Study On Characteristics Of The Muskmelon Fruits Source-Sink Carbohydrate Transport During Fruit Enlargement

In this study, We use various parts of fruit inflating stageas Muskmelon from the "source" to "sink" photosynthate transport pathway as materials by measuring auxin (IAA) content, sugar composition and content of the sucrose metabolism-related enzyme activity, initially identified the carbohydrate transport of Muskmelon fruit inflating stage and metabolic characteristics between the source and sink; on this basis, further treatment of exogenous Spraying and fruit incubation of IAA on the enlargement of the Loop honeydew melon fruit sugar accumulation and sucrose metabolism control characteristics of the enzyme activity. The main findings are as follows:1During the Muskmelon Fruit Enlargement the "Source" leaves starch content is highest, The next was successively stage sucrose, glucose and fructose; sucrose metabolizing enzyme activity of the synthetic direction of sucrose synthase (SS+), is the highest, secondly for activity of starch phosphorylase, activity of invertase enzyme (Inv) is lower.2During the Muskmelon fruit Enlargement the "Sink" fruit, glucose and fructose content is higher, sucrose and starch content is lower, the fruit wsa mainly accumulated hexose; activity of sucrose metabolism-related enzyme SS, starch phosphorylase and acid invertase (AI) activity was higher, in different parts of fruits the the sucrose synthase decomposition direction (SS-) activity is different.3Of the various parts Muskmelon from the "source" leaves to "Sink" fruit sugar transport pathway, during the Muskmelon fruit Enlargement. The sugar content is different. Leaves Mainly containing starch and sucrose; the vascular system and fruit, mainly containing glucose and fructose, the sucrose and starch content are lower. Sucrose metabolism-related enzyme activity. In the leaves and vascular system, SS activity is the Highest, followed by the starch starch phosphorylase activity. Sugar phosphorylase (SPS), the SS-and Inv activity were lower; In the fruit SS, starch starch phosphorylase and soluble AI enzyme activities were higher.4Of the various parts Muskmelon from the "source" leaves to "Sink" fruit Sugar transport pathway, During the Muskmelon fruit Enlargement. IAA content of the petiole is the highest, secondly for veins, mesophyll, seeds, the pedicle pulp, stem, stalk, umbilical pulp, the middle pulp. In fruit inflating stageas. exogenous IAA Spraying for1～2d. fruit sucrose and sugar content and activity of sucrose metabolism enzyme were significantly imProove; After IAA incubation, fruit sucrose content was significantly lower, hexose and soluble sugar content of the fruit was significantly imProoved. while the net activity of sucrose metabolizing enzymes were lower. Conjecture the IAA may regulate the metabolism of carbon compounds through Proomotion source to the sink sucrose input and speed up the decomposition of sucrose in the sink fruits.