Abstract:

The sorbitol, fructose and glucose contents and the changes in activities of sorbitol oxidase (SOX), sorbitol dehydrogenase (SDH), which are the enzymes participated in sorbitol metabolism, were investigated respectively in the endocarp, mesocarp, leaf and phloem during the development of fruits of ‘Jingyu'and ‘Okubao' peach. The results demonstrated that the pattems of sugar accumulation were analogous in the two varieties. In addition, sorbitol content in leaf was the highest in leaf, followed by that in phloem, and then in pericarp. The contents of glucose and fructose had obvious diversity in disparate parts. At the same time, the changes of SDH and SOX activities had same trend in the two varieties, with a big wave in fruit, and relative unchanged over time in leaf and phloem. Moreover, the testing value of every index was close to zero in endocarp around the 60th day or so after anthesis, which suggested that the basic metabolism was stagnated. However, the sorbitol metabolism in mesocarp increased sharply, which reflected it came into a new development stage.

Key words: peach, fruit development, sorbitol, enzyme activities