Relationship Between Respiratory Quotient and Water Uptake of Sweet Cherry Fruit

抄録

The water uptake inducing cracking of sweet cherry fruit (Prunus avium L.) was investigated in relation to the respiratory characteristics of the fruit. Respiratory quotient (CO₂: O₂ ratio; RQ) decreased from 0.63 on 22 days after bloom (DAB) to 0.36 on 30 DAB when fruit susceptibility to cracking was generally highest, while it increased to 0.45 on 35 DAB. Water uptake per fruit was higher in the fruits in which the RQ was lower, demonstrating a negative correlation with RQ. Multiple regression analysis using RQ, stomatal density and total soluble solids content as independent variables, while water uptake per fruit as dependent variable indicated that RQ seemed to be predominant factor for water uptake of fruit. An RQ value lower than 1 may induce reduction in pressure in the intercellular spaces as compared to atmospheric pressure when the stomatal pore is covered with water; therefore, water on the fruit surface may be forced into the intercellular spaces of the mesocarp through the stomatal pore.