Changes in carbohydrate composition in pumpkins (kabocha) during fruit growth

To elucidate the mechanism of carbohydrate accumulation by two developing p umpkins (kabocha), 'Miyako'(Cucurbita maxima Duch.) and 'Hayato'(Cucurbita moschata Duch.), which differ in taste and textures when cooked, their carb ohydrate compositions were compared. The changes of total sugar content dur ing fruit growth differed between 'Miyako' and 'Hayato'. The total sugar co ntent of 'Miyako' fruit increased gradually after 30 days from flowering( D AF) while that of 'Hyato' fruit increased steadily during fruit growth. 'Mi yako' fruit accumulated starch faster than did fruits of 'Hayato'. A high n egative correlation exists between starch and moisture contents in both cul tivars, indicating that the moisture content decreased as starch content in creased. Raffinose oligosaccharides, monosaccharides and sucrose were the p rincipal soluble sugars accumulated by the fruit. Raffinose oligosaccharide content was higher in 'Hayato' than in 'Miyako'.