Relationship between anthocyanin biosynthesis and related enzyme activities in Pyrus communis L. cv. 'early red comice' and its green bud mutant.

Anthocyanin content and the activities of related enzymes of anthocyanin biosynthesis including phenylalanine ammonialyase(PAL),chalcone ismoerase(CHI) and flavonoid 3-O-glucosyltransferase(UFGT) were studied in the pericarp of Pyrus communis L.cv.‘Early Red Comice’ and its green bud mutant during the fruit development.The results showed,the ‘Early Red Comice’ entailed the attainment of the best red color and highest anthocyanin content a month or more before harvest and a tendency of color to fade toward harvest,the anthocyanin content was decreased from 258.4 μg·g-1 to 118.3 μg·g-1 in pericarp of harvest fruit;the activity of PAL revealed similar changing trends in both varieties and decreased during the fruit development.Whereas the activity of CHI was increased slowly as fruit ripened.The activity of UFGT demonstrated significantly difference in both varieties in the experiment.The activity of UFGT was higher significantly than that in green bud mutant.The activity of UFGT was closely related to the synthesis of anthocyanin.In summary,the index of color of 'Early Red Comice'and its bud green mutant is anthocyanin content and UFGT activity.