Studies On The Factors Of The Formation Of Inner Quality Difference Between Huangguogan Under The Same Management Level

This test at the same level of the management, take the Huangguogan as the material, witch with the same stock, and the basic consistent old, tree potential, such as the tree loading, explored the impact of sugar and acid metabolism enzyme activities and gene expression between strains of Huangguogan fruit sugar and acid accumulation. The results are as follows:(1):Huangguogan fruit to accumulate sucrose mainly, from the turning-color period to fructescence (210-330 days after flowering), sucrose content of 46.66% -69.73% of the total sugar content, fruit sugar content differences between strains mainly caused by the difference of sucrose content.(2):In the period of the late fructescence, high SS (synthetic direction) activity can promote the accumulation of sugar in Huangguogan fruit, while SPS activity mainly in the pre-mature plays a key role in the sugar accumulation. The change of SS (synthetic direction) and SPS activity is a key factor witch leading to sugar content discrepancy between the fruit of Huangguogan strains. The difference of sugar accumulation in Huangguogan is related to the net activity of sucrose metabolizing enzymes, early ripening (210-250 days after flowering), the net activity of sucrose metabolizing enzymes is about 35mg·g-1·h-1 FW, late ripening (270-330 days after flowering), the net activity of sucrose metabolizing enzymes is between 10-25 mg·g-1·h-1.(3):The expression of SS (synthetic direction), SPS, AI and NI genes in Huangguogan fruit, have the same trend as its corresponding enzyme activity, it is the main factor to the enzyme activity, and the expression of SPS and AI gene is the limiting factor of the sugar accumulation in Huangguogan. The difference of sugar content in fruit among Huangguogan strains was mainly caused by differences in SS (synthetic direction) and AI expression levels.(4):Huangguogan fruit to accumulate citric acid mainly, from the turning-color period to fructescence (210-330 days after flowering), citric acid content of more than 90% of the total acid content, fruit acid content differences between strains mainly caused by the difference of citric acid content.(5):The content of organic acid in Huangguogan fruit has little relationship with the activity of CS decreased, but the inhibition of PEPC activity could reduce the amount of organic acids in the fruit. ACO and IDH activity improved, can promote organic acid decomposition in Huangguogan, which reduces the total acid content of fruit. The difference of organic acid content between Huangguogan strains is the combined effect of ACO and IDH activity results.(6):The differential expression of CS gene and IDH gene in strains of Huangguogan fruit lead to the corresponding quality change, and the strains of Huangguogan real IDH expression level and total acid content were significantly negatively correlated, is the limiting factor of the organic acid accumulation in the fruit of Huangguogan strains.