after full blossom) bagging.3、The bagging experiment with 6 different types of bags and at four different periods on the internal quality of Kiyomi tangor fruits were conducted, the result indicated that effect of different bagging time and different kinds of fruit bags on Kiyomi tangor fruit internal quality were inconsistent. Titratable acids and total soluble sugar of the bagged fruits were improved as compared with the non-bagged fruits, the single white non-woven bagging and outer brown red double-bagging at 225 days after flowering increased the content of soluble solids significantly, outer brown inner black double-layer.kraft paper bagging, the outer brown and inner red double bag and outer yellow and inner black double bag, the outer brown and inner red double bag treatments increased the content of vitamin C significantly, at after 180,195 and 210 days after blossoming, respectively, the bagging treatment at 225 days after blossoming significantly reduced the content of vitamin C. Integrated the effects of bagging on fruit quality, white single bagging at 195 days after blossoming was the best treatment.