Changing Of Pericarp Ultrastructure And Activity Of Relative Enzymes During Fruit Development Of Bagging 'RedFuji' Apple

The main study contents of the thesis were the changing of the fruit hardness, the solublesolid matter, the pericarp pectin and the coarse fibre and the activity of the enzymes involved thepericarp cell wall by using Red'Fuji'apple as material during apple development. At the sametime, the thesis observed the systemic ultrastructure changing of the pericarp of the bagged andunbagged apple with electron microscope. The mainly study results including: 1. The fruit hardness was unchanged in two months after bagging, decreased after threemonths, the hardness discrepancy of the bagged and unbagged apple was 2.90 kg/cm2 at theharvesting time. The soluble solid matter of the bagged apple was still increasing, but always lessthan than the unbagged apple, and increasing gently at the first and third month after bagging, andincreasing relatively quick at the second and fourth month. The soluble solid matter discrepancyof the bagged and unbagged apple was 1.88 percent at the harvesting time. 2. The coarse fibre always decreased in former two months after bagging, increased at thethird and fourth months, and the coarse fibre of the bagged apple was still less than the unbaggedapple. The original pectin of the bagged and unbagged apple was approximately same, howeverthe content of the bagged apple was always less than that of the unbagged. The soluble pectin ofthe bagged apple was still less than that of the unbagged, the content increased at first month,decreased in two month after bagging. 3. The polygalacturonase activity of the bagged apple increased linearly, and always morethan that of the unbagged apple, and the discrepancy of the bagged and unbagged apple was0.04 percent at the harvesting time. The cellulose enzyme activity of the bagged andunbagged apple changed from low to high, and the changing extent was almost same, thefomer was still higher than the after. The polyphenolo xidase activity of the bagged apple waslower than that of the unbagged apple, and increased at the former period, decrease at themiddle and after period. The eperoxldase activity of the bagged apple was always lower thanthat of the unbagged apple, increased at the former period, and decreased at the after period. 4. The pericarp cell wall structure of the bagged and unbagged apple was compact at theformer period of the fruit growth, the electron density was high, the cellulose micro filamentwas invisible, the middle glue layer, the next and first cell wall were not distinguished; Thecell wall of the bagged apple began relaxing at the middle period of fruit growth, however theunbagged apple's was still relatively compact; The mostly cell wall of the bagged apple begandecomposing, and Incipient plasrmlysis appeared, whereas the unbagged apple's just beganrelaxing. 5. The chloroplast of the bagged and unbagged apple existed with the orginal chloroplastform at the former period of fruit growth, and its all space was held by the large starch grain,however the unbagged apple's was development. The chloroplast structure of the baggedapple was primarily formed at the middle period of fruit growth, just the segmentlayer structure was not development, whereas that of the unbagged apple was already intact.Because the bagged apples were expose to the sun after removing the paper bag, the potentialplastid changed into the intact segment layer structure at the short time, however that of theunbagged apple was largely decreasing, maybe it participate in the anabolism andtransforming. 6. The mitochondrion of the bagged apple was abundance and development during allcourse of fruit growth, the lipid bodies were richness, the central big vacuole besprinkled theall cell, the osmiophilic globules abounded at the harvesting time, whereas the mitochondrionand the lipid body of the unbagged apple were relatively less.