CHANGES IN CARBOHYDRATES AND CARBOHYDRATE METABOLIZING ENZYMES DURINGTHE DEVELOPMENT, MATURATION, AND RIPENING OF BUTTERCUP SQUASH (CUCURBITA-MAXIMA D DELICA)
De. Irving et al., CHANGES IN CARBOHYDRATES AND CARBOHYDRATE METABOLIZING ENZYMES DURINGTHE DEVELOPMENT, MATURATION, AND RIPENING OF BUTTERCUP SQUASH (CUCURBITA-MAXIMA D DELICA), Journal of the American Society for Horticultural Science, 122(3), 1997, pp. 310-314
During this study, we divided the developmental growth pattern of butt
ercup squash into three phases: 1) early growth, from flowering up to
30 days after flowering; 2) maturation, from 30 days until 60 days aft
er flowering (or harvest); and 3) ripening, from 60 days (or harvest)
until approximate to 100 days after flowering. Harvest occurred at 48
days after flowering. Fruit growth (expansion), starch, and dry matter
accumulation were largely completed during early growth, and there wa
s a progressive decline in the respiration rate. Extractable activitie
s of acid and alkaline invertases, sucrose synthase, alkaline a-galact
osidase, and sucrose phosphate synthase (assayed with saturating subst
rates) were high initially but declined markedly during this phase. Gl
ucose, fructose, and low concentrations of raffinose saccharides were
present, but no sucrose was detected. During maturation, starch and dr
y matter remained nearly constant and sucrose began to accumulate. Dur
ing ripening, starch was degraded, sucrose synthase activity was signi
ficant but relatively constant, sucrose phosphate synthase activity in
creased, and sucrose continued to accumulate.