M. Kishimoto’s scientific contributions

Post-harvest characteristics of Rosa hybrida L. cv. 'Delilah', a long-lived cultivar, were compared with those of cv. 'Sonia', a short-lived cultivar. The vase-life of 'Delilah' was 10.6 d whereas that of 'Sonia' was 5.6 d. Petals of 'Sonia' flowers kept in water did not reflect fully and showed blueing. However, treatment with sucrose plus 8-hydroxyquinoline sulphate (HQS) markedly promoted petal reflection and inhibited blueing. In contrast, 'Delilah' flowers kept in water reflected fully and did not show blueing. In both cultivars, hydraulic conductance of stem segments in the control treatment decreased rapidly after harvest. Treatment with HQS suppressed this decrease. Concentrations of glucose, fructose and sucrose in petals of 'Delilah' were much higher throughout the experimental period than those of 'Sonia'. There was no difference between 'Sonia' and 'Delilah' in soluble carbohydrate concentrations in stems and leaves. Starch concentration in petals of 'Sonia' was higher than in 'Delilah'. However, the starch concentration in both cultivars was much lower than the total soluble carbohydrate concentration in 'Delilah'. Sensitivity to ethylene in 'Delilah' was greater than in 'Sonia'. There was little difference in ethylene production trends between 'Sonia' and 'Delilah' flowers. The results suggest that complete petal reflection and the longer vase-life of 'Delilah' versus 'Sonia' flowers may be attributed to higher soluble carbohydrate concentrations in petals of the former.