The changes in sugar content and the selection of key genes at different developmental stages of 'Katy' and 'Kuijin' apricots.

'Katy' and 'Kuijin' apricots are the main cultivated varieties in Shandong province. The flavor of the fruit is mainly determined by sugars and acids, with soluble sugar components serving as important nutritional elements in fruits as well as crucial indicators of fruit sweetness and flavor quality. However, little is known about the changes in soluble sugar content, especially sucrose content, and the sucrose metabolism mechanism during the entire fruit growth and development process of 'Katy' and 'Kuijin' apricots.