Early water absorption in petals causes malformed flower in rose cultivar Yves Piaget
In roses, malformed flowers are often generated before and after harvest, affecting cut flower production. Malformed flower symptoms vary depending on flower cultivar and cultivation. Some double flower cultivars, such as fragrant cultivar Yves Piaget often produce malformed flowers with petals that curve toward opposite axis. These malformed petals prevent normal flowering and weaken fragrance emission in this cultivar. We termed this malformed flower as incurved flower. Our previous study (Kaneeda et al., 2019) revealed differences in acid invertase activities and carbohydrate content of petals between incurved flower and normal flower; however, water absorption in petals has not been fully investigated. In this study, we investigated fresh weight, water uptake, water potential, osmotic potential, and turgor pressure before and after harvest. Incurved flower had grater fresh and dry weight in petal, flower receptacle, and stem than normal flower at flower opening stage. Water absorption of incurved flower on day 0-2 after harvest was significantly increased compared to that of normal flower. Maximum flower diameter of incurved flower was smaller than that of normal flower continuously after harvest. Water potential of petals in incurved flower was significantly higher than that of normal flower on day 0 after harvest. Calculated values of petal turgor pressure tended to be higher in incurved flower than in normal flower on day 0-1, but reversed on day 2. These results suggest that water absorption of petals in incurved flower is considered to be inhibited, and this could be due to early water absorption at the time of harvest. From our finding, regulation of early water potential supposed to be important to suppress malformed flower.
Kaneeda, R., Hirose, T., Yoshida, C. and Handa, T. (2023). Early water absorption in petals causes malformed flower in rose cultivar Yves Piaget. Acta Hortic. 1368, 41-48
Rosa × hybrida, incurved flower, petal growth, osmoregulation, petal water potential