Abstract: The contents of different sugars(sucrose,fructose,total soluble sugar and starch) and the activities of sucrose phosphate synthase,sucrose synthase acid invertase,neutral invertase involved in sucrose metabolism was measured in order to know the sugar metabolism in developing tomato fruit.According to the development and the relative growth rate of tomato fruit,we can devide the tomato fruit development into two PHA_Ses.The first PHA_Se before 39 days after anthysis forms the main output and in the PHA_Se after this the inner quality forms.In the first PHA_Se the contents of fructose and soluble total sugar increase gradually,the content of starch decreases and sucrose's content changes little.At the same time the activities of sucrose synthase and sucrose phosphate synthase relatively high,the invertases'activity relatively low.In the second PHA_Se,the content of fructose increase,the starch's content decrease and the contents of total soluble sugar and sucrose change little.The activities of invertases rise acutely,but the activities of sucrose synthase and sucrose phosphate synthase maintain very low and change little.By statistic analysis,we find the single fruit weight and the content of starch have significant correlation,while the content of starch has significant correlation with neutral invertase,so we can consult the content of starch and the activity of neutral as the index to gain high output.The contents of fructose、total soluble sugar and starch have the significant correlation,the contents of fructose and the activity of SS,AI,NI have significant correlation.The contents of total soluble sugar and the activity of sucrose synthase have significant correlation,so we can consult the activity of synthase and invertases as the index to gain high contents of fructose.

Key words: Tomato fruit, Sugar metabolism, Main enzymes in sucrose metabolism

CLC Number: 

• S641.2