Effects Of Fruit-bearing Agents On The Changes Of The Fruit Development, Nutreent Components And Sucrose-metabolizing Enzymes In Muskmelon

With "Zaomi" as the experimental material, the changes of fruit development, nutrientcomponents and activities of enzymes related to sucrose metabolism were compared in thedevelopment of muskmelon under three conditions, artificial pollination, spraying No.1fruit-bearing agent and No.2fruit-bearing agent. The physiological indexes were exploitedevery5days. When muskmelon fruit was ripe and harvested, seven quality parameters,including fruit firmness, mass loss rate, soluble solids content, organic acid content, VCcontent, soluble protein content and soluble sugar content, were measured every three daysduring storage. The main results of this reasearch are as follows:1. The fruit set percentage of muskmelon treated with the two fruit-bearing agents couldreach over98%, which was a little higher than artificial pollination. The growth curve ofmuskmelon was an S-shaped curve. It included the rapid expanding stage in the earlydevelopment and the accumulation of nutrient components at the late growth stage. In thisstudy, the rapid expanding period was within20days after anthesis, and in this period, thefruit volume and single fruit weight increased quickly. The sugar content mainly accumulatedin the late development stage. Under the condition of treating with No.1fruit-bearing agent,the fruit width, fruit length and single fruit weight slightly increased, as well as the fruit indexhad a little decrease. But there was no remarkable effect with the condition of spraying withNo.2fruit-bearing agent.2. The acid content of muskmelon showed a transition from decrease to increase. Afterfruit-bearing agents treatments, the acid content decreased significantly in the previousdevelopment of muskmelon. The content of VC decreased qucikyly at the rapid expandingstage, and then accumulated a little at the mature stage. The protine content decreased veryquickly from5days to10days after treatment, and then kept stability essentially. Sprayingfruit-bearing agents made the content of protine lower significantly after5days compariedwith artificial pollination.3. The sucrose and fructose content increased very slowly in the early developmentwhile accumulated ranpidly in the late development stage. Sugar mainly accumulated in maturing stage. And there was a obvious "knee point" in20days after blooming. There was ahigher activity of sucrose invertase enzyme in the early fruit development and highersynthase activity in the mature. Muskmelon fruit that used No.1fruit-bearing agent has asignificant increase in soluble sugar content and sugar content, while the soluble sugarcontent and sugar content decreased. The sucrose synthase activites increased significantlyand the inverts activities reduced under the condition of using No.1fruit-bearing agent in thelater developing period.4. After muskmelon fruit was ripe and harvested, during the room temperature storage,fruit hardness continuously decreased, and the mass loss rate was continuously increasing,that led to the fruit marketability decreasing. The firmness of muskmelon fruit that using thefruit-bearing agents decreased slowlier than artificial pollination, the mass loss rate was lowertoo. However, the difference did not reach significant level. Many nutrient components,including soluble solids content, organic acid content, VC content, soluble protein contentand soluble sugar content, reduced in different degree, and the nutritional quality got poorer.The soluble solids content of muskmelon fruit that treated with fruit-bearing agents was alittle higher than artificial pollination. Also, the content of soluble sugar in muskmelon thatspraying fruit-bearing agents reduced slowly, and the difference reached significant levelcompared with artificial pollination in the end of the storage. For all that, the appearancequality and inherent quality of muskmelon got poor so much, and the commodity had beenalmost disappeared.