Dynamic Changes of Carbohydrate and Vitamin C in Fruits of Actinidia chinensis and A.eriantha during Growing Season

Dynamic changes of carbohydrate and vitamin C in the kiwifruits of Actinidia eriantha ‘6113’ and A.chinensis ‘Jintao’ were investigated during fruit growth and development.The soluble solids content of both species remained relatively stable during the first 146 days after flower withering before beginning to rise,while the starch contents of their fruits increased to the maximum and then declined.The variable curves of total sugar and reducing sugar contents in both species were similar to those of their soluble solids contents.However,total sugar and reducing sugar contents in fruits of A.chinensis ‘Jintao’ began to increase rapidly one month earlier than in fruits of A.eriantha‘6113’.The changes of vitamin C content of the two species were similar,whereby they increased to a peak in early to middle July and then decreased as the fruit developed.The vitamin C content of A.chinensis ‘Jintao’ reduced to the minimum on August 14^th,while that of A.eriantha ‘6113’ decreased to the minimum on September 13.The vitamin C content of both species began to rise slowly from the minimum and reached a second peak at the full ripe stage(that is,soft ripe stage naturally on the vines).The second peak in vitamin C content of A.eriantha ‘6113’fruits at full ripe stage was much higher than at the first peak in early July.The ANOVA analyses showed significant differences(p<0.05) between A.chinensis ‘Jintao’ and A.eriantha‘6113’ in regard to Vc content,whereas there were no differences in soluble solids content,starch content,total sugar,and reducing sugar were observed.