Abstract
Effects of NaCl addition to the nutrient solution on the activities of acid and neutral invertases (AI and NI) (EC 3.2.1.26) and sucrose synthase (SS) (EC 2.4.1.13) of cucumber (Cucumis sativus L. cv. Asomidori No. 5) fruits were studied. In spring of 1992, cucumber plants were grown with solution culture in a greenhouse. The aeration rate of the solution was kept low. Sixty millimolar NaCl was added to the solution when 10th leaf was expanding. In control fruits, AT activity was fairly constant until 7 d after anthesis. On the day of anthesis, AT activity at 60 mM NaCl tended to be higher than control. At 60 mM NaCl, AT activity tended to be higher in the proximal half than in the distal half of a fruit. In control fruits, SS activity declined as fruits grew. SS activity tended to be lower in fruit at 60 mM NaCl. The developmental changes in the activities of AT and SS tended to be different between pollinated and parthenocarpic fruit. The activity of NI was much lower than those of AT and SS.
